我有一个递归函数检查每半秒左右的一些数据.该函数返回一个promise.一旦找到数据,我想解决承诺并将数据作为分辨率传递.问题是,承诺不会在函数外部调用.then().这是小提琴：
http://jsfiddle.net/btyg1u0g/1/.
这是小提琴代码：
服务：
myApp.factory('myService',function($q,$timeout) {
var checkStartTime = false;
var checkTimeout = 30000;
function checkForContent() {
var deferred = $q.defer();
// simulating an $http request here
$timeout(function () {
console.log("Checking...");
if (!checkStartTime) checkStartTime = new Date();
// this would normally be 'if (data)'
if ((new Date()) - checkStartTime > 3000) {
deferred.resolve("Finished check");
checkStartTime = false; // reset the timeout start time
} else {
// if we didn't find data,wait a bit and check again
$timeout(function () {
checkForContent();
},400);
}
},5);
// then is called in here when we find data
deferred.promise.then(function(message) {
console.log("Resolved inside checkForContent");
});
return deferred.promise;
}
return {
runCheck: function() {
return checkForContent()
}
}
});
控制器：
myApp.controller('MyCtrl',function ($scope,myService) {
$scope.name = 'Superhero';
// then is never called
myService.runCheck()
.then(function (message) {
console.log("Resolved outside checkForContent");
});
});
解决方法
查看
this fiddle.
out $$timeout命名为可以从内部调用.
$timeout(function inner() {
// ...
然后像这样递归调用它：
$timeout(function () {
inner();
},400);
