modules/topichubs/topichubs.module

<?php
/*
  Copyright (C) 2008 by Phase2 Technology.
  Author(s): Frank Febbraro, Irakli Nadareishvili

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License.
  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY. See the LICENSE.txt file for more details.

  $Id: topichubs.module,v 1.1 2009/03/03 23:53:11 febbraro Exp $
*/
/**
 * @file
 */
 
define ('TOPICHUB_NO_RENDER_PLUGIN', 'TOPICHUB_NO_RENDER_PLUGIN');

module_load_include('inc', 'topichubs', 'topichubs.plugins');

/**
* Determine the rendering plugin of topichubs. Returns FALSE if none
* of the modules define a plugin;
*/
function topichubs_render_plugin() {
  static $pluginName;
  
  if (empty($pluginName)) {
    // Only one render plugin can be used at a time, so we are fetching the first one.
    $plugins = module_implements('topichubs_render_plugin');
    if (is_array($plugins) && sizeof($plugins)>0) {
      $pluginName = $plugins[0];
    }
    else {
      $pluginName = TOPICHUB_NO_RENDER_PLUGIN;
    }
  }

  return ($pluginName!=TOPICHUB_NO_RENDER_PLUGIN) ? $pluginName : FALSE;
}

/**
* We need to make sure pass-by-reference works, so we can't func_get_args
**/
function topichubs_render_invoke($hook, &$arg0=null, &$arg1=null, &$arg2=null, &$arg3=null) {
  $render_plugin = topichubs_render_plugin();
  if (!empty($render_plugin)) {
    
    $module = $render_plugin;

    $function = $module .'_topichubs_render_'. $hook;
    
    $result = $function($arg0, $arg1, $arg2, $arg3);
    return $result;        
  } else {
    return "#!#TH_RENDER_NO_IMPL#!#"; //None of the render implementation modules are enabled
  }
}

/**
 * Declare the views version we support (and provide views)
 */
function topichubs_views_api() {
  return array(
    'api' => 2.0,
    'path' => drupal_get_path('module', 'topichubs') .'/views',
  );
}

/**
 * Implementation of hook_perm().
 */
function topichubs_perm() {
  return array(
    'administer topichubs',
  );
}

/**
 * Implementation of hook_menu().
 */
function topichubs_menu() {
  $items = array();
  $items['admin/content/topichubs'] = array(
    'title' => 'Topic Hubs',
    'description' => 'Topic Hubs',
    'page callback' => 'topichubs_admin_overview',
    'access arguments' =>  array('administer topichubs'),
    'file' => 'topichubs.admin.inc',
  );
  $items['admin/content/topichubs/list'] = array(
    'title' => 'List',
    'description' => 'List all site Topic Hubs',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => 10,
  );
  $items['admin/content/topichubs/hot'] = array(
    'title' => 'Hot Topics',
    'description' => 'What Topics are Hot.',
    'page callback' => 'topichubs_hot_topics_page',
    'access arguments' =>  array('administer topichubs'),
    'file' => 'topichubs.admin.inc',
    'type' => MENU_LOCAL_TASK,
    'weight' => 15,
  );
  $items['admin/content/topichubs/settings'] = array(
    'title' => t('Settings'),
    'description' => 'Configuration for Topic Hubs.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('topichubs_settings'),
    'access arguments' =>  array('administer topichubs'),
    'file' => 'topichubs.admin.inc',
    'type' => MENU_LOCAL_TASK,
    'weight' => 20,
  );
  if (_get_panels_version() >= 6300 && !variable_get('topichubs_panel_update_run', 0)) {
    $items['admin/content/topichubs/update'] = array(
      'title' => t('Update'),
      'description' => 'Update existing Topic Hubs from Panels 2 to Panels 3.',
      'page callback' => 'topichubs_update_page',
      'access arguments' =>  array('administer topichubs'),
      'file' => 'topichubs.admin.inc',
      'type' => MENU_LOCAL_TASK,
      'weight' => 25,
    );
   }
  
  $items['node/%node/topichub'] = array(
    'title' => 'Topic Hub Configuration',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('topichubs_config_form', 1),
    'access callback' => 'topichubs_access',
    'access arguments' => array(1),
    'weight' => 2,
    'type' => MENU_LOCAL_TASK
  );

