Download the PHP package wpsmith/templates without Composer

Template Loader

A class to copy into your WordPress plugin, to allow loading template parts with fallback through the child theme > parent theme > plugin.

This is largely based on Gary Jones's Gamajo_Template_Loader. The main difference between Gary's version and this one is twofold:

1. I didn't want to extend the class for each and every plugin I created...call me lazy.
2. I didn't want to load the template parts automatically.

Description

Easy Digital Downloads, WooCommerce, and Events Calendar plugins, amongst others, allow you to add files to your theme to override the default templates that come with the plugin. As a developer, adding this convenience in to your own plugin can be a little tricky.

The get_template_part() function in WordPress was never really designed with plugins in mind, since it relies on locate_template() which only checks child and parent themes. So we can add in a final fallback that uses the templates in the plugin, we have to use a custom locate_template() function, and a custom get_template_part() function. The solution here just wraps them up as a class for convenience.

Installation

This isn't a WordPress plugin on its own, so the usual instructions don't apply. Instead:

Manually install class

1. Copy Templates/src/TemplateLoader.php for basic usage

or:

1. Copy Templates/src/TemplateLoaderData.php and Templates/src/TemplateLoader.php](TemplateLoader.php) into your plugin. It can be into a file in the plugin root, or better, an includes directory.

or:

Install class via Composer

1. Tell Composer to install this class as a dependency: composer require wpsmith/templates
2. Recommended: Install the Mozart package: composer require coenjacobs/mozart --dev and configure it.
3. The class is now renamed to use your own prefix, to prevent collisions with other plugins bundling this class.

Implementation & Usage

Unlike Gamajo's Gamajo_Template_Loader, you do not have to implement a new class.

Assuming...

// Set at the root folder of your plugin (e.g., wp-content/plugins/yourplugin/yourplugin.php).
// Defines YOUR_PLUGIN_DIRNAME as yourplugin.
define( 'YOUR_PLUGIN_DIRNAME', dirname( __FILE__ ) );

Initialization

We can initialize TemplateLoader:

// Create the loader with my prefix and directory.
// This assumes:
//  - plugin templates are found in the plugin folder: wp-content/plugins/yourplugin/templates/...
//  - theme templates are found in the plugin folder: wp-content/themes/yourtheme/templates/...
$template_loader = new TemplateLoader( [
    'prefix'           => 'wps',
    'plugin_directory' => YOUR_PLUGIN_DIRNAME,
] );

Or,

// Create the loader with all the parts.
// This declares:
//  - plugin templates are found in the plugin folder: wp-content/plugins/yourplugin/templates/...
//  - theme templates are found in the plugin folder: wp-content/themes/yourtheme/templates/yourplugin/...
$template_loader = new TemplateLoader( [
    'prefix'                   => 'wps',
    'theme_template_directory' => 'templates/yourplugin',
    'templates_directory'      => 'templates',
    'plugin_directory'         => WPS_PLUGIN_DIRNAME,
] );

You could utilize a template loader helper which will always return the same template loader:

/**
 * Gets the plugin template loader.
 *
 * @return \WPS\WP\Templates\TemplateLoader
 */
function yourprefix_get_template_loader() {
    static $loader;
    if ( $loader === null ) {
        $loader = new \WPS\WP\Templates\TemplateLoader( [
            'prefix'                   => 'wps',
            'theme_template_directory' => 'templates/yourplugin',
            'templates_directory'      => 'templates',
            'plugin_directory'         => WPS_PLUGIN_DIRNAME,
        ) );
    }

    return $loader;
}

Finally, you can use it for configuration purposes too.

/**
 * Gets a configuration file as a data array.
 *
 * @return array
 */
function yourprefix_get_config( $config ) {
    static $loader;

    if ( $loader === null ) {
        $loader = new TemplateLoader( [
            'filter_prefix'            => 'wps',
            'theme_template_directory' => 'config',
            'templates_directory'      => 'config',
            'plugin_directory'         => WPS_PLUGIN_DIRNAME,
        ] );
    }

    $template = $loader->get_template_part( 'config', $config );

    $data = array();
    if ( is_readable( $template ) ) {
        $data = require $template;
    }

    return (array) $data;
}

Usage

• Use it to call the load_template_part() method. This could be within a shortcode callback, or something you want theme developers to include in their files.

  $template_loader->load_template_part( 'recipe' );

• Use it to call the get_template_part() method. This could be within a shortcode callback, or something you want theme developers to include in their files.

  // This will return the path to the particular template part.
  $template_loader->get_template_part( 'recipe' );
  
  // This will load the particular template part.
  $template_loader->get_template_part( 'recipe', null, true );

• If you want to pass data to the template, call the set_template_data() method with an array before calling get_template_part(). set_template_data() returns the loader object to allow for method chaining.

  $data = [ 'foo' => 'bar', 'baz' => 'boom' ];
  $template_loader
    ->set_template_data( $data );
    ->get_template_part( 'recipe' );

  The value of bar is now available inside the recipe template as $wps_data->foo.

  If you wish to use a different variable name, add a second parameter to set_template_data():

  $data = array( 'foo' => 'bar', 'baz' => 'boom' );
  $meal_planner_template_loader
    ->set_template_data( $data, 'context' )
    ->get_template_part( 'recipe', 'ingredients' );

  The value of bar is now available inside the recipe template as $context->foo.

  This will try to load up:

  • Theme Templates:
    • wp-content/themes/my-theme/meal-planner/recipe-ingredients.php
    • wp-content/themes/my-theme/meal-planner/ingredients.php
    • wp-content/themes/my-theme/meal-planner/recipe.php
  • Plugin Templates:
    • wp-content/plugins/meal-planner/templates/recipe-ingredients.php
    • wp-content/plugins/meal-planner/templates/ingredients.php.
    • wp-content/plugins/meal-planner/templates/recipe.php.

Change Log

See the change log.

License

GPL 2.0 or later.

Contributions

Contributions are welcome - fork, fix and send pull requests against the develop branch please.

Credits

Based upon Gary Jones's Gamajo_Template_Loader Built by Travis Smith
Copyright 2013-2020 Travis Smith