context_ui/context_ui_admin.inc

   1 <?php
   2 // $Id$
   3 /**
   4  * Page callback for context_ui admin landing page.
   5  */
   6 function context_ui_admin() {
   7   drupal_add_css(drupal_get_path("module", "context_ui") ."/context_ui.css");
   8
   9   // rebuild blocks
  10   _block_rehash();
  11
  12   // rebuild default contexts
  13   context_ui_rebuild();
  14
  15   // User defined contexts
  16   $output = "<h3>". t('User context definitions') ."</h3>";
  17   $contexts = context_ui_tree('ui');
  18   if ($contexts) {
  19     $output .= theme('context_ui_admin', $contexts);
  20   }
  21   else {
  22     $output .= "<p>". t('Please !add_context to get started.', array('!add_context' => l(t('add a context'), 'admin/build/context/add'))) ."</p>";
  23   }
  24
  25   // Module defined contexts
  26   $output .= "<h3>". t('Module context definitions') ."</h3>";
  27   $contexts = context_ui_tree('system');
  28   if ($contexts) {
  29     $output .= theme('context_ui_admin', $contexts);
  30   }
  31   else {
  32     $output .= "<p>". t('There are currently no module defined contexts.') ."</p>";
  33   }
  34
  35   return $output;
  36 }
  37
  38 /**
  39  * Generates the omnibus context definition editing form.
  40  * Note: submission and validation handlers are in context_ui_admin.inc
  41  *
  42  * @param $op
  43  *   The type of form to build. Either "add", "view" or "edit"
  44  * @param $cid
  45  *   The db context identifier - required when $op == "edit"
  46  *
  47  * @return
  48  *   A Drupal form array.
  49  */
  50 function context_ui_form(&$form_state, $op, $cid = NULL, $context = NULL) {
  51   drupal_add_css(drupal_get_path("module", "context_ui") ."/context_ui.css");
  52   drupal_add_js(drupal_get_path("module", "context_ui") ."/context_ui.js");
  53
  54   switch ($op) {
  55     case 'add':
  56       if (is_object($context)) {
  57         $context->system = true;
  58         if ($exists = context_ui_context('load', $context)) {
  59           drupal_set_message(t('A module is already providing a context with this space/key/value identifier. Your context definition will override its settings.'));
  60         }
  61         $context->system = false;
  62       }
  63       break;
  64     case 'view':
  65       if (is_numeric($cid) && $context = context_ui_context('load', $cid)) {
  66         drupal_set_title(t('View %title', array('%title' => $context->value)));
  67       }
  68       else {
  69         drupal_goto('admin/build/context'); return;
  70       }
  71       break;
  72     case 'edit':
  73       if (is_numeric($cid) && $context = context_ui_context('load', $cid)) {
  74         if (!$context->system) {
  75           drupal_set_title(t('Edit context: %title', array('%title' => $context->value)));
  76         }
  77         else {
  78           drupal_goto('admin/build/context'); return;
  79         }
  80       }
  81       break;
  82   }
  83
  84   // Core context definition
  85   $form['#theme'] = 'context_ui_form';
  86   $form['value'] =
  87   $form['ckey'] =
  88   $form['space'] = array(
  89     '#type' => 'textfield',
  90     '#required' => true,
  91     '#maxlength' => 64,
  92     '#size' => 20,
  93   );
  94
  95   $form['value']['#title'] = t('Value');
  96   $form['value']['#description'] =  t('A system name for this context. May only contain lowercase letters, underscores, and numbers. Example: <b>science_blog</b>');
  97
  98   $form['ckey']['#title'] = t('Key');
  99   $form['ckey']['#default_value'] = 'section';
 100   $form['ckey']['#description'] = t('The type of context information provided in this namespace. Example: <b>section</b>');
 101
 102   $form['space']['#title'] = t('Namespace');
 103   $form['space']['#default_value'] = 'context_ui';
 104   $form['space']['#description'] = t('The namespace for this context definition. Example: <b>context_ui</b>');
 105
 106   $form['items'] = array(
 107     '#tree' => true,
