functions.php

<?php

/**
 * Common Functions
 *
 * This file contains the common functions shared between the ACF 5 and ACF 4
 * versions.
 *
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */


 /**
  * Get Fonts To Enqueue
  *
  * Retrieves the fonts to enqueue on the current page
  *
  * @return array The array of fonts to enqueue
  * @author Daniel Pataki
  * @since 3.0.0
  *
  */
 function acfgfs_get_fonts_to_enqueue() {
     if( is_singular() ) {
         global $post;
         $post_fields = get_field_objects( $post->ID );
     }
     $post_fields = ( empty( $post_fields ) ) ? array() : $post_fields;
     $option_fields = get_field_objects( 'options' );
     $option_fields = ( empty( $option_fields ) ) ? array() : $option_fields;
     $fields = array_merge( $post_fields, $option_fields );
     $font_fields = array();
     foreach( $fields as $field ) {
         if( !empty( $field['type'] ) && 'google_font_selector' == $field['type'] && !empty( $field['value'] ) ) {
             $font_fields[] = $field['value'];
         }
     }

     $font_fields = apply_filters( 'acfgfs/enqueued_fonts', $font_fields );

     return $font_fields;
 }

 /**
  * Enqueue Fonts
  *
  * Retrieves the fonts to enqueue on the current page
  *
  * @uses acfgfs_get_fonts_to_enqueue()
  * @author Daniel Pataki
  * @since 3.0.0
  *
  */
function acfgfs_google_font_enqueue(){
    $fonts = acfgfs_get_fonts_to_enqueue();
    if( empty( $fonts ) ) {
        return;
    }
    $subsets = array();
    $font_element = array();
    foreach( $fonts as $font ) {
        $subsets = array_merge( $subsets, $font['subsets'] );
        $font_name = str_replace( ' ', '+', $font['font'] );
        if( $font['variants'] == array( 'regular' ) ) {
            $font_element[] = $font_name;
        }
        else {
            $regular_variant = array_search( 'regular', $font['variants'] );
            if( $regular_variant !== false ) {
                $font['variants'][$regular_variant] = '400';
            }
            $font_element[] = $font_name . ':' . implode( ',', $font['variants'] );
        }
    }
    $subsets = ( empty( $subsets ) ) ? array('latin') : array_unique( $subsets );
    $subset_string = implode( ',', $subsets );
    $font_string = implode( '|', $font_element );
    $request = '//fonts.googleapis.com/css?family=' . $font_string . '&subset=' . $subset_string;
    wp_enqueue_style( 'acfgfs-enqueue-fonts', $request );
}



/**
 * Font Dropdown Array
 *
 * Retrieves a list of fonts as an array. The array uses the
 * font name as the key and value. Uses the acfgfs_get_web_safe_fonts()
 * function to add a list of we safe fonts if the user enabled it in the
 * options.
 *
 * @param array $field The field data
 * @uses acfgfs_get_web_safe_fonts()
 * @return array The array of fonts
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */
function acfgfs_get_font_dropdown_array( $field = null ) {
    $fonts = acfgfs_get_fonts();

    $font_array = array();
    foreach( $fonts as $font => $data ) {
        $font_array[$font] = $font;
    }

    if( !empty( $field['include_web_safe_fonts'] ) ) {
        $web_safe = acfgfs_get_web_safe_fonts();
        foreach( $web_safe as $font ) {
            $font_array[$font] = $font;
        }
    }

    asort( $font_array );

    $font_array = apply_filters( 'acfgfs/font_dropdown_array', $font_array );

    return $font_array;
}

/**
 * Get Font
 *
 * Retrieves the details of a single font
 *
 * @param string $font The name of the font to retrieve
 * @uses acfgfs_get_fonts()
 * @return array The details of the font
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */
function acfgfs_get_font( $font ) {
    $fonts = acfgfs_get_fonts();
    return $fonts[$font];
}

