How do I require multiple input fields in AngularJS? - javascript

I'm trying to write a simple page with a couple of inputs which should be required to not be empty.
Here's the code to do that (self-contained):
<!DOCTYPE html>
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<script>
var app = angular.module("myApp", []);
app.controller('myController', ['$scope', function($scope) {
}]);
</script>
<style>
input.ng-invalid {
background-color: pink;
}
input.ng-valid {
background-color: lightgreen;
}
</style>
</head>
<body ng-app="myApp">
<div ng-controller="myController">
Description: *<input type="text" id="input-description" ng-model="req-text" required></input><br/>
Order: *<input type="number" id="input-order" ng-model="req-number" value="100" step="100" required></input><br/>
</div>
</body>
</html>
What I was hoping it would do is start with the text field being blank and red (invalid), and the number field being 100 and green (valid).
The first thing I tried was setting both ng-models for the inputs to the same thing, but that caused the number field to update the text field when it was updated (but not the other way around).
Since that obviously didn't work, I tried using different models for the inputs, as shown in my code. However, now both inputs have a value of 0 (even the text field, which should still be blank), and both inputs cannot be typed into or otherwise edited.
What am I doing wrong, and how do I just get both inputs to be required separately by Angular?

What you're doing wrong first of all is using illegal identifiers for models. req-number is not a valid identifier for a variable. (remember all of these models are actually refered as $scope.variableName, imagine $scope.req-number). Hence your inputs are made readonly. You can actually see that when you examine console of your browser.
Second, html attribute value is ignored for input in this case. Use controller function to set default values for your models.
app.controller('myController', ['$scope', function($scope) {
$scope.req_number = 100;
}]);
....
<div ng-controller="myController">
Description: *<input type="text" ng-model="req_text" REQUIRED><br/>
Order: *<input type="number" ng-model="req_number" required><br/>
</div>
Alternatively you can use ng-init to initiate the model. However as mentioned by #developer0333, this is not recommended because initialization logic is part of business logic and with project evolving can get more complicated then just setting primitive values.
<input type="number" ng-model="req_number" ng-init="req_number=100" required><br/>
Plunker with correct code
PS and a small remark, closing tags are ignored for <input>

Related

AngularJS passing data to Javascript variables and opposite

I am looking for a solution on passing data from a specific input text field to AngularJS. it may be a Javascript variable too. If the variable is changed from inside a javascript code it is not updating on AngularJS side. If i take the same variable and in the text field add at least one character or modify something i see variable updating and everything working as it should.
I tried something with angular.element(document.getElementById('ControllerElementID')).scope().funct(); but still no luck. When i update at least one field from the keyboard, all text fields that are related to "ng-model="sig.sigBase6422"" are updating properly as it should. If i call this updates through a JavaScript function i see updates only on specific text field and no updates at all on ng-model happening. How to make it updating as simple as possible? Below i will post a small example. I was able to store data from variable to a external file and in AngularJS read it from file and use it. this is way too long, complicated and ridiculous. I am sure there should be a better way.
Thank you!
<script type="text/javascript">
function addtext1() {document.getElementById("myID1").value = "1111111111111111";}
function addtext2() {document.getElementById("myID2").value = "2222222222222222";}
</script>
<div>
<form action="#" name="FORM1">
<TEXTAREA NAME="sigData" ng-model="sig.sigBase6422" ROWS="10" COLS="20">String: </TEXTAREA>
</form><br>
<input type="text" name="myID1" id="myID1" ng-model="sig.sigBase6422" ><br>
<input type="text" name="myID2" id="myID2" ng-model="sig.sigBase6422" ><br>
<p>Value {{sig.sigBase6422}}!</p>
</div>
<!-- test field -->
Add text 1
Add text 2
Indeed if you want to use AngularJS for what it was created, you have to rewrite your code completely using directive or controller. You variables and functions accessible from the view should be attached to the $scope too.
var myApp = angular.module("myApp", []);
myApp.controller("myCtrl", function($scope){
$scope.addtext1 = function () {
$scope.sig.sigBase6422 += "1111111111111111";
};
$scope.addtext2 = function () {
$scope.sig.sigBase6422 += "2222222222222222";
};
$scope.sig = {
sigBase6422: ""
};
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<div ng-app="myApp" ng-controller="myCtrl">
<form action="#" name="FORM1">
<TEXTAREA ng-model="sig.sigBase6422" ROWS="10" COLS="20">String: </TEXTAREA>
</form><br/>
<input type="text" name="myID1" id="myID1" ng-model="sig.sigBase6422" /><br/>
<input type="text" name="myID2" id="myID2" ng-model="sig.sigBase6422" /><br/>
<p>Value {{sig.sigBase6422}}!</p>
<!-- test field -->
<button ng-click="addtext1()">Add text 1</button>
<button ng-click="addtext2()">Add text 2</button>
</div>
You seem to have misunderstood how angular works. What you're trying to do is not how angular works. What you're trying to do with native JavaScript can be done with angular. Angular can update dom and Dom updates angular as it's responsible for causing updates.... anyway without getting any deeper. You need to read more on how angular works and try sticl within the bounds of angular instead of mixing.
That being said :
Tigger change on the Dom element after you have updated its value. Or better yet get access to scope variable on the Dom and call a function in angular with the value you're and set they value from inside of a angular.
Use this code while updating the value.
pick the controller first using
var scope = angular.element(document.getElementById('yourControllerElementID')).scope();
scope.<variablename> = <your operation>;
then
scope.$apply();
the remaining thing will be taken care by Angular.