  $items_render = topichubs_render_invoke('menu');

  if(is_array($items_render)) {
    $items = array_merge($items, $items_render);
  }
  
  return $items;
}

/**
 * Implementation of hook_access().
 */
function topichubs_access($node) {
  return user_access('administer topichubs') && $node->type == 'topichub';
}

/**
 * Implementation of hook_theme().
 */
function topichubs_theme() {
  $themes = array();
  
  $themes['topichubs_config_form'] = array(
    'arguments' => array('form' => array()),
  );
  
  $plugins = topichubs_discover_plugins();
  foreach ($plugins as $type => $definition) {
    $themes["topichubs_{$type}"] = array(
		  'pattern' => "topichubs_{$type}__",
		  'arguments' => array('topichub' => NULL, 'items' => array()),
		  'path' => $definition['theme path'],
		  'template' => "topichubs-{$type}",
    );
  }
  return $themes;
}

/**
 * Implementation of hook_theme_registry_alter().
 *
 * This is so that it will look for the node-topichub.tpl.php file here too.
 */
function topichubs_theme_registry_alter(&$theme_registry) {
  $modulepath = drupal_get_path('module', 'topichubs');
  array_unshift($theme_registry['node']['theme paths'], $modulepath);
}

/**
 * Implementation of hook_preprocess_node().
 *
 * This is so that it will look for the node-topichub-[nid].tpl.php
 */
function topichubs_preprocess_node(&$variables) {
  $node = $variables['node'];
  if($node->type == 'topichub') {
    $variables['template_files'][] = 'node-' . $node->type . '-' . $node->nid;
  }
}

/**
 * Implementation of hook_nodeapi().
 */
function topichubs_nodeapi(&$node, $op, $param3 = NULL, $param4 = NULL) {
  if ($node->type == 'topichub') {
    switch ($op) {
      case 'prepare':
        topichubs_render_invoke('load', $node);      
      	// covers add coming from hot topic page.
        if (arg(1) == 'add' && isset($_GET['tid'])) {
          $tid = $_GET['tid'];
          $term = taxonomy_get_term($tid);
          $node->title = "{$term->name} Topic Hub";
          $node->topichub_tid = $tid;
        }
        break;
      case 'load':
        topichub_load($node);
        topichubs_render_invoke('load', $node);              
        break;
      case 'validate':
        topichubs_render_invoke('validate', $node);
        break;
      case 'insert': 
        if(property_exists($node, 'topichub_tid')) {
          $node->topichub->conditions = array(array($node->topichub_tid));
          topichub_insert($node);
        }
        // Since calling topichub_insert is conditional, we have to call this outside that function
        // This does a redirect too, so cal it last
        topichubs_render_invoke('insert', $node);
        break;      
      case 'update':
        topichubs_render_invoke('update', $node);
        break;
      case 'delete':
        topichubs_render_invoke('delete', $node);                    
        topichub_delete($node->nid);
        break;
      case 'view':
        if(topichub_is_initialized($node)) {
          $res = topichubs_render_invoke('view', $node);
          if ($res == '#!#TH_RENDER_NO_IMPL#!#') { //default, TPL_based implementationvai 
            $path = drupal_get_path('module', 'topichubs');
            drupal_add_css("$path/topichubs.css");
            topichub_view($node);
          }
        }
        else {
          drupal_set_message(t('Topic Hub not initialized. Please !config.', array('!config' => l('configure an expression',  "node/{$node->nid}/topichub"))));
        }
        break;
    }
    
  }
}

/**
 * Implementation of hook_taxonomy().
 *
 * Make sure deleted terms are removed from existing expressions
 */
function topichubs_taxonomy($op, $type, $data) {
  if($op == 'delete' && $type == 'term') {
    topichub_term_delete($data['tid']);
  }
}

