/** * @ngdoc object * @name ui.router.util.$resolve * * @requires $q * @requires $injector * * @description * Manages resolution of (acyclic) graphs of promises. */ $Resolve.$inject = ['$q', '$injector']; function $Resolve( $q, $injector) { var VISIT_IN_PROGRESS = 1, VISIT_DONE = 2, NOTHING = {}, NO_DEPENDENCIES = [], NO_LOCALS = NOTHING, NO_PARENT = extend($q.when(NOTHING), { $$promises: NOTHING, $$values: NOTHING }); /** * @ngdoc function * @name ui.router.util.$resolve#study * @methodOf ui.router.util.$resolve * * @description * Studies a set of invocables that are likely to be used multiple times. *
* $resolve.study(invocables)(locals, parent, self) ** is equivalent to *
* $resolve.resolve(invocables, locals, parent, self) ** but the former is more efficient (in fact `resolve` just calls `study` * internally). * * @param {object} invocables Invocable objects * @return {function} a function to pass in locals, parent and self */ this.study = function (invocables) { if (!isObject(invocables)) throw new Error("'invocables' must be an object"); var invocableKeys = objectKeys(invocables || {}); // Perform a topological sort of invocables to build an ordered plan var plan = [], cycle = [], visited = {}; function visit(value, key) { if (visited[key] === VISIT_DONE) return; cycle.push(key); if (visited[key] === VISIT_IN_PROGRESS) { cycle.splice(0, indexOf(cycle, key)); throw new Error("Cyclic dependency: " + cycle.join(" -> ")); } visited[key] = VISIT_IN_PROGRESS; if (isString(value)) { plan.push(key, [ function() { return $injector.get(value); }], NO_DEPENDENCIES); } else { var params = $injector.annotate(value); forEach(params, function (param) { if (param !== key && invocables.hasOwnProperty(param)) visit(invocables[param], param); }); plan.push(key, value, params); } cycle.pop(); visited[key] = VISIT_DONE; } forEach(invocables, visit); invocables = cycle = visited = null; // plan is all that's required function isResolve(value) { return isObject(value) && value.then && value.$$promises; } return function (locals, parent, self) { if (isResolve(locals) && self === undefined) { self = parent; parent = locals; locals = null; } if (!locals) locals = NO_LOCALS; else if (!isObject(locals)) { throw new Error("'locals' must be an object"); } if (!parent) parent = NO_PARENT; else if (!isResolve(parent)) { throw new Error("'parent' must be a promise returned by $resolve.resolve()"); } // To complete the overall resolution, we have to wait for the parent // promise and for the promise for each invokable in our plan. var resolution = $q.defer(), result = silenceUncaughtInPromise(resolution.promise), promises = result.$$promises = {}, values = extend({}, locals), wait = 1 + plan.length/3, merged = false; silenceUncaughtInPromise(result); function done() { // Merge parent values we haven't got yet and publish our own $$values if (!--wait) { if (!merged) merge(values, parent.$$values); result.$$values = values; result.$$promises = result.$$promises || true; // keep for isResolve() delete result.$$inheritedValues; resolution.resolve(values); } } function fail(reason) { result.$$failure = reason; resolution.reject(reason); } // Short-circuit if parent has already failed if (isDefined(parent.$$failure)) { fail(parent.$$failure); return result; } if (parent.$$inheritedValues) { merge(values, omit(parent.$$inheritedValues, invocableKeys)); } // Merge parent values if the parent has already resolved, or merge // parent promises and wait if the parent resolve is still in progress. extend(promises, parent.$$promises); if (parent.$$values) { merged = merge(values, omit(parent.$$values, invocableKeys)); result.$$inheritedValues = omit(parent.$$values, invocableKeys); done(); } else { if (parent.$$inheritedValues) { result.$$inheritedValues = omit(parent.$$inheritedValues, invocableKeys); } parent.then(done, fail); } // Process each invocable in the plan, but ignore any where a local of the same name exists. for (var i=0, ii=plan.length; i