 108   );
 109
 110   // Generate settings for context item associations
 111   foreach (context_ui_types('full') as $type => $item) {
 112     if (in_array($item['#type'], array('select', 'radios', 'checkboxes', 'textfield'))) {
 113       $form['items'][$type] = $item;
 114     }
 115   }
 116
 117   // Control block visibility
 118   init_theme(); // we need to initialize theme in order to deal with blocks
 119   global $theme_key;
 120   $block_options =
 121   $block_defaults = array();
 122   $blocks = _context_ui_get_blocks();
 123   $regions = system_region_list($theme_key);
 124   // $blocks in [0] have not been assigned a region
 125   foreach ($blocks[0] as $block) {
 126     if (!isset($context->block[$block->bid])) {
 127       $block_options[$block->module][$block->bid] = $block->label ." ($block->bid)";
 128     }
 129   }
 130   ksort($block_options);
 131
 132   $form['block'] = array(
 133     '#tree' => true,
 134   );
 135
 136   $form['block']['selector'] = array(
 137     '#description' => t('Control block visibility using context. Selected blocks will be shown when this context is set provided that custom block visibility settings and/or throttling do not hide them. Grayed out blocks are those provided by Drupal\'s standard block settings. These settings apply to the current theme and any enabled themes with regions in common.'),
 138     '#type' => 'item',
 139     '#tree' => true,
 140     '#prefix' => '<div class="context-ui-block-selector">',
 141     '#suffix' => '</div>',
 142     'blocks' => array(
 143       '#type' => 'select',
 144       '#multiple' => true,
 145       '#size' => 15,
 146       '#title' => t('Blocks'),
 147       '#options' => $block_options,
 148     ),
 149     'regions' => array(
 150       '#type' => 'select',
 151       '#title' => t('Regions'),
 152       '#options' => $regions,
 153     ),
 154     'add' => array(
 155       '#type' => 'markup',
 156       '#value' => "<input id='edit-block-selector-add' class='form-submit' type='button' value='+ ". t('Add') ."'/>",
 157     ),
 158   );
 159   $form['block']['regions'] = array(
 160     '#type' => 'item',
 161     '#tree' => true,
 162     '#prefix' => '<div class="context-ui-block-regions">',
 163     '#suffix' => '</div>',
 164     '#value' => theme('context_ui_block_ui', $regions, $context),
 165   );
 166   foreach (array_keys($regions) as $region) {
 167     $defaults = array();
 168     $midpoint = false;
 169     foreach (_context_ui_get_blocks($region, $context) as $block) {
 170       if ($block->type == 'context_ui') {
 171         $defaults[] = $block->bid;
 172       }
 173       else if (!$midpoint) {
 174         $midpoint = true;
 175         $defaults[] = 'system';
 176       }
 177     }
 178     if (!$defaults) {
 179       $defaults = array('system');
 180     }
 181     $defaults = implode(',', $defaults);
 182     $form['block']['regions'][$region] = array(
 183       '#type' => 'hidden',
 184       '#default_value' => $defaults,
 185     );
 186   }
 187
 188   if ($op == 'view') {
 189     $form['back'] = array(
 190       '#type' => 'item',
 191       '#value' => l(t('Back'), 'admin/build/context'),
 192     );
 193   }
 194
 195   if ($op != 'view') {
 196     $form['submit'] = array(
 197       '#type' => 'submit',
 198       '#value' => t('Save'),
 199     );
 200   }
 201
 202   if ($op == 'edit') {
 203     $form['delete'] = array(
 204       '#type' => 'submit',
 205       '#value' => t('Delete'),
 206     );
 207   }
 208
 209   if ($op == 'view' || $op == 'edit' || ($op == 'add' && $context)) {
 210     if ($context) {
 211       $form['value']['#default_value'] = $context->value;
 212       $form['ckey']['#default_value'] = $context->ckey;
 213       $form['space']['#default_value'] = $context->space;
 214       $form['cid'] = array(
 215         '#type' => 'value',
 216         '#value' => $cid,
 217       );
 218       $form['system'] = array(
