first import

sites/all/modules/context/plugins/context_condition_book.inc

@@ -0,0 +1,22 @@
+<?php
+
+/**
+ * Expose book properties as a context condition.
+ */
+class context_condition_book extends context_condition {
+  function condition_values() {
+    $values = array();
+    foreach (book_get_books() as $book) {
+      $values[$book['menu_name']] = check_plain($book['title']);
+    }
+    return $values;
+  }
+
+  function execute($node, $op) {
+    if (isset($node->book, $node->book['menu_name'])) {
+      foreach ($this->get_contexts($node->book['menu_name']) as $context) {
+        $this->condition_met($context, $node->book['menu_name']);
+      }
+    }
+  }
+}