Data Manager customization: preFetchRecordsForGridListing

The preFetchRecordsForGridListing customization can be used to modify the arguments sent to getRecordsForGridListing() method. The args struct sent to the customization action represents the arguments to be sent to getRecordsForGridListing(). No return value is expected.

A common example might be to add an extra filter to the the query. For example:

// /application/handlers/admin/datamanager/blog_post.cfc
component {

	private void function preFetchRecordsForGridListing( event, rc, prc, args={} ) {
		var category = rc.category ?: "";

		if ( !IsEmpty( category ) ) {
			args.extraFilters = args.extraFilters ?: [];
			
			args.extraFilters.append( { filter={ category=category } } );		
		}

	}

}

Note, that this example would rely on rc.category somehow being present in the ajax request that fetches the record set. One method of achieving this would be to make use of Data Manager customization: getAdditionalQueryStringForBuildAjaxListingLink. For example:

// /application/handlers/admin/datamanager/blog_post.cfc
component {

	// this is run when building the ajax link, i.e. in the main
	// request for the listing page
	private string function getAdditionalQueryStringForBuildAjaxListingLink( event, rc, prc, args={} ) {
		// category here could have been placed in the URL
		// by a category drop down button, for example
		
		var category = rc.category ?: "";

		return "category=#category#";
	}


	// this is run during the ajax fetch of records
	private void function preFetchRecordsForGridListing( event, rc, prc, args={} ) {
		var category = rc.category ?: "";

		if ( !IsEmpty( category ) ) {
			args.extraFilters = args.extraFilters ?: [];
			
			args.extraFilters.append( { filter={ category=category } } );		
		}

	}

}