Get and update json using angular.js

Question

I am very new to angular.js and am having some trouble with a seemingly simple task.

I need to get the json below from a json file on a website, then place the keys (english, spanish, etc.) inside label tags in my html file, then load their corresponding values (0, 1, 3, 2, 1) into html range inputs.

The json file contains:

[{"english":0,"spanish":1,"german":3,"russian":2,"korean":1}]

The html produced after loading the json should look like:

<form>
    <label>English</label>
    <input type="range" min="0" max="4" value="ENGLISH_VALUE_RETRIEVED_FROM_JSON_FILE" >
    <label>Spanish</label>
    <input type="range" min="0" max="4" value="SPANISH_VALUE_RETRIEVED_FROM_JSON_FILE" >
    <label>German</label>
    <input type="range" min="0" max="4" value="GERMAN_VALUE_RETRIEVED_FROM_JSON_FILE" >
    <label>Russian</label>
    <input type="range" min="0" max="4" value="RUSSIAN_VALUE_RETRIEVED_FROM_JSON_FILE" >
    <label>Korean</label>
    <input type="range" min="0" max="4" value="KOREAN_VALUE_RETRIEVED_FROM_JSON_FILE" >
    <input type="submit" text="Save">
</form>

Finally I want to hit Save on the form and have the values for the corresponding keys updated on the json file online.

What are all the files necessary (using MVC) to build this example? If your answer involves any code, can you please explicitly say which file to add the code to?

Thanks in advance!

Answer 1

Here's something to get you started. I changed your json to something that I believe is more appropriate, but you can change it back for your purposes if you wish. If you do use your json, you'll have a problem with ng-repeat finding duplicate values and you'll need to use track by $index to fix it. See this post (click) .

Live demo here (click).

var app = angular.module('myApp', []);

/* $http ajax calls really belongs in a service, 
but I'll be using them inside the controller for this demo */ 

app.controller('myCtrl', function($scope, $http) {
  /*$http.get('path/to/json').then(function(data) {
    $scope.languages = data;
  });*/
  //inputting json directly for this example
  $scope.languages = [        
    {name:"English", value:0},
    {name:"Spanish", value:1},
    {name:"German", value:3},
    {name:"Russian", value:2},
    {name:"Korean", value:1}
  ];
  $scope.save = function() {
    /*$http.post('path/to/server/file/to/save/json', $scope.languages).then(function(data) {
      $scope.msg = 'Data saved';
    });*/
    $scope.msg = 'Data sent: '+ JSON.stringify($scope.languages);
  };
});

You'll want to read the information in this post (click) if you want to avoid wrapping your markup in an extra div.

<form>
    <div ng-repeat="lang in languages">
      <label>{{lang.name}}</label>
      <input type="range" min="0" max="4" ng-model="lang.value" >
    </div>
    <button ng-click="save()">Save</button>
    <p>{{msg}}</p>
</form>

Answer 2

You can not use $http.post in angular to save. Client side code can not and should not save to the server. You can imagine how DANGEROUS this would be.

Instead... you can setup a NodeJS/Express (or whatever) to accept the JSON data in an $http.post. Then you can write the data to a file using a server-side platform. However, I would recommend not saving data to a .json file on the server. I make my .json files read-only and mainly used to populate static variables. You should look into storing these types of documents in a document store like CouchDB or MongoDB.

Answer 3

您无法修改服务器上的文件， $http.post无法正常工作。