Composer Namespace Collisions in WordPress Plugin Development - php

I'm encountering a wholly predictable yet incredibly annoying and tough to resolve problem.
I've been working on a PHP framework for developing WordPress plugins. It's using Composer for dependency management. Of course, the problem is if you have two instances of my framework in the same installation of WordPress, you have two vendor folders, and two copies of any packages required by the framework. Which leads to an error.
The framework functions as a separate plugin which is then inherited by any apps/plugins that are build on it.
Move the vendor folder to the core framework folder?
Problems: I don't know what would happen if I have two composer.json files and two composer.phar files writing to the same vendor folder and using the same autoloader. Presumably it wouldn't be good. Besides that, it doesn't solve the problem of collisions with composer packages that could be used by any other script or plugin outside of what I'm trying to handle.
So I'm stuck. Is this a problem that can be solved, or is it just inherent in PHP?

Composer is not really meant to be used multiple times in same project. On other hand there is nothing terribly wrong with it either, however you lose its dependencies features and need to treat this like generic case of dependencies in WordPress environment.
In other words - if you are not doing dependencies Composer way and WordPress is not doing dependencies at all, it becomes your personal problem how to deal with it.
I don't know what would happen if I have two composer.json files and two composer.phar files writing to the same vendor folder and using the same autoloader
I am not following why the vendor folder would be same if you are using multiple composer installs... Could you elaborate on how you structure it and is it meant for public or private use?

I'm not very familar with Composer or the plugin framework you are using, but in general - avoiding function/class name collisions in WordPress plugins is done in the following manner:
Assuming that your plugin (e.g. MyCoolPlugin) is written object-oriented, e.g. as a class named MyCoolPlugin, you may include the helper class/library as a subclass of MyCoolPlugin.
class_exists(), this is PHPs way of finding if a class has been defined. Assuming your helper class the following:
class MyHelperClass{
}
You may use the following check before declaring the class in each of your plugins:
if(!class_exists('MyHelperClass')){
class MyHelperClass{
}
}
Of course, there is a trade-off here, because only the first instance of the class will be used throughour WordPress. E.g. if you have two plugins with two different versions of the helper class - only one of them will be active and available at any given moment.
A global variable - e.g. define('MY_HELPER_IS_LOADED', true); in the helper files (in case you are including them via include() or require()). Then in the beginning of each included helper file check with if(defined('MY_HELPER_IS_LOADED')) return;, which will cause the currently requested file for include/require to NOT be included.
Again the tactics above are used in PHP in general, I am not sure how your plugin framework is set up exactly.

Related

Use the same part of code in multiple WP plugins [duplicate]

