AngularJS 验证和承诺 [英] AngularJS validation and promises

问题描述

在 Angular 应用中，表单在提交之前通过自定义 JS 函数进行验证.根据条件，我需要向用户显示一个确认对话框，等待确认或拒绝，然后进行验证.我在异步实现这一点时遇到了困难.我相信我没有正确使用承诺，但不确定需要更新什么.

In an Angular app, form is validated via custom JS function before submitting. Based on a condition, I need to show a confirmation dialog to the user, wait for confirmation or rejection, then proceed with validation. I'm having difficulties with achieving this asynchronously. I believe I am not using the promise correctly, but not sure what needs to be updated.

工厂

app.factory("confirmDialogService", ['$q', 'ngDialog',
  function ($q, ngDialog ) {
  return {
    popConfirm: function () {
        var deferred = $q.defer();
        var confirmed;
        setTimeout(function () {
                ngDialog.openConfirm({
                    template: 'template/confirmDialog.html',
                    className: 'ngdialog-theme-default'
                }).then(function (value) {
                    console.log('Modal promise resolved. Value: ', value);
                    deferred.resolve(confirmed =  true);
                }, function (reason) {
                    console.log('Modal promise rejected. Reason: ', reason);
                    deferred.reject(confirmed =  false);
                });
        }, 1000);
        return deferred.promise;
      }
  };
}]);

控制器

  $scope.checkSomething = function (){
    if(needsConfirmation)
    {
        console.log('about to pop confirm');
        confirmationService.popConfirm().then(function(confirmed){
            console.log( 'from popConfirm() ' + confirmed + ''); // never logged
            return confirmed;
        }, function(){
        // something went wrong
            return false;
        });
    }
    else
        return true;
}

显示确认对话框，但在对话框中单击是或否不会产生预期的结果.

The confirmation dialog is shown, but clicking yes or no in the dialog does not produce results as expected.

我希望能够做的是根据用户是确认还是关闭对话框来获得真/假值，沿着

What I'd like to be able to do is get a true/false value depending whether a user confirmed or dismissed the dialog, along the lines of

var canProceed = $scope.checkSomething();

我想我需要把它包装成另一个承诺，但不确定如何.任何帮助将不胜感激.

I think I need to wrap this into another promise but not sure how. Any help will be greatly appreciated.

谢谢，

推荐答案

既然 openConfirm 已经返回了一个 Promise，你不需要再用 $q.defer() 创建一个:

Since openConfirm already returns a Promise, you don't need to create one more with $q.defer():

app.factory("confirmDialogService", ['$q', 'ngDialog', function ($q, ngDialog) {
    return {
        popConfirm: function () {
            return ngDialog.openConfirm({
                template: 'template/confirmDialog.html',
                className: 'ngdialog-theme-default'
            }).then(function (value) {
                console.log('Modal promise resolved. Value: ', value);
                return true;
            }, function (reason) {
                console.log('Modal promise rejected. Reason: ', reason);
                return false;
            });
        }
    };
}]);

之后 checkSomething 会这样使用它:

After that checkSomething would use it this way:

$scope.checkSomething = function () {
    if (needsConfirmation) {
        return confirmationService.popConfirm().then(function (confirmed) {
            return confirmed;
        }, function () {
            return false;
        });
    } else {
        return $q.when(true);
    }
}

注意它如何不再返回 true 或 false，而是返回一个 promise 对象.最后，你应该使用 $scope.checkSomething() 像异步操作和 promise 一样:

Note how it no longer returns true or false, but rather a promise object. Finally you should use $scope.checkSomething() like asynchronous operation with promises:

$scope.checkSomething().then(function() {
    // ok, proceed
}, function() {
    // something failed
});

总而言之，最重要的是要理解 checkSomething 应该返回一个 promise 而不仅仅是 true/false.

Summarizing, the most important thing to understand it that checkSomething should return a promise and not just true/false.

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