Backbone Webdav Adapter MKCOL support

Usually Backbone collections cannot be created and just simply exists.
But in the Webdav world they need to be creatable.

This enhancement makes it possible to use a Backbone Model to represent
such collections and when creating it, it will use MKCOL instead of PUT.

Signed-off-by: Morris Jobke <hey@morrisjobke.de>

core/js/oc-backbone-webdav.js

@@ -120,7 +120,15 @@
 		}
 
 		var parts = url.split('/');
-		return parts[parts.length - 1];
+		var result;
+		do {
+			result = parts[parts.length - 1];
+			parts.pop();
+			// note: first result can be empty when there is a trailing slash,
+			// so we take the part before that
+		} while (!result && parts.length > 0);
+
+		return result;
 	}
 
 	function isSuccessStatus(status) {
@@ -190,6 +198,25 @@
 
 	}
 
+	function callMkCol(client, options, model, headers) {
+		// call MKCOL without data, followed by PROPPATCH
+		return client.request(
+			options.type,
+			options.url,
+			headers,
+			null
+		).then(function(result) {
+			if (!isSuccessStatus(result.status)) {
+				if (_.isFunction(options.error)) {
+					options.error(result);
+				}
+				return;
+			}
+
+			callPropPatch(client, options, model, headers);
+		});
+	}
+
 	function callMethod(client, options, model, headers) {
 		headers['Content-Type'] = 'application/json';
 		return client.request(
@@ -206,7 +233,7 @@
 			}
 
 			if (_.isFunction(options.success)) {
-				if (options.type === 'PUT' || options.type === 'POST') {
+				if (options.type === 'PUT' || options.type === 'POST' || options.type === 'MKCOL') {
 					// pass the object's own values because the server
 					// does not return anything
 					var responseJson = result.body || model.toJSON();
@@ -247,6 +274,8 @@
 			return callPropFind(client, options, model, headers);
 		} else if (options.type === 'PROPPATCH') {
 			return callPropPatch(client, options, model, headers);
+		} else if (options.type === 'MKCOL') {
+			return callMkCol(client, options, model, headers);
 		} else {
 			return callMethod(client, options, model, headers);
 		}
@@ -259,9 +288,16 @@
 		var params = {type: methodMap[method] || method};
 		var isCollection = (model instanceof Backbone.Collection);
 
-		if (method === 'update' && (model.usePUT || (model.collection && model.collection.usePUT))) {
-			// use PUT instead of PROPPATCH
-			params.type = 'PUT';
+		if (method === 'update') {
+			// if a model has an inner collection, it must define an
+			// attribute "hasInnerCollection" that evaluates to true
+			if (model.hasInnerCollection) {
+				// if the model itself is a Webdav collection, use MKCOL
+				params.type = 'MKCOL';
+			} else if (model.usePUT || (model.collection && model.collection.usePUT)) {
+				// use PUT instead of PROPPATCH
+				params.type = 'PUT';
+			}
 		}
 
 		// Ensure that we have a URL.