I am developing a plugin that used composer.. meaning it has a vendor folder inside the plugin folder which includes Guzzle HTTP dependency
On wordpress site we installed this plugin, there is an existing plugin that has Guzzle HTTP
Now when we activate this plugin i am getting an error something like this:
Fatal error: Cannot redeclare GuzzleHttp\uri_template() (previously declared in /nas/content/staging/project/wp-content/plugins/my-plugin/vendor/guzzlehttp/guzzle/src/functions.php:17) in /nas/content/staging/project/wp-content/plugins/other-plugin/includes/lib/aws-sdk/GuzzleHttp/functions.php on line 31
I tried installing Plugins Load Order to force the 'other-plugin' to load first before 'my-plugin'
currently the error is happening on the other-plugin's resources.
this way, The error will yield in our autoload and we can catch that.
unfortunately.. Plugins Load Order did not work..
any ideas how to solve this?
Welcome to WordPress hell. We have 2018 and WordPress still does not have any dependency management and still didn't notice Composer existence.
WordPress ecosystem simply relies on assumption, that functions/classes names of plugins/themes should be unique. Obviously distributing popular 3rd-part Composer libraries with your plugin/theme is asking for trouble - it is easy to get names collision when other plugin is doing the same. There is no good way out of this situation.
If you want a bulletproof solution for standalone plugins, you should prefix namespaces of every package in your vendor directory with plugin prefix, for example myplygin\vendor. Then GuzzleHttp\Client becomes myplugin\vendors\GuzzleHttp\Client, so there is no risk of name collisions. This will require some work to write script for this (or you may use some existing solutions, like humbug/php-scoper), and you may get many duplicated dependencies (10 plugins may bring the same library 10 times, but with different namespaces), but this is the cost of integrating modern tools and patterns into outdated software.
If you're writing this plugin for yourself and you're controlling final installation, you may try to use Composer for installing WordPress and its plugins. You still may need to fix 3rd-party plugins (via forking) if they're have bundled some composer library, but in the long run it should simplify many things and you may avoid duplicating libraries for every plugin.
By design, PHP and Composer assume that you develop and distribute your code in a controlled environment. However, when you publish plugins on WordPress or modules on Joomla, you distribute the code on systems where you don't have control over what other authors install. This situation can result in name collisions such as Cannot redeclare GuzzleHttp\uri_template()....
To prepare your code for multi-vendor setups, you must prefix the PHP code to avoid name collisions or version collisions (the same library with a different version is loaded first). For instance, Guzzle is a well-known and widely used library, so if you publish a plugin including it, you must prefix it before distribution.
At first glance, you may think that prefixing only the namespaces would get the job done. But other named elements such as global functions and traits must also be prefixed to avoid all possible error types.
To prefix PHP code, there are tools or services to execute the task:
humbug/php-scoper. Prefixes all PHP namespaces in a file/directory to isolate the code bundled in PHARs.
Interfacelab/namespacer. Namespacer allows you to rename the namespace of any composer packages. It works by adding a namespace prefix to all of the namespaces. Namespacer also prefixes the package names. It then generates a folder called "lib" that you can safely include in your WordPress plugin.
coenjacobs/mozart. Developers tool for WordPress plugins: Wraps all your projects dependencies in your own namespace. This prevents conflicts with other plugins that load the same dependencies but in different versions.
PHP-Prefixer. It's an automated online service powered by a complex rule-based system to apply prefixes to Composer dependencies. In the composer.json, you just define the prefix to apply without worrying about the nitty-gritty details.
Disclaimer: I'm the lead PHP-Prefixer developer.
This is not suggested but use it if you must
function this_plugin_last() {
$wp_path_to_this_file = preg_replace('/(.*)plugins\/(.*)$/', WP_PLUGIN_DIR."/$2", __FILE__);
$this_plugin = plugin_basename(trim($wp_path_to_this_file));
$active_plugins = get_option('active_plugins');
$this_plugin_key = array_search($this_plugin, $active_plugins);
array_splice($active_plugins, $this_plugin_key, 1);
array_push($active_plugins, $this_plugin);
update_option('active_plugins', $active_plugins);
}
add_action("activated_plugin", "this_plugin_last");
I make use of this library which is a more maintained version of mozart: https://github.com/BrianHenryIE/strauss
It lets you set a namespace prefix for your vendor libaries of choice and add them to a separate library which you can then autoload into you project.
It also has a lot of other useful features.
I'm guessing there's a function at GuzzleHttp/functions.php on line 31 so you can use something like that:
if (function_exists('Do_Something')){
echo "Function Exists";
}else{
echo "Function Not Found, This name Can be used!";
}
or you can use is_plugin_active function to check if the plugin is already installed. In that case, you can ignore including the files
https://codex.wordpress.org/Function_Reference/is_plugin_active

