Binding data on a model for dynamic nested forms i

问题:

I'm generating nested form from a json object say formObject and binding the values in the json object itself. I'm parsing the values recursively and pulling out the actual data say dataObject at submit.

I can retrieve the dataObject in a linear form like this one. http://jsfiddle.net/DrQ77/80/.

<select ng-model="Answers[question.Name]" ng-options="option for option in question.Options">

In contrast to the above, http://jsfiddle.net/DrQ77/92/ has some recursion. I've renamed question to element for it to represent both questions & sections. Every section can have multiple questions & again, multiple sections (this is what I meant by nesting). What I want eventually is an object in a form below with any level of nesting.

Answers=[{
    section:"Personal",
    values:[{GenderQuestion:"Male"},{MaritalStatus:"Married"},{section:"Sub Personal",values:[{LivingWith:"Alone"}]}]
}, {
    section:"Random",
    values:[{ColorQuestion:"Red"}],
},
{SectionLess:"opt1"}]

This is one solution & I can get it on submit, $scope.Answers from the first fiddle does not (I think) allow that kind of nesting. But when I have to update an existing dataObject, I felt a need to map the dataObjects onto the formObject before rendering it, and then parsing again on submit. Now this isn't MVC, doesn't look elegant (due to the recursion) & I think there's an 'angular way' for this.

Has anybody tried this & got it working in a better fashion? How do I get around it?

回答1:

Not very pretty, but this is an alternative to the solution you've already proposed.

http://jsfiddle.net/DrQ77/84/

function QuestionController($scope) {
    $scope.answers = {};
    $scope.tempOption = "";
    $scope.questions = [
    {
        "text": "Gender?",
        "name": "GenderQuestion",
        "options": ["Male", "Female"]},
    {
        "text": "Favorite color?",
        "name": "ColorQuestion",
        "options": ["Red", "Blue", "Green"]}
    ];

    $scope.showAnswers = function () {
      console.log($scope.answers);
    };

    $scope.pumpOption = function (name, tempOption) {
      $scope.answers[name] = tempOption;
    };
};

<ul ng-repeat="question in questions">
    <li>
        <div>{{question.text}}</div>
        <select ng-model="tempOption" ng-options="opt for opt in question.options" ng-change="pumpOption(question.name, tempOption)">
        </select>
    </li>
</ul>    

We bind the value of the selected option in the select tag to a $scope.tempOption variable.

We then listen for the ng-change event to occur on this select tag, where we run a function that takes the $scope.tempOption variable plus the {{question.name}} associated with the select tag.

This function then sets answers[name] to the current value of $scope.tempOption.

Hope this works out for you, good luck :)

回答2:

var model = {
    colors:["Red","Blue","Green","Black","White"],
    genders:["Male", "Female"],
    topic:["Gender", "Color"],
    category:["Favorite", "Least favorite"],
};

function makeQuestion(topic, category){
    return (category+1 ? model.category[category] + ' ' : '') 
    + ' ' + model.topic[topic] + '?'
}

function QuestionController($scope){

    $scope.Answers = {};
    $scope.Questions = [
        {
            "Text": makeQuestion(0),
            "Name": "GenderQuestion",
            "Options": model.genders 
        },{
            "Text": makeQuestion(1,0),
            "Name": "ColorQuestion",
            "Options": model.colors.slice(0,3)
        },{
            "Text": makeQuestion(0,1),
            "Name": "SexistQuestion",
            "Options": model.genders
        },{
            "Text": makeQuestion(1,1),
            "Name": "RacistQuestion",
            "Options":model.colors.slice(3)
        }
    ];

    $scope.ShowAnswers = function()
    {
        console.log($scope.Answers);
    };
}    

Ok, i was kidding around. But have you tried using a flat related object relational table approach instead of nested?

{
  sections:[
    { "Name": 'Personal', "questions":[0], sub:[1] },
    { "Name": 'SubPersonal', "questions":[3], sub:[]},
    { "Name": 'Random',   "questions":[1,2], sub:[] }
  ],
  questions:[
    { "Name":"Gender",     "Text":"Gender?",         "Options":["Male", "Female"] },
    { "Name":"Color",      "Text":"Favorite Color?", "Options":["Red","Blue","Green"] },
    { "Name":"LivingWith", "Text":"Living With?",    "Options":["Alone","Someone"] },
    { "Name":"Random",     "Text":"SectionLess",     "Options":["opt1", "opt2"] }
  ]
}

回答3:

simply create $scope.Answer = {}; and link ng-model to it. http://jsfiddle.net/2AwLM/40/

回答4:

Ok - this wasn't as trivial as I first thought, so I hope it's what you're after - you'll want to use a directive that dynamically generates its template HTML (better yet, use templateUrl and a function which passes in type)

TLDR: See the fiddle at http://jsfiddle.net/cirrusinno/SzaNW/2

The HTML is quite simple

<div ng-controller="questionsController">

<!-- for each question, render section or question -->
<div ng-repeat="item in Questions">
    <!-- we ignore section here as it's a root section -->
    <question item="item"></question>
</div>

You'll need to create a directive that can render both questions & sections. It will also need to keep track of the section so it can build the answers

.directive('question', ['$compile', '$templateCache', function ($compile, $templateCache) {
    var generateHtmlTemplate = function (item, section) {
        return item.type != 'section' ?
        // render the question    
        'question ' + item.name + '<br/>' +
            '<select ng-model="optionValue" ng-options="opt for opt in item.options" ng-change="pushAnswer(item.name, section, optionValue)"></select>' :
        // or the template for a section
        '<br/><hr/>section ' + item.sectionName + '<br/>' +
            '<div ng-repeat="q in item.questions"><question item="q" section="item"></question></div><hr/>';
    }

    var currentSection = null;

    return {
        scope: {
            item: '=',
            section: '='
        },
        restrict: 'E',
        link: function ($scope, element, attrs) {
            // check current section
            if ($scope.item.type == 'section') {
                // set new current section
                $scope.currentSection = $scope.item;
            } else {
                // use section passed in from parent section
                $scope.currentSection = $scope.section;
            }

            // get template html
            var t = generateHtmlTemplate($scope.item, $scope.currentSection);

            // set the scope function to set the value
            $scope.pushAnswer = function (q, section, value) {
                // build the Answers object here however you want...
                if (section != null) {
                    console.log('pushAnswer q=' + q.name + ' - section=' + section.sectionName + ' - value=' + value);
                } else {
                    console.log('pushAnswer q=' + q.name + ' - section=rootSection - value=' + value);
                }

            };

            // chuck it into element as template
            element.html(t);

            // compile it up and return it
            $compile(element.contents())($scope);
        },
    };
}])