| Title: | Tools for Working with URLs and HTTP |
| Version: | 1.4.7 |
| Description: | Useful tools for working with HTTP organised by HTTP verbs (GET(), POST(), etc). Configuration functions make it easy to control additional request components (authenticate(), add_headers() and so on). |
| License: | MIT + file LICENSE |
| URL: | https://httr.r-lib.org/,https://github.com/r-lib/httr |
| BugReports: | https://github.com/r-lib/httr/issues |
| Depends: | R (≥ 3.5) |
| Imports: | curl (≥ 5.0.2), jsonlite, mime, openssl (≥ 0.8), R6 |
| Suggests: | covr, httpuv, jpeg, knitr, png, readr, rmarkdown, testthat(≥ 0.8.0), xml2 |
| VignetteBuilder: | knitr |
| Config/Needs/website: | tidyverse/tidytemplate |
| Encoding: | UTF-8 |
| RoxygenNote: | 7.2.3 |
| NeedsCompilation: | no |
| Packaged: | 2023-08-15 02:56:56 UTC; hadleywickham |
| Author: | Hadley Wickham [aut, cre], Posit, PBC [cph, fnd] |
| Maintainer: | Hadley Wickham <hadley@posit.co> |
| Repository: | CRAN |
| Date/Publication: | 2023-08-15 09:00:02 UTC |
httr makes http easy.
Description
httr is organised around the six most common http verbs:GET(),PATCH(),POST(),HEAD(),PUT(), andDELETE().
Details
Each request returns aresponse() object which provideseasy access to status code, cookies, headers, timings, and other usefulinfo. The content of the request is available as a raw vector(content()), character vector (text_content()),or parsed into an R object (parsed_content()), currently forhtml, xml, json, png and jpeg).
Requests can be modified by various config options likeset_cookies(),add_headers(),authenticate(),use_proxy(),verbose(), andtimeout()
httr supports OAuth 1.0 and 2.0. Useoauth1.0_token() andoauth2.0_token() to get user tokens, andsign_oauth1.0() andsign_oauth2.0() to signrequests. The demos directory has twelve demos of using OAuth: four for 1.0(linkedin, twitter, vimeo, and yahoo) and eight for 2.0 (azure, facebook,github, google, linkedin, reddit, yahoo, and yelp).
Author(s)
Maintainer: Hadley Wickhamhadley@posit.co
Other contributors:
Posit, PBC [copyright holder, funder]
See Also
Useful links:
Report bugs athttps://github.com/r-lib/httr/issues
Open specified url in browser.
Description
(This isn't really a http verb, but it seems to follow the same format).
Usage
BROWSE(url = NULL, config = list(), ..., handle = NULL)Arguments
url | the url of the page to retrieve |
config | All configuration options are ignored because the requestis handled by the browser, notRCurl. |
... | Further named parameters, such as |
handle | The handle to use with this request. If notsupplied, will be retrieved and reused from the |
Details
Only works in interactive sessions.
Value
Aresponse() object.
See Also
Other http methods:DELETE(),GET(),HEAD(),PATCH(),POST(),PUT(),VERB()
Examples
BROWSE("http://google.com")BROWSE("http://had.co.nz")Send a DELETE request.
Description
Send a DELETE request.
Usage
DELETE( url = NULL, config = list(), ..., body = NULL, encode = c("multipart", "form", "json", "raw"), handle = NULL)Arguments
url | the url of the page to retrieve |
config | Additional configuration settings such as httpauthentication ( |
... | Further named parameters, such as |
body | One of the following:
|
encode | If the body is a named list, how should it be encoded? Can beone of form (application/x-www-form-urlencoded), multipart,(multipart/form-data), or json (application/json). For "multipart", list elements can be strings or objects created by |
handle | The handle to use with this request. If notsupplied, will be retrieved and reused from the |
Value
Aresponse() object.
RFC2616
The DELETE method requests that the origin server delete the resourceidentified by the Request-URI. This method MAY be overridden by humanintervention (or other means) on the origin server. The client cannot beguaranteed that the operation has been carried out, even if the status codereturned from the origin server indicates that the action has beencompleted successfully. However, the server SHOULD NOT indicate successunless, at the time the response is given, it intends to delete theresource or move it to an inaccessible location.
A successful response SHOULD be 200 (OK) if the response includes an entitydescribing the status, 202 (Accepted) if the action has not yet beenenacted, or 204 (No Content) if the action has been enacted but theresponse does not include an entity.
If the request passes through a cache and the Request-URI identifies one ormore currently cached entities, those entries SHOULD be treated as stale.Responses to this method are not cacheable.
See Also
Other http methods:BROWSE(),GET(),HEAD(),PATCH(),POST(),PUT(),VERB()
Examples
## Not run: DELETE("http://httpbin.org/delete")POST("http://httpbin.org/delete")## End(Not run)GET a url.
Description
GET a url.
Usage
GET(url = NULL, config = list(), ..., handle = NULL)Arguments
url | the url of the page to retrieve |
config | Additional configuration settings such as httpauthentication ( |
... | Further named parameters, such as |
handle | The handle to use with this request. If notsupplied, will be retrieved and reused from the |
Value
Aresponse() object.
RFC2616
The GET method means retrieve whatever information (in the form of anentity) is identified by the Request-URI. If the Request-URI refers to adata-producing process, it is the produced data which shall be returned asthe entity in the response and not the source text of the process, unlessthat text happens to be the output of the process.
The semantics of the GET method change to a "conditional GET" if therequest message includes an If-Modified-Since, If-Unmodified-Since,If-Match, If-None-Match, or If-Range header field. A conditional GET methodrequests that the entity be transferred only under the circumstancesdescribed by the conditional header field(s). The conditional GET method isintended to reduce unnecessary network usage by allowing cached entities tobe refreshed without requiring multiple requests or transferring dataalready held by the client.
The semantics of the GET method change to a "partial GET" if the requestmessage includes a Range header field. A partial GET requests that onlypart of the entity be transferred, as described inhttps://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35The partial GET method is intended to reduce unnecessary network usage byallowing partially-retrieved entities to be completed without transferringdata already held by the client.
See Also
Other http methods:BROWSE(),DELETE(),HEAD(),PATCH(),POST(),PUT(),VERB()
Examples
GET("http://google.com/")## Not run: GET("http://google.com/", path = "search")GET("http://google.com/", path = "search", query = list(q = "ham"))## End(Not run)# See what GET is doing with httpbin.org## Not run: url <- "http://httpbin.org/get"GET(url)GET(url, add_headers(a = 1, b = 2))GET(url, set_cookies(a = 1, b = 2))GET(url, add_headers(a = 1, b = 2), set_cookies(a = 1, b = 2))GET(url, authenticate("username", "password"))GET(url, verbose())## End(Not run)# You might want to manually specify the handle so you can have multiple# independent logins to the same website.## Not run: google <- handle("http://google.com")GET(handle = google, path = "/")GET(handle = google, path = "search")## End(Not run)Get url HEADers.
