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內primeData電話有四種查詢到後端的Web API服務之前完成：Q - 等待操作的DataContext調用接下來的操作
function primeData(forceRefresh) {
return (getLookups(forceRefresh) // this needs to complete before moving on
.then(success))
.then(model.initialize(datacontext)) // depends on getLookups
.then(getDatasetOne()) // depends on model.initialize
.then(getDataSetTwo()) // depends on model.initialize
.then(getNonDependantDataset); // doesn't depend on previous calls
function success(data) {
if (!initialized) {
datacontext.lookups = data.results[0];
initialized = true;
} else {
datacontext.lookups = {
teams: getLocal('Teams', 'id'),
// other lookup values here
};
}
// should I call model.initialize(datacontext) here??
}
}
查詢2和3（getDatasetOne（）和getDatasetTwo （））依賴於model.initialize - 這取決於第一個查詢（getLookups（））的結果。我想知道如何確保在getLookups成功完成之前不調用model.initialize - 並確保在模型初始化之前不調用getDatasetOne/Two。儘可能減少/簡化代碼以顯示完整圖片。顯然，我不明白Q.任何援助將不勝感激。
控制器：
'use strict';
app.controller('HomeController',
['$scope', 'breeze', 'datacontext', 'logger',
function HomeController($scope, breeze, datacontext, logger) {
function initialize(forceRefresh) {
datacontext.initialize(forceRefresh)
.then(getSucceeded)
.fail(queryFailed)
.fin(refreshView);
}
initialize();
$scope.refresh = refresh;
function refresh() {
initialize(true);
}
function getSucceeded() {
$scope.lookups = datacontext.lookups;
$scope.datasetOne = datacontext.datasetOne;
$scope.datasetTwo = datacontext.datasetTwo;
}
function refreshView() {
$scope.$apply();
}
function queryFailed(error) {
logger.error(error);
}
}]);
的DataContext：
app.factory('datacontext',
['breeze', 'Q', 'logger', 'model',
function (breeze, q, logger, model) {
var initialized;
var manager = configureBreezeManager();
var datacontext = {
initialize: initialize,
metadataStore: manager.metadataStore,
saveEntity: saveEntity
};
return datacontext;
//#region private members
function initialize(forceRefresh) {
if (!initialized || forceRefresh) {
return primeData(forceRefresh).then(function() {
logger.log("Running Initialize");
});
} else {
logger.log("Already Initialized");
return q();
}
}
function primeData(forceRefresh) {
return (getLookups(forceRefresh)
.then(success))
.then(model.initialize(datacontext))
.then(getDatasetOne())
.then(getDataSetTwo())
.then(getNonDependantDataset);
function success(data) {
if (!initialized) {
datacontext.lookups = data.results[0];
initialized = true;
} else {
datacontext.lookups = {
teams: getLocal('Teams', 'id'),
// other lookup values here
};
}
// should I call model.initialize(datacontext) here??
}
}
function getLookups(forceRefresh) {
var query = breeze.EntityQuery
.from('Lookups');
if (initialized && !forceRefresh) {
return true;
}
return manager.executeQuery(query);
}
function getDatasetOne() {
var query = breeze.EntityQuery
.from("EntityNameOne");
return manager.executeQuery(query).then(getSucceeded);
function getSucceeded(data) {
datacontext.datasetOne = model.process(data.results)
return q();
}
}
function getDatasetTwo() {
var query = breeze.EntityQuery
.from("EntityNameTwo");
return manager.executeQuery(query).then(getSucceeded);
function getSucceeded(data) {
datacontext.datasetTwo = model.process(data.results);
return q();
}
}
function getNonDependentDataset() {
var query = breeze.EntityQuery
.from('EntityNameThree');
return manager.executeQuery(query).then(success);
function success(data) {
datacontext.nonNependentDataset = data.results;
}
}
function saveEntity(masterEntity, message) {
// standard implementation
}
function getLocal(resource, ordering) {
var query = breeze.EntityQuery.from(resource)
.orderBy(ordering);
return manager.executeQueryLocally(query);
}
function configureBreezeManager() {
// standard implementation
}
}]);
MODEL：
app.factory('model', ['logger', function (logger) {
var datacontext;
extendDatasetOne();
extendDatasetTwo();
var model = {
initialize: initialize,
getDatasetOne: getDatasetOne,
getDatasetTwo: getDatasetTwo
};
return model;
function initialize(context) {
datacontext = context;
}
function getDatasetOne(input) {
var ret = [];
for (var i = 0; i < input.length; i++) {
var item = new TypeOne(input[i]);
ret.push(item);
}
return ret;
}
function getDatasetTwo(input) {
var ret = [];
for (var i = 0; i < input.length; i++) {
var item = new TypeTwo(input[i]);
ret.push(item);
}
return ret;
}
function TypeOne(item) {
var self = this;
for (var prop in item) {
if (item.hasOwnProperty(prop)) {
self[prop] = item[prop];
}
}
self.name = getNameForId(item.id);
}
function TypeTwo(item) {
var self = this;
for (var prop in item) {
if (item.hasOwnProperty(prop)) {
self[prop] = item[prop];
}
}
self.name = getNameForId(item.id);
}
function extendDatasetOne() {
// add properties to prototype
}
function extendDatasetOne() {
// add properties to prototype
}
function getNameForId(id) {
var set = datacontext.lookups.items;
for (var i = 0; i < set.length; i++) {
if (id == set[i].id) {
return set[i].name;
}
}
return null;
}
}]);