Develop Reference

Find related element using jQuery

Based on this DOM tree below when a comment reply button is clicked I need to use $(this) and then navigate to the next comment textarea .task-modal-cmt-reply-textarea
I am using jQuery and tried to use .parent().parent().closest('.task-modal-cmt-reply-textarea') and a few other combination without luck so far.
Can someone show me an efficient way to get this element into a var?
What I am trying to accomplish...
I have a click even on a comment reply button which insert a reply form into the DOM below a parent comment when the reply button is clicked using...
$document.on('click', '.cmt-reply-btn', function(e) {}
In this click event the reply form is put into the DOM with...
$parentCmtDomNode.after(cmtReplyFormTemplateHtml);
After the form is in the DOM I try to attach a jQuery plugin to it for #mention style capability using...
$('.task-modal-cmt-reply-textarea').mentionsInput({});
The problem
The #mention library works for the 1st clicked on comment form but all other reply forms do not work

another way to get a reference to that element, would be to do this:
var el = $(this).parent().parent().next().find('.task-modal-cmt-reply-textarea').eq(0);
note that the eq(0) just gives a single object back instead of an array with one element, which may or may not be necessary depending on what you want to do with it.

You need to do another .parent(), the two parent() you did only bring you up to the level of class "Activity-item Activity-comment" with data-activity-id = 12. Do another parent and you should be fine.

try this
var textarea_value=$(this).closest('.Activity-item').next('.Activity-item').find('form .task-model-cmt-reply-textarea').val();
or if its related with data-activityid = "12" so you can use
$(document).on('click','.cmt-reply-btn',function(){
var textarea_value = $(form[data-comment-parent-id = "'+$(this).attr('data-activityid')+' .task-modal-cmt-reply-textarea"]).val();
});

A more efficient way would be to use the parents api from jQuery then followed by your .closests
.parents('div')
The .parents() and .parent() methods are similar, except that the latter only travels a single level up the DOM tree. Also, $( "html" ).parent() method returns a set containing document whereas $( "html" ).parents() returns an empty set.
Then add the following sub selector to your closest chain.
.closest('textarea[name=^"task-modal-cmt-textarea"]')
This looks for the closest textarea with the name starting with task-modal-cmt-textarea. This is more efficient than what you have as this will eliminate any lookups on non textarea elements then it will only filter out the textareas that have that particular name.
EDIT: Updated Answer to the OP's recent edit.
$('.task-modal-cmt-reply-textarea').mentionsInput({});
This will select all of the ".task-modal-cmt-reply-textarea" that are on the screen at the time, it will not account for future ones. To achieve what you are looking for you should put a sub selector on this chain to allow it to attach to the newest form that was created.
$('.task-modal-cmt-reply-textarea',$($parentCmtDomNode).next('textarea')).mentionsInput({});
This should be placed after the
$parentCmtDomNode.after(cmtReplyFormTemplateHtml);

Try this:
var txt_html = $(this).parents('.Activity').children("textarea:first").html();
var txt_val = $(this).parents('.Activity').children("textarea:first").val();
In the parents() function you need to use the closest parent class/ id.

var el = $(this).parents('.Activity-item').next().find('.task-modal-cmt-reply-textarea').eq(0);

add attribute to DOM element

I have a modal form that is generated using bootstrap 3. It doesn't look like there is a reliable way to determine when that form is being shown onscreen. I am attempting to create one. I attached two events to my DOM element that signal when it is shown and when it is hidden.
jq_modal_login_form = $('#modal-login-form')[0]
jq_modal_login_form.on('shown.bs.modal', function () {
jq_modal_login_form.active_onscreen = true;
});
jq_modal_login_form.on('hidden.bs.modal', function () {
jq_modal_login_form.active_onscreen = false;
});
I tried to give an attribute named active_onscreen to the DOM element above. When I look at the DOM element in the debugger later, the attribute is not present.
I should