Description
Get url HEADers.
Usage
HEAD(url = NULL, config = list(), ..., handle = NULL)Arguments
url | the url of the page to retrieve |
config | Additional configuration settings such as httpauthentication ( |
... | Further named parameters, such as |
handle | The handle to use with this request. If notsupplied, will be retrieved and reused from the |
Value
Aresponse() object.
RFC2616
The HEAD method is identical to GET except that the server MUST NOT returna message-body in the response. The metainformation contained in the HTTPheaders in response to a HEAD request SHOULD be identical to theinformation sent in response to a GET request. This method can be used forobtaining metainformation about the entity implied by the request withouttransferring the entity-body itself. This method is often used for testinghypertext links for validity, accessibility, and recent modification.
The response to a HEAD request MAY be cacheable in the sense that theinformation contained in the response MAY be used to update a previouslycached entity from that resource. If the new field values indicate that thecached entity differs from the current entity (as would be indicated by achange in Content-Length, Content-MD5, ETag or Last-Modified), then thecache MUST treat the cache entry as stale.
See Also
Other http methods:BROWSE(),DELETE(),GET(),PATCH(),POST(),PUT(),VERB()
Examples
HEAD("http://google.com")headers(HEAD("http://google.com"))Send PATCH request to a server.
Description
Send PATCH request to a server.
Usage
PATCH( url = NULL, config = list(), ..., body = NULL, encode = c("multipart", "form", "json", "raw"), handle = NULL)Arguments
url | the url of the page to retrieve |
config | Additional configuration settings such as httpauthentication ( |
... | Further named parameters, such as |
body | One of the following:
|
encode | If the body is a named list, how should it be encoded? Can beone of form (application/x-www-form-urlencoded), multipart,(multipart/form-data), or json (application/json). For "multipart", list elements can be strings or objects created by |
handle | The handle to use with this request. If notsupplied, will be retrieved and reused from the |
Value
Aresponse() object.
See Also
Other http methods:BROWSE(),DELETE(),GET(),HEAD(),POST(),PUT(),VERB()
POST file to a server.
Description
POST file to a server.
Usage
POST( url = NULL, config = list(), ..., body = NULL, encode = c("multipart", "form", "json", "raw"), handle = NULL)Arguments
url | the url of the page to retrieve |
config | Additional configuration settings such as httpauthentication ( |
... | Further named parameters, such as |
body | One of the following:
|
encode | If the body is a named list, how should it be encoded? Can beone of form (application/x-www-form-urlencoded), multipart,(multipart/form-data), or json (application/json). For "multipart", list elements can be strings or objects created by |
handle | The handle to use with this request. If notsupplied, will be retrieved and reused from the |
Value
Aresponse() object.
See Also
Other http methods:BROWSE(),DELETE(),GET(),HEAD(),PATCH(),PUT(),VERB()
Examples
## Not run: b2 <- "http://httpbin.org/post"POST(b2, body = "A simple text string")POST(b2, body = list(x = "A simple text string"))POST(b2, body = list(y = upload_file(system.file("CITATION"))))POST(b2, body = list(x = "A simple text string"), encode = "json")# body can also be provided as a json string directly to deal# with specific case, like an empty element in the json string.# passing as string directlyPOST(b2, body = '{"a":1,"b":{}}', encode = "raw")# or building the json string beforejson_body <- jsonlite::toJSON(list(a = 1, b = NULL), auto_unbox = TRUE)POST(b2, body = json_body, encode = "raw")# Various types of empty body:POST(b2, body = NULL, verbose())POST(b2, body = FALSE, verbose())POST(b2, body = "", verbose())## End(Not run)Send PUT request to server.
Description
Send PUT request to server.
Usage
PUT( url = NULL, config = list(), ..., body = NULL, encode = c("multipart", "form", "json", "raw"), handle = NULL)Arguments
url | the url of the page to retrieve |
config | Additional configuration settings such as httpauthentication ( |
... | Further named parameters, such as |
body | One of the following:
|
encode | If the body is a named list, how should it be encoded? Can beone of form (application/x-www-form-urlencoded), multipart,(multipart/form-data), or json (application/json). For "multipart", list elements can be strings or objects created by |
handle | The handle to use with this request. If notsupplied, will be retrieved and reused from the |
See Also
Other http methods:BROWSE(),DELETE(),GET(),HEAD(),PATCH(),POST(),VERB()
Examples
## Not run: POST("http://httpbin.org/put")PUT("http://httpbin.org/put")b2 <- "http://httpbin.org/put"PUT(b2, body = "A simple text string")PUT(b2, body = list(x = "A simple text string"))PUT(b2, body = list(y = upload_file(system.file("CITATION"))))PUT(b2, body = list(x = "A simple text string"), encode = "json")## End(Not run)Retry a request until it succeeds.
Description
Safely retry a request until it succeeds, as defined by theterminate_onparameter, which by default means a response for whichhttp_error()isFALSE. Will also retry on error conditions raised by the underlying curl code,but if the last retry still raises one,RETRY will raise it again withstop().It is designed to be kind to the server: after each failurerandomly waits up to twice as long. (Technically it uses exponentialbackoff with jitter, using the approach outlined inhttps://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/.)If the server returns status code 429 and specifies aretry-after value, thatvalue will be used instead, unless it's smaller thanpause_min.
Usage
RETRY( verb, url = NULL, config = list(), ..., body = NULL, encode = c("multipart", "form", "json", "raw"), times = 3, pause_base = 1, pause_cap = 60, pause_min = 1, handle = NULL, quiet = FALSE, terminate_on = NULL, terminate_on_success = TRUE)Arguments
verb | Name of verb to use. |
url | the url of the page to retrieve |
config | Additional configuration settings such as httpauthentication ( |
... | Further named parameters, such as |
body | One of the following:
|
encode | If the body is a named list, how should it be encoded? Can beone of form (application/x-www-form-urlencoded), multipart,(multipart/form-data), or json (application/json). For "multipart", list elements can be strings or objects created by |
times | Maximum number of requests to attempt. |
pause_base,pause_cap | This method uses exponential back-off with fulljitter - this means that each request will randomly wait between |
pause_min | Minimum time to wait in the backoff; generallyonly necessary if you need pauses less than one second (which maynot be kind to the server, use with caution!). |
handle | The handle to use with this request. If notsupplied, will be retrieved and reused from the |
quiet | If |
terminate_on | Optional vector of numeric HTTP status codes that if foundon the response will terminate the retry process. If |
terminate_on_success | If |
Value
The last response. Note that if the request doesn't succeed aftertimes times this will be a failed request, i.e. you still needto usestop_for_status().
