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The autoloader for autoloading classes, enums, functions, typedefs, and constants on HHVM.

1. Add anhh_autoload.json file (see section below)
2. composer require hhvm/hhvm-autoload
3. Require the autoload file from your entrypoint functions usingrequire_once (__DIR__ . '(/..)(repeat as needed)/vendor/autoload.hack');
4. CallFacebook\AutoloadMap\initialize() to register the autoloader with hhvm.
5. To re-generate the map, runvendor/bin/hh-autoload,composer dump-autoload, or any other command that generates the map

A minimal configuration file is:

{"roots": ["src/" ]}

This will look for autoloadable definitions insrc/, and also look invendor/.Projects invendor/ are only processed if they also contain ahh_autoload.json file.

Previously we also supported projects withouthh_autoload.json by simulating Composer's autoload behavior, but we no longer do because that mostly applied to PHP files which HHVM can no longer parse.

The following settings are optional:

• "extraFiles": ["file1.hack"] - files that should not be autoloaded, but should berequire()ed byvendor/autoload.hack. This should be needed much less frequently than under Composer
• "includeVendor": false - do not includevendor/ definitions invendor/autoload.hack
• "devRoots": [ "path/", ...] - additional roots to only include in dev mode, not when installed as a dependency.
• "relativeAutoloadRoot": false - do not use a path relative to__DIR__ for autoloading. Instead, use the path to the folder containinghh_autoload.json when building the autoload map.
• "failureHandler:" classname<Facebook\AutoloadMap\FailureHandler> - use the specified class to handle definitions that aren't the Map. Defaults to none.
• "devFailureHandler": classname<Facebook\AutoloadMap\FailureHandler> - use a different handler for development environments. Defaults to the same value asfailureHandler.
• "parser:" any of [ext-factparse]" - select a parser to use, but there is only one valid option. Defaults to a sensible parser.
• "useFactsIfAvailable": false - use ext-facts (HH\Facts...) to back Facebook\AutoloadMap\Generated\map() instead of a codegenned dict. SeeUse with HH\Facts for more information about this mode.

When you add, remove, or move definitions, there are several options available:

• runcomposer dump-autoload to regenerate the map
• runvendor/bin/hh-autoload to regenerate the map faster
• specifydevFailureHandler asFacebook\AutoloadMap\HHClientFallbackHandler
• specify a custom subclass ofFacebook\AutoloadMap\FailureHandler
• use a filesystem monitor such aswatchman to invoke one of the abovecommands when necessary

Facebook\AutoloadMap\HHClientFallbackHandler is probably the mostconvenient for Hack development.

If you are working in Hack, this handler will remove the need to manuallyrebuild the map in almost all circumstances.

It askshh_client for definitions that aren't in the map, and has thefollowing additional behaviors:

• it is disabled if theCI,CONTINUOUS_INTEGRATION, orTRAVISenvironment variables are set to a Truthy value; this is because itis not a recommended approach for production environments, and youprobably want your automated testing environment to reflectproduction
• results are cached in both APC and a file in vendor/, if vendor/ iswritable

You can override these behaviors in a subclass.

Information you may need is available from:

• Facebook\AutoloadMap\Generated\build_id(): this is unique IDregenerated every time the map is rebuilt; it includes the date,time, and a long random hex string. If your failure handler has acache, it most likely should be invalidated when this changes, forexample, by including it in the cache key.
• Facebook\AutoloadMap\Generated\map(): the autoload map
• Facebook\AutoloadMap\Generated\root(): the directory containing theproject root, i.e. the parent directory ofvendor/

HHVM 4.109 introduced ext-facts and ext-watchman. Unlike the static pre-built autoloader which is built into arepo authoratative build, this native autoloader works incrementally and is suitable for autoloading in your development environment. For more information about setting up this autoloader, see theblog post for hhvm 4.109.

When using a native autoloader (either the repo auth or ext-facts autoloader), you do not need hhvm-autoload to require classes/functions/types/constants at runtime. If you (and your vendor dependencies) do not call any functions in theFacebook\AutoloadMap namespace, other thanFacebook\AutoloadMap\initialize(), you don't need hhvm-autoload anymore. In that case, you could drop this dependency and remove the calls toinitialize(). If you are using other functions, likeFacebook\AutoloadMap\Generated\map(), you'd still need the vendor/autoload.hack file that hhvm-autoload generates.

Hhvm-autoload supports outputting a vendor/autoload.hack file which forwards all queries to ext-facts.Facebook\AutoloadMap\Generated\map_uncached() will always be up to date in this mode, sinceHH\Facts is always up to date.Facebook\AutoloadMap\Generated\map() is memoized (within a request), since some code may rely on getting the same result from multiple calls. You can enable this mode by adding"useFactsIfAvailable": true to the hh_autoload.json config file. Hhvm-autoload will emit a shim file instead of a full map. This option is ignored ifHH\Facts\enabled() returns false, or when--no-facts is passed tovendor/bin/hh-autoload. We recommend passing--no-facts when building for production (specifically repo auth mode). Returning a hardcoded dict is faster than askingHH\Facts.

Important to note. Autoloading with a native autoloader does not respect hh_autoload.json. The repo auth autoloader allows any code to use any symbol. The facts autoloader honors the configuration in .hhvmconfig.hdf instead. Make sure that the configuration in hh_autoload.json and .hhvmconfig.hdf match.

• A parser (FactParse) provides a list of all Hack definitions in the specified locations
• This is used to generate something similar to a classmap, except including other kinds of definitions
• The map is provided to HHVM withHH\autoload_set_paths()
• If a native autoloader is registered, this autoloader will intentionally not register itself. So callingFacebook\AutoloadMap\initialize() in repo auth mode or when the facts based autoloader is registered is a noop.

We welcome GitHub issues and pull requests - please see CONTRIBUTING.md for details.

hhvm-autoload isMIT-licensed.