 219         '#type' => 'value',
 220         '#value' => $context->system,
 221       );
 222       if ($op == 'view' || $context->system) {
 223         $form['value']['#disabled'] =
 224         $form['ckey']['#disabled'] =
 225         $form['space']['#disabled'] =
 226         $form['block']['selector']['blocks']['#disabled'] =
 227         $form['block']['selector']['regions']['#disabled'] = true;
 228       }
 229       // Set default values for each item type (except blocks)
 230       foreach (context_ui_types('full') as $type => $item) {
 231         if (is_array($context->{$type})) {
 232           if ($item['#type'] == 'checkboxes' || ($item['#type'] == 'select' && $item['#multiple'] == true)) {
 233             $defaults = array();
 234             foreach ($context->{$type} as $id) {
 235               $defaults[$id] = $id;
 236             }
 237           }
 238           else {
 239             $defaults = current($context->{$type});
 240           }
 241           $form['items'][$type]['#default_value'] = $defaults;
 242         }
 243         $form['items'][$type]['#disabled'] = $op == 'view' ? true : false;
 244       }
 245       // Blocks must be selected by region
 246       if (is_array($context->block)) {
 247         foreach ($regions as $region => $label) {
 248           if (isset($form['block'][$region]) && is_array($form['block'][$region])) {
 249             $defaults = array();
 250             foreach ($form['block'][$region]['#options'] as $block => $label) {
 251               if (array_search($block, $context->block) !== false) {
 252                 $defaults[$block] = $block;
 253               }
 254             }
 255             $form['block'][$region]['#default_value'] = $defaults;
 256           }
 257           $form['block'][$region]['#disabled'] = $op == 'view' ? true : false;
 258         }
 259       }
 260     }
 261     else {
 262       return drupal_goto('admin/build/context');
 263     }
 264   }
 265
 266   return $form;
 267 }
 268
 269 /**
 270  * Theme function for context_ui_form()
 271  */
 272 function theme_context_ui_form($form) {
 273   $output = '';
 274
 275   // Render space / key / value trio in a 3-column table
 276   $header = array(t('Namespace'), t('Key'), t('Value'));
 277   unset($form['space']['#title']);
 278   unset($form['ckey']['#title']);
 279   unset($form['value']['#title']);
 280   $rows = array(
 281     array(
 282       drupal_render($form['space']),
 283       drupal_render($form['ckey']),
 284       drupal_render($form['value']),
 285     ),
 286   );
 287   $output .= theme('table', $header, $rows, array('class' => 'context-ui-3col'));
 288
 289   // Render setters / getters as a two column split
 290   $header = array(t('Set context'), t('Respond to context'));
 291   $setters = $getters = '';
 292   foreach (context_ui_types('full') as $type => $item) {
 293     if ($item['#context_ui'] == 'getter') {
 294       $getters .= drupal_render($form['items'][$type]);
 295     }
 296     else {
 297       $setters .= drupal_render($form['items'][$type]);
 298     }
 299   }
 300   $rows = array(
 301     array(
 302       array('data' => $setters, 'class' => 'setters left'),
 303       array('data' => $getters, 'class' => 'getters right'),
 304     ),
 305   );
 306   $output .= theme('table', $header, $rows, array('class' => 'context-ui-2col'));
 307
 308   // Block visibility
 309   $header = array(t('Blocks'), t('Regions'));
 310   $rows = array(
 311     array(
 312       array('data' => drupal_render($form['block']['selector']), 'class' => 'left'),
 313       array('data' => drupal_render($form['block']['regions']), 'class' => 'right'),
 314     ),
 315   );
 316   $output .= theme('table', $header, $rows, array('id' => 'context-ui-blocks', 'class' => 'context-ui-2col'));
 317
 318   $output .= drupal_render($form);
 319   return $output;
 320 }
 321
 322 /**
 323  * Provide a form to confirm deletion of a context definition.