Examples
## Not run: # Succeeds straight awayRETRY("GET", "http://httpbin.org/status/200")# Never succeedsRETRY("GET", "http://httpbin.org/status/500")# Invalid hostname generates curl error condition and is retried but eventually# raises an error condition.RETRY("GET", "http://invalidhostname/")## End(Not run)OAuth token objects.
Description
These objects represent the complete set of data needed for OAuth access:an app, an endpoint, cached credentials and parameters. They should becreated through their constructor functionsoauth1.0_token()andoauth2.0_token().
Format
An R6 class object.
Methods
cache(): caches token to disksign(method, url): returns list of url and configrefresh(): refresh access token (if possible)validate(): TRUE if the token is still valid, FALSE otherwise
Caching
OAuth tokens are cached on disk in a file called.httr-oauthsaved in the current working directory. Caching is enabled if:
The session is interactive, and the user agrees to it, OR
The
.httr-oauthfile is already present, ORgetOption("httr_oauth_cache")isTRUE
You can suppress caching by setting thehttr_oauth_cache option toFALSE.
Tokens are cached based on their endpoint and parameters.
The cache file should not be included in source code control or R packages(because it contains private information), so httr will automatically addthe appropriate entries to.gitignore and.Rbuildignore if needed.
VERB a url.
Description
Use an arbitrary verb.
Usage
VERB( verb, url = NULL, config = list(), ..., body = NULL, encode = c("multipart", "form", "json", "raw"), handle = NULL)Arguments
verb | Name of verb to use. |
url | the url of the page to retrieve |
config | Additional configuration settings such as httpauthentication ( |
... | Further named parameters, such as |
body | One of the following:
|
encode | If the body is a named list, how should it be encoded? Can beone of form (application/x-www-form-urlencoded), multipart,(multipart/form-data), or json (application/json). For "multipart", list elements can be strings or objects created by |
handle | The handle to use with this request. If notsupplied, will be retrieved and reused from the |
Value
Aresponse() object.
See Also
Other http methods:BROWSE(),DELETE(),GET(),HEAD(),PATCH(),POST(),PUT()
Examples
r <- VERB( "PROPFIND", "http://svn.r-project.org/R/tags/", add_headers(depth = 1), verbose())stop_for_status(r)content(r)## Not run: VERB("POST", url = "http://httpbin.org/post")VERB("POST", url = "http://httpbin.org/post", body = "foobar")## End(Not run)Add additional headers to a request.
Description
Wikipedia provides a useful list of common http headers:https://en.wikipedia.org/wiki/List_of_HTTP_header_fields.
Usage
add_headers(..., .headers = character())Arguments
... | named header values. To stop an existing header from beingset, pass an empty string: |
.headers | a named character vector |
See Also
accept() andcontent_type() forconvenience functions for setting accept and content-type headers.
Other config:authenticate(),config(),set_cookies(),timeout(),use_proxy(),user_agent(),verbose()
Examples
add_headers(a = 1, b = 2)add_headers(.headers = c(a = "1", b = "2"))## Not run: GET("http://httpbin.org/headers")# Add arbitrary headersGET( "http://httpbin.org/headers", add_headers(version = version$version.string))# Override default headers with empty stringsGET("http://httpbin.org/headers", add_headers(Accept = ""))## End(Not run)Use http authentication.
Description
It's not obvious how to turn authentication off after using it, soI recommend using custom handles with authentication.
Usage
authenticate(user, password, type = "basic")Arguments
user | user name |
password | password |
type | type of HTTP authentication. Should be one of the followingtypes supported by Curl: basic, digest, digest_ie, gssnegotiate,ntlm, any. It defaults to "basic", the most common type. |
See Also
Other config:add_headers(),config(),set_cookies(),timeout(),use_proxy(),user_agent(),verbose()
Examples
## Not run: GET("http://httpbin.org/basic-auth/user/passwd")GET( "http://httpbin.org/basic-auth/user/passwd", authenticate("user", "passwd"))## End(Not run)Compute caching information for a response.
Description
cache_info() gives details of cacheability of a response,rerequest() re-performs the original request doing as little workas possible (if not expired, returns response as is, or performsrevalidation if Etag or Last-Modified headers are present).
Usage
cache_info(r)rerequest(r)Arguments
r | A response |
Examples
# Never cached, always causes redownloadr1 <- GET("https://www.google.com")cache_info(r1)r1$datererequest(r1)$date# Expires in a yearr2 <- GET("https://www.google.com/images/srpr/logo11w.png")cache_info(r2)r2$datererequest(r2)$date## Not run: # Has last-modified and etag, so does revalidationr3 <- GET("http://httpbin.org/cache")cache_info(r3)r3$datererequest(r3)$date# Expires after 5 secondsr4 <- GET("http://httpbin.org/cache/5")cache_info(r4)r4$datererequest(r4)$dateSys.sleep(5)cache_info(r4)rerequest(r4)$date## End(Not run)Set curl options.
Description
Generally you should only need to use this function to set CURL optionsdirectly if there isn't already a helpful wrapper function, likeset_cookies(),add_headers() orauthenticate(). To use this function effectively requiressome knowledge of CURL, and CURL options. Usehttr_options() tosee a complete list of available options. To see the libcurl documentationfor a given option, usecurl_docs().
Usage
config(..., token = NULL)Arguments
... | named Curl options. |
token | An OAuth token (1.0 or 2.0) |
Details
Unlike Curl (and RCurl), all configuration options are per request, notper handle.
See Also
set_config() to set global config defaults, andwith_config() to temporarily run code with set options.
All known available options are listed inhttr_options()
Other config:add_headers(),authenticate(),set_cookies(),timeout(),use_proxy(),user_agent(),verbose()
Other ways to set configuration:set_config(),with_config()
Examples
# There are a number of ways to modify the configuration of a request# * you can add directly to a requestHEAD("https://www.google.com", verbose())# * you can wrap with with_config()with_config(verbose(), HEAD("https://www.google.com"))# * you can set global with set_config()old <- set_config(verbose())HEAD("https://www.google.com")# and re-establish the previous settings withset_config(old, override = TRUE)HEAD("https://www.google.com")# orreset_config()HEAD("https://www.google.com")# If available, you should use a friendly httr wrapper over RCurl# options. But you can pass Curl options (as listed in httr_options())# in configHEAD("https://www.google.com/", config(verbose = TRUE))Extract content from a request.
Description
There are currently three ways to retrieve the contents of a request:as a raw object (as = "raw"), as a character vector,(as = "text"), and as parsed into an R object where possible,(as = "parsed"). Ifas is not specified,contentdoes its best to guess which output is most appropriate.