/**
 * Get Fonts
 *
 * Gets all fonts. It first checks a transient. If the transient doesn't
 * exist it gets all fonts from Google. If this fails for some reason we
 * fall back on a file which has a font list.
 *
 * We then create a special format that works for us and finally
 * add the web safe fonts if they are needed.
 *
 * @uses acfgfs_retrieve_fonts()
 * @uses acfgfs_get_web_safe_fonts()
 * @return array The final font list
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */
function acfgfs_get_fonts() {
    $fonts = get_transient( 'acfgfs_fonts' );
    if( empty( $fonts ) ) {
        $fonts = acfgfs_retrieve_fonts();
    }
    if( empty( $fonts ) ) {
        $fonts = include( 'font-list.php' );
    }

    $acfgfs_fonts = array();
    foreach( $fonts['items'] as $font ) {
        $acfgfs_fonts[$font['family']] = array(
            'variants' => $font['variants'],
            'subsets' => $font['subsets']
        );
    }

    if( !empty( $field['include_web_safe_fonts'] ) ) {
        $web_safe = acfgfs_get_web_safe_fonts();
        foreach( $web_safe as $font ) {
            $acfgfs_fonts[$font] = array(
                'variants' => array( 'regular', '700' ),
                'subsets' => array( 'latin' )
            );
        }
    }


    return $acfgfs_fonts;
}


/**
 * Retrieve Google Fonts
 *
 * Gets all Google fonts from the Google API. It uses the API key which is
 * either saved or defined as a constant.
 *
 * @return array The Google font list
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */
function acfgfs_retrieve_fonts() {

    $api_key = get_option('acfgfs_api_key');
    if( defined( 'ACFGFS_API_KEY' ) ) {
        $api_key = ACFGFS_API_KEY;
    }

    $request = wp_remote_get( 'https://www.googleapis.com/webfonts/v1/webfonts?key=' . $api_key );
    $response = json_decode( $request['body'], true );
    if( !empty( $response['items'] ) ) {
        $timeout = ( defined( 'ACFGFS_REFRESH' ) ) ? ACFGFS_REFRESH : WEEK_IN_SECONDS;
        set_transient( 'acfgfs_fonts', $response, $timeout );
    }

    return $request;

}

/**
 * Web Safe Fonts
 *
 * A simple array of web safe fonts
 *
 * @return array Array of web safe fonts
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */
function acfgfs_get_web_safe_fonts() {
    $web_safe = array( 'Georgia', 'Palatino Linotype', 'Book Antiqua', 'Palatino', 'Times New Roman', 'Times', 'Arial', 'Helvetica', 'Arial Black', 'Gadget', 'Impact', 'Charcoal', 'Lucida Sans Unicode', 'Lucida Grande', 'Tahoma', 'Geneva', 'Trebuchet MS', 'Helvetica', 'Verdana', 'Geneva', 'Courier New', 'Courier', 'Lucida Console', 'Monaco' );
    return $web_safe;
}


/**
 * Font Variant Array
 *
 * Gets an array of font variants for a given font
 *
 * @param string $font The font to retrieve variants for
 * @uses acfgfs_get_font()
 * @return array The variant list for this font
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */
function acfgfs_get_font_variant_array( $font ) {
    $font = acfgfs_get_font( $font );
    return $font['variants'];
}


/**
 * Font Subset Array
 *
 * Gets an array of font subsets for a given font
 *
 * @param string $font The font to retrieve variants for
 * @uses acfgfs_get_font()
 * @return array The subset list for this font
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */
function acfgfs_get_font_subset_array( $font ) {
    $font = acfgfs_get_font( $font );
    return $font['subsets'];
}