 324  */
 325 function context_ui_delete_confirm(&$form_state, $cid) {
 326   $context = context_ui_context('load', $cid);
 327   if (!$context) {
 328     return drupal_goto('admin/build/context');
 329   }
 330   $form['cid'] = array('#type' => 'value', '#value' => $cid);
 331   $form = confirm_form($form,
 332     t('Are you sure you want to delete %title?', array('%title' => $context->value)),
 333     'admin/build/context',
 334     t('This action cannot be undone.'),
 335     t('Delete'), t('Cancel')
 336   );
 337   return $form;
 338 }
 339
 340 /**
 341  * Submit hook for context_ui delete confirmation form.
 342  */
 343 function context_ui_delete_confirm_submit($form, &$form_state) {
 344   context_ui_context('delete', $form_state['values']['cid']);
 345   context_ui_rebuild();
 346   $form_state['redirect'] = 'admin/build/context';
 347 }
 348
 349 /**
 350  * Page callback for import form. Switches form output to context form
 351  * if import submission has occurred.
 352  */
 353 function context_ui_import_page() {
 354   if (!empty($_POST) && $_POST['form_id'] == 'context_ui_form') {
 355     return drupal_get_form('context_ui_form', 'add');
 356   }
 357   return drupal_get_form('context_ui_import');
 358 }
 359
 360 /**
 361  * Import form. Provides simple helptext instructions and textarea for
 362  * pasting a context definition.
 363  */
 364 function context_ui_import() {
 365   drupal_set_title(t('Import context'));
 366   $help = t('You can import a context definition by pasting the exported context object code into the field below.');
 367   $form = array();
 368   $form['help'] = array(
 369     '#type' => 'item',
 370     '#value' => $help,
 371   );
 372   $form['import'] = array(
 373     '#title' => t('Context Object'),
 374     '#type' => 'textarea',
 375     '#rows' => 10,
 376     '#required' => true,
 377   );
 378   $form['submit'] = array(
 379     '#type' => 'submit',
 380     '#value' => t('Import'),
 381   );
 382
 383   return $form;
 384 }
 385
 386 /**
 387  * Import form submit handler. Evaluates import code and transfers to
 388  * context definition form.
 389  */
 390 function context_ui_import_submit($form, &$form_state) {
 391   $items = array();
 392   if ($import = $form_state['values']['import']) {
 393     ob_start();
 394     eval($import);
 395     ob_end_clean();
 396   }
 397   if (is_array($items) && count($items)) {
 398     $context = current($items);
 399   }
 400   if (is_array($context)) {
 401     $context = (object) $context;
 402     $context->system = FALSE;
 403     if ($exists = context_ui_context('load', $context)) {
 404       drupal_set_message(t('A user-defined context definition with this space/key/value identifier already exists. Please remove the existing context before importing this definition.'), 'error');
 405       $form_state['redirect'] = 'admin/build/context';
 406     }
 407     else {
 408       drupal_set_title(t('Add context'));
 409       $output = drupal_get_form('context_ui_form', 'add', null, (object) $context);
 410       print theme('page', $output);
 411       exit;
 412     }
 413   }
 414   else {
 415     drupal_set_message(t('An error occurred while importing. Please check your context definition.', 'error'));
 416     $form_state['redirect'] = 'admin/build/context';
 417   }
 418 }
 419
 420 /**
 421  * Provides a form with an exported context definition for use in modules.
 422  *
 423  * @param $cid
 424  *   A context id.
 425  *
 426  * @return
 427  *   A FormAPI array.