Usage
content(x, as = NULL, type = NULL, encoding = NULL, ...)Arguments
x | request object |
as | desired type of output: |
type | MIME type (aka internet media type) used to overridethe content type returned by the server. Seehttps://en.wikipedia.org/wiki/Internet_media_type for a list ofcommon types. |
encoding | For text, overrides the charset or the Latin1 (ISO-8859-1)default, if you know that the server is returning the incorrect encodingas the charset in the content-type. Use for text and parsed outputs. |
... | Other parameters passed on to the parsing functions, if |
Details
content currently knows about the following mime types:
text/html:xml2::read_html()text/xml:xml2::read_xml()text/csv:readr::read_csv()text/tab-separated-values:readr::read_tsv()application/json:jsonlite::fromJSON()application/x-www-form-urlencoded:parse_queryimage/jpeg:jpeg::readJPEG()image/png:png::readPNG()
as = "parsed" is provided as a convenience only: if the type youare trying to parse is not available, useas = "text" and parseyourself.
Value
For "raw", a raw vector.
For "text", a character vector of length 1. The character vector is alwaysre-encoded to UTF-8. If this encoding fails (usually because the pagedeclares an incorrect encoding),content() will returnNA.
For "auto", a parsed R object.
WARNING
When usingcontent() in a package, DO NOT use onas = "parsed".Instead, check the mime-type is what you expect, and then parse yourself.This is safer, as you will fail informatively if the API changes, andyou will protect yourself against changes to httr.
See Also
Other response methods:http_error(),http_status(),response(),stop_for_status()
Examples
## Not run: r <- POST("http://httpbin.org/post", body = list(a = 1, b = 2))content(r) # automatically parses JSONcat(content(r, "text"), "\n") # text contentcontent(r, "raw") # raw bytes from serverrlogo <- content(GET("https://httpbin.org/image/png"))plot(0:1, 0:1, type = "n")rasterImage(rlogo, 0, 0, 1, 1)## End(Not run)Set content-type and accept headers.
Description
These are convenient wrappers aroudadd_headers().
Usage
content_type(type)content_type_json()content_type_xml()accept(type)accept_json()accept_xml()Arguments
type | A mime type or a file extension. If a file extension (i.e. startswith |
Details
accept_json/accept_xml andcontent_type_json/content_type_xml are useful shortcuts toask for json or xml responses or tell the server you are sending json/xml.
Examples
## Not run: GET("http://httpbin.org/headers")GET("http://httpbin.org/headers", accept_json())GET("http://httpbin.org/headers", accept("text/csv"))GET("http://httpbin.org/headers", accept(".doc"))GET("http://httpbin.org/headers", content_type_xml())GET("http://httpbin.org/headers", content_type("text/csv"))GET("http://httpbin.org/headers", content_type(".xml"))## End(Not run)Access cookies in a response.
Description
Access cookies in a response.
Usage
cookies(x)Arguments
x | A response. |
See Also
set_cookies() to send cookies in request.
Examples
## Not run: r <- GET("http://httpbin.org/cookies/set", query = list(a = 1, b = 2))cookies(r)## End(Not run)Install or uninstall a callback function
Description
Supported callback functions:
- ‘request’
This callback is called before an HTTP requestis performed, with the
requestobject as an argument.If the callback returns a value other thanNULL, the HTTPrequest is not performed at all, and the return value of the callbackis returned. This mechanism can be used to replay previouslyrecorded HTTP responses.- ‘response’
This callback is called after an HTTP requestis performed. The callback is called with two arguments: the
requestobject and theresponseobject of the HTTPrequest. If this callback returns a value other thanNULL,then this value is returned byhttr.
Usage
get_callback(name)set_callback(name, new_callback = NULL)Arguments
name | Character scalar, name of the callback to query or set. |
new_callback | The callback function to install, a function object;or |
Details
Note that it is not possible to install multiple callbacks of the sametype. The installed callback overwrites the previously intalled one.To uninstall a callback function, set it toNULL withset_callback().
See thehttrmock package for a proper example that usescallbacks.
Value
get_callback returns the currently installedcallback, orNULL if none is installed.
set_callback returns the previously installed callback,orNULL if none was installed.
Examples
## Not run: ## Log all HTTP requests to the screeenreq_logger <- function(req) { cat("HTTP request to", sQuote(req$url), "\n")}old <- set_callback("request", req_logger)g1 <- GET("https://httpbin.org")g2 <- GET("https://httpbin.org/ip")set_callback("request", old)## Log all HTTP requests and response status codes as wellreq_logger2 <- function(req) { cat("HTTP request to", sQuote(req$url), "... ")}res_logger <- function(req, res) { cat(res$status_code, "\n")}old_req <- set_callback("request", req_logger2)old_res <- set_callback("response", res_logger)g3 <- GET("https://httpbin.org")g4 <- GET("https://httpbin.org/ip")set_callback("request", old_req)set_callback("response", old_res)## Return a recorded response, without performing the HTTP requestreplay <- function(req) { if (req$url == "https://httpbin.org") g3}old_req <- set_callback("request", replay)grec <- GET("https://httpbin.org")grec$date == g3$dateset_callback("request", old_req)## End(Not run)Guess the media type of a path from its extension.
Description
DEPRECATED: please usemime::guess_type instead.
Usage
guess_media(x)Arguments
x | path to file |
Create a handle tied to a particular host.
Description
This handle preserves settings and cookies across multiple requests. It isthe foundation of all requests performed through the httr package, althoughit will mostly be hidden from the user.
Usage
handle(url, cookies = TRUE)Arguments
url | full url to site |
cookies | DEPRECATED |
Note
Because of the way argument dispatch works in R, using handle() in thehttp methods (SeeGET()) will cause problems when trying topass configuration arguments (See examples below). Directly specifying thehandle when using http methods is not recommended in general, since theselection of the correct handle is taken care of when the user passes an url(Seehandle_pool()).
Examples
handle("http://google.com")handle("https://google.com")h <- handle("http://google.com")GET(handle = h)# Should see cookies sent back to serverGET(handle = h, config = verbose())h <- handle("http://google.com", cookies = FALSE)GET(handle = h)$cookies## Not run: # Using the preferred way of configuring the http methods# will not work when using handle():GET(handle = h, timeout(10))# Passing named arguments will work properly:GET(handle = h, config = list(timeout(10), add_headers(Accept = "")))## End(Not run)Maintain a pool of handles.
Description
The handle pool is used to automatically reuse Curl handles for the samescheme/host/port combination. This ensures that the http session isautomatically reused, and cookies are maintained across requests to a sitewithout user intervention.
Usage
handle_poolhandle_find(url)handle_reset(url)Format
An environment.
Does the request have content associated with it?
Description
Does the request have content associated with it?
Usage
has_content(x)Examples
## Not run: has_content(POST("http://httpbin.org/post", body = FALSE))has_content(HEAD("http://httpbin.org/headers"))## End(Not run)Extract the headers from a response
Description
Extract the headers from a response
Usage
headers(x)Arguments
x | A request object |
See Also
add_headers() to send additional headers in arequest
Examples
## Not run: r <- GET("http://httpbin.org/get")headers(r)## End(Not run)HMAC SHA1
Description
As described inhttps://datatracker.ietf.org/doc/rfc2104/.
