当我在工厂中调用方法(database.readOnlyStock())时，我不断收到错误 - TypeError:无法调用未定义的方法“then”。另外，我发现有点尴尬的是，该函数确实相应地运行，因为我看到了 console.log 消息。
这是工厂代码:
stocks.factory('database', ['$resource', '$http', '$q', function($resource, $http, $q) {
var dataMethods = {
createConnection: function() {
/*moved to onload below */
},
addStock: function(stock, nameofcompany) {
var _this = this;
console.log("About to add stock");
//Get a transaction
//default for OS list is all, default for type is read
var transaction = this.db.transaction(["portfolio"],"readwrite");
//Ask for the objectStore
var store = transaction.objectStore("portfolio");
//Define a person
var stockTemplate = {
company_name: nameofcompany,
name:stock,
created:new Date()
}
//Perform the add
var request = store.add(stockTemplate);
request.onerror = function(e) {
console.log("failed to add stock to portflio",e.target.error.name);
//some type of error handler
}
request.onsuccess = function(e) {
console.log("successfully added stock to portfolio");
//console.log(store);
//_this.readOnlyStock();
}
},
readOnlyStock: function() {
var deferred = $q.defer();
var transaction = this.db.transaction(["portfolio"],"readonly");
var store = transaction.objectStore("portfolio");
// var cursorRequest = store.openCursor();
var arrayOfStocks = [];
var keyRange = IDBKeyRange.lowerBound(0);
var cursorRequest = store.openCursor(keyRange);
cursorRequest.onsuccess = function(e) {
var cursor = e.target.result;
if(cursor){
arrayOfStocks.push(cursor.value);
cursor.continue();
}
else{
console.log(arrayOfStocks);
console.log('done!');
deferred.resolve(arrayOfStocks);
return deferred.promise;
//return arrayOfStocks;
}
}
cursorRequest.onerror = function(){
console.log('could not fetch data');
}
},
deleteStock: function() {}
}
//return dataMethods;
if (window.indexedDB) {
console.log('indexeddb is supported');
var openRequest = indexedDB.open("users_stocks", 4);
openRequest.onupgradeneeded = function(e) {
var thisDB = e.target.result;
if (!thisDB.objectStoreNames.contains("portfolio")) {
console.log('created object store');
thisDB.createObjectStore("portfolio", {
autoIncrement: true
});
}
}
openRequest.onsuccess = function(e) {
console.log('connection opened');
dataMethods.db = e.target.result
}
openRequest.onerror = function(e) {
console.log('could not open connection');
}
return dataMethods;
}
else {
console.log('indexedDB not supported');
}
}]);
然后这是我的 Controller 代码:
stocks.controller('portfolio', ['$scope', '$http', 'stockData', 'database', function portfolio($scope, $http, stockData, database) {
$scope.getAllStocks = function(){
console.log('running getll stocks');
database.readOnlyStock().then(function(result) {
console.log('done');
$scope.allstuff = result;
}, function(){
console.log('no');
});
}
}]);
不确定问题出在哪里。
最佳答案
您需要从 readOnluStock 方法返回 promise ，而不是从其中的成功处理程序返回
readOnlyStock: function () {
var deferred = $q.defer();
var transaction = this.db.transaction(["portfolio"], "readonly");
var store = transaction.objectStore("portfolio");
// var cursorRequest = store.openCursor();
var arrayOfStocks = [];
var keyRange = IDBKeyRange.lowerBound(0);
var cursorRequest = store.openCursor(keyRange);
cursorRequest.onsuccess = function (e) {
var cursor = e.target.result;
if (cursor) {
arrayOfStocks.push(cursor.value);
cursor.
continue ();
} else {
console.log(arrayOfStocks);
console.log('done!');
deferred.resolve(arrayOfStocks);
//return arrayOfStocks;
}
}
cursorRequest.onerror = function () {
console.log('could not fetch data');
}
// the return should be here
return deferred.promise;
},
关于javascript - 获取类型错误 : Cannot call method 'then' of undefined in angularjs controller，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/19781505/