How to select an element by classname using jqLite?

Question

I'm trying to remove jquery from my Angular.js app in order to make it lighter, and put Angular's jqLite instead. But the app makes heavy use of find('#id') and find ('.classname'), which are not supported by jqLite, only 'tag names' (as per documentation)

wondered what do u feel would be the best approach to change it. One approach I thought about is to create custom HTML tags. for example: change
<span class="btn btn-large" id="add-to-bag">Add to bag</span>

to

<a2b style="display:none;"><span class="btn btn-large" >Add to bag</span></a2b>

and

$element.find('#add-to-bag') 

to

$element.find('a2b')

Any thoughts? other ideas?

thanks

Lior

Crepuscule

ID's must be unique, therefore it makes no sense to find an element that is a child of another element by ID. Simply select the element by Id. If your Id's aren't unique, change your ID to a class. Also, you can use DomElement.querySelector(".myclassname") to select a single decendant element using a css selector, or all matching by adding All to it: DomElement.querySelectorAll(".myclassname") That of course doesn't work in IE<9. – Shaven

If you define an a2b element, you must have defined a directive. Can you do what needs to be done in the link function of the directive, and therefore avoid the need to call find() entirely? Similarly with your classes -- can you define directives and put the functionality you need into the directives' link (or compile) functions? – Moneywort

@KevinB Angular's jqLite is said to support 'only tag names' – Crepuscule

@MarkRajcok I didnt define a directive. it seems to work in IE and chrome. but even if I would define a directive, why would it help? I would still need to get hold of a DOM element. – Crepuscule

How come find('span.btn') or similar doesn't work for you? – Weal

@Weal .find in jqLite doesn't support the .btn portion of that string – Shaven

oh im sorry I didnt catch the "only tag names" part – Weal

In the link function of a directive, the second argument, element is the DOM element (wrapped in jQuery or jqLite). – Moneywort

Maybe you've already read this, but I thought I should share anyways - jaketrent.com/post/angularjs-find-element-in-context – Weal

@Weal jqLite does not support class names see docs.angularjs.org/api/angular.element $element.find('span.btn'); [] $element.find('a2b'); [ <a2b style=​"display:​none;​">​…​</a2b>​ ] – Crepuscule

parent.find('#id') is an uncommon but perfectly valid thing to want to do. It provides element #id only when that element is a child of parent, excluding it otherwise. – Nevanevada

Answer 1

Essentially, and as-noted by @kevin-b:

// find('#id')
angular.element(document.querySelector('#id'))

//find('.classname'), assumes you already have the starting elem to search from
angular.element(elem.querySelector('.classname'))

Note: If you're looking to do this from your controllers you may want to have a look at the "Using Controllers Correctly" section in the developers guide and refactor your presentation logic into appropriate directives (such as <a2b ...>).

Wooton

Thanks! to add from Ricardo Bin answer (angular's mailing list), $document injectable could be used too: jsfiddle.net/ricardohbin/fTQcs – Crepuscule

Unfortunately, the referred URL is no longer valid (docs.angularjs.org/guide/dev_guide.mvc.understanding_controller), and there doesn't seem to be any replacement in that section. – Wandering

No. angular.element(document.querySelector('#id')) is the alternative to: $('#id'), not for: elementArray.find('#id') – Senegal

Right - but as we have found as we build new parts of our application in angular we sometimes need to "duct tape" older parts onto it for a while until they can be updated or re-factored. In our case we needed to load some old jquery/ajax data without modifying the existing mess so we did the following- $http.get('/Task/GetTaskStatsByTaskId/' + taskId).success(function (data) { angular.element(document.querySelector('#userTasksContainer')).html(data); }); – Syllabize

If elem is a jqlite object it would be angular.element(elem[0].querySelector('.classname')); – Krilov

Can we select element using ng-model? Using Angular element. – Pray

Answer 2

angualr uses the lighter version of jquery called as jqlite which means it doesnt have all the features of jQuery. here is a reference in angularjs docs about what you can use from jquery. Angular Element docs

In your case you need to find a div with ID or class name. for class name you can use

var elems =$element.find('div') //returns all the div's in the $elements
    angular.forEach(elems,function(v,k)){
    if(angular.element(v).hasClass('class-name')){
     console.log(angular.element(v));
}}

or you can use much simpler way by query selector

angular.element(document.querySelector('#id'))

angular.element(elem.querySelector('.classname'))

it is not as flexible as jQuery but what

Terricolous

Answer 3

If elem.find() is not working for you, check that you are including JQuery script before angular script....

Abscond

Although the OP specifically asked about jqLite, for those using jQuery and expecting find() to work with classes and ID's as well this answer may certainly help. – Reggi

To clarify: "If jQuery is available, angular.element is an alias for the jQuery function. If jQuery is not available, angular.element delegates to Angular's built-in subset of jQuery, called "jQuery lite" or jqLite.". Quote from: docs.angularjs.org/api/ng/function/angular.element . jqLite contains find(). – Petuu