Usage
hmac_sha1(key, string)Arguments
key | secret key |
string | data to securely hash |
Generate a classed http condition.
Description
This function generate S3 condition objects which are passed tostop() orwarning() to generate classes warningsand error. These can be used in conjunction withtryCatch()to respond differently to different type of failure.
Usage
http_condition(x, type, task = NULL, call = sys.call(-1))Arguments
x | a response, or numeric http code (or other object with |
type | type of condition to generate. Must be one of error,warning or message. |
task | The text of the message: either |
call | The call stored in the condition object. |
Value
An S3 object that inherits from (e.g.) condition,type,http_error, http_400 and http_404.
See Also
http://adv-r.had.co.nz/Exceptions-Debugging.html#condition-handlingfor more details about R's condition handling model
Examples
## Not run: # You can use tryCatch to take different actions based on the type# of error. Note that tryCatch will call the first handler that# matches any classes of the condition, not the best matching, so# always list handlers from most specific to least specificf <- function(url) { tryCatch(stop_for_status(GET(url)), http_404 = function(c) "That url doesn't exist", http_403 = function(c) "You need to authenticate!", http_400 = function(c) "You made a mistake!", http_500 = function(c) "The server screwed up" )}f("http://httpbin.org/status/404")f("http://httpbin.org/status/403")f("http://httpbin.org/status/505")## End(Not run)Check for an http error.
Description
Check for an http error.
Usage
http_error(x, ...)Arguments
x | Object to check. Default methods are provided for strings(which perform an |
... | Other arguments passed on to methods. |
Value
TRUE if the request fails (status code 400 or above),otherwiseFALSE.
See Also
Other response methods:content(),http_status(),response(),stop_for_status()
Examples
## Not run: # You can pass a url:http_error("http://www.google.com")http_error("http://httpbin.org/status/404")# Or a requestr <- GET("http://httpbin.org/status/201")http_error(r)## End(Not run)# Or an (integer) status codehttp_error(200L)http_error(404L)Give information on the status of a request.
Description
Extract the http status code and convert it into a human readable message.
Usage
http_status(x)Arguments
x | a request object or a number. |
Details
http servers send a status code with the response to each request. This codegives information regarding the outcome of the execution of the requeston the server. Roughly speaking, codes in the 100s and 200s mean the requestwas successfully executed; codes in the 300s mean the page was redirected;codes in the 400s mean there was a mistake in the way the client sent therequest; codes in the 500s mean the server failed to fulfillan apparently valid request. More details on the codes can be found athttp://en.wikipedia.org/wiki/Http_error_codes.
Value
If the status code does not match a known status, an error.Otherwise, a list with components
category | the broad category of the status |
message | the meaning of the status code |
See Also
Other response methods:content(),http_error(),response(),stop_for_status()
Examples
http_status(100)http_status(404)## Not run: x <- GET("http://httpbin.org/status/200")http_status(x)http_status(GET("http://httpbin.org/status/300"))http_status(GET("http://httpbin.org/status/301"))http_status(GET("http://httpbin.org/status/404"))# errors out on unknown statushttp_status(GET("http://httpbin.org/status/320"))## End(Not run)Extract the content type of a response
Description
Extract the content type of a response
Usage
http_type(x)Arguments
x | A response |
Value
A string giving the complete mime type, with all parametersstripped off.
Examples
## Not run: r1 <- GET("http://httpbin.org/image/png")http_type(r1)headers(r1)[["Content-Type"]]r2 <- GET("http://httpbin.org/ip")http_type(r2)headers(r2)[["Content-Type"]]## End(Not run)Diagnose common configuration problems
Description
Currently one check: that curl uses nss.
Usage
httr_dr()List available options.
Description
This function lists all available options forconfig().It provides both the short R name which you use with httr, and the longerCurl name, which is useful when searching the documentation.curl_docopens a link to the libcurl documentation for an option in your browser.
Usage
httr_options(matches)curl_docs(x)Arguments
matches | If not missing, this restricts the output so that eitherthe httr or curl option matches this regular expression. |
x | An option name (either short or full). |
Details
RCurl and httr use slightly different names to libcurl: the initialCURLOPT_ is removed, all underscores are converted to periods andthe option is given in lower case. Thus "CURLOPT_SSLENGINE_DEFAULT"becomes "sslengine.default".
Value
A data frame with three columns:
httr | The short name used in httr |
libcurl | The full name used by libcurl |
type | The type of R object that the option accepts |
Examples
httr_options()httr_options("post")# Use curl_docs to read the curl documentation for each option.# You can use either the httr or curl option name.curl_docs("userpwd")curl_docs("CURLOPT_USERPWD")Retrieve OAuth 1.0 access token.
Description
See demos for use.
Usage
init_oauth1.0( endpoint, app, permission = NULL, is_interactive = interactive(), private_key = NULL)Arguments
endpoint | An OAuth endpoint, created by |
app | An OAuth consumer application, created by |
permission | optional, a string of permissions to ask for. |
is_interactive | DEPRECATED |
private_key | Optional, a key provided by |
Retrieve OAuth 2.0 access token.
Description
See demos for use.
Usage
init_oauth2.0( endpoint, app, scope = NULL, user_params = NULL, type = NULL, use_oob = getOption("httr_oob_default"), oob_value = NULL, is_interactive = interactive(), use_basic_auth = FALSE, config_init = list(), client_credentials = FALSE, query_authorize_extra = list())oauth2.0_authorize_url( endpoint, app, scope, redirect_uri = app$redirect_uri, state = nonce(), query_extra = list())oauth2.0_access_token( endpoint, app, code, user_params = NULL, type = NULL, use_basic_auth = FALSE, redirect_uri = app$redirect_uri, client_credentials = FALSE, config = list())Arguments
endpoint | An OAuth endpoint, created by |
app | An OAuth consumer application, created by |
scope | a character vector of scopes to request. |
user_params | Named list holding endpoint specific parameters to pass tothe server when posting the request for obtaining or refreshing theaccess token. |
type | content type used to override incorrect server response |
use_oob | if FALSE, use a local webserver for the OAuth dance.Otherwise, provide a URL to the user and prompt for a validationcode. Defaults to the of the |
oob_value | if provided, specifies the value to use for the redirect_uriparameter when retrieving an authorization URL. Defaults to "urn:ietf:wg:oauth:2.0:oob".Requires |
is_interactive | DEPRECATED |
use_basic_auth | if |
config_init | Additional configuration settings sent to |
client_credentials | Default to |
query_authorize_extra | Default to |
query_extra | See |
Create a vector with case insensitive name matching.
Description
Create a vector with case insensitive name matching.
Usage
insensitive(x)Arguments
x | vector to modify |
Examples
x <- c("abc" = 1, "def" = 2)x["ABC"]y <- insensitive(x)y["ABC"]y[["ABC"]]Generate a JWT signature given credentials.