/**
 * Implementation of hook_form_alter().
 *
 * If we are creating a Topic Hub form a Taxonomy Term, set the value for save processing
 */
function topichubs_form_alter(&$form, $form_state, $form_id) {
  if($form_id == 'topichub_node_form'){
    $node = $form['#node'];
    if($node->topichub_tid) {
      $form['topichub_tid'] = array(
        '#type' => 'hidden',
        '#value' => $node->topichub_tid,
      );
    }
    
    topichubs_render_invoke('form', $node, $form);    
  }
}

/**
 * Determine if a topichub has any conditions setup.
 */
function topichub_is_initialized($node) {
  if(is_numeric($node)) {
    $node = node_load($node);
  }
  else if (is_object($node) && is_numeric($node->nid)) {
    return !empty($node->topichub->conditions);
  }
  
  return FALSE;
}


/**
 * Lookup topichub data from the DB
 *
 * @param $node
 *      The node to load with configuration. It will populate an object property of <em>topichub</em> 
 *      with the taxonomy expression and plugin configuration.
 */
function topichub_load(&$node) {
  $result = db_query('SELECT * FROM {topichub} WHERE nid = %d', $node->nid);
  if ($topichub = db_fetch_object($result)) {
    $node->topichub = $topichub;
    $node->topichub->config = unserialize($topichub->config);
    $node->topichub->conditions = topichub_load_conditions($node->nid);  
  }
}

/**
 * Lookup topichub condition from the DB
 *
 * @param $nid
 *      The node id to load the conditions.
 */
function topichub_load_conditions($nid) {
  $result = db_query('SELECT * FROM {topichub_condition} WHERE nid = %d ORDER BY `condition` ASC, tcid ASC', $nid);
  $conditions = array();
  while($cond = db_fetch_object($result)) {
    $conditions[$cond->condition][] = $cond->tid;
  }
  return $conditions;
}

/**
 * Load all topichub data from providers.
 *
 * @param $node
 *      The node to load with data. It should have an object property of <em>topichub</em> which
 *      will get populated with a <em>data</em> array.
 */
function topichub_view(&$node) {  
  $plugins = topichubs_discover_plugins();
  foreach ($plugins as $type => $def) {
    $impl = _topichubs_new_handler_class($def);
    if($impl) {
      $impl->init($type, $def, $node, $node->topichub->config[$type]);
      $node->topichub->data[$type] = $impl->execute();
    }
  }

  return $node;
}

/**
 * Insert topichub data.
 *
 * @param $node
 *      The node to persist. It should have an object property of <em>topichub</em>
 */
function topichub_insert($node) {
  db_query("INSERT INTO {topichub} (nid, config) VALUES (%d, %b)", $node->nid, serialize($node->topichub->config));
  topichub_insert_conditions($node->nid, $node->topichub->conditions);
}

/**
 * Update topichub data.
 *
 * @param $node
 *      The node to persist. It should have an object property of <em>topichub</em>
 */
function topichub_update($node) {
  db_query("UPDATE {topichub} SET config = %b WHERE nid = %d", serialize($node->topichub->config), $node->nid);
  topichub_insert_conditions($node->nid, $node->topichub->conditions);
}

/**
 * Insert condition data for the topichub expression.
 *
 * @param $nid
 *    Node ID
 * @param $conditions
 *    Array of conditions and term IDs for each condition
 */
function topichub_insert_conditions($nid, $conditions) {
  db_query("DELETE FROM {topichub_condition} WHERE nid = %d", $nid);
  foreach($conditions as $key => $tids) {
    foreach($tids as $tid) {
      db_query("INSERT INTO {topichub_condition} (nid, `condition`, tid) VALUES (%d, %d, %d)", $nid, $key, $tid);
    }
  }
}

/**
 * Remove topichub data.
 *
 * @param $nid
 *      The node to delete
 */
function topichub_delete($nid) {
  db_query("DELETE FROM {topichub} WHERE nid = %d", $nid);
  db_query("DELETE FROM {topichub_condition} WHERE nid = %d", $nid);
}

/**
 * Topichub remove term from conditions. We also need to load the conditions and reorder them
 * b/c the first condition might have only 1 term and if we remove it conditions woudl start ordering @ 1.
 *
 * @param $nid
 *      The node to delete
 */
function topichub_term_delete($tid) {
  $result = db_query("SELECT DISTINCT(nid) FROM {topichub_condition} WHERE tid = %d", $tid);
  db_query("DELETE FROM {topichub_condition} WHERE tid = %d", $tid);
  while($cond = db_fetch_object($result)) {
    $conditions = topichub_load_conditions($cond->nid);
    $conditions = array_merge($conditions);
    topichub_insert_conditions($cond->nid, $conditions);
  }
}