What causes AngularJS variable change to fire html update?

I got this example from the W3Schools tutorial on AngularJS. I made a small change from binding the value of the checkbox span to using an expression. I figured that the todo list wouldn't update any more. But it still does. What causes the ng-repeat to fire just because I have added a todo item?
http://plnkr.co/edit/Kojz2ODWDS8dFDNzjYR5?p=preview
<!DOCTYPE html>
<html>
<script src= "http://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js"></script>
<body ng-app="myApp" ng-controller="todoCtrl">
<h2>My Todo List</h2>
<form ng-submit="todoAdd()">
<input type="text" ng-model="todoInput" size="50" placeholder="Add New">
<input type="submit" value="Add New">
</form>
<br>
<div ng-repeat="x in todoList">
<input type="checkbox" ng-model="x.done"> <span>{{x.todoText}}</span>
</div>
<p><button ng-click="remove()">Remove marked</button></p>
<script>
var app = angular.module('myApp', []);
app.controller('todoCtrl', function($scope) {
$scope.todoList = [{todoText:'Clean House', done:false}];
$scope.todoAdd = function() {
$scope.todoList.push({todoText:$scope.todoInput, done:false});
$scope.todoInput = "";
};
$scope.remove = function() {
var oldList = $scope.todoList;
$scope.todoList = [];
angular.forEach(oldList, function(x) {
if (!x.done) $scope.todoList.push(x);
});
};
});
</script>
</body>
</html>
Clicking the Add New Button submits the corresponding form and by using ng-submit="todoAdd()" it will call this function. This in turn adds an entry to the todoList in your scope. As this array has been modified the angular digest cycle is triggered and the list is updated.
Some suggestions for your questions: First of all, you mean W3Schools, not the W3C (which is a standardization organization and normally is not doing tutorials, which is why I got curios - Also, you will find lots of reasons why not to use W3Schools when goolgin around or looking at meta). Also, if you compare to some other code, you should include it or at least link to it.
I found it by googling and it seems your only change is using <span>{{x.todoText}}</span> instead of <span ng-bind="x.todoText"></span>. There really is no difference in terms of the digest cycle here. The only difference is that by using {{}} it might at first be rendered as curly brackets in the browser window, before the variable is actually replaced. Thus, it is usually better to use ng-bind.

HTML input has both {{}} and ng-model

I have a form which contains two input fields, I want to sync the next input field when user is typing in the first input field by default, and user can edit the second field as they like, below code works fine:
<input type="text" ng-model="name">
<input type='text' value='{{name}}'>
<button ng-click='submit()'>submit</button>
However, to be able to get the value of second field, I need to put ng-model to the second field, and once I put ng-model, it won't sync anymore.
This is the example
How should I get the second field's value if I don't put a ng-model to it.
Thank you.
You can use ng-change. When user changes input 1 the ng-change method will be called and input2 will be updated .but when user change input 2 nothing will be called .
<DIV ng-app='app'>
<form ng-controller='myController'>
<input type='text' ng-model='name' ng-change="callMe()"/>
<input type='text' ng-model="name2" />{{name2}}
</form>
</DIV>
and controller js
var app = angular.module('app', []);
app.controller('myController', function($scope){
$scope.callMe =function(){
$scope.name2=$scope.name;
}
//$scope.name
//$scope.name2
})
update fiddle example
You could use the $scope.$watch Method for your needings.
I have updatet your fiddle.
What i did is easy, everytime the model changes, the $watch will be called with the new value of the model, then you just need to copy the value into the second model.
First approach that came to my mind was to ng-bind a property with a setter that would do what you want:
<input type='text' ng-model='nameModel' />
then
app.controller('myController', function($scope) {
Object.defineProperty($scope, 'nameModel', {
get: function() { return $scope.name1; },
set: function(x) { $scope.name1 = $scope.name2 = x; }
});
});
This causes any edit to nameModel to affect both name1 and name2.
Fiddle
You could do a similar wrapper around name2 to track whether it has ever been modified (dirty/pristine), and have nameModel only change scope.name2 if it is pristine.
Fiddle with better user experience
(If you're using Angular forms, it tracks the field status for you, so you could directly look at form.name2.$pristine.)
It seems that what you need is to set the value to the scope variable.
So your code would then look like this:
<input type="text" ng-model="name">
<input type='text' value="{{name}}" ng-model="somethingelse">
<button ng-click='submit()'>submit</button>
Hope that helps.