Description
As described inhttps://developers.google.com/identity/protocols/oauth2/service-account
Usage
jwt_signature( credentials, scope, aud, sub = NULL, iat = as.integer(Sys.time()), exp = iat + duration, duration = 60L * 60L)Arguments
credentials | Parsed contents of the credentials file. |
scope | A space-delimited list of the permissions that the applicationrequests. |
aud | A descriptor of the intended target of the assertion. Thistypically comes from the service auth file. |
sub | The email address of the user for which the application isrequesting delegated access. |
iat | The time the assertion was issued, measured in seconds since00:00:00 UTC, January 1, 1970. |
exp | The expiration time of the assertion, measured in seconds since00:00:00 UTC, January 1, 1970. This value has a maximum of 1 hour fromthe issued time. |
duration | Duration of token, in seconds. |
Examples
## Not run: cred <- jsonlite::fromJSON("~/Desktop/httrtest-45693cbfac92.json")jwt_signature(cred, "https://www.googleapis.com/auth/userinfo.profile")## End(Not run)Modify a url.
Description
Modify a url by first parsing it and then replacing components withthe non-NULL arguments of this function.
Usage
modify_url( url, scheme = NULL, hostname = NULL, port = NULL, path = NULL, query = NULL, params = NULL, fragment = NULL, username = NULL, password = NULL)Arguments
url | the url to modify |
scheme,hostname,port,path,query,params,fragment,username,password | components of the url to change |
Generate an oauth1.0 token.
Description
This is the final object in the OAuth dance - it encapsulates the app,the endpoint, other parameters and the received credentials.
Usage
oauth1.0_token( endpoint, app, permission = NULL, as_header = TRUE, private_key = NULL, cache = getOption("httr_oauth_cache"))Arguments
endpoint | An OAuth endpoint, created by |
app | An OAuth consumer application, created by |
permission | optional, a string of permissions to ask for. |
as_header | If |
private_key | Optional, a key provided by |
cache | A logical value or a string. |
Details
SeeToken() for full details about the token object, and thecaching policies used to store credentials across sessions.
Value
AToken1.0 reference class (RC) object.
See Also
Other OAuth:oauth2.0_token(),oauth_app(),oauth_endpoint(),oauth_service_token()
Generate an oauth2.0 token.
Description
This is the final object in the OAuth dance - it encapsulates the app,the endpoint, other parameters and the received credentials. It is areference class so that it can be seamlessly updated (e.g. using$refresh()) when access expires.
Usage
oauth2.0_token( endpoint, app, scope = NULL, user_params = NULL, type = NULL, use_oob = getOption("httr_oob_default"), oob_value = NULL, as_header = TRUE, use_basic_auth = FALSE, cache = getOption("httr_oauth_cache"), config_init = list(), client_credentials = FALSE, credentials = NULL, query_authorize_extra = list())Arguments
endpoint | An OAuth endpoint, created by |
app | An OAuth consumer application, created by |
scope | a character vector of scopes to request. |
user_params | Named list holding endpoint specific parameters to pass tothe server when posting the request for obtaining or refreshing theaccess token. |
type | content type used to override incorrect server response |
use_oob | if FALSE, use a local webserver for the OAuth dance.Otherwise, provide a URL to the user and prompt for a validationcode. Defaults to the of the |
oob_value | if provided, specifies the value to use for the redirect_uriparameter when retrieving an authorization URL. Defaults to "urn:ietf:wg:oauth:2.0:oob".Requires |
as_header | If |
use_basic_auth | if |
cache | A logical value or a string. |
config_init | Additional configuration settings sent to |
client_credentials | Default to |
credentials | Advanced use only: allows you to completely customisetoken generation. |
query_authorize_extra | Default to |
Details
SeeToken() for full details about the token object, and thecaching policies used to store credentials across sessions.
Value
AToken2.0 reference class (RC) object.
See Also
Other OAuth:oauth1.0_token(),oauth_app(),oauth_endpoint(),oauth_service_token()
Create an OAuth application.
Description
See the demos for instructions on how to create an OAuth app for linkedin,twitter, vimeo, facebook, github and google. When wrapping an API from apackage, the author may want to include a default app to facilitate early andcasual use and then provide a method for heavy or advanced users to supplytheir own app or key and secret.
Usage
oauth_app(appname, key, secret = NULL, redirect_uri = oauth_callback())Arguments
appname | name of the application. This is not used for OAuth, but isused to make it easier to identify different applications. |
key | consumer key, also sometimes called the client ID |
secret | consumer secret, also sometimes called the client secret.Despite its name, this does not necessarily need to be protected like apassword, i.e. the user still has to authenticate themselves and grant theapp permission to access resources on their behalf. For example, seeGoogle's docs forOAuth2 for installed applications. |
redirect_uri | The URL that user will be redirected to afterauthorisation is complete. You should generally leave this as the defaultunless you're using a non-standard auth flow (like with shiny). |
See Also
Other OAuth:oauth1.0_token(),oauth2.0_token(),oauth_endpoint(),oauth_service_token()
Examples
## Not run: google_app <- oauth_app( "google", key = "123456789.apps.googleusercontent.com", secret = "abcdefghijklmnopqrstuvwxyz")## End(Not run)The oauth callback url.
Description
The url thatoauth_listener() expects that the client bereferred to.
Usage
oauth_callback()Describe an OAuth endpoint.
Description
Seeoauth_endpoints() for a list of popular OAuth endpointsbaked into httr.
Usage
oauth_endpoint(request = NULL, authorize, access, ..., base_url = NULL)Arguments
request | url used to request initial (unauthenticated) token.If using OAuth2.0, leave as |
authorize | url to send client to for authorisation. Set to |
access | url used to exchange unauthenticated for authenticated token. |
... | other additional endpoints. |
base_url | option url to use as base for |
See Also
Other OAuth:oauth1.0_token(),oauth2.0_token(),oauth_app(),oauth_service_token()
Examples
linkedin <- oauth_endpoint("requestToken", "authorize", "accessToken", base_url = "https://api.linkedin.com/uas/oauth")github <- oauth_endpoint(NULL, "authorize", "access_token", base_url = "https://github.com/login/oauth")facebook <- oauth_endpoint( authorize = "https://www.facebook.com/dialog/oauth", access = "https://graph.facebook.com/oauth/access_token")oauth_endpointsPopular oauth endpoints.
Description
Provides some common OAuth endpoints.
Usage
oauth_endpoints(name)Arguments
name | One of the following endpoints: linkedin, twitter,vimeo, google, facebook, github, azure. |
Examples
oauth_endpoints("twitter")Walk the user through the OAuth2 dance without a local webserver.
Description
This performs a similar function tooauth_listener(),but without running a local webserver. This manual process can be usefulin situations where the user is remotely accessing the machine outside abrowser (say via ssh) or when it's not possible to successfully receive acallback (such as when behind a firewall).