/**
 * Form for configuring a Topic Hub.  
 * This form allows for the building of a taxonomy
 * expression (in conjunction with topichubs.js). It also provides the configuration
 * options for each of the enabled Topic Hub plugins.
 */
function topichubs_config_form(&$form_state, $node) {
  $path = drupal_get_path('module', 'topichubs');
  drupal_add_css("$path/topichubs-admin.css");
  drupal_add_js("$path/topichubs.js");

  // Add image as an array so the JS can always use [0]. Somethign wierd was happening where
  // the multistep form was setting this value twice and causign the JS to barf when adding
  // a term to the UI. This way it is always an array and even if there are many, [0] works.
  drupal_add_js(array(
    'topichubs' => array(
      'delete_img' => array(theme('image', "$path/images/delete.gif")),
    )
  ), 'setting');

  topichub_load($node);
  
  $form = array();
  $form['#node'] = $node;
  $form['nid'] = array(
    '#type' => 'hidden',
    '#value' => $node->nid,
  );
  
  _topichub_plugin_expression_form($form, $form_state, $node);
  _topichub_plugin_config_form($form, $form_state, $node);

  $form['#tree'] = TRUE;
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
  );
  
  return $form;
}

/**
 * Render the Topic Hub Expression Builder form.
 */
function _topichub_plugin_expression_form(&$form, &$form_state, $node) {
  $conditions = $form_state['storage']['conditions'];   
  if(!isset($conditions)) {
    $conditions = array();
    if(is_array($node->topichub->conditions)) {
      foreach($node->topichub->conditions as $cond => $tids) {
        $conditions[$cond] = implode(',', $tids);
      }
    }
  } 
      
  $form['expression']['help'] = array(
    '#type' => 'markup',
    '#value' => t('Content meeting any of the following conditions will be included in this Topic Hub. <b>Adding multiple terms</b> will make a specific condition more stringent. <b>Adding conditions</b> will broaden the context of your Topic Hub by increasing the likelyhood of matching. Be careful, large expressions can have a significant performance penalty.'),
  );
      
  $form['expression']['buttons']['add_condition'] = array(
    '#type' => 'submit',
    '#value' => t('New Condition'),
    '#submit' => array('topichubs_config_form_add_condition'),
    '#skip_validate' => TRUE,
  );  
  
  $vocab_options = array('' => '<select>');
  $options = array();
  $vocabs = taxonomy_get_vocabularies();
  foreach ($vocabs as $vocab) {
    $tree = taxonomy_get_tree($vocab->vid);
    if ($tree) {
      $vocab_options[$vocab->vid] = $vocab->name;
      foreach ($tree as $term) {
        $options[$vocab->vid][$term->tid] = $term->name;
      }
    }
  }  

  $form['expression']['taxonomy'] = array(
    '#type' => 'fieldset',
    '#title' => t('Add a Term to an existing Condition'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
  );

  $form['expression']['taxonomy']['pre'] = array(
    '#value' => '<div id="condition-builder" class="clear-block">',
  );        
  
  $form['expression']['taxonomy']['vocab'] = array(
    '#type' => 'select',
    '#title' => t('Choose a Vocabulary'),
    '#value' => '',
    '#options' => $vocab_options,
    '#attributes' => array('id' => 'vocabulary-selector'),
  );
  
  foreach($options as $vid => $terms) {
    $form['expression']['taxonomy']['term'][$vid] = array(
      '#type' => 'select',
      '#title' => t('@vocab Terms', array('@vocab' => $vocab_options[$vid])),
      '#options' => $terms,
      '#attributes' => array('id' => "term-{$vid}-selector"),
      '#prefix' => "<div id='terms-{$vid}-selector-wrapper' class='topichub-term-selector'>",
      '#suffix' => '</div>',
    );
  }
  