 428  */
 429 function context_ui_export(&$form_state, $cid = NULL) {
 430   if (is_numeric($cid) && $context = context_ui_context('load', $cid)) {
 431     drupal_set_title(t('Export %title', array('%title' => $context->value)));
 432
 433     // help text -- too bad the help module in 5 doesn't take wildcards
 434     $help = t('You can use exported contexts in your modules by returning an array of defined contexts in <code>hook_context_define()</code>.');
 435
 436     // prune system specific information and cast for Drupal's AOP (array oriented programming)
 437     unset($context->cid);
 438     unset($context->status);
 439     unset($context->system);
 440     $context = (array) $context;
 441
 442     // clean up blocks
 443     foreach ($context['block'] as $bid => $block) {
 444       unset($block->bid);
 445       $context['block'][$bid] = (array) $block;
 446     }
 447
 448     // export
 449     $export = '$items[] = '. var_export($context, true) .';';
 450
 451     // build the form
 452     $form = array();
 453     $form['help'] = array(
 454       '#type' => 'item',
 455       '#value' => $help,
 456     );
 457     $form['export'] = array(
 458       '#type' => 'textarea',
 459       '#rows' => 24,
 460       '#default_value' => $export,
 461     );
 462     return $form;
 463   }
 464   else {
 465     drupal_goto('admin/build/context'); return;
 466   }
 467 }
 468
 469 /*
 470  * Generates an array tree representation of available space/key/value context definitions.
 471  */
 472 function context_ui_tree($op = '') {
 473   static $tree;
 474   if (!$tree) {
 475     $tree = array(
 476       'system' => array(),
 477       'ui' => array(),
 478     );
 479     $result = db_query("
 480       SELECT *
 481       FROM {context_ui}
 482       ORDER BY system ASC, space ASC, ckey ASC, value ASC");
 483     while ($context = db_fetch_object($result)) {
 484       $branch = $context->system ? 'system' : 'ui';
 485       $tree[$branch][$context->space][$context->ckey][$context->value] = $context;
 486     }
 487   }
 488   switch ($op) {
 489     case 'ui':
 490       return $tree['ui'];
 491     case 'system':
 492       return $tree['system'];
 493     default:
 494       return $tree;
 495   }
 496 }
 497
 498 /**
 499  * Cache system contexts
 500  */
 501 function context_ui_rebuild() {
 502   $default_contexts = context_ui_defaults();
 503   $types = context_ui_types();
 504
 505   // Grab existing user defined contexts
 506   $ui = context_ui_tree('ui');
 507
 508   // Retrieve existing system contexts
 509   $system = array();
 510   $result = db_query("SELECT * FROM {context_ui} WHERE system = 1");
 511   while ($existing = db_fetch_object($result)) {
 512     $system[$existing->cid] = true;
 513   }
 514
 515   // Insert or update system contexts
 516   foreach ($default_contexts as $c) {
 517     // flag this context's type + status
 518     $c->system = 1;
 519     $c->status = isset($ui[$c->space][$c->ckey][$c->value]) ? 0 : 1;
 520
 521     if ($context = context_ui_context('load', $c)) {
 522       $c->cid = $context->cid;
 523       context_ui_context('update', $c);
 524       unset($system[$c->cid]); // remove this context from unused list
 525     }
 526     else {
 527       context_ui_context('insert', $c);
 528     }
 529   }
 530
 531   // Remove any unused contexts
 532   foreach ($system as $c => $dummy) {
 533     context_ui_context('delete', $c);
 534   }
 535 }
 536
 537 /**
 538  * Generates the main context_ui admin page with a tiered context listing.
