hover_preview.module in Hover Preview for ImageCache 6

Hover Preview for Imagecache.

File

hover_preview.module

<?php

/**
 * @file
 * Hover Preview for Imagecache.
 */

/**
 * Implementation of hook_theme().
 */
function hover_preview_theme() {
  $presets_a = imagecache_presets();
  $presets_b = $presets_a;
  $items = array();
  $items['hover_preview'] = array(
    'arguments' => array(
      'node' => NULL,
      'field_name' => '',
      'preset_a' => '',
      'preset_b' => '',
    ),
  );
  foreach ($presets_a as $preset_a) {
    foreach ($presets_b as $preset_b) {

      // Hover only
      $id = $preset_a['presetname'] . '_hover_preview_' . $preset_b['presetname'];
      $items['hover_preview_formatter_' . $id] = array(
        'arguments' => array(
          'element' => NULL,
        ),
        'function' => 'theme_hover_preview_formatter',
      );

      // Linked to node
      $id = $preset_a['presetname'] . '_hover_preview_' . $preset_b['presetname'] . '_linked';
      $items['hover_preview_formatter_' . $id] = array(
        'arguments' => array(
          'element' => NULL,
        ),
        'function' => 'theme_hover_preview_formatter',
      );
    }
  }
  return $items;
}

/**
 * Implementation of hook_field_formatter_info().
 * Adds formatters to CCK image fields
 */
function hover_preview_field_formatter_info() {
  $presets_a = imagecache_presets();
  $presets_b = $presets_a;
  $formatters = array();
  foreach ($presets_a as $preset_a) {
    foreach ($presets_b as $preset_b) {

      // Hover only
      $id = $preset_a['presetname'] . '_hover_preview_' . $preset_b['presetname'];
      $formatters[$id] = array(
        'label' => t('Hover: @preset_a TO: @preset_b', array(
          '@preset_a' => $preset_a['presetname'],
          '@preset_b' => $preset_b['presetname'],
        )),
        'field types' => array(
          'image',
          'filefield',
        ),
      );

      // Hover, linked to original node
      $id = $preset_a['presetname'] . '_hover_preview_' . $preset_b['presetname'] . '_linked';
      $formatters[$id] = array(
        'label' => t('Hover: @preset_a TO: @preset_b linked to node', array(
          '@preset_a' => $preset_a['presetname'],
          '@preset_b' => $preset_b['presetname'],
        )),
        'field types' => array(
          'image',
          'filefield',
        ),
      );
    }
  }
  return $formatters;
}

/**
 * Display a field like an imagecache formatter but with a wrapper to facilitate
 * the hover preview.
 *
 * Some parts of this function are inspired from
 * theme_imagecache_formatter_default() since hover preview is just extra stuff
 * around an imagecache-generated img tag.
 */
function theme_hover_preview_formatter($element) {

  // Generate unique id's for an image and it's corresponding preview url
  $unique = $element['#item']['fid'] . '-' . $element['#item']['timestamp'];

  // Inside a view $element may contain NULL data. In that case, just return.
  if (empty($element['#item']['fid'])) {
    return '';
  }
  drupal_add_js(drupal_get_path('module', 'hover_preview') . '/hover_preview.js');
  drupal_add_css(drupal_get_path('module', 'hover_preview') . '/hover_preview.css');

  // Extract the two constituent presets
  if (substr($element['#formatter'], strlen($element['#formatter']) - 7, strlen($element['#formatter'])) == '_linked') {
    $linked = TRUE;
    list($preset_a, $preset_b) = explode('_hover_preview_', substr($element['#formatter'], 0, strlen($element['#formatter']) - 7));
  }
  else {
    list($preset_a, $preset_b) = explode('_hover_preview_', $element['#formatter']);
  }

  // Generate the preview data
  $preview_id = "hover-preview-" . $unique;
  $preview_url = imagecache_create_url($preset_b, $element['#item']['filepath']);
  $item = $element['#item'];
  $item['data']['alt'] = isset($item['data']['alt']) ? $item['data']['alt'] : '';
  $item['data']['title'] = isset($item['data']['title']) ? $item['data']['title'] : '';
  $preview_text = theme('imagecache', $preset_b, $element['#item']['filepath'], $item['data']['alt'], $item['data']['title'], array(
    'class' => 'hover-preview-preview-url',
    'style' => 'display: none',
    'id' => $preview_id . '-url',
  ));

  // Generate stuff needed for imagecache
  $style = 'default';
  $item = $element['#item'];

  // Set the image alt and title if suitable values are available
  if (!empty($item['data']['alt'])) {
    $alt = $item['data']['alt'];
  }
  elseif (isset($element['#node']->node_title)) {
    $alt = $element['#node']->node_title;
  }
  elseif (isset($element['#node']->title)) {
    $alt = $element['#node']->title;
  }
  if (!empty($item['data']['title'])) {
    $title = $item['data']['title'];
  }
  elseif (isset($element['#node']->node_title)) {
    $title = $element['#node']->node_title;
  }
  else {
    $title = $alt;
  }

  // Generate the imagecache html
  $class = "imagecache imagecache-{$preset_a} imagecache-{$style} imagecache-{$element['#formatter']}";
  $class .= " hover-preview";
  $output = theme('imagecache', $preset_a, $item['filepath'], $alt, $title, array(
    'class' => $class,
    'id' => $preview_id,
  ));
  if ($linked == TRUE && isset($element['#node']->path)) {
    $return = l($output, $element['#node']->path, array(
      'html' => array(
        'html' => 'true',
      ),
    )) . $preview_text;
  }
  else {
    $return = $output . $preview_text;
  }
  return $return;
}

/**
 * Convenience function to display an applicable field from a node using
 * hover_preview
 *
 * Usage: theme('hover_preview', $node, 'field_photo', 'small_preset', 'large_preset', 'link to node (TRUE)');
 */
function theme_hover_preview($node, $field_name, $preset_a, $preset_b, $linked = NULL) {
  $field = content_fields($field_name, $node->type);
  if ($field) {

    // If necessary, pass the node through node_view first to sanitise it
    if (empty($node->content)) {
      $node->build_mode = NODE_BUILD_NORMAL;
      node_view($node);
    }

    // Poke CCK's display settings to use the formatter we want
    if (isset($linked)) {
      $format = $preset_a . '_hover_preview_' . $preset_b . '_linked';
    }
    else {
      $format = $preset_a . '_hover_preview_' . $preset_b;
    }
    $field['display_settings']['full']['format'] = $format;

    // Invoke CCK to assemble the data structure for us and then render it
    $data = content_field('view', $node, $field, $node->{$field_name}, FALSE, FALSE);
    $output = drupal_render($data);
    return $output;
  }
}

Functions

Name	Description
hover_preview_field_formatter_info	Implementation of hook_field_formatter_info(). Adds formatters to CCK image fields
hover_preview_theme	Implementation of hook_theme().
theme_hover_preview	Convenience function to display an applicable field from a node using hover_preview
theme_hover_preview_formatter	Display a field like an imagecache formatter but with a wrapper to facilitate the hover preview.