[英]Angular: Return data only once several promises are fulfilled
我想從Service函數返回數據,並通過routeProvider將其注入到控制器中,但是只有在數據完全加載后才可以。
app.js:
.when('/sources', {
templateUrl: 'views/app/source/inventory.html',
controller: 'InventoryCtrl',
pageTitle: 'Data Inventory',
resolve: {
orders: function (OrderService) {
return OrderService.getOrders();
},
sources: function (SourceService) {
return SourceService.getSources();
}
}
})
SourceService:
angular.module('wp.source')
.factory('SourceService', function ($http, $q) {
return {
getSources: function () {
var model = {
sources: []
};
var promises = [];
return $http.get('datasets/project.json')
.then(function (data) {
if(localStorage['files'] != null) {
var files = JSON.parse(localStorage['files']);
for (var i = 0; i < files.length; i++) {
model.sources.push(files[i]);
}
}
var sources = [];
for (var sourceId in data.data.sources) {
var source = data.data.sources[sourceId];
source.id = sourceId;
sources.push(source);
}
angular.forEach(sources, function (source) {
promises.push($http.get('datasets/' + source.filename).then(function (datasource, resolve) {
var metadata = datasource.data.metadata;
var source = {
name: metadata.name,
address: metadata.url,
frequency: metadata.refresh,
type: metadata.type,
tags: metadata.tags,
size: metadata.size,
active: source.active,
sourceID: source.id,
sourceFile: source.filename
};
return source;
}));
});
//var finalPromise = sources.reduce(function (promise, source, index, array) {
// return promise.then(function (a) {
// var query = $http.get('datasets/' + source.filename)
// .then(function (datasource) {
// var metadata = datasource.data.metadata;
// model.sources.push({
// name: metadata.name,
// address: metadata.url,
// frequency: metadata.refresh,
// type: metadata.type,
// tags: metadata.tags,
// size: metadata.size,
// active: source.active,
// sourceID: source.id,
// sourceFile: source.filename
// });
// });
// });
//}, $q.when([]));
//
//finalPromise.finally(function () {
// return model;
//})
$q.all(function () {
return model;
});
});
}
}
});
控制器:
angular.module('wp.source')
.controller('InventoryCtrl', function ($scope, orders, sources) {
$scope.orders = orders.data;
$scope.gridView = true;
$scope.rowView = false;
$scope.allSources = sources.sources;
$scope.shownSources = $scope.allSources;
...
當前,我遇到的問題是,在“模型”完全加載之前已注入值。 我試圖將子查詢打包成$ q.all的承諾,但我不知道從那里到底要去哪里
任何幫助,將不勝感激
您要使用$ q.defer()並返回延遲的Promise對象。 您的代碼將如下所示。
angular.module('wp.source')
.factory('SourceService', function ($http, $q) {
return {
getSources: function () {
var model = {
sources: []
};
var deffered = $q.defer();
var promises = [];
return $http.get('datasets/project.json')
.then(function (data) {
if(localStorage['files'] != null) {
var files = JSON.parse(localStorage['files']);
for (var i = 0; i < files.length; i++) {
model.sources.push(files[i]);
}
}
var sources = [];
for (var sourceId in data.data.sources) {
var source = data.data.sources[sourceId];
source.id = sourceId;
sources.push(source);
}
angular.forEach(sources, function (source) {
promises.push($http.get('datasets/' + source.filename).then(function (datasource, resolve) {
var metadata = datasource.data.metadata;
var source = {
name: metadata.name,
address: metadata.url,
frequency: metadata.refresh,
type: metadata.type,
tags: metadata.tags,
size: metadata.size,
active: source.active,
sourceID: source.id,
sourceFile: source.filename
};
return source;
}));
});
//var finalPromise = sources.reduce(function (promise, source, index, array) {
// return promise.then(function (a) {
// var query = $http.get('datasets/' + source.filename)
// .then(function (datasource) {
// var metadata = datasource.data.metadata;
// model.sources.push({
// name: metadata.name,
// address: metadata.url,
// frequency: metadata.refresh,
// type: metadata.type,
// tags: metadata.tags,
// size: metadata.size,
// active: source.active,
// sourceID: source.id,
// sourceFile: source.filename
// });
// });
// });
//}, $q.when([]));
//
//finalPromise.finally(function () {
// return model;
//})
$q.all(promises).then(function () {
deferred.resolve(model);
});
});
}
return deferred.promise();
}
});
編輯正如其他人提到的那樣,您需要將您的諾言數組傳遞給$ q.all,以使其正常工作。 同樣值得注意的是,$ q.all將返回一個數組,其中每個promise的結果按照它們在promise數組中的順序排列。
Angular的Docs中還有更多的$ q.defer和$ q.all。
您將需要將$q.all
與$q.all
數組一起使用,並從外部promise返回它:
angular.module('wp.source')
.factory('SourceService', function($http, $q) {
return {
getSources: function() {
var model = {
sources: []
};
return $http.get('datasets/project.json').then(function(data) {
if (localStorage['files'] != null) {
var files = JSON.parse(localStorage['files']);
for (var i = 0; i < files.length; i++) {
model.sources.push(files[i]);
}
}
var sources = [],
promises = [];
for (var sourceId in data.data.sources) {
var source = data.data.sources[sourceId];
source.id = sourceId;
sources.push(source);
}
var promises = sources.map(function(source) {
return $http.get('datasets/' + source.filename).then(function(datasource, resolve) {
var metadata = datasource.data.metadata;
model.sources.push({
name: metadata.name,
address: metadata.url,
frequency: metadata.refresh,
type: metadata.type,
tags: metadata.tags,
size: metadata.size,
active: source.active,
sourceID: source.id,
sourceFile: source.filename
});
});
});
return $q.all(promises).then(function() {
return model;
});
});
}
}
});
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.