 539  */
 540 function theme_context_ui_admin($context_tree) {
 541   foreach ($context_tree as $space => $keys) {
 542     $rows[] = array(
 543       "<span class='context-space'>". $space ."</span>",
 544       null
 545     );
 546     foreach ($keys as $key => $contexts) {
 547       if (is_array($contexts)) {
 548         $rows[] = array(
 549           "<span class='context-key'>". $key ."</span>",
 550           null
 551         );
 552         foreach ($contexts as $value => $context) {
 553           $links = array();
 554           $class = '';
 555           if ($context->system) {
 556             $links[] = l(t('View'), "admin/build/context/view/$context->cid");
 557           }
 558           else {
 559             $links[] = l(t('Edit'), 'admin/build/context/edit/'. $context->cid);
 560             $links[] = l(t('Export'), "admin/build/context/export/$context->cid");
 561             $links[] = l(t('Delete'), 'admin/build/context/delete/'. $context->cid);
 562           }
 563           if (!$context->status) {
 564             $class = 'overridden';
 565             $value = "$value (". t('Overridden') .")";
 566           }
 567           $rows[] = array(
 568             "<span class='context-value $class'>". $value ."</span>",
 569             implode(' | ', $links),
 570           );
 571         }
 572       }
 573       else {
 574         $links = array();
 575         $class = '';
 576         if ($contexts->system) {
 577           $links[] = l(t('View'), "admin/build/context/view/$contexts->cid");
 578         }
 579         else {
 580           $links[] = l(t('Edit'), 'admin/build/context/edit/'. $contexts->cid);
 581           $links[] = l(t('Delete'), 'admin/build/context/delete/'. $contexts->cid);
 582         }
 583         if ($contexts->overridden) {
 584           $class = 'overridden';
 585           $key = "$key (". t('Overridden') .")";
 586         }
 587         $rows[] = array(
 588           "<span class='context-key'>". $key ."</span>",
 589           implode(' | ', $links),
 590         );
 591       }
 592     }
 593   }
 594   return theme('table', array(t('Context'), t('Actions')), $rows, array('class' => 'context-ui'));
 595 }
 596
 597 /**
 598  * Generates the AJAX enabled block administration portion of the context_ui admin form.
 599  */
 600 function theme_context_ui_block_ui($regions, $context = null) {
 601   $output = '';
 602
 603   $tools = "<div class='tools'><span class='up'></span><span class='down'></span><span class='remove'></span></div>";
 604   foreach ($regions as $region => $label) {
 605     $items = array();
 606
 607     $system = _context_ui_get_blocks($region);
 608     $system_item = array();
 609     foreach ($system as $block) {
 610       $system_item[] = $block->label ." ($block->bid)";
 611     }
 612     $system_item = implode("<br/>", $system_item);
 613
 614     $options = _context_ui_get_blocks($region, $context);
 615     $midpoint = false;
 616     if ($options) {
 617       foreach ($options as $block) {
 618         if ($block->type == 'context_ui' && !$context->system) {
 619           $items[] = array(
 620             'data' => $tools . $block->label ." ($block->bid)",
 621             'title' => $block->bid,
 622           );
 623         }
 624         else if ($block->type == 'context_ui' && $context->system) {
 625           $items[] = array(
 626             'data' => $block->label ." ($block->bid)",
 627             'title' => $block->bid,
 628             'class' => 'default',
 629           );
 630         }
 631         else if (!$midpoint) {
 632           $midpoint = true;
 633           $items[] = array(
 634             'data' => $system_item,
 635             'title' => 'system',
 636             'class' => 'disabled',
 637           );
 638         }
 639       }
 640     }
 641     else if ($system_item) {
 642       $items[] = array(