  $condition_options = array('' => '<select>');
  $conditionKeys = array_keys($conditions);
  foreach ($conditionKeys as $key) {
    $condition_options[$key] = t("Condition @num", array('@num' => ($key+1)));
  }
  $form['expression']['taxonomy']['condition'] = array(
    '#type' => 'select',
    '#title' => t('Condition'),
    '#value' => '',
    '#attributes' => array('id' => "condition-selector"),
    '#options' => $condition_options,
  );
  $form['expression']['taxonomy']['add'] = array(
    '#value' => '<a id="topichub-add-term" href="javascript:void(0);">' . t('Add Term') . '</a>',
    '#prefix' => "<div id='add-term'>",
    '#suffix' => '</div>',
  );
  
  $form['expression']['taxonomy']['post'] = array(
    '#value' => '</div>',
  );        
  
  // Hide the condition builder if there are no conditions
  if(count($conditions) == 0) {
    $form['expression']['taxonomy']['#attributes'] = array('style' => "display:none;");
  }
  
  foreach ($conditions as $conditionKey => $tids) {
    $form['expression']['condition'][$conditionKey] = array(
      '#type' => 'fieldset',
      '#title' => t("Condition @num", array('@num' => ($conditionKey + 1))),
      '#collapsible' => FALSE,
      '#collapsed' => FALSE,
      '#tree' => TRUE,
      '#attributes' => array('id' => "condition-wrapper-{$conditionKey}"),
      '#prefix' => '<div class="clear-block">',
      '#suffix' => '</div>',
    );
    if($conditionKey + 1 < count($conditions)) {
      $form['expression']['condition'][$conditionKey]['#suffix'] .= '<div class="operator">' . t('OR') . '</div>';
    }
    $form['expression']['condition'][$conditionKey]['remove'] = array(
      '#type' => 'submit',
      '#value' => t('Remove Condition @num', array('@num' => ($conditionKey + 1))),
      '#submit' => array('topichubs_config_form_remove_condition'),
      '#prefix' => '<div class="remove-condition">',
      '#suffix' => '</div>',
      '#skip_validate' => TRUE,
      '#condition' => $conditionKey,
    );
    $path = drupal_get_path('module', 'topichubs');
    $delete_img = theme('image', "$path/images/delete.gif");
    $tids_array = empty($tids) ? array() : explode(',', $tids);
    foreach($tids_array as $index => $tid) {
      $term = taxonomy_get_term($tid);
      $vocab = taxonomy_vocabulary_load($term->vid);
      $operator = ($index > 0) ? '<span class="operator">' . t('AND') . '</span>' : '';
      $form['expression']['condition'][$conditionKey][] = array(
        '#value' => "<span class='vocab-name'>" . $vocab->name . "</span>: <span class='term-name'>" . $term->name . '</span>',
        '#prefix' => '<span class="condition-term">' . $operator,
        '#suffix' => "<a class='topichub-term-remove' href='javascript:void(0);' title='Remove' tid='{$tid}' condition='{$conditionKey}'>{$delete_img}</a></span>",
      );
    }
    // FAPI does not allow for overriding ID of hidden via #attributes
    $form['expression']['conditions'][$conditionKey] = array(
      '#type' => 'hidden',
      '#default_value' => $tids,
      '#id' => "conditions-{$conditionKey}",
    );
  }  
    
}

/**
 * Render the Topic Hub Plugin configuration form.
 */
function _topichub_plugin_config_form(&$form, &$form_state, $node) {

  $config = $form_state['storage']['config'];   
  if(!isset($config)) {
    $config = $node->topichub->config;
  } 
  
  $plugins = topichubs_discover_plugins();
  foreach ($plugins as $type => $def) {
    $impl = _topichubs_new_handler_class($def);
    if($impl) {
      $impl->init($type, $def, $node, $config[$type]);
      $impl->build_form('options', $form['config'], $form_state);
    }
  }
}

/**
 * Validate handler for the Topic Hub configuration.
 */
function topichubs_config_form_validate($form, &$form_state) {
  
  if(!$form_state['clicked_button']['#skip_validate']) {
    $node = $form['#node'];

