Simple Local Avatars 2.1 unofficial

<?php
/**
 Plugin Name: Simple Local Avatars
 Plugin URI: http://10up.com/plugins/simple-local-avatars-wordpress/
 Description: Adds an avatar upload field to user profiles. Generates requested sizes on demand, just like Gravatar! Simple and lightweight. Now with srcset 2x support.
 Version: 2.1
 Author: Jake Goldman, 10up, Ov3rfly
 Author URI: http://10up.com
 License: GPLv2 or later
*/

/**
 * add field to user profiles
 */

class Simple_Local_Avatars {
    private $user_id_being_edited, $avatar_upload_error, $remove_nonce, $avatar_ratings;
    public $options;

    /**
     * Set up the hooks and default values
     */
    public function __construct() {
        load_plugin_textdomain( 'simple-local-avatars', false, dirname( plugin_basename( __FILE__ ) ) . '/localization/' );

        $this->options = (array) get_option( 'simple_local_avatars' );
        $this->avatar_ratings = array(
            'G' => __('G &#8212; Suitable for all audiences'),
            'PG' => __('PG &#8212; Possibly offensive, usually for audiences 13 and above'),
            'R' => __('R &#8212; Intended for adult audiences above 17'),
            'X' => __('X &#8212; Even more mature than above')
        );

        // supplement remote avatars, but not if inside "local only" mode
        if ( empty( $this->options['only'] ) )
            add_filter( 'get_avatar', array( $this, 'get_avatar' ), 10, 5 );

        add_action( 'admin_init', array( $this, 'admin_init' ) );

        add_action( 'admin_enqueue_scripts', array( $this, 'admin_enqueue_scripts' ) );
        add_action( 'show_user_profile', array( $this, 'edit_user_profile' ) );
        add_action( 'edit_user_profile', array( $this, 'edit_user_profile' ) );

        add_action( 'personal_options_update', array( $this, 'edit_user_profile_update' ) );
        add_action( 'edit_user_profile_update', array( $this, 'edit_user_profile_update' ) );
        add_action( 'admin_action_remove-simple-local-avatar', array( $this, 'action_remove_simple_local_avatar' ) );
        add_action( 'wp_ajax_assign_simple_local_avatar_media', array( $this, 'ajax_assign_simple_local_avatar_media' ) );
        add_action( 'wp_ajax_remove_simple_local_avatar', array( $this, 'action_remove_simple_local_avatar' ) );
        add_action( 'user_edit_form_tag', array( $this, 'user_edit_form_tag' ) );

        add_filter( 'avatar_defaults', array( $this, 'avatar_defaults' ) );
    }

    /**
     * Retrieve the local avatar for a user who provided a user ID or email address.
     *
     * @param string $avatar Avatar return by original function
     * @param int|string|object $id_or_email A user ID,  email address, or comment object
     * @param int $size Size of the avatar image
     * @param string $default URL to a default image to use if no avatar is available
     * @param string $alt Alternative text to use in image tag. Defaults to blank
     * @return string <img> tag for the user's avatar
     */
    public function get_avatar( $avatar = '', $id_or_email, $size = 96, $default = '', $alt = '' ) {
        if ( is_numeric( $id_or_email ) )
            $user_id = (int) $id_or_email;
        elseif ( is_string( $id_or_email ) && ( $user = get_user_by( 'email', $id_or_email ) ) )
            $user_id = $user->ID;
        elseif ( is_object( $id_or_email ) && ! empty( $id_or_email->user_id ) )
            $user_id = (int) $id_or_email->user_id;

        if ( empty( $user_id ) )
            return $avatar;

        // fetch local avatar from meta and make sure it's properly ste
        $local_avatars = get_user_meta( $user_id, 'simple_local_avatar', true );
        if ( empty( $local_avatars['full'] ) )
            return $avatar;

