MDL-52154 mod_lti: Add cartridge support to LTI

mod/lti/instructor_edit_tool_type.php

@@ -25,6 +25,7 @@
 
 require_once('../../config.php');
 require_once($CFG->dirroot.'/mod/lti/edit_form.php');
+require_once($CFG->dirroot.'/mod/lti/lib.php');
 
 $courseid = required_param('course', PARAM_INT);
 
@@ -56,6 +57,8 @@ if ($data = $form->get_data()) {
         $type->id = $typeid;
         $name = json_encode($data->lti_typename);
 
+        lti_load_type_if_cartridge($data);
+
         lti_update_type($type, $data);
 
         $fromdb = lti_get_type($typeid);
@@ -77,6 +80,8 @@ if ($data = $form->get_data()) {
         $type->state = LTI_TOOL_STATE_CONFIGURED;
         $type->course = $COURSE->id;
 
+        lti_load_type_if_cartridge($data);
+
         $id = lti_add_type($type, $data);
 
         $fromdb = lti_get_type($id);

mod/lti/lib.php

@@ -97,6 +97,8 @@ function lti_add_instance($lti, $mform) {
         $lti->toolurl = '';
     }
 
+    lti_load_tool_if_cartridge($lti);
+
     $lti->timecreated = time();
     $lti->timemodified = $lti->timecreated;
     $lti->servicesalt = uniqid('', true);
@@ -137,6 +139,8 @@ function lti_update_instance($lti, $mform) {
     global $DB, $CFG;
     require_once($CFG->dirroot.'/mod/lti/locallib.php');
 
+    lti_load_tool_if_cartridge($lti);
+
     $lti->timemodified = time();
     $lti->id = $lti->instance;
 
@@ -542,3 +546,155 @@ function lti_view($lti, $course, $cm, $context) {
     $completion = new completion_info($course);
     $completion->set_module_viewed($cm);
 }
+
+/**
+ * Loads the cartridge information into the tool type, if the launch url is for a cartridge file
+ *
+ * @param stdClass $type The tool type object to be filled in
+ * @since Moodle 3.1
+ */
+function lti_load_type_if_cartridge($type) {
+    if (lti_is_cartridge($type->lti_toolurl)) {
+        lti_load_type_from_cartridge($type->lti_toolurl, $type);
+    }
+}
+
+/**
+ * Loads the cartridge information into the new tool, if the launch url is for a cartridge file
+ *
+ * @param stdClass $lti The tools config
+ * @since Moodle 3.1
+ */
+function lti_load_tool_if_cartridge($lti) {
+    if (lti_is_cartridge($lti->toolurl)) {
+        lti_load_tool_from_cartridge($lti->toolurl, $lti);
+    }
+}
+
+/**
+ * Determines if the given url is for a IMS basic cartridge
+ *
+ * @param  string $type    The tool type object to be filled in
+ * @return True if the url is for a cartridge
+ * @since Moodle 3.1
+ */
+function lti_is_cartridge($url) {
+    // If it has xml at the end of the url, it's a cartridge.
+    if (preg_match('/\.xml$/', $url)) {
+        return true;
+    }
+    // Even if it doesn't have .xml, load the url to check if it's a cartridge..
+    $toolinfo = lti_load_cartridge($url,
+        array(
+            "launch_url" => "launchurl"
+        )
+    );
+    if (!empty($toolinfo['launchurl'])) {
+        return true;
+    }
+    return false;
+}
+
+/**
+ * Allows you to load settings for an external tool type from an IMS cartridge.
+ *
+ * @param  string   $url     The URL to the cartridge
+ * @param  stdClass $type    The tool type object to be filled in
+ * @since Moodle 3.1
+ */
+function lti_load_type_from_cartridge($url, $type) {
+    $toolinfo = lti_load_cartridge($url,
+        array(
+            "title" => "lti_typename",
+            "launch_url" => "lti_toolurl",
+            "secure_launch_url" => "lti_securltoolurl",
+            "description" => "lti_description",
+        ),
+        array(
+            "icon_url" => "lti_icon"
+        )
+    );
+    foreach($toolinfo as $property => $value) {
+        $type->$property = $value;
+    }
+}
+
+/**
+ * Allows you to load in the configuration for an external tool from an IMS cartridge.
+ *
+ * @param  string   $url    The URL to the cartridge
+ * @param  stdClass $lti    LTI object
+ * @since Moodle 3.1
+ */
+function lti_load_tool_from_cartridge($url, $lti) {
+    $toolinfo = lti_load_cartridge($url,
+        array(
+            "launch_url" => "toolurl",
+            "secure_launch_url" => "securetoolurl",
+            "title" => "name"
+        )
+    );
+    foreach($toolinfo as $property => $value) {
+        $lti->$property = $value;
+    }
+}
+
+/**
+ * Search for a tag within an XML DOMDocument
+ *
+ * @param  stdClass $tagName The name of the tag to search for
+ * @param  array    $map The map of tags to keys in the return array
+ * @param  array    $properties The map of properties to keys in the return array
+ * @return array An associative array with the given keys and their values from the cartridge
+ * @since Moodle 3.1
+ */
+function lti_load_cartridge($url, $map, $propertiesmap = array()) {
+    global $CFG;
+    require_once($CFG->libdir. "/filelib.php");
+    $curl = new curl();
+    $response = $curl->get($url);
+    $document = new DOMDocument();
+    $document->loadXML($response);
+    $cartridge = new DomXpath($document);
+    $errors = libxml_get_errors();
+    foreach ($errors as $error) {
+        print_error(sprintf("%s at line %d. ", trim($error->message, "\n\r\t ."), $error->line));
+    }
+
+    $toolinfo = array();
+    foreach ($map as $tag => $key) {
+        $value = get_tag($tag, $cartridge);
+        if ($value) {
+            $toolinfo[$key] = $value;
+        }
+    }
+    if (!empty($propertiesmap)) {
+        foreach ($propertiesmap as $property => $key) {
+            $value = get_tag("property", $cartridge, $property);
+            error_log("\n\nProperty is: " . $value . "\n\n");
+            if ($value) {
+                $toolinfo[$key] = $value;
+            }
+        }
+    }
+    return $toolinfo;
+}
+
+/**
+ * Search for a tag within an XML DOMDocument
+ *
+ * @param  stdClass $tagName The name of the tag to search for
+ * @param  XPath    $xpath   The XML to find the tag in
+ * @since Moodle 3.1
+ */
+function get_tag($tagname, $xpath, $attribute = null) {
+    if ($attribute) {
+        $result = $xpath->query('//*[local-name() = \'' . $tagname . '\'][@name="' . $attribute . '"]');
+    } else {
+        $result = $xpath->query('//*[local-name() = \'' . $tagname . '\']');
+    }
+    if ($result->length > 0) {
+        return $result->item(0)->nodeValue;
+    }
+    return null;
+}