 643         'data' => $system_item,
 644         'title' => 'system',
 645         'class' => 'disabled',
 646       );
 647     }
 648     else {
 649       $items[] = array(
 650         'data' => '',
 651         'class' => 'dummy',
 652       );
 653     }
 654     $output .= theme('item_list', $items, $label, 'ul', array('class' => $region));
 655   }
 656   return $output;
 657 }
 658
 659 /**
 660  * hook_validate()
 661  */
 662 function context_ui_form_validate($form, &$form_state) {
 663   if ($form_state['clicked_button']['#id'] == 'edit-submit' && $form_state['values']['value']) {
 664     // Check for string identifier sanity
 665     foreach (array('value', 'ckey', 'space') as $elem) {
 666       if (!preg_match('!^[a-z0-9_]+$!', $form_state['values'][$elem])) {
 667         form_set_error($elem, t('The context !elem can only consist of lowercase letters, underscores, and numbers.', array('!elem' => $elem)));
 668       }
 669     }
 670     if (!isset($form_state['values']['cid'])) {
 671       // Check that no other user-defined context definition has taken this identifier already
 672       $context = new stdClass();
 673       $context->space = $form_state['values']['space'];
 674       $context->ckey = $form_state['values']['ckey'];
 675       $context->value = $form_state['values']['value'];
 676       $context->system = 0;
 677       if ($exists = context_ui_context('load', $context)) {
 678         form_set_error($form_state['values']['value'], t('A user-defined context with this space/key/value identifier already exists. Please delete the existing definition before creating a new one.'));
 679       }
 680     }
 681   }
 682 }
 683
 684 /**
 685  * Produces a context object from submitted form values.
 686  *
 687  * @param $form
 688  *   A form array with submitted values
 689  *
 690  * @return
 691  *   A context object
 692  */
 693 function context_ui_form_process($form) {
 694   $context = new stdClass();
 695
 696   // Context space/key/value definition
 697   $context->cid = isset($form['cid']) ? $form['cid'] : null;
 698   $context->system = isset($form['system']) ? $form['system'] : null;
 699   $context->space = $form['space'] ? $form['space'] : null;
 700   $context->ckey = $form['ckey'] ? $form['ckey'] : null;
 701   $context->value = $form['value'] ? $form['value'] : null;
 702   $context->status = 1; // all user defined contexts have status 1
 703
 704   // Values for most item types
 705   $item_types = context_ui_types();
 706   foreach ($item_types as $element_id) {
 707     if (is_array($form['items'][$element_id])) {
 708       foreach ($form['items'][$element_id] as $option => $value) {
 709         if ($value) {
 710           $context->{$element_id}[] = $option;
 711         }
 712       }
 713     }
 714     else if (isset($form['items'][$element_id])) {
 715       $context->{$element_id}[] = $form['items'][$element_id];
 716     }
 717   }
 718
 719   // Blocks must be done by region
 720   $context->block = array();
 721   global $theme_key;
 722   // Get list of "valid" available blocks
 723   $valid = _context_ui_get_blocks();
 724   $valid = $valid[0];
 725   foreach (system_region_list($theme_key) as $region => $label) {
 726     if ($blocks = $form['block']['regions'][$region]) {
 727       $blocks = explode(',', $blocks);
 728       $midpoint = array_search('system', $blocks);
 729       foreach ($blocks as $position => $bid) {
 730         if ($bid != 'system') {
 731           $block = $valid[$bid];
 732           $modifier = $position < $midpoint ? -10 : 10;
 733           $block->weight = $position - $midpoint + $modifier;
 734           $block->region = $region;
 735           $block->type = 'context_ui';
 736           $context->block[$block->bid] = $block;
 737         }
 738       }
 739     }
 740   }
 741   return $context;
 742 }
 743
 744 /**
 745  * Submit handler for main context_ui form.
