README.md
# Gamajo Template Loader
[](https://codeclimate.com/github/GaryJones/Gamajo-Template-Loader)
A class to copy into your WordPress plugin, to allow loading template parts with fallback through the child theme > parent theme > plugin.
## 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 [`class-gamajo-template-loader.php`](class-gamajo-template-loader.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 gamajo/template-loader`
2. Recommended: Install the Mozart package: `composer require coenjacobs/mozart --dev` and [configure it](https://github.com/coenjacobs/mozart#configuration).
3. The class is now renamed to use your own prefix, to prevent collisions with other plugins bundling this class.
## Implement class
1. Create a new file, such as `class-your-plugin-template-loader.php`, in the same directory.
2. Create a class in that file that extends `Gamajo_Template_Loader` (or the new prefixed name, if you installed via Composer/Mozart). You can see the Meal Planner Template Loader example class below as a starting point if it helps.
3. Override the class properties to suit your plugin. You could also override the `get_templates_dir()` method if it isn't right for you.
4. You can now instantiate your custom template loader class, and 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.
~~~php
// Template loader instantiated elsewhere, such as the main plugin file.
$meal_planner_template_loader = new Meal_Planner_Template_Loader();
~~~
* 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.
~~~php
$meal_planner_template_loader->get_template_part( 'recipe' );
~~~
* 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.
~~~php
$data = array( 'foo' => 'bar', 'baz' => 'boom' );
$meal_planner_template_loader
->set_template_data( $data )
->get_template_part( 'recipe' );
~~~
The value of `bar` is now available inside the recipe template as `$data->foo`.
If you wish to use a different variable name, add a second parameter to `set_template_data()`:
~~~php
$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 `wp-content/themes/my-theme/meal-planner/recipe-ingredients.php`, or `wp-content/themes/my-theme/meal-planner/recipe.php`, then fallback to `wp-content/plugins/meal-planner/templates/recipe-ingredients.php` or `wp-content/plugins/meal-planner/templates/recipe.php`.
* You can also pass the template loader object into the template as well:
~~~php
$template_loader = new Your_Template_Loader();
$template_loader->set_template_data(
array(
'template_loader' => $template_loader,
// Optional other data as needed.
)
);
~~~
Then in the template you can use:
~~~php
$data->template_loader->get_template_part( 'recipe' );
~~~
### Meal Planner Example Class
```php
<?php
/**
* Meal Planner
*
* @package Meal_Planner
* @author Gary Jones
* @link http://example.com/meal-planner
* @copyright 2013 Gary Jones
* @license GPL-2.0+
*/
if ( ! class_exists( 'Gamajo_Template_Loader' ) ) {
require plugin_dir_path( __FILE__ ) . 'class-gamajo-template-loader.php';
}
/**
* Template loader for Meal Planner.
*
* Only need to specify class properties here.
*
* @package Meal_Planner
* @author Gary Jones
*/
class Meal_Planner_Template_Loader extends Gamajo_Template_Loader {
/**
* Prefix for filter names.
*
* @since 1.0.0
*
* @var string
*/
protected $filter_prefix = 'meal_planner';
/**
* Directory name where custom templates for this plugin should be found in the theme.
*
* @since 1.0.0
*
* @var string
*/
protected $theme_template_directory = 'meal-planner';
/**
* Reference to the root directory path of this plugin.
*
* Can either be a defined constant, or a relative reference from where the subclass lives.
*
* In this case, `MEAL_PLANNER_PLUGIN_DIR` would be defined in the root plugin file as:
*
* ~~~
* define( 'MEAL_PLANNER_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );
* ~~~
*
* @since 1.0.0
*
* @var string
*/
protected $plugin_directory = MEAL_PLANNER_PLUGIN_DIR;
/**
* Directory name where templates are found in this plugin.
*
* Can either be a defined constant, or a relative reference from where the subclass lives.
*
* e.g. 'templates' or 'includes/templates', etc.
*
* @since 1.1.0
*
* @var string
*/
protected $plugin_template_directory = 'templates';
}
```
## Usage Example
The [Cue](https://github.com/AudioTheme/cue) plugin from [AudioTheme](http://audiotheme.com/) uses this class. Starting at [https://github.com/AudioTheme/cue/tree/develop/includes](https://github.com/AudioTheme/cue/tree/develop/includes), it has this class in the vendor directory, then the required subclass of my class in the `class-cue-template-loader.php` file, which sets a few basic properties. It also has a template in [https://github.com/AudioTheme/cue/tree/develop/templates](https://github.com/AudioTheme/cue/tree/develop/templates).
If you wanted the playlist to have different markup for your theme, you'd copy `templates/playlist.php` to `wp-content/themes/{your-active-theme}/cue/playlist.php` and do whatever changes you wanted. WordPress will look for that file first, before then checking a parent theme location (if your active theme is a child theme), before falling back to the default template that comes with the Cue plugin.
## Change Log
See the [change log](CHANGELOG.md).
## License
[GPL 2.0 or later](LICENSE).
## Contributions
Contributions are welcome - fork, fix and send pull requests against the `develop` branch please.
## Credits
Built by [Gary Jones](https://twitter.com/GaryJ)
Copyright 2013 [Gary Jones](https://garyjones.io)