3rd party dependency conflict in developing Wordpress Plugin

I am developing a plugin that used composer.. meaning it has a vendor folder inside the plugin folder which includes Guzzle HTTP dependency
On wordpress site we installed this plugin, there is an existing plugin that has Guzzle HTTP
Now when we activate this plugin i am getting an error something like this:
Fatal error: Cannot redeclare GuzzleHttp\uri_template() (previously declared in /nas/content/staging/project/wp-content/plugins/my-plugin/vendor/guzzlehttp/guzzle/src/functions.php:17) in /nas/content/staging/project/wp-content/plugins/other-plugin/includes/lib/aws-sdk/GuzzleHttp/functions.php on line 31
I tried installing Plugins Load Order to force the 'other-plugin' to load first before 'my-plugin'
currently the error is happening on the other-plugin's resources.
this way, The error will yield in our autoload and we can catch that.
unfortunately.. Plugins Load Order did not work..
any ideas how to solve this?
Welcome to WordPress hell. We have 2018 and WordPress still does not have any dependency management and still didn't notice Composer existence.
WordPress ecosystem simply relies on assumption, that functions/classes names of plugins/themes should be unique. Obviously distributing popular 3rd-part Composer libraries with your plugin/theme is asking for trouble - it is easy to get names collision when other plugin is doing the same. There is no good way out of this situation.
If you want a bulletproof solution for standalone plugins, you should prefix namespaces of every package in your vendor directory with plugin prefix, for example myplygin\vendor. Then GuzzleHttp\Client becomes myplugin\vendors\GuzzleHttp\Client, so there is no risk of name collisions. This will require some work to write script for this (or you may use some existing solutions, like humbug/php-scoper), and you may get many duplicated dependencies (10 plugins may bring the same library 10 times, but with different namespaces), but this is the cost of integrating modern tools and patterns into outdated software.
If you're writing this plugin for yourself and you're controlling final installation, you may try to use Composer for installing WordPress and its plugins. You still may need to fix 3rd-party plugins (via forking) if they're have bundled some composer library, but in the long run it should simplify many things and you may avoid duplicating libraries for every plugin.
By design, PHP and Composer assume that you develop and distribute your code in a controlled environment. However, when you publish plugins on WordPress or modules on Joomla, you distribute the code on systems where you don't have control over what other authors install. This situation can result in name collisions such as Cannot redeclare GuzzleHttp\uri_template()....
To prepare your code for multi-vendor setups, you must prefix the PHP code to avoid name collisions or version collisions (the same library with a different version is loaded first). For instance, Guzzle is a well-known and widely used library, so if you publish a plugin including it, you must prefix it before distribution.
At first glance, you may think that prefixing only the namespaces would get the job done. But other named elements such as global functions and traits must also be prefixed to avoid all possible error types.
To prefix PHP code, there are tools or services to execute the task:
humbug/php-scoper. Prefixes all PHP namespaces in a file/directory to isolate the code bundled in PHARs.
Interfacelab/namespacer. Namespacer allows you to rename the namespace of any composer packages. It works by adding a namespace prefix to all of the namespaces. Namespacer also prefixes the package names. It then generates a folder called "lib" that you can safely include in your WordPress plugin.
coenjacobs/mozart. Developers tool for WordPress plugins: Wraps all your projects dependencies in your own namespace. This prevents conflicts with other plugins that load the same dependencies but in different versions.
PHP-Prefixer. It's an automated online service powered by a complex rule-based system to apply prefixes to Composer dependencies. In the composer.json, you just define the prefix to apply without worrying about the nitty-gritty details.
Disclaimer: I'm the lead PHP-Prefixer developer.
This is not suggested but use it if you must
function this_plugin_last() {
$wp_path_to_this_file = preg_replace('/(.*)plugins\/(.*)$/', WP_PLUGIN_DIR."/$2", __FILE__);
$this_plugin = plugin_basename(trim($wp_path_to_this_file));
$active_plugins = get_option('active_plugins');
$this_plugin_key = array_search($this_plugin, $active_plugins);
array_splice($active_plugins, $this_plugin_key, 1);
array_push($active_plugins, $this_plugin);
update_option('active_plugins', $active_plugins);
}
add_action("activated_plugin", "this_plugin_last");
I make use of this library which is a more maintained version of mozart: https://github.com/BrianHenryIE/strauss
It lets you set a namespace prefix for your vendor libaries of choice and add them to a separate library which you can then autoload into you project.
It also has a lot of other useful features.
I'm guessing there's a function at GuzzleHttp/functions.php on line 31 so you can use something like that:
if (function_exists('Do_Something')){
echo "Function Exists";
}else{
echo "Function Not Found, This name Can be used!";
}
or you can use is_plugin_active function to check if the plugin is already installed. In that case, you can ignore including the files
https://codex.wordpress.org/Function_Reference/is_plugin_active

Where should I put a custom class file in zend framework 3?

