first import

sites/all/modules/ctools/plugins/access/compare_users.inc

@@ -0,0 +1,70 @@
+<?php
+
+/**
+ * @file
+ * Ctools access plugin to provide access/visiblity if two user contexts are equal.
+ */
+
+/**
+ * Plugins are described by creating a $plugin array which will be used
+ * by the system that includes this file.
+ */
+$plugin = array(
+  'title' => t("User: compare"),
+  'description' => t('Compare two users (logged-in user and user being viewed, for example)'),
+  'callback' => 'ctools_compare_users_access_check',
+  'default' => array(
+    'equality' => 1,
+  ),
+  'settings form' => 'ctools_compare_users_settings',
+  'summary' => 'ctools_compare_users_ctools_access_summary',
+  'required context' => array(
+    new ctools_context_required(t('First User'), 'user'),
+    new ctools_context_required(t("Second User"), 'user')
+  ),
+);
+
+/**
+ * Settings form for the 'by perm' access plugin
+ */
+function ctools_compare_users_settings($form, &$form_state, $conf) {
+
+  $form['settings']['helptext'] = array(
+    '#type' => 'markup',
+    '#value' => '<div>' . t('Grant access based on comparison of the two user contexts. For example, to grant access to a user to view their own profile, choose "logged in user" and "user being viewed" and say "grant access if equal". When they\'re the same, access will be granted.') . '</div>',
+  );
+
+  $form['settings']['equality'] = array(
+    '#type' => 'radios',
+    '#title' => t('Grant access if user contexts are'),
+    '#options' => array(1 => t('Equal'), 0 => t('Not equal')),
+    '#default_value' => $conf['equality'],
+  );
+  return $form;
+}
+
+/**
+ * Check for access.
+ */
+function ctools_compare_users_access_check($conf, $context) {
+
+  if (empty($context) || count($context) != 2 || empty($context[0]->data) || empty($context[1]->data)) {
+    return FALSE;
+  }
+  $account1 = $context[0]->data;
+  $account2 = $context[1]->data;
+
+  // xor returns false if the two bools are the same, and true if they are not.
+  // i.e, if we asked for equality and they are equal, return true.
+  // If we asked for inequality and they are equal, return false.
+  return ($account1->uid == $account2->uid) xor empty($conf['equality']);
+}
+
+/**
+ * Describe an instance of this plugin.
+ */
+function ctools_compare_users_ctools_access_summary($conf, $context) {
+  $comparison = !empty($conf['equality']) ? "is" : 'is not';
+
+  return t('@id1 @comp @id2', array('@comp' => $comparison, '@id1' => $context[0]->identifier, '@id2' => $context[1]->identifier));
+}