DOM manipulation by angularjs direction - angularjs-directive

I read that Angularjs directives require a different approach than jquery. I am new to angularjs, so it will be great if somebody can explain how to use directives for this simple example. If you click on bottom div, then it moves (re-parent) the top image to the bottom div. I could add this jquery code on ng-click... but is there a better way?
JQUERY INTENT:
$("#bottom").click(function(){
$("#myimage").appendTo("#bottom");
});
ANGULARJS:
<div ng-app="myapp">
<div data-ng-controller="mycontroller">
<div id="top" style="background-color:red;width:200px;height:200px">
<img id="myimage" src="//placehold.it/150x150">
</div>
<div id="bottom" style="background-color:green;width:200px;height:200px">
</div>
</div>
</div>

Instead of listening for a click in jQuery, you can use Angular's ng-click directive to specify a function to call when the element is clicked and you can use the ng-if directive to add/remove the image, for example...
<div ng-click="appendImage()" id="bottom" style="background-color:green;width:200px;height:200px">
<img ng-if="showImage" id="myimage" src="//placehold.it/150x150">
</div>
Then in your controller...
angular.controller('myController', function ($scope) {
$scope.showImage = false;
$scope.appendImage = function (event) {
$scope.showImage = true;
};
});
A key difference between plain jQuery and Angular is that in jQuery you have to write code to manipulate the DOM yourself (like appending the image). If you use directives properly in Angular, you simply make changes to the $scope and directives will update the DOM for you automatically

Related

Jquery change css class from variable

For my site, I code a button allowing to change the css of a class present in a div card. My button is located in the card-footer. Having several cards, I can't / don't think to retrieve the element with an id (as there will be X times the same ID)
In order to circumvent this system, I therefore use a parentElement which goes up to the div card
<div class="card">
<div class="card-body">
<p class="change">Change one</p>
<p class="change">Change two</p>
<p class="change">Change three</p>
</div>
<div class="card-footer">
<i id="updateData">change</i>
</div>
</div>
jQuery($ => {
$('#updateData').click(e => {
var element = e.target.parentElement.parentElement;
$('.change').css('display','none');
});
});
I would like to indicate that only the class "changes" present in my element variable and not all the classes in the page.
I don't know how to add a variable to my ".css" command, do you know how ?
Thanks in advance !
First of all since you will have multiple elements with same id that means that you should not use ID and use class instead. Id is meant to be unique. So yours id="updateData" should become class="updateData". Now you can grab all of those buttons and assign event to all of them instead of just first like you were by using id selector.
$('.updateData').click(e=> {});
Next in order to be able to use clicked element in jQuery way convert from arrow function to regular anonymous function since arrow function overrides this keyword. And now you can use jQuery to hide like
$('.updateData').click(function() {
element = $(this).parent().parent();
element.hide();
});
If you want more precise selection to hide only .change elements use
$('.updateData').click(function() {
element = $(this).parent().parent();
element.find(".change").hide();
});
Not bad, but more efficient, when you have multiple click targets, is delegation:
$(document).on("click", ".updateData", function() { ... });
Also .hide() is convenient, but rather then "change the css of a class" add a class "hidden" or something! In best case the class further describes what the element is. CSS is just on top.

Manipulating inline style with angular does not work in IE

I wanted to set the position of a div based on the return value of a function in an angular controller
The following works fine in FireFox and in chrome but in Internet explorer {{position($index)}}% is interpreted as a literal string value and therefore has no effect
<div ng-repeat="item in items" style="left:{{position($index)}}%"></div>
Here is an example of the issue:
var app = angular.module('app', []);
app.controller('controller', function($scope) {
$scope.items=[1,2,3,4,5,6,7,8,9,10];
$scope.position=function(i){
var percent =[5,10,15,20,25,30,35,40,45,50,55,60,65,70];
return percent[i+1];
}
});
And here is a Fiddle to demonstrate
Does anyone have suggestions on how to rectify?
You must use ng-style instead of style, otherwise some browsers like IE will remove invalid style attribute values (presence of {{}} etc makes it invalid) before even angular has a chance to render it. When you use ng-style angular will calculate the expression and add the inline style attributes to it.
<div ng-repeat="item in items" ng-style="{left: position($index) + '%'}"></div>
Since you are anyways calculating the position you could as well add % from the position and send it. Also remember that calling a function in ng-repeat will invoke the function every digest cycle, so you may want to be careful not to do too much intensive operations inside the method.
<div ng-repeat="item in items" ng-style="{left: position($index)}">{{item}}</div>
and return
return percent[i+1] + "%";
Demo
If you want to use angular binding expression {{}} just like normal style attribute like style="width:{{someScopeVar}}",
use ng-attr-style and it will work perfectly IE (and obviously other smarter ones) :)
check my jsFiddle ... Checked with Angular JS 1.4.8
here I have shown the usage of style, ng-style and ng-attr-style
THE HTML
<div ng-app="app">
<div ng-controller="controller">
<div style="background:{{bgColor}}">
This will NOT get colored in IE
</div>
<div ng-attr-style="background:{{bgColor}}">
But this WILL get colored in IE
</div>
<div ng-style="styleObject">
And so is this... as this uses a json object and gives that to ng-style
</div>
</div>
</div>
THE JS
var app = angular.module('app', []);
app.controller('controller', function($scope) {
$scope.bgColor = "yellow";
$scope.styleObject = {"background": "yellow"};
});
Yes, ng-style will work to resolve this problem. You can use conditionally style using ternary operator.
HTML:
<div ng-style="{'display':showInfo?'block':'none'}">
</div>