I have created a set of class files that helps to create the route configuration array. I, however, do not know where to put the source files. I browsed around a little and found some answers that suggested I put up the code in packagist and install it via composer, but my classes are relatively small. So, I wanted to ask if there is another way to do it. The files must be accessible in all the modules.
Your application code is organised into modules and lives in module/<Modulename>/src/. If the code is something you might want to reuse in other applications, then it might make more sense to have it as a standalone library that you install via. Composer.
You're code is accessibly through all the application if it is configured in the composer.json's autoload section.
Code structure in ZF is quite simple. You have your modules and in every module you have an src directory. This src directory should have its own namespace. And there you can place your custom route configurator under this namespace, like 'ModuleName\RouteConfigurator'.
But if you use this logic through multiple modules, I suggest you to create a separate module for it. In this case, after a long road, you may consider creating a separate composer package from it. But it's not necessary.
If you're not familiar with defining modules, please read the zend-modulemanager's documentation (https://docs.zendframework.com/zend-modulemanager/intro/)

Composer dependecies in Prestashop per module

In Prestashop I can write my modules. But I have some code that is framework independent and I want to reuse in other Prestamodules AND in other frameworks I use.
So far so good. My solution was to put an Vendor folder and a composer.json to my Prestamodules to get those libaries I needed.
Now comes the problem that (offcourse) duplicated namespaces get into conflict. Is there a way around for this or should I do a global vendor folder in the root of Presta (what I want to avoid at any cost, I want to decide when I upgrade a single module or not. So the vendors should be per-module)
Vendors can't be per module if they are executed in the same request. You have to use a central vendor folder for all your dependencies - or you avoid using Composer and try to manage individual dependencies yourself - with the same problem as before: You cannot have two versions of the same class in your code.
Which one gets used? The first that the code encounters, depending on how autoloading is configured. Assume "random" order - it will break your code at the most inconvenient time.

Can we use Composer with sparse SVN checkout to share dependencies?

Our current development setup uses a single Subversion repository containing multiple projects, each with branches, tags, and trunk. We then use a "sparse checkout" to select the projects, and branches of those projects, to work with.
The result is that the directory structure of a working copy matches that of the repository, including branch information, and we never use svn switch. (This style of working will probably be familiar to anyone who uses SVN, but may be surprising to those who don't.)
We are thinking of using Composer to manage both external and internal dependencies, but I'm not sure how this can work with the sparse checkout style of working.
I would like some way of using a directory within the existing checkout to satisfy a dependency, rather than each "root project" needing a separate copy.
For example:
sites/Foo/trunk
depends on lib Aaa, so references lib/Aaa/trunk
depends on lib Bbb 1.5.*, so references lib/Bbb/branches/release-1.5
sites/Bar/trunk
depends on lib Aaa 1.0.*, so references lib/Aaa/branches/release-1.0
depends on lib Bbb 1.5.*, so references lib/Bbb/branches/release-1.5
At present, if I edit the code in lib/Bbb/branches/release-1.5, I can test those changes on both sites, without needing to commit one and update the other.
Is there any way of using Composer to manage these dependencies?
(PS: Please don't answer with "give up on SVN, use Git, it is teh awesomez"; that is an answer to a different question.)
No - I do not believe that you can do this with Composer as standard: it expects to copy the files from whichever source (Packagist/VCS/Zips) to the local vendor folder, which is not what you want.
That said, I believe there are two potential ways you could get this working (at least in part):
Autoloader
You could try using the autoload field in the composer.json file to include the correct files into the project. You would still need to manage the checkouts of the relevant branches/versions manually (like I assume you do now), but you would be able to manage the inclusion of the internal libraries through Composer. This will probably require that your libraries are properly namespaced. The paths to the files for each namespace are relative to the root of the project, but can go below the root (via the /../ path) if required.
To be honest though, if you already have an autoloader for these files, there may not be much advantage to this solution. Relevant Docs
Composer Plugin
You could also write a composer plugin/"custom installer" that could probably manage this. This would have the advantage that you could have it manage checking out the correct parts of the sparse repository to have the correct version available, as well as doing correct wildstar version checking, but would be a much more difficult and riskier venture.
The basic process would be that you would define a new package type (e.g. 'internal-svn-package'). You would create the plugin as an external library that gets installed normally via Composer, which declares (via it's composer.json) that it handles this new type of package. Your custom logic would then be used for any packages that are listed with this custom type. I'm not sure how much of the internal composer logic for SVN checkouts you would be able to reuse however. Relevant Docs

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