Let export continue when a missing file is found (bug #749863)

If a missing file is found during export, instead of failing, just skip
the artefact and continue, displaying a message when the export file is
served.

Change-Id: I37d3410e7e8fb9acf4bf07d8bc901f2c6dc8fc0f
Signed-off-by: Richard Mansfield <richard.mansfield@catalyst.net.nz>

htdocs/export/download.php

@@ -114,4 +114,4 @@ $SESSION->set('exportfile', $exporter->get('exportdir') . $zipfile);
 $wwwroot = get_config('wwwroot');
 $strexportgeneratedsuccessfullyjs = get_string('exportgeneratedsuccessfullyjs', 'export', '<a href="' . $wwwroot . 'export/" target="_top">', '</a>');
 $strexportgeneratedsuccessfully   = get_string('exportgeneratedsuccessfully', 'export', '<a href="download.php" target="_top">', '</a>');
-print_export_footer($strexportgeneratedsuccessfully, $strexportgeneratedsuccessfullyjs);
+print_export_footer($strexportgeneratedsuccessfully, $strexportgeneratedsuccessfullyjs, $exporter->get('messages'));

htdocs/export/leap/lib.php

@@ -526,9 +526,17 @@ class PluginExportLeap extends PluginExport {
                 if (!$element->is_leap()) {
                     continue;
                 }
-                $element->add_attachments();
-                $element->assign_smarty_vars();
-                $this->xml .= $element->get_export_xml();
+                try {
+                    $element->add_attachments();
+                    $element->assign_smarty_vars();
+                    $this->xml .= $element->get_export_xml();
+                }
+                catch (FileNotFoundException $e) {
+                    // If we don't find a file on disk, just continue the export,
+                    // but leave this artefact out.
+                    $this->messages[] = $e->getMessage();
+                    log_debug('Missing file in leap2a export for artefact ' . $artefact->get('id'));
+                }
             }
         }
     }
@@ -564,7 +572,7 @@ class PluginExportLeap extends PluginExport {
     */
     public function add_attachment($filepath, $newname) {
         if (!file_exists($filepath) || empty($newname)) {
-            throw new ParamOutOfRangeException(get_string('nonexistentfile', 'export', $newname));
+            throw new FileNotFoundException(get_string('nonexistentfile', 'export', $newname));
         }
         $newname = substr(str_replace('/', '_', $newname), 0, 245);
         $this->attachments[] = (object)array('file' => $filepath, 'name' => $newname);

htdocs/export/lib.php

@@ -293,6 +293,8 @@ abstract class PluginExport extends Plugin {
             throw new SystemException("Couldn't create the temporary export directory $this->exportdir");
         }
 
+        $this->messages = array();
+
         $this->notify_progress_callback(10, 'Setup');
     }
 

htdocs/lib/errors.php

@@ -869,6 +869,11 @@ class UploadException extends UserException {}
  */
 class CollectionNotFoundException extends NotFoundException {}
 
+/**
+ * Exception - file not found in dataroot
+ */
+class FileNotFoundException extends NotFoundException {}
+
 /**
  * Exception - Access denied. Throw this if a user is trying to view something they can't
  */

htdocs/lib/htmloutput.php

@@ -63,7 +63,7 @@ function print_iframe_progress_handler($percent, $status) {
     echo '<p class="progress-text">' . hsc($status) . "</p>\n";
 }
 
-function print_export_footer($strexportgeneratedsuccessfully, $strexportgeneratedsuccessfullyjs) {
+function print_export_footer($strexportgeneratedsuccessfully, $strexportgeneratedsuccessfullyjs, $jsmessages=array()) {
 ?>
         <script type="text/javascript">
             document.write('<div class="progress-bar" style="width: 100%;"><p><?php echo $strexportgeneratedsuccessfullyjs; ?></p></div>');
@@ -72,6 +72,10 @@ function print_export_footer($strexportgeneratedsuccessfully, $strexportgenerate
                 // download inline in the iframe
                 document.location = 'download.php';
             }
+            var messages = <?php echo json_encode(join('; ', $jsmessages)); ?>;
+            if (messages) {
+                parent.displayMessage(messages);
+            }
         </script>
         <div class="progress-bar" style="width: 100%;">
             <p><?php echo $strexportgeneratedsuccessfully; ?></p>