AbstractRendererEngine::getResourceHierarchyLevel()

Returns the hierarchy level at which a resource can be found.

A block hierarchy is an array which starts with the root of the hierarchy and continues with the child of that root, the child of that child etc. The following is an example for a block hierarchy:

formwidget textwidget url_widget

The second parameter $hierarchyLevel determines the level of the hierarchy that should be rendered.

If we call this method with the hierarchy level 2, the engine will first look for a resource for block "urlwidget". If such a resource exists, the method returns 2. Otherwise it tries to find a resource for block "textwidget" (at level 1) and, again, returns 1 if a resource was found. The method continues to look for resources until the root level was reached and nothing was found. In this case false is returned.

The type of the resource is decided by the implementation. The resource is later passed to {@link renderBlock()} by the rendering algorithm.