        // check rating
        $avatar_rating = get_user_meta( $user_id, 'simple_local_avatar_rating', true );
        if ( ! empty( $avatar_rating ) && 'G' != $avatar_rating && ( $site_rating = get_option( 'avatar_rating' ) ) ) {
            $ratings = array_keys( $this->avatar_ratings );
            $site_rating_weight = array_search( $site_rating, $ratings );
            $avatar_rating_weight = array_search( $avatar_rating, $ratings );
            if ( false !== $avatar_rating_weight && $avatar_rating_weight > $site_rating_weight )
                return $avatar;
        }

        // handle "real" media
        if ( ! empty( $local_avatars['media_id'] ) ) {
            // has the media been deleted?
            if ( ! $avatar_full_path = get_attached_file( $local_avatars['media_id'] ) ) {
                // only allowed logged in users to delete bad data to mitigate performance issues
                if ( is_user_logged_in() )
                    $this->avatar_delete( $user_id );

                return $avatar;
            }
        }

        $size = (int) $size;

        if ( empty( $alt ) )
            $alt = get_the_author_meta( 'display_name', $user_id );

        // generate a new size
        if ( ! array_key_exists( $size, $local_avatars ) ) {
            $local_avatars[$size] = $local_avatars['full']; // just in case of failure elsewhere

            // allow automatic rescaling to be turned off
            if ( $allow_dynamic_resizing = apply_filters( 'simple_local_avatars_dynamic_resize', true ) ) :

                $upload_path = wp_upload_dir();

                // get path for image by converting URL, unless its already been set, thanks to using media library approach
                if ( ! isset( $avatar_full_path ) )
                    $avatar_full_path = str_replace( $upload_path['baseurl'], $upload_path['basedir'], $local_avatars['full'] );

                // generate the new size
                $editor = wp_get_image_editor( $avatar_full_path );
                if ( ! is_wp_error( $editor ) ) {
                    $resized = $editor->resize( $size, $size, true );
                    if ( ! is_wp_error( $resized ) ) {
                        $dest_file = $editor->generate_filename();
                        $saved = $editor->save( $dest_file );
                        if ( ! is_wp_error( $saved ) )
                            $local_avatars[$size] = str_replace( $upload_path['basedir'], $upload_path['baseurl'], $dest_file );
                    }
                }

                // save updated avatar sizes
                update_user_meta( $user_id, 'simple_local_avatar', $local_avatars );

            endif;
        }

        // Ov3rfly, generate a new size
        $size_2x = $size * 2;

        if ( ! array_key_exists( $size_2x, $local_avatars ) ) {
            $local_avatars[$size_2x] = $local_avatars['full']; // just in case of failure elsewhere

            // allow automatic rescaling to be turned off
            if ( $allow_dynamic_resizing = apply_filters( 'simple_local_avatars_dynamic_resize', true ) ) :

                $upload_path = wp_upload_dir();

                // get path for image by converting URL, unless its already been set, thanks to using media library approach
                if ( ! isset( $avatar_full_path ) )
                    $avatar_full_path = str_replace( $upload_path['baseurl'], $upload_path['basedir'], $local_avatars['full'] );

                // generate the new size_2x
                $editor = wp_get_image_editor( $avatar_full_path );
                if ( ! is_wp_error( $editor ) ) {
                    $resized = $editor->resize( $size_2x, $size_2x, true );
                    if ( ! is_wp_error( $resized ) ) {
                        $dest_file = $editor->generate_filename();
                        $saved = $editor->save( $dest_file );
                        if ( ! is_wp_error( $saved ) )
                            $local_avatars[$size_2x] = str_replace( $upload_path['basedir'], $upload_path['baseurl'], $dest_file );
                    }
                }

                // save updated avatar sizes
                update_user_meta( $user_id, 'simple_local_avatar', $local_avatars );

            endif;
        }

        if ( 'http' != substr( $local_avatars[$size], 0, 4 ) )
            $local_avatars[$size] = home_url( $local_avatars[$size] );

        // Ov3rfly
        if ( 'http' != substr( $local_avatars[$size_2x], 0, 4 ) )
            $local_avatars[$size_2x] = home_url( $local_avatars[$size_2x] );

        // Ov3rfly, fix warning
        // https://wordpress.org/support/topic/plugin-simple-local-avatars-undefined-property-errors-on-admin-side-of-custom-posts-when-plugin-activated
        $author_class = @is_author( $user_id ) ? ' current-author' : '' ;

        // Ov3rfly, add srcset
        $avatar = "<img alt='" . esc_attr( $alt ) . "' src='" . esc_url( $local_avatars[$size] ) . "' srcset='" . esc_attr( $local_avatars[$size_2x] ) . " 2x' class='avatar avatar-{$size}{$author_class} photo' height='{$size}' width='{$size}' />";

        return apply_filters( 'simple_local_avatar', $avatar );
    }

    public function admin_init() {
        // upgrade pre 2.0 option
        if ( $old_ops = get_option( 'simple_local_avatars_caps' ) ) {
            if ( ! empty( $old_ops['simple_local_avatars_caps'] ) )
                update_option( 'simple_local_avatars', array( 'caps' => 1 ) );

            delete_option( 'simple_local_avatar_caps' );
        }

        register_setting( 'discussion', 'simple_local_avatars', array( $this, 'sanitize_options' ) );
        add_settings_field( 'simple-local-avatars-only', __('Local Avatars Only','simple-local-avatars'), array( $this, 'avatar_settings_field' ), 'discussion', 'avatars', array( 'key' => 'only', 'desc' => 'Only allow local avatars (still uses Gravatar for default avatars)' ) );
        add_settings_field( 'simple-local-avatars-caps', __('Local Upload Permissions','simple-local-avatars'), array( $this, 'avatar_settings_field' ), 'discussion', 'avatars', array( 'key' => 'caps', 'desc' => 'Only allow users with file upload capabilities to upload local avatars (Authors and above)' ) );
    }

    /**
     * Add scripts to the profile editing page
     *
     * @param string $hook_suffix Page hook
     */
    public function admin_enqueue_scripts( $hook_suffix ) {
        if ( 'profile.php' != $hook_suffix && 'user-edit.php' != $hook_suffix )
            return;

        if ( current_user_can( 'upload_files' ) )
            wp_enqueue_media();

        $user_id = ( 'profile.php' == $hook_suffix ) ? get_current_user_id() : (int) $_GET['user_id'];

        $this->remove_nonce = wp_create_nonce( 'remove_simple_local_avatar_nonce' );

        $script_name_append = ( defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ) ? '.dev' : '';
        wp_enqueue_script( 'simple-local-avatars', plugins_url( '', __FILE__ ) . '/simple-local-avatars' . $script_name_append . '.js', array('jquery'), false, true );
        wp_localize_script( 'simple-local-avatars', 'i10n_SimpleLocalAvatars', array(
            'user_id'           => $user_id,
            'insertMediaTitle'  => __('Choose an Avatar','simple-local-avatars'),
            'insertIntoPost'    => __('Set as avatar','simple-local-avatars'),
            'deleteNonce'       => $this->remove_nonce,
            'mediaNonce'        => wp_create_nonce( 'assign_simple_local_avatar_nonce' ),
        ) );
    }

    /**
     * Sanitize new settings field before saving
     *
     * @param array|string $input Passed input values to sanitize
     * @return array|string Sanitized input fields
     */
    public function sanitize_options( $input ) {
        $new_input['caps'] = empty( $input['caps'] ) ? 0 : 1;
        $new_input['only'] = empty( $input['only'] ) ? 0 : 1;
        return $new_input;
    }

    /**
     * Settings field for avatar upload capabilities
     *
     * @param array $args Field arguments
     */
    public function avatar_settings_field( $args ) {
        $args = wp_parse_args( $args, array(
            'key'   => '',
            'desc'  => '',
        ) );

        if ( empty( $this->options[$args['key']] ) )
            $this->options[$args['key']] = 0;

        echo '
            <label for="simple-local-avatars-' . $args['key'] . '">
                <input type="checkbox" name="simple_local_avatars[' . $args['key'] . ']" id="simple-local-avatars-' . $args['key'] . '" value="1" ' . checked( $this->options[$args['key']], 1, false ) . ' />
                ' . __($args['desc'],'simple-local-avatars') . '
            </label>
        ';
    }

    /**
     * Output new Avatar fields to user editing / profile screen
     *
     * @param object $profileuser User object
     */
    public function edit_user_profile( $profileuser ) {
    ?>
    <h3><?php _e( 'Avatar','simple-local-avatars' ); ?></h3>

    <table class="form-table">
        <tr>
            <th scope="row"><label for="simple-local-avatar"><?php _e('Upload Avatar','simple-local-avatars'); ?></label></th>
            <td style="width: 50px;" id="simple-local-avatar-photo">
                <?php
                    add_filter( 'pre_option_avatar_rating', '__return_null' );  // ignore ratings here
                    echo get_simple_local_avatar( $profileuser->ID );
                    remove_filter( 'pre_option_avatar_rating', '__return_null' );
                ?>
            </td>
            <td>
            <?php
                if ( ! $upload_rights = current_user_can('upload_files') )
                    $upload_rights = empty( $this->options['caps'] );

                if ( $upload_rights ) {
                    do_action( 'simple_local_avatar_notices' );
                    wp_nonce_field( 'simple_local_avatar_nonce', '_simple_local_avatar_nonce', false );
                    $remove_url = add_query_arg(array(
                        'action'    => 'remove-simple-local-avatar',
                        'user_id'   => $profileuser->ID,
                        '_wpnonce'  => $this->remove_nonce,
                    ) );
            ?>
                    <p style="display: inline-block; width: 26em;">
                        <span class="description"><?php _e( 'Choose an image from your computer:' ); ?></span><br />
                        <input type="file" name="simple-local-avatar" id="simple-local-avatar" class="standard-text" />
                        <span class="spinner" id="simple-local-avatar-spinner"></span>
                    </p>
                    <p>
                        <?php if ( current_user_can( 'upload_files' ) && did_action( 'wp_enqueue_media' ) ) : ?><a href="#" class="button hide-if-no-js" id="simple-local-avatar-media"><?php _e( 'Choose from Media Library', 'simple-local-avatars' ); ?></a> &nbsp;<?php endif; ?>
                        <a href="<?php echo $remove_url; ?>" class="button item-delete submitdelete deletion" id="simple-local-avatar-remove"<?php if ( empty( $profileuser->simple_local_avatar ) ) echo ' style="display:none;"'; ?>><?php _e('Delete local avatar','simple-local-avatars'); ?></a>
                    </p>
            <?php
                } else {
                    if ( empty( $profileuser->simple_local_avatar ) )
                        echo '<span class="description">' . __('No local avatar is set. Set up your avatar at Gravatar.com.','simple-local-avatars') . '</span>';
                    else
                        echo '<span class="description">' . __('You do not have media management permissions. To change your local avatar, contact the blog administrator.','simple-local-avatars') . '</span>';
                }
            ?>
            </td>
        </tr>
        <tr>
            <th scope="row" class="simple-local-avatar-rating-headline"><?php _e('Rating'); ?></th>
            <td colspan="2">
                <fieldset id="simple-local-avatar-ratings" <?php disabled( empty( $profileuser->simple_local_avatar ) ); ?>>
                    <legend class="screen-reader-text"><span><?php _e('Rating'); ?></span></legend>
                    <?php
                        if ( empty( $profileuser->simple_local_avatar_rating ) || ! array_key_exists( $profileuser->simple_local_avatar_rating, $this->avatar_ratings ) )
                            $profileuser->simple_local_avatar_rating =  'G';

                        foreach ( $this->avatar_ratings as $key => $rating ) :
                            echo "\n\t<label><input type='radio' name='simple_local_avatar_rating' value='" . esc_attr( $key ) . "' " . checked( $profileuser->simple_local_avatar_rating, $key, false ) . "/> $rating</label><br />";
                        endforeach;
                    ?>
                    <p class="description"><?php _e( 'If the local avatar is inappropriate for this site, Gravatar will be attempted.' ); ?></p>
                </fieldset></td>
        </tr>
    </table>
    <?php
    }

    /**
     * Ensure that the profile form has proper encoding type
     */
    public function user_edit_form_tag() {
        echo 'enctype="multipart/form-data"';
    }

    /**
     * Saves avatar image to a user
     *
     * @param int|string $url_or_media_id Local URL for avatar or ID of attachment
     * @param int $user_id ID of user to assign image to
     */
    private function assign_new_user_avatar( $url_or_media_id, $user_id ) {
        // delete the old avatar
        $this->avatar_delete( $user_id );   // delete old images if successful

        $meta_value = array();

        // set the new avatar
        if ( is_int( $url_or_media_id ) ) {
            $meta_value['media_id'] = $url_or_media_id;
            $url_or_media_id = wp_get_attachment_url( $url_or_media_id );
        }

        $meta_value['full'] = $url_or_media_id;

        update_user_meta( $user_id, 'simple_local_avatar', $meta_value );   // save user information (overwriting old)
    }

    /**
     * Save any changes to the user profile
     *
     * @param int $user_id ID of user being updated
     */
    public function edit_user_profile_update( $user_id ) {
        // check nonces
        if( empty( $_POST['_simple_local_avatar_nonce'] ) || ! wp_verify_nonce( $_POST['_simple_local_avatar_nonce'], 'simple_local_avatar_nonce' ) )
            return;

        // check for uploaded files
        if ( ! empty( $_FILES['simple-local-avatar']['name'] ) ) :

            // need to be more secure since low privelege users can upload
            if ( false !== strpos( $_FILES['simple-local-avatar']['name'], '.php' ) ) {
                $this->avatar_upload_error = __('For security reasons, the extension ".php" cannot be in your file name.','simple-local-avatars');
                add_action( 'user_profile_update_errors', array( $this, 'user_profile_update_errors' ) );
                return;
            }

            // front end (theme my profile etc) support
            if ( ! function_exists( 'wp_handle_upload' ) )
                require_once( ABSPATH . 'wp-admin/includes/file.php' );

            // allow developers to override file size upload limit for avatars
            add_filter( 'upload_size_limit', array( $this, 'upload_size_limit' ) );

            $this->user_id_being_edited = $user_id; // make user_id known to unique_filename_callback function
            $avatar = wp_handle_upload( $_FILES['simple-local-avatar'], array(
                'mimes'                     => array(
                    'jpg|jpeg|jpe'  => 'image/jpeg',
                    'gif'           => 'image/gif',
                    'png'           => 'image/png',
                ),
                'test_form'                 => false,
                'unique_filename_callback'  => array( $this, 'unique_filename_callback' )
            ) );

            remove_filter( 'upload_size_limit', array( $this, 'upload_size_limit' ) );

            if ( empty($avatar['file']) ) {     // handle failures
                switch ( $avatar['error'] ) {
                    case 'File type does not meet security guidelines. Try another.' :
                        $this->avatar_upload_error = __('Please upload a valid image file for the avatar.','simple-local-avatars');
                        break;
                    default :
                        $this->avatar_upload_error = '<strong>' . __('There was an error uploading the avatar:','simple-local-avatars') . '</strong> ' . esc_html( $avatar['error'] );
                }

                add_action( 'user_profile_update_errors', array( $this, 'user_profile_update_errors' ) );

                return;
            }

            $this->assign_new_user_avatar( $avatar['url'], $user_id );

        endif;

        // handle rating
        if ( isset( $avatar['url'] ) || $avatar = get_user_meta( $user_id, 'simple_local_avatar', true ) ) {
            if ( empty( $_POST['simple_local_avatar_rating'] ) || ! array_key_exists( $_POST['simple_local_avatar_rating'], $this->avatar_ratings ) )
                $_POST['simple_local_avatar_rating'] = key( $this->avatar_ratings );

            update_user_meta( $user_id, 'simple_local_avatar_rating', $_POST['simple_local_avatar_rating'] );
        }
    }

    /**
     * Allow developers to override the maximum allowable file size for avatar uploads
     *
     * @param int $bytes WordPress default byte size check
     * @return int Maximum byte size
     */
    public function upload_size_limit( $bytes ) {
        return apply_filters( 'simple_local_avatars_upload_limit', $bytes );
    }

    /**
     * Runs when a user clicks the Remove button for the avatar
     */
    public function action_remove_simple_local_avatar() {
        if ( ! empty( $_GET['user_id'] ) &&  ! empty( $_GET['_wpnonce'] ) && wp_verify_nonce( $_GET['_wpnonce'], 'remove_simple_local_avatar_nonce' ) ) {
            $user_id = (int) $_GET['user_id'];

            if ( ! current_user_can('edit_user', $user_id) )
                wp_die( __('You do not have permission to edit this user.') );

            $this->avatar_delete( $user_id );   // delete old images if successful

            if ( defined( 'DOING_AJAX' ) && DOING_AJAX )
                echo get_simple_local_avatar( $user_id );
        }

        if ( defined( 'DOING_AJAX' ) && DOING_AJAX )
            die;
    }

    /**
     * AJAX callback for assigning media ID fetched from media library to user
     */
    public function ajax_assign_simple_local_avatar_media() {
        // check required information and permissions
        if ( empty( $_POST['user_id'] ) || empty( $_POST['media_id'] ) || ! current_user_can( 'upload_files' ) || ! current_user_can( 'edit_user', $_POST['user_id'] ) || empty( $_POST['_wpnonce'] ) || ! wp_verify_nonce( $_POST['_wpnonce'], 'assign_simple_local_avatar_nonce' ) )
            die;

        $media_id = (int) $_POST['media_id'];
        $user_id = (int) $_POST['user_id'];

        // ensure the media is real is an image
        if ( wp_attachment_is_image( $media_id ) )
            $this->assign_new_user_avatar( $media_id, $user_id );

        echo get_simple_local_avatar( $user_id );

        die;
    }

    /**
     * remove the custom get_avatar hook for the default avatar list output on options-discussion.php
     */
    public function avatar_defaults( $avatar_defaults ) {
        remove_action( 'get_avatar', array( $this, 'get_avatar' ) );
        return $avatar_defaults;
    }

    /**
     * Delete avatars based on a user_id
     *
     * @param int $user_id
     */
    public function avatar_delete( $user_id ) {
        $old_avatars = (array) get_user_meta( $user_id, 'simple_local_avatar', true );

        if ( empty( $old_avatars ) )
            return;

        // if it was uploaded media, don't erase the full size or try to erase an the ID
        if ( array_key_exists( 'media_id', $old_avatars ) )
            unset( $old_avatars['media_id'], $old_avatars['full'] );

        if ( ! empty( $old_avatars ) ) {
            $upload_path = wp_upload_dir();

            foreach ($old_avatars as $old_avatar ) {
                // derive the path for the file based on the upload directory
                $old_avatar_path = str_replace( $upload_path['baseurl'], $upload_path['basedir'], $old_avatar );
                if ( file_exists( $old_avatar_path ) )
                    unlink( $old_avatar_path );
            }
        }

        delete_user_meta( $user_id, 'simple_local_avatar' );
        delete_user_meta( $user_id, 'simple_local_avatar_rating' );
    }

    /**
     * Creates a unique, meaningful file name for uploaded avatars.
     *
     * @param string $dir Path for file
     * @param string $name Filename
     * @param string $ext File extension (e.g. ".jpg")
     * @return string Final filename
     */
    public function unique_filename_callback( $dir, $name, $ext ) {
        $user = get_user_by( 'id', (int) $this->user_id_being_edited );
        // Ov3rfly
        //$name = $base_name = sanitize_file_name( $user->display_name . '_avatar_' . time() );
        // http://wordpress.org/support/topic/avatar-file-name-should-not-be-based-on-display-name
        $name = $base_name = sanitize_title( $user->display_name . '_avatar_' . time() );
        // ensure no conflicts with existing file names
        $number = 1;
        while ( file_exists( $dir . "/$name$ext" ) ) {
            $name = $base_name . '_' . $number;
            $number++;
        }

        return $name . $ext;
    }

    /**
     * Adds errors based on avatar upload problems.
     *
     * @param WP_Error $errors Error messages for user profile screen.
     */
    public function user_profile_update_errors( WP_Error $errors ) {
        $errors->add( 'avatar_error', $this->avatar_upload_error );
    }
}

$simple_local_avatars = new Simple_Local_Avatars;

/**
 * more efficient to call simple local avatar directly in theme and avoid gravatar setup
 *
 * @param int|string|object $id_or_email A user ID,  email address, or comment object
 * @param int $size Size of the avatar image
 * @param string $default URL to a default image to use if no avatar is available
 * @param string $alt Alternate text to use in image tag. Defaults to blank
 * @return string <img> tag for the user's avatar
 */
function get_simple_local_avatar( $id_or_email, $size = 96, $default = '', $alt = '' ) {
    global $simple_local_avatars;
    $avatar = $simple_local_avatars->get_avatar( '', $id_or_email, $size, $default, $alt );

    if ( empty ( $avatar ) ) {
        remove_action( 'get_avatar', array( $simple_local_avatars, 'get_avatar' ) );
        $avatar = get_avatar( $id_or_email, $size, $default, $alt );
        add_action( 'get_avatar', array( $simple_local_avatars, 'get_avatar' ) );
    }

    return $avatar;
}

if ( ! function_exists( 'get_avatar' ) && ( $simple_local_avatars_options = get_option('simple_local_avatars') ) && ! empty( $simple_local_avatars_options['only'] ) ) :

    /**
     * Retrieve the avatar for a user who provided a user ID or email address.
     *
     * @param int|string|object $id_or_email A user ID,  email address, or comment object
     * @param int $size Size of the avatar image
     * @param string $default URL to a default image to use if no avatar is available
     * @param string $alt Alternative text to use in image tag. Defaults to blank
     * @return string <img> tag for the user's avatar
     */
    function get_avatar( $id_or_email, $size = 96, $default = '', $alt = '' ) {
        global $simple_local_avatars;

        if ( ! get_option('show_avatars') )
            return false;

        $safe_alt =  empty( $alt ) ? '' : esc_attr( $alt );

        if ( !is_numeric($size) )
            $size = 96;

        if ( ! $avatar = $simple_local_avatars->get_avatar( '', $id_or_email, $size, $default, $alt ) ) :

            if ( empty($default) ) {
                $avatar_default = get_option('avatar_default');
                if ( empty($avatar_default) )
                    $default = 'mystery';
                else
                    $default = $avatar_default;
            }

            $host = is_ssl() ? 'https://secure.gravatar.com' : 'http://0.gravatar.com';

            if ( 'mystery' == $default )
                $default = "$host/avatar/ad516503a11cd5ca435acc9bb6523536?s={$size}"; // ad516503a11cd5ca435acc9bb6523536 == md5('unknown@gravatar.com')
            elseif ( 'blank' == $default )
                $default = includes_url( 'images/blank.gif' );
            elseif ( 'gravatar_default' == $default )
                $default = "$host/avatar/?s={$size}";
            else
                $default = "$host/avatar/?d=$default&amp;s={$size}";

            $avatar = "<img alt='{$safe_alt}' src='" . $default . "' class='avatar avatar-{$size} photo avatar-default' height='{$size}' width='{$size}' />";

        endif;

        return apply_filters('get_avatar', $avatar, $id_or_email, $size, $default, $alt);
    }

endif;

/**
 * on uninstallation, remove the custom field from the users and delete the local avatars
 */

register_uninstall_hook( __FILE__, 'simple_local_avatars_uninstall' );

function simple_local_avatars_uninstall() {
    $simple_local_avatars = new Simple_Local_Avatars;
    $users = get_users(array(
        'meta_key'  => 'simple_local_avatar',
        'fields'    => 'ids',
    ));

    foreach ( $users as $user_id ):
        $simple_local_avatars->avatar_delete( $user_id );
    endforeach;

    delete_option('simple_local_avatars');
}