footnotes/class/template.php

<?php
/**
 * Includes the Template Engine to load and handle all Template files of the Plugin.
 *
 * @filesource
 * @author Stefan Herndler
 * @since 1.5.0 14.09.14 10:58
 *
 * Last modified: 2021-01-02T2352+0100
 *
 * Edited:
 * @since 2.0.3  prettify reference container template
 * @since 2.0.3  further minify template content
 * @since 2.0.4  regex to delete multiple spaces
 * @since 2.0.6  prettify other templates (footnote, tooltip script, ref container row)
 * @since 2.2.6  delete a space before a closing pointy bracket
 * @since 2.2.6  support for custom templates in fixed location, while failing to add filter thanks to @misfist   2020-12-19T0606+0100
 * @see <https://wordpress.org/support/topic/template-override-filter/>
 * @since 2.4.0  templates may be in active theme, thanks to @misfist
 * @see <https://wordpress.org/support/topic/template-override-filter/#post-13846598>
 */


/**
 * Handles each Template file for the Plugin Frontend (e.g. Settings Dashboard, Public pages, ...).
 * Loads a template file, replaces all Placeholders and returns the replaced file content.
 *
 * @author Stefan Herndler
 * @since 1.5.0
 */
class MCI_Footnotes_Template {

    /**
     * Directory name for dashboard templates.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_DASHBOARD = "dashboard";

    /**
     * Directory name for public templates.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_PUBLIC = "public";

    /**
     * Contains the content of the template after initialize.
     *
     * @author Stefan Herndler
     * @since  1.5.0
     * @var string
     */
    private $a_str_OriginalContent = "";

    /**
     * Contains the content of the template after initialize with replaced place holders.
     *
     * @author Stefan Herndler
     * @since  1.5.0
     * @var string
     */
    private $a_str_ReplacedContent = "";

    /**
     * Plugin Directory
     * 
     * @author Patrizia Lutz @misfist
     * @since 2.4.0d3
     *
     * @var string
     */
    public $plugin_directory;

    /**
     * Class Constructor. Reads and loads the template file without replace any placeholder.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @param string $p_str_FileType Template file type (take a look on the Class constants).
     * @param string $p_str_FileName Template file name inside the Template directory without the file extension.
     * @param string $p_str_Extension Optional Template file extension (default: html)
     *
     * Edited:
     * @since 2.0.3  further minify template content
     * @since 2.0.4  regex to delete multiple spaces
     *
     * @since 2.2.6  support for custom templates   2020-12-19T0606+0100
     * @see <https://wordpress.org/support/topic/template-override-filter/>
     *
     * @since 2.2.6  delete a space before a closing pointy bracket
     * 
     * @since 2.4.0  look for custom template in the active theme first, thanks to @misfist
     * @see <https://wordpress.org/support/topic/template-override-filter/#post-13846598>
     */
    public function __construct($p_str_FileType, $p_str_FileName, $p_str_Extension = "html") {
        // no template file type and/or file name set
        if (empty($p_str_FileType) || empty($p_str_FileName)) {
            return;
        }

        /**
         * Define plugin root path
         * 
         * @since 2.4.0d3
         * 
         * @author Patrizia Lutz @misfist
         */
        $this->plugin_directory = plugin_dir_path( dirname( __FILE__ ) );

        /**
         * Modularize functions
         * 
         * @since 2.4.0d3
         * 
         * @author Patrizia Lutz @misfist
         */
        if( $template = $this->get_template( $p_str_FileType, $p_str_FileName, $p_str_Extension ) )  {
            $this->process_template( $template );
        } else {
            return;
        }

    }

    /**
     * Replace all placeholders specified in array.
     *
     * @author Stefan Herndler
     * @since  1.5.0
     * @param array $p_arr_Placeholders Placeholders (key = placeholder, value = value).
     * @return bool True on Success, False if Placeholders invalid.
     */
    public function replace($p_arr_Placeholders) {
        // no placeholders set
        if (empty($p_arr_Placeholders)) {
            return false;
        }
        // template content is empty
        if (empty($this->a_str_ReplacedContent)) {
            return false;
        }
        // iterate through each placeholder and replace it with its value
        foreach($p_arr_Placeholders as $l_str_Placeholder => $l_str_Value) {
            $this->a_str_ReplacedContent = str_replace("[[" . $l_str_Placeholder . "]]", $l_str_Value, $this->a_str_ReplacedContent);
        }
        // success
        return true;
    }

    /**
     * Reloads the original content of the template file.
     *
     * @author Stefan Herndler
     * @since  1.5.0
     */
    public function reload() {
        $this->a_str_ReplacedContent = $this->a_str_OriginalContent;
    }

    /**
     * Returns the content of the template file with replaced placeholders.
     *
     * @author Stefan Herndler
     * @since  1.5.0
     * @return string Template content with replaced placeholders.
     */
    public function getContent() {
        return $this->a_str_ReplacedContent;
    }

        /**
     * Process template file
     * 
     * @author Patrizia Lutz @misfist
     * 
     * @since 2.4.0d3
     *
     * @param string $template
     * @return void
     */
    public function process_template( $template ) {
        $this->a_str_OriginalContent = str_replace( "\n", "", file_get_contents( $template ) );
        $this->a_str_OriginalContent = str_replace( "\r", "", $this->a_str_OriginalContent );
        $this->a_str_OriginalContent = str_replace( "\t", " ", $this->a_str_OriginalContent );
        $this->a_str_OriginalContent = preg_replace( '# +#', " ", $this->a_str_OriginalContent );
        $this->a_str_OriginalContent = str_replace( " >", ">", $this->a_str_OriginalContent );
        $this->reload();
    }

    /**
     * Get the template
     * 
     * @author Patrizia Lutz @misfist
     * 
     * @since 2.4.0d3
     *
     * @param string $p_str_FileType
     * @param string $p_str_FileName
     * @param string $p_str_Extension
     * @return mixed false | template path
     */
    public function get_template( $p_str_FileType, $p_str_FileName, $p_str_Extension = "html" ) {
        $located = false;

        /**
         * The directory change be modified
         * @usage to change location of templates to `template_parts/footnotes/':
         * add_filter( 'mci_footnotes_template_directory', function( $directory ) {
         *  return 'template_parts/footnotes/;
         * } );
         */
        $template_directory = apply_filters( 'mci_footnotes_template_directory', 'footnotes/templates/' );
        $custom_directory = apply_filters( 'mci_footnotes_custom_template_directory', 'footnotes-custom/' );
        $template_name = $p_str_FileType . '/' . $p_str_FileName . '.' . $p_str_Extension;

        /**
         * Look in active (child) theme
         */
		if ( file_exists( trailingslashit( get_stylesheet_directory() ) . $template_directory . $template_name ) ) {
            $located = trailingslashit( get_stylesheet_directory() ) . $template_directory . $template_name;
        
        /**
         * Look in parent theme
         */
        } elseif ( file_exists( trailingslashit( get_template_directory() ) . $template_directory . $template_name ) ) {
            $located = trailingslashit( get_template_directory() ) . $template_directory . $template_name;
            
        /**
         * Look custom directory
         */
        } elseif ( file_exists( trailingslashit( WP_PLUGIN_DIR ) . $custom_directory . 'templates/' . $template_name ) ) {
            $located = trailingslashit( WP_PLUGIN_DIR ) . $custom_directory . 'templates/' . $template_name;

        /**
         * Look in plugin
         */
        } elseif ( file_exists( $this->plugin_directory . 'templates/' . $template_name ) ) {
            $located = $this->plugin_directory . 'templates/' . $template_name;
        }

        return $located;
    }

} // end of class