MDL-63694 core_block: New block class method for external content

New method added block_base::get_content_for_external().
It will return all the block contents rendered for external functions.
If your block is returning formatted content or provide files for download,
you should override this method to use the external_format_text,
external_format_string functions for formatting or
external_util::get_area_files for files.
See block_html as example.

blocks/moodleblock.class.php

@@ -272,6 +272,39 @@ public function get_content_for_output($output) {
         return $bc;
     }
 
+
+    /**
+     * Return an object containing all the block content to be returned by external functions.
+     *
+     * If your block is returning formatted content or provide files for download, you should override this method to use the
+     * external_format_text, external_format_string functions for formatting or external_util::get_area_files for files.
+     *
+     * @param  core_renderer $output the rendered used for output
+     * @return stdClass      object containing the block title, central content, footer and linked files (if any).
+     * @since  Moodle 3.6
+     */
+    public function get_content_for_external($output) {
+        $bc = new stdClass;
+        $bc->title = null;
+        $bc->content = null;
+        $bc->contentformat = FORMAT_HTML;
+        $bc->footer = null;
+        $bc->files = [];
+
+        if ($this->instance->visible) {
+            $bc->content = $this->formatted_contents($output);
+            if (!empty($this->content->footer)) {
+                $bc->footer = $this->content->footer;
+            }
+        }
+
+        if (!$this->hide_header()) {
+            $bc->title = $this->title;
+        }
+
+        return $bc;
+    }
+
     /**
      * Convert the contents of the block to HTML.
      *

blocks/upgrade.txt

@@ -5,6 +5,10 @@ information provided here is intended especially for developers.
 
 * The timeline view from block_myoverview has been split out into block_timeline.
 * External function core_blocks::get_course_blocks now returns the block visible status and weight for ordering.
+* New method added block_base::get_content_for_external(). It will return all the block contents rendered for external functions.
+  If your block is returning formatted content or provide files for download, you should override this method to use the
+  external_format_text, external_format_string functions for formatting or external_util::get_area_files for files.
+  See block_html as example.
 
 === 3.4 ===