Plugins and Themes (.php)¶

Plugins and themes (either your own or plugins and themes downloaded from WordPress directory) need to be added during the development process and compiled. This article describes how and how it works.

Sample project: https://github.com/iolevel/peachpie-wordpress/tree/master/MyContent

Project Structure¶

The following project structure respects the /wp-content/ directory used by WordPress. Sources of the plugin complies with the regular WordPress codex. See Writing a Plugin for more details. Put the plugin source files in plugins folder, and themes in themes folder (as you would do in WordPress).

Following is the file structure for the basic WordPress Hello Dolly plugin.

┬ MyContent
└  plugins
   └ hello.php

Name of the folder is not relevant.

Note, the plugin must contain the standard plugin metadata. The main source file needs to specify following minimal metadata at the top of the file:

hello.php:

<?php
/*
Plugin Name: Hello Dolly
Version: 1.7.2
*/

Project File¶

In order to compile the plugin, create a project file in the plugin folder.

┬ MyContent
├  MyContent.msbuildproj  <---
└  plugins
   └ hello.php

Project file is an XML file with the following content:

MyContent.msbuildproj:

<Project Sdk="PeachPied.WordPress.Build.Plugin/6.5.4-rc-020">
</Project>

For most cases, the project file does not specify anything else as all the properties are defined by default in the Sdk. In case a build property or a build item needs to be altered, add it to your project file.

Note the project file specifies a version after the slash, i.e. "/6.5.4-rc-020". This corresponds to the version of PeachPied.WordPress.* packages which should be identical across all your application.

Build¶

In order to build plugins and themes, run dotnet build command:

dotnet build

The process will build the project. Eventual warnings will be outputed. Any error in the code will cause the build to fail.

If the process is run for the first time, it will first download the project Sdk and dependency packages (it means it requires an Internet connection).

Build Errors¶

Building the project may result in compile-time errors. It is very common for a WordPress plugin to contain an invalid code.

Errors need to be fixed. Sometimes whole files or directories may be excluded from the compilation since they may contain a dead code (usually tests or adapters for other plugins you don't use).

Add Project Reference¶

Assuming you have ASP.NET Core Application (named app) with WordPress (see quick start), add project reference to MyContent.msbuildproj.

Either add project reference to the plugin in Visual Studio IDE, or on command line, or edit the application's project file:

app.csproj:
<ItemGroup>
  <ProjectReference Include="../MyContent/MyContent.msbuildproj" />
</ItemGroup>
Note, the plugin still needs to be activated in WordPress dashboard once you compile and run the application.