Usage
oauth_exchanger(request_url)Arguments
request_url | the url to provide to the user |
Details
This function should generally not be called directly by the user.
Create a webserver to listen for OAuth callback.
Description
This opens a web browser pointing torequest_url, and opens awebserver on port 1410 to listen to the reponse. The redirect url shouldeither be set previously (during the OAuth authentication dance) orsupplied as a parameter to the url. Seeoauth1.0_token() andoauth2.0_token() for examples of both techniques.
Usage
oauth_listener(request_url, is_interactive = interactive())Arguments
request_url | the url to send the browser to |
is_interactive | DEPRECATED |
Details
This function should not normally be called directly by the user.
Generate OAuth token for service accounts.
Description
Service accounts provide a way of using OAuth2 without user intervention.They instead assume that the server has access to a private key usedto sign requests. The OAuth app is not needed for service accounts:that information is embedded in the account itself.
Usage
oauth_service_token(endpoint, secrets, scope = NULL, sub = NULL)Arguments
endpoint | An OAuth endpoint, created by |
secrets | Secrets loaded from JSON file, downloaded from console. |
scope | a character vector of scopes to request. |
sub | The email address of the user for which the application isrequesting delegated access. |
See Also
Other OAuth:oauth1.0_token(),oauth2.0_token(),oauth_app(),oauth_endpoint()
Examples
## Not run: endpoint <- oauth_endpoints("google")secrets <- jsonlite::fromJSON("~/Desktop/httrtest-45693cbfac92.json")scope <- "https://www.googleapis.com/auth/bigquery.readonly"token <- oauth_service_token(endpoint, secrets, scope)## End(Not run)Generate oauth signature.
Description
For advanced use only. Occassionally needed for sites that use somecomponents of the OAuth spec, but not all of them (e.g. 2-legged oauth)
Usage
oauth_signature( url, method = "GET", app, token = NULL, token_secret = NULL, private_key = NULL, other_params = NULL)oauth_header(info)Arguments
url,method | Url and http method of request. |
app |
|
token,token_secret | OAuth token and secret. |
other_params | Named argument providing additional parameters(e.g. |
Value
A list of oauth parameters.
Parse and print http dates.
Description
As defined in RFC2616,https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.3, there arethree valid formats:
Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123
Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format
Usage
parse_http_date(x, failure = structure(NA_real_, class = "Date"))http_date(x)Arguments
x | For For |
failure | What to return on failure? |
Value
A POSIXct object if succesful, otherwisefailure
Examples
parse_http_date("Sun, 06 Nov 1994 08:49:37 GMT")parse_http_date("Sunday, 06-Nov-94 08:49:37 GMT")parse_http_date("Sun Nov 6 08:49:37 1994")http_date(Sys.time())Parse a media type.
Description
Parsed according to RFC 2616, as athttps://www.rfc-editor.org/rfc/rfc2616#section-3.7.
Usage
parse_media(x)Arguments
x | String to parse |
Details
A simplified minimal EBNF is:
media-type =
type "/" subtype *( ";" parameter )type =
tokensubtype =
tokenparameter =
attribute "=" valueattribute =
tokenvalue =
token | quoted-stringtoken =
1*<any CHAR except CTLs or ()<>@,;:\"/[]?=\{\}
Examples
parse_media("text/plain")parse_media("text/plain; charset=utf-8")parse_media("text/plain; charset=\"utf-8\"")parse_media("text/plain; randomparam=\";=;=\"")Parse and build urls according to RFC3986.
Description
Seehttps://www.rfc-editor.org/rfc/rfc3986 for details of parsingalgorithm.
Usage
parse_url(url)build_url(url)Arguments
url | For |
Value
a list containing:
scheme
hostname
port
path
params
fragment
query, a list
username
password
Examples
parse_url("http://google.com/")parse_url("http://google.com:80/")parse_url("http://google.com:80/?a=1&b=2")url <- parse_url("http://google.com/")url$scheme <- "https"url$query <- list(q = "hello")build_url(url)Add a progress bar.
Description
Add a progress bar.
Usage
progress(type = c("down", "up"), con = stdout())Arguments
type | Type of progress to display: either number of bytes uploadedor downloaded. |
con | Connection to send output too. Usually |
Examples
cap_speed <- config(max_recv_speed_large = 10000)## Not run: # If file size is known, you get a progress bar:x <- GET("http://httpbin.org/bytes/102400", progress(), cap_speed)# Otherwise you get the number of bytes downloaded:x <- GET("http://httpbin.org/stream-bytes/102400", progress(), cap_speed)## End(Not run)The response object.
Description
The response object captures all information from a request. It includesfields:
urlthe url the request was actually sent to (after redirects)handlethe handle associated with the urlstatus_codethe http status codeheadera named list of headers returned by the servercookiesa named list of cookies returned by the servercontentthe body of the response, as raw vector. Seecontent()for various ways to access the content.timerequest timing informationconfigconfiguration for the request
Details
For non-http(s) responses, some parts including the status andheader may not be interpretable the same way as http responses.
See Also
Other response methods:content(),http_error(),http_status(),stop_for_status()
Revoke all OAuth tokens in the cache.
Description
Use this function if you think that your token may have been compromised,e.g. you accidentally uploaded the cache file to github. It's not possibleto automatically revoke all tokens - this function will warn when it can't.
Usage
revoke_all(cache_path = NA)Arguments
cache_path | Path to cache file. Defaults to |
Set (and reset) global httr configuration.
Description
Set (and reset) global httr configuration.
Usage
set_config(config, override = FALSE)reset_config()Arguments
config | Settings as generated by |
override | if |
Value
invisibility, the old global config.
See Also
Other ways to set configuration:config(),with_config()
Examples
GET("http://google.com")set_config(verbose())GET("http://google.com")reset_config()GET("http://google.com")Set cookies.
Description
Set cookies.
Usage
set_cookies(..., .cookies = character(0))Arguments
... | a named cookie values |
.cookies | a named character vector |
See Also
cookies() to see cookies in response.
Other config:add_headers(),authenticate(),config(),timeout(),use_proxy(),user_agent(),verbose()
Examples
set_cookies(a = 1, b = 2)set_cookies(.cookies = c(a = "1", b = "2"))## Not run: GET("http://httpbin.org/cookies")GET("http://httpbin.org/cookies", set_cookies(a = 1, b = 2))## End(Not run)SHA1 hash
Description
Creates a SHA1 hash of data using either HMAC or RSA.
Usage
sha1_hash(key, string, method = "HMAC-SHA1")Arguments
key | The key to create the hash with |
string | data to securely hash |
method | The method to use, either HMAC-SHA1 or RSA-SHA1 |
Sign an OAuth request
Description
Deprecated. Instead create a config object directly usingconfig(token = my_token).
