These APIs are still in experiment, we're trying to make file access related Web API polyfills so that browser libraries which uses Blob, File, FileReader ..etc. can still work in React Native.

• XMLHttpRequest
• Blob
• File
• EventTarget
• ProgressEvent
• XMLHttpRequestEventTarget

0.8.0

Replacing window.XMLHttpRequest will break the functionality of officialfetch polyfill since it's base on XMLHttpRequest polyfill. However,fetch replacement andRNFetchBlob.fetch are still working and has more features, consider use them as an alternative offetch when using XMLHttpRequest polyfill.

Though React Native already have XMLHttpRequest polyfill, but it's not a complete implementation, for example, it's not extendedEventTarget, and it does not support Blob. Our XMLHttpRequest polyfill has good integration withRNFetchBlob.fs API, because it usesRNFetchBlob.fetch under the hood. Also it's built for compatible with browser libraries.

0.8.2

An array contains MIME type string, when responseContent-Type contains substring in this array, the data will be automatically converted to Blob().

0.8.2

Add a binaryContentType to XMLHttpRequest.binaryContentTypes.

0.8.2

Remove a binaryContentType from XMLHttpRequest.binaryContentTypes.

0.9.4

Enable logs from polyfill,level should be a number, when level is-1 disable logs.

The state of XMLHttpRequest

Set this property will change the type ofresponse.

The response data, its type is decided byContent-Type in response header. This is the strategy so far :

1. If the Content-Type field contains stringtext/plain the response data will be string, and XMLHttprequest.responseType will betext
2. If the Content-Type field contains stringapplication/json the response data will be an Object, and XMLHttprequest.responseType will bejson
3. Otherwise it would be a Blob, and XMLHttprequest.responseType will beblob

Constructor, does not accept any argument.

This method simply sets the request destination of XMLHttpRequest and changereadystate toOPENED when finished.

Set request header, this method can only be called afterreadstate isOPENED, otherwise it will throw anInvalidStateError.

TODO

Send request with the given body, this method can only be called whenreadstate isOPENED, otherwise it will throw anInvalidStateError.

0.8.0

Blob(Binary Large Object) usually contains a reference to a binary data which stored in file, and it is used very often in HTML5 when upload and download file. Blob object can be created by directly pass an Array, ArrayBuffer, ArrayBufferView, or an array contains mix of any of such objects to its constructor. In RNFetchBlob, you can also create a Blob object fromstring,BASE64 encoded string, andpath of a file byspecifying correspond content type to the Blob object.

This static method remove any blob files in storage, it's useful when you're going to clean up the cache folder.

Similar toConstructor but the Blob instance will resolved by a promise

constBlob=RNFetchBlob.polyfill.BlobBlob.build(SOME_BASE64_ENCODED_DATA,{type:'image/png;base64'}).then((blob)=>{// do something with the Blob})

0.9.4

Enable logs from Blob polyfill,level should be a number, when level is-1 disable logs.

The content of Blob object will always stored in file system ( in DocumentDir/RNFetchBlob-blob/). You should manage these filesmanually. RNFetchBlob automatically decide how to store the Blob object by checkingoptions.type and type ofdata. In the following steps :

1. If type of data is aBlob, it will create a new file which copies data from given Blob object as its content.
2. Else if the data is aString which starts with prefixRNFetchBlob-file://, it simply uses the existing file as its content. However if it does not have the prefix, RNFetchBlob will check ifoptions.type is a string containsapplication/octet or;BASE64. If it does, create a file by decode the string using BASE64 decoder. If it does not, write the string to file as utf8 string.
3. Else if the data is anArrayBuffer, it will be created using the bytes in array buffer (simply applying RNFetchBlob.fs.writeFile(path, data, 'ascii')). (NOT IMPLEMENTED)
4. Else create Blob by store the data as utf8 string text file.