/**
 * Display Variant List
 *
 * Displays a checkbox list of font variants. If only a field is given it
 * looks up the current font (or uses the default). The second parameter
 * is used when a new font is selected and we grab a variant list via AJAX.
 *
 * At this stage the new font is not saved but we still need to show the
 * variant list for that font. When the $new_font parameter is given the
 * value of $field is not used.
 *
 * @param string $field The field to retrieve variants for
 * @param string $new_font The font to retrieve variants for
 * @uses acfgfs_get_font()
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */
function acfgfs_display_variant_list( $field, $new_font = null ) {
    $font = $new_font;
    if( empty( $new_font ) ) {
        $font = ( empty( $field['value']['font'] ) ) ? $field['default_font'] :     $field['value']['font'];
    }

    $font = acfgfs_get_font( $font );
    $font['variants'] = (empty( $font['variants'] )) ? array() : $font['variants'];
    $i = 1;
    foreach( $font['variants'] as $variant ) :
        if( empty( $new_font ) ) {
            $checked = ( empty( $field['value'] ) || ( !empty( $field['value'] ) && in_array( $variant, $field['value']['variants'] ) ) ) ? 'checked="checked"' : '';
        }
        else {
            $checked = ( $variant == 'regular' ) ? 'checked="checked"' : '';
        }

        ?>

        <input <?php echo $checked ?> type="checkbox" id="<?php echo $field['key'] ?>_variants_<?php echo $i ?>" name="<?php echo $field['key'] ?>_variants[]" value="<?php echo $variant ?>"><label for="<?php echo $field['key'] ?>_variants_<?php echo $i ?>"><?php echo $variant ?></label> <br>

        <?php $i++; endforeach;

}


/**
 * Display Subset List
 *
 * Displays a checkbox list of font subsets. If only a field is given it
 * looks up the current font (or uses the default). The second parameter
 * is used when a new font is selected and we grab a subset list via AJAX.
 *
 * At this stage the new font is not saved but we still need to show the
 * subset list for that font. When the $new_font parameter is given the
 * value of $field is not used.
 *
 * @param string $field The field to retrieve subsets for
 * @param string $new_font The font to retrieve subsets for
 * @uses acfgfs_get_font()
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */
function acfgfs_display_subset_list( $field, $new_font = null ) {

    $font = $new_font;
    if( empty( $new_font ) ) {
        $font = ( empty( $field['value']['font'] ) ) ? $field['default_font'] :     $field['value']['font'];
    }

    $font = acfgfs_get_font( $font );
    $font['subsets'] = (empty( $font['subsets'] )) ? array() : $font['subsets'];
    $i = 1;
    foreach( $font['subsets'] as $subset ) :
        if( empty( $new_font ) ) {
            $checked = ( empty( $field['value'] ) || ( !empty( $field['value'] ) && in_array( $subset, $field['value']['subsets'] ) ) ) ? 'checked="checked"' : '';
        }
        else {
            $checked = ( $subset == 'latin' ) ? 'checked="checked"' : '';
        }
        ?>
        <input <?php echo $checked ?> type="checkbox" id="<?php echo $field['key'] ?>_subsets_<?php echo $i ?>" name="<?php echo $field['key'] ?>_subsets[]" value="<?php echo $subset ?>"><label for="<?php echo $field['key'] ?>_subsets_<?php echo $i ?>"><?php echo $subset ?></label> <br>

        <?php $i++; endforeach;

}

/**
 * Get Font Details
 *
 * Used in AJAX requests to output the HTML needed to display the UI for
 * the newly chosen font.
 *
 * @uses acfgfs_display_subset_list()
 * @uses acfgfs_display_variant_list()
 * @author Daniel Pataki
 * @since 3.0.0
 *
 */
function acfgfs_action_get_font_details() {
    $details = array();
    $field = json_decode( stripslashes( $_POST['data'] ), true );
    unset( $field['value'] );

    ob_start();
    acfgfs_display_subset_list( $field, $_POST['font_family'] );
    $details['subsets'] = ob_get_clean();

    ob_start();
    acfgfs_display_variant_list( $field, $_POST['font_family'] );
    $details['variants'] = ob_get_clean();

    echo json_encode( $details );

    die();
}