    $conditions = $form_state['values']['expression']['conditions'];
    if(isset($conditions)) {
      foreach($conditions as $key => $terms) {
        if(empty($terms)) {
          form_set_error("condition-$key", t('Condition @num cannot be empty.', array('@num' => ($key + 1))));
        }
      }
    }
    
    $config = $form_state['values']['config'];
    $plugins = topichubs_discover_plugins();
    foreach ($plugins as $type => $def) {
      $impl = _topichubs_new_handler_class($def);
      if($impl) {
        $impl->init($type, $def, $node, $config[$type]);
        $impl->options_validate($node, $form);
      }
    }
  }  
}


/**
 * Submit handler for the Topic Hub configuration.
 */
function topichubs_config_form_submit($form, &$form_state) {
  $values = $form_state['values'];
  
  $node = new stdClass;
  $node->nid = $values['nid'];
  topichub_load($node);
   
  $save_function = 'topichub_update';
  if(!$node->topichub) {
    $node->topichub = new stdClass;
    $save_function = 'topichub_insert';
  }
  
  $conditions = $values['expression']['conditions'];
  foreach($conditions as $key => $tids) {
    $conditions[$key] = empty($tids) ? array() : explode(',', $tids);
  }
  
  $node->topichub->config = $values['config'];
  $node->topichub->conditions = $conditions;
  $save_function($node);
    
  unset($form_state['storage']); // Otherwise redirect won't work, it will just rebuild
  $form_state['redirect'] = "node/{$node->nid}";
}

/**
 * Handle the Add Condition button. Adds a new condition and saves them away for form rebuild
 */
function topichubs_config_form_add_condition($form, &$form_state) {

  $conditions = $form_state['values']['expression']['conditions'];
  if(!isset($conditions)) {
    $conditions = array();
  }  
  array_push($conditions, '');  
  $form_state['storage']['conditions'] = $conditions;
  $form_state['storage']['config'] = $form_state['values']['config'];
  $form_state['rebuild'] = TRUE;
}

/**
 * Handle the Remove Condition button. Removes and existing condition and saves them away for form rebuild
 */
function topichubs_config_form_remove_condition($form, &$form_state) {
  $removeKey = $form_state['clicked_button']['#condition'];
  $conditions = $form_state['values']['expression']['conditions'];
  if(isset($conditions)) {
    unset($conditions[$removeKey]);
    $conditions = array_merge($conditions); //reorder keys
  }  
  $form_state['storage']['conditions'] = $conditions;
  $form_state['storage']['config'] = $form_state['values']['config'];
  $form_state['rebuild'] = TRUE;
}

/**
 * Lookup installed version of panels
 * @return int
 *    version
 */
 function _get_panels_version() {
   return db_result(db_query("SELECT schema_version from {system} where name = 'panels'"));
 }


/**
 * Theme the Topic Hub Config form.
 */
function theme_topichubs_config_form($form) {
  $output = '<div id="topichub-config">';
  $output .= '<h3>' . t('Topic Hub Expression') . '</h3>';
  $output .= drupal_render($form['expression']['help']);
  $output .= "<div>";
  $output .= drupal_render($form['expression']['buttons']);
  $output .= "</div>";
  $output .= drupal_render($form['expression']['taxonomy']);
  $output .= drupal_render($form['expression']['condition']);
  $output .= '<h3>' . t('Plugin Configuration') . '</h3>';
  $config = &$form['config'];
  foreach(element_children($config) as $index => $type) {
    $labels[] .= "<div id='plugin-{$type}' class='plugin-label'>" . $config[$type]['#title'] . '</div>';    
    $settings[] .= "<div id='plugin-{$type}-form' class='plugin-settings'>" . drupal_render($config[$type]) . '</div>';    
  }
  $labels[] .= '<div class="plugin-label-bottom">&nbsp;</div>';

  $header = array(
    t('Plugin'),
    t('Configuration'),
  );
  $rows = array(
    array(
      array(
        'data' => implode($labels), 
        'class' => 'topichub-plugin-labels'
      ), 
      array(
        'data' => implode($settings),
        'class' => 'topichub-plugin-settings'
      ),
    ),
  );
  $output .= theme('table', $header, $rows, array('class' => 'topichub-plugin-config'));

  $output .= drupal_render($form);
  $output .= '</div>';
  return $output;
}