Basically you can create a RNFetchBlob flavor Blob object in these way (use Blob.build)

importRNFetchBlobfrom'react-native-fetch-blob'constBlob=RNFetchBlob.polyfill.Blob// create a blob from BASE64 encoded string, the ';base64' in `type` is crucialBlob.build(BASE64_ENCODED_STRING,{type :'image/png;base64'}).then((blob)=>{ ...})// create a blob which has content of a fileBlob.build(RNFetchBlob.wrap(PATH_TO_A_FILE),{type :'text/plain'}).then((blob)=>{ ...})// create a blob from another blobBlob.build('foo',{type :'text/plain'}).then((first_blob)=>Blob.build(first_blob,{type :'text/plain'})).then((second_blob)=>{ ...})// create a blob from mice-typed array, e.g multipart form dataBlob.build(['--806254942825131805744870237569977¥r¥n','Content-Type: application/json; charset=utf-8¥r¥n¥r¥n','{"name":"rn-firebase-upload/image.png","contentType":"image/png"}¥r¥n','--806254942825131805744870237569977¥r¥n','Content-Type: image/png¥r¥n¥r¥n',blob,'--806254942825131805744870237569977--']).then((blob)=>{ ...})

Keep in mind that in RNFetchBlob the creation process is asynchronous, blob data becomes available afteronCreated event triggered. This is not a part ofBlob object standard, however this helps you create Blob object easier.

0.9.2

This is a synchronous method which immediately returns aBlob object after invoked just like what it is in W3C spec. However, there's a caveat, due to limitation of React Native architecture, there the method is doingasynchronously under the hood, therefore if you're going to access the content of its returned object, you should still register an event handler viaBlob.onCreated() insure the object is initialized.

blob.slice(0,262144).onCreated((slicedBlob)=>{// get path of sliced blob objectletpath=blob.getRNFetchBlobRef()// read content of sliced blobfs.readFile(path,'utf8').then((data)=>{// there we go !})})

However, you can use it as it's sync when dealing with Web API polyfills, because poyfills will take care of the asychrnous problem under the hood.

letxhr=newXMLHttpRequest()// use blob.slice as if it's synchronousxhr.send(blob.slice(0,262144,'octet-binary'))

An index into the Blob indicating the first byte to include in the new Blob. If you specify a negative value, it's treated as an offset from the end of the string toward the beginning. For example, -10 would be the 10th from last byte in the Blob. The default value is 0. If you specify a value for start that is larger than the size of the source Blob, the returned Blob has size 0 and contains no data.

An index into the Blob indicating the first byte that willnot be included in the new Blob (i.e. the byte exactly at this index is not included). If you specify a negative value, it's treated as an offset from the end of the string toward the beginning. For example, -10 would be the 10th from last byte in the Blob. The default value is size.

The content type to assign to the new Blob; this will be the value of its type property. The default value is an empty string.

Register an event handler that will be invoked when blob constructor finished the creation process, if the object already created, the handler will be invoked instantly.

0.10.5

An alternative toclose(), this method also release the resources but it does not remove the Blob from disk if it's created from an existing file.

Blob.build(RNFetchBlob.wrap(PathOfSomeFile)).then((blob)=>{// the file at `PathOfSomeFile` will be removed too !// blob.close()// the source file will not be removed// blob.safeClose()})

0.8.0

Remove the blob content release the resource from storage. Beware that If the blob is created from an existing file path, the original file willBE REMOVED when blob.close() since the blob simply uses the same file as it's content (for performance concern).

0.8.0

Description onMDN

A File object is a specific kind of a Blob, and can be used in any context that a Blob can. In particular, FileReader, URL.createObjectURL(), createImageBitmap(), and XMLHttpRequest.send() accept both Blobs and Files.

A method overridesBlob.build but it take on extra argumentfilename, which will be set as the instance'sfilename property.

0.8.0

TODO

0.8.0

TODO

0.8.0

TODO