 746  */
 747 function context_ui_form_submit($form, &$form_state) {
 748   switch (t($form_state['values']['op'])) {
 749     // Send user to delete confirmation page
 750     case 'Delete':
 751       $form_state['redirect'] = 'admin/build/context/delete/'. $form_state['values']['cid'];
 752       return;
 753     // Process form values and save and/or update the context in the db
 754     case 'Save':
 755       $context = context_ui_form_process($form_state['values']);
 756       if (!$context->cid) {
 757         $result = context_ui_context('insert', $context);
 758         if ($result) {
 759           drupal_set_message(t('The context %title was saved successfully.', array('%title' =>  $context->value)));
 760           break;
 761         }
 762       }
 763       else if (context_ui_context('load', $context->cid)) {
 764         $result = context_ui_context('update', $context);
 765         if ($result) {
 766           drupal_set_message(t('The context %title was saved successfully.', array('%title' =>  $context->value)));
 767           break;
 768         }
 769       }
 770       drupal_set_message(t('An error occurred while attempting to save your context information.'), 'error');
 771       break;
 772   }
 773   // rebuild cache
 774   context_ui_rebuild();
 775   $form_state['redirect'] = 'admin/build/context';
 776 }
 777
 778 /**
 779  * Helper function to generate a list of blocks from a specified region. If provided a context object,
 780  * will generate a full list of blocks for that region distinguishing between system blocks and
 781  * context-provided blocks.
 782  *
 783  * @param $region
 784  *   The string identifier for a theme region. e.g. "left"
 785  * @param $context
 786  *   A context object.
 787  *
 788  * @return
 789  *   A keyed (by "module_delta" convention) array of blocks.
 790  */
 791 function _context_ui_get_blocks($region = null, $context = null) {
 792   global $theme_key;
 793   static $block_info, $valid, $system_blocks;
 794   // we don't static cache context blocks
 795   $context_blocks = $blocks = array();
 796
 797   if (!$system_blocks) {
 798     // initialize regions
 799     foreach (system_region_list($theme_key) as $r => $l) {
 800       $system_blocks[$r] = array();
 801     }
 802     // load blocks from database
 803     $result = db_query("SELECT module, delta, weight, region, status FROM {blocks} WHERE theme = '%s' ORDER BY weight, module, delta", $theme_key);
 804     while ($block = db_fetch_object($result)) {
 805       // load block info
 806       $block_info[$block->module] = isset($block_info[$block->module]) ? $block_info[$block->module] : module_invoke($block->module, 'block', 'list');
 807       $block->label = $block_info[$block->module][$block->delta]['info'];
 808       $block->type = 'system';
 809       $block->bid = $block->module .'_'. $block->delta;
 810       // add block to region
 811       if ($block->region && $block->status) {
 812         $system_blocks[$block->region][$block->bid] = $block;
 813       }
 814       else {
 815         $system_blocks[0][$block->bid] = $block;
 816       }
 817       // mark block as available in DB
 818       $valid[$block->module ."_". $block->delta] = true;
 819     }
 820   }
 821
 822   // load system blocks into main block array
 823   $blocks = $system_blocks;
 824
 825   // load context blocks if provided
 826   if (is_object($context) && is_array($context->block)) {
 827     // iterate over context-associated blocks
 828     foreach ($context->block as $block) {
 829       $block = (object) $block;
 830       // check that this is a valid block
 831       if ($valid[$block->module ."_". $block->delta]) {
 832         // if region has been specified, ensure that block belongs to it
 833         if (!$region || (isset($region) && $block->region == $region)) {
 834           // load block info
 835           $block_info[$block->module] = $block_info[$block->module] ? $block_info[$block->module] : module_invoke($block->module, 'block', 'list');
 836           $block->label = $block_info[$block->module][$block->delta]['info'];
 837           $block->type = 'context_ui';
 838           $block->bid = $block->module .'_'. $block->delta;
 839           // add block to region
 840           if ($block->region) {
 841             $blocks[$block->region][$block->bid] = $block;
 842           }
 843           else {
 844             $blocks[0][$block->bid] = $block;
 845           }
 846         }
 847       }
 848     }
 849   }
 850
 851   foreach ($blocks as $r => &$sort_region) {
 852     if ($r !== 0) {
 853       uasort($sort_region, "_context_ui_block_compare");
 854     }
 855   }
 856
 857   return $region ? $blocks[$region] : $blocks;
 858 }