Usage
sign_oauth1.0(app, token = NULL, token_secret = NULL, as_header = TRUE, ...)sign_oauth2.0(access_token, as_header = TRUE)Extract status code from response.
Description
Extract status code from response.
Usage
status_code(x)Arguments
x | A response |
Take action on http error.
Description
Converts http errors to R errors or warnings - these should alwaysbe used whenever you're creating requests inside a function, sothat the user knows why a request has failed.
Usage
stop_for_status(x, task = NULL)warn_for_status(x, task = NULL)message_for_status(x, task = NULL)Arguments
x | a response, or numeric http code (or other object with |
task | The text of the message: either |
Value
If request was successful, the response (invisibly). Otherwise,raised a classed http error or warning, as generated byhttp_condition()
See Also
http_status() andhttp://en.wikipedia.org/wiki/Http_status_codes for more informationon http status codes.
Other response methods:content(),http_error(),http_status(),response()
Examples
## Not run: x <- GET("http://httpbin.org/status/200")stop_for_status(x) # nothing happenswarn_for_status(x)message_for_status(x)x <- GET("http://httpbin.org/status/300")stop_for_status(x)warn_for_status(x)message_for_status(x)x <- GET("http://httpbin.org/status/404")stop_for_status(x)warn_for_status(x)message_for_status(x)# You can provide more information with the task argumentwarn_for_status(x, "download spreadsheet")message_for_status(x, "download spreadsheet")## End(Not run)Set maximum request time.
Description
Set maximum request time.
Usage
timeout(seconds)Arguments
seconds | number of seconds to wait for a response until giving up.Can not be less than 1 ms. |
Details
This timeout is passed on tocurl::handle_setopt().See there andcurl::curl_options() for more details.
See Also
Other config:add_headers(),authenticate(),config(),set_cookies(),use_proxy(),user_agent(),verbose()
Examples
## Not run: GET("http://httpbin.org/delay/3", timeout(1))GET("http://httpbin.org/delay/1", timeout(2))## End(Not run)Upload a file withPOST() orPUT().
Description
Upload a file withPOST() orPUT().
Usage
upload_file(path, type = NULL)Arguments
path | path to file |
type | mime type of path. If not supplied, will be guess by |
Examples
citation <- upload_file(system.file("CITATION"))## Not run: POST("http://httpbin.org/post", body = citation)POST("http://httpbin.org/post", body = list(y = citation))## End(Not run)Use a proxy to connect to the internet.
Description
Use a proxy to connect to the internet.
Usage
use_proxy(url, port = NULL, username = NULL, password = NULL, auth = "basic")Arguments
url,port | location of proxy |
username,password | login details for proxy, if needed |
auth | type of HTTP authentication to use. Should be one of thefollowing: basic, digest, digest_ie, gssnegotiate, ntlm, any. |
See Also
Other config:add_headers(),authenticate(),config(),set_cookies(),timeout(),user_agent(),verbose()
Examples
# See http://www.hidemyass.com/proxy-list for a list of public proxies# to test with# GET("http://had.co.nz", use_proxy("64.251.21.73", 8080), verbose())Set user agent.
Description
Override the default RCurl user agent ofNULL
Usage
user_agent(agent)Arguments
agent | string giving user agent |
See Also
Other config:add_headers(),authenticate(),config(),set_cookies(),timeout(),use_proxy(),verbose()
Examples
## Not run: GET("http://httpbin.org/user-agent")GET("http://httpbin.org/user-agent", user_agent("httr"))## End(Not run)Give verbose output.
Description
A verbose connection provides much more information about the flow ofinformation between the client and server.
Usage
verbose(data_out = TRUE, data_in = FALSE, info = FALSE, ssl = FALSE)Arguments
data_out | Show data sent to the server. |
data_in | Show data recieved from the server. |
info | Show informational text from curl. This is mainly usefulfor debugging https and auth problems, so is disabled by default. |
ssl | Show even data sent/recieved over SSL connections? |
Prefixes
verbose() uses the following prefixes to distinguish betweendifferent components of the http messages:
*informative curl messages->headers sent (out)>>data sent (out)*>ssl data sent (out)<-headers received (in)<<data received (in)<*ssl data received (in)
See Also
with_verbose() makes it easier to use verbose modeeven when the requests are buried inside another function call.
Other config:add_headers(),authenticate(),config(),set_cookies(),timeout(),use_proxy(),user_agent()
Examples
## Not run: GET("http://httpbin.org", verbose())GET("http://httpbin.org", verbose(info = TRUE))f <- function() { GET("http://httpbin.org")}with_verbose(f())with_verbose(f(), info = TRUE)# verbose() makes it easy to see exactly what POST requests sendPOST_verbose <- function(body, ...) { POST("https://httpbin.org/post", body = body, verbose(), ...) invisible()}POST_verbose(list(x = "a", y = "b"))POST_verbose(list(x = "a", y = "b"), encode = "form")POST_verbose(FALSE)POST_verbose(NULL)POST_verbose("")POST_verbose("xyz")## End(Not run)Execute code with configuration set.
Description
Execute code with configuration set.
Usage
with_config(config = config(), expr, override = FALSE)with_verbose(expr, ...)Arguments
config | Settings as generated by |
expr | code to execute under specified configuration |
override | if |
... | Other arguments passed on to |
See Also
Other ways to set configuration:config(),set_config()
Examples
with_config(verbose(), { GET("http://had.co.nz") GET("http://google.com")})# Or even easier:with_verbose(GET("http://google.com"))Control where the response body is written.
Description
The default behaviour is to usewrite_memory(), which cachesthe response locally in memory. This is useful when talking to APIs asit avoids a round-trip to disk. If you want to save a file that's biggerthan memory, usewrite_disk() to save it to a known path.
Usage
write_disk(path, overwrite = FALSE)write_memory()Arguments
path | Path to content to. |
overwrite | Will only overwrite existing |
Examples
tmp <- tempfile()r1 <- GET("https://www.google.com", write_disk(tmp))readLines(tmp)# The defaultr2 <- GET("https://www.google.com", write_memory())# Save a very large file## Not run: GET( "http://www2.census.gov/acs2011_5yr/pums/csv_pus.zip", write_disk("csv_pus.zip"), progress())## End(Not run)S3 object to define response writer.
Description
This S3 object allows you to control how the response body is saved.
Usage
write_function(subclass, ...)Arguments
subclass,... | Class name and fields. Used in class constructors. |
Process output in a streaming manner.
Description
This is the most general way of processing the response from the server -you receive the raw bytes as they come in, and you can do whatever you wantwith them.
Usage
write_stream(f)Arguments
f | Callback function. It should have a single argument, a rawvector containing the bytes recieved from the server. This will usuallybe 16k or less. The return value of the function is ignored. |
Examples
GET( "https://github.com/jeroen/data/raw/gh-pages/diamonds.json", write_stream(function(x) { print(length(x)) length(x) }))