Make WordPress Core

Opened 3 years ago

Closed 3 years ago

Last modified 3 years ago

#52400 closed enhancement (duplicate)

Dependency management for plugins and libraries

Reported by: joppuyo's profile joppuyo Owned by:
Milestone: Priority: normal
Severity: normal Version:
Component: Plugins Keywords:
Focuses: Cc:


Many plugin developers use Composer to manage PHP dependencies in their plugins, however, this may cause hard-to-debug issues if two plugins use the same library. Because of how Composer works, it will only load one version of that dependency at a time. Imagine the following scenario:

Plugin Developer 1 creates a plugin named Foo that uses version 2.0 of a library Bar
Library Bar developer releases version 3.0 of their library which renames function get_baz() to get_qux().
Plugin Developer 2 creates a plugin name Quuz that uses version 3.0 of the library Bar

User installs both plugins at the same time. Now their site crashes because one of the plugins calls a missing function.

There are some ways developers have worked around this, for example using , or which add an extra unique namespace to files defined as Composer dependencies but these tools are error-prone and don't work if the library checks dependencies in runtime.

I think it could be great to have some sort of way to fix this in the core. According to the Composer developers, Composer was never meant to be used on plugin level, only at the project level where each plugin would be its own dependency and Composer could calculate any dependency conflicts run time.

I think two ways to fix this would be:

  1. Install WordPress (and its plugins) using Composer like Drupal does . I think this would be the best way to fix this but it's not really that great if the majority of WordPress installations are on shared hosting and can't run composer. Drupal has a thing named Ludwig which works from the Drupal admin interface and allows you to manually download and install the required dependencies.
  1. Distribute libraries on plugin directory. This used to an option but now libraries are disallowed in the plugin directory . If libraries would be distributed on, you could at least check if the library is the correct version in your plugin before using it. There's also the issue of ownership, who will upload the libraries and keep them up to date?

Without any solution to this plugin developers who want to use libraries will have to use workarounds or simply hope that users do not install libraries with different versions. Please note that this issue is not unique to Composer, you can run into the same problem even if two plugins require the library manually.

Some more info about this issue is in this blog post:

Change History (2)

#1 @TimothyBlynJacobs
3 years ago

  • Milestone Awaiting Review deleted
  • Resolution set to duplicate
  • Status changed from new to closed

Hi @joppuyo,

Welcome to trac! This is a conversation that is already being tracked in #22316. To keep the discussion all in one place, I'm going to close out this ticket. I'd invite you to post your thoughts in a comment on the existing ticket.

#2 @joppuyo
3 years ago

Thanks, I'll do that.

I did try to search for any duplicate issue before creating this one but unfortunately, I did not come across that one.

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