Data binding not working in AngularJS with input tag

Below is my angularjs code,
When I try to enter any text in the textbox, it doesn't appear in the binding.
<!DOCTYPE html>
<html lang="en">
<head>
<script src="js/angular.js"></script>
<script type="text/javascript">
var app = angular.module('myApp', []);
app.controller('cont', ['$scope', function($scope) {
}]);
</script>
</head>
<body ng-app="myApp">
<input type="text" ng-bind="user"></input>
<p>{{user}}</p>
</body>
</html>
You would need to use ng-model directive for 2-way binding. ng-bind is just one-way which updates the bound element with data (model value) when a digest cycle happens. Without ng-model when you update the textbox there wont be any digest cycle. Angular has directive definition for types like input and other form controls which requires optional ng-model directive. And these element directives registers events like change/input etc only if it gets the optional ng-model controller on the target element. And when you have them it uses ng-model controller to set the view-value, model-value and triggers the digest cycle when that event occurs. Of course with the new angular versions there is an ng-model-options which you can set at the element level or at a global level to specify when do you want the model value update (and form validation) to happen.
So do:-
<input type="text" ng-model="user" name="user"></input>
<p>{{user}}</p>
Though not an issue in your case, you are missing the usage of ng-controller="cont". Without it all properties will be attached to the rootScope in your case. So may be:
<body ng-app="myApp">
<div ng-controller="cont">
<input type="text" ng-model="user" name="user"></input>
<p>{{user}}</p>
</div>
</body>

Using AngularJS to style label when ng-model changes in a text field

A few days back, I asked the following question:
I've searched for how to do this, and I've not had any luck. I'm fairly inexperienced with web stuff, so perhaps it's so trivial that no one needs to ask how to do it :(
Suppose I have an HTML text input field with a label, like this:
<label for = "stuff">Stuff</label>
<input type = "text" name = "stuffz" id="stuff" value = "hello!">
Now suppose the text input field value is changed. Is there a way to use AngularJS to restyle the label (Like, turn it green, for example) when this change occurs? I've looked into using ng-change and ng-class, but I'm not knowledgeable enough about how these work to use them in this manner.
When I tested the solution provided, which was:
CSS
.marvellous {
color: green;
}
HTML
<div ng-app="demo">
<label for="stuff" ng-class="{ 'marvellous' : !!hasChanged }">Stuff</label>
<input type="text" id="stuff" ng-model="myModel" ng-change="hasChanged = true"></div>
It worked, but only when I manually changed the text field (i.e. I typed stuff in the text field directly). However, in the particular application I'm working on, I need for the labels to be restyled when the value stored in ng-model changes. Unfortunately, I falsely assumed that if this method worked when I manually changed the text field, it must work if ng-model were to change as well. I've come to find out that it doesn't.
What's the reason for this? And how can I make the label re-style when ng-model changes?
Thanks!
EDIT: When I say "ng-model changes," what I mean is..in my controller, there is a variable that is used to populate the text fields of the app that I'm working on. However, when the user clicks an "import changes" button, this variable is changed according to the changes that they are importing, which consequently changes the corresponding text fields linked to that variable. Ultimately, I want all of the labels attached to these changed text fields to be highlighted for the user to see. I'm sorry for my vagueness.
Each input in an angular js form has meta data properties to help you. For example
<form id="form">
<label for="stuff" ng-class="{ 'marvellous' : form.stuff.$dirty}">Stuff</label>
<input type="text" id="stuff" ng-model="myModel" ng-change="hasChanged = true">
</form>
https://docs.angularjs.org/api/ng/type/form.FormController
You can achieve that using $scope.$watch :
function demoCtrl ($scope) {
$scope.$watch('myModel', function (newValue, oldValue) {
if (newValue) {
$scope.hasChanged = true;
}
});
$scope.changeMyModel = function () {
$scope.myModel = 'wonderful';
};
}
.marvellous {
color: green;
}
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app ng-controller="demoCtrl">
<label for="stuff" ng-class="{ 'marvellous' : !!hasChanged }">Stuff</label>
<input type="text" id="stuff" ng-model="myModel" ng-change="hasChanged = true">
<button ng-click="changeMyModel()">change model</button>
</div>
<!--Use ng-style !!! replace your lable with this--->
<label for="stuff" ng-style="hasChanged()">Stuff</label>
and define your function like this below---
$scope.hasChanged = function(){
if($scope.myModel !== initValue){
return { color: "green" }
}
}

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