Event binding not working on div

I have a structure like this:
<ul id="container">
<li>
<div tabindex="1" class="selectThis">
<div>
<div>
<span class="textToEdit" contenteditable="true"></span>
</div>
</div>
</div>
</li>
<ul>
Where it works to bind an event to the contenteditable span:
$("#container").on("keydown", ".textToEdit", function (e) {
alert("yes");
});
But the div itself doesn't react:
$("#container").on("keydown", ".selectThis", function () {
alert("no");
});
Using .on because the whole thing is dynamically generated, besides the container. I'm using jquery UI's sortable on said container. What is wrong with the binding? I've tried giving the ul and li a tabindex too, but the div still won't give me an alert.
The problem was that the div wasn't being focused after sortable is called on the ul--manually calling $(".selectThis").focus() makes it work. Thanks to Pilgerstorfer Franz for making me aware of this!

how to change properties of a parent div on hover of child div

how to change properties of a parent div on hover of child div.
can it be done with pure css ?
html:
<div class="parent">
<div class="child">
</div>
</div>
css:
.parent{width:200px;height:100px;background:#cccccc;}
.child{width:200px;height:100px;background:transparent;}
Not with plain CSS you need some form of script to notify the parent that the child is being hovered(eg.):
<div id="parentId" class="parent">
<div id="childId" onmouseover="doOnMouseOver()" onmouseout="doOnMouseOut()" class="child">
</div>
</div>
<script type="text/javascript">
function doOnMouseOver() {
var parentNode = this.parentNode;
var newParentClass = parentNode.getAttribute('class') + 'child-beeing-hovered';
parentNode.setAttribute('class', parentClass);
}
function doOnMouseOut() {
var parentNode = this.parentNode;
var newParentClass = parentNode.getAttribute('class').replace('child-beeing-hovered', '');
parentNode.setAttribute('class', parentClass);
}
</script>
Note that I've added ids to your html elements so that I can get a hold of them with javascript without making the code unnecessary complex nor using a third party library like jQuery.
Note that you need also to bind onmouseout or otherwise the parent element will keep the new class child-beeing-hovered.
jQuery actually makes your job easier but you should try doing this with javascript at least once.
I hope it helps.
Is there a reason you do not want to use JavaScript or JQuery?
You could simply:
$("#child_id").hover(function (){
$(this).parent("div").addClass("some-class")
});
There is no parent selector in CSS.
You can find quite good explanation why it's not supported here: http://snook.ca/archives/html_and_css/css-parent-selectors

mootools load content with function

I am using mootools and i want to load in a div (named response) content.
The div content i pass in javascript with $('response').set('html', content) where content is variable. in the content variable i have some html code with buttons and want to create a event handle ( click ).
the content I load with a json request and pass to the element:
<div id="undo">
<ul>
<li> <button value="1">foo</button> </li>
<li> <button value="2">bar</button> </li>
</ul>
</div>
my javascript looks like
$('undo').addEvents({
'click:relay(button)': function(ev, element){
alert('a button clicked!');
}
});
but I don't know why the event didn't work.
I think the problem is that $('undo') doesn't exist when the dom object is ready but i don't know how to fix this.
Delegate further up the dom tree to an element that is there at the time of domready block running. eg, if you have <div id=content>... </div> (or response if it's static)
document.id('content').addEvents({
'click:relay(#undo button)': function(event, element){
event.stop();
console.log(element.get('value'));
}
});
given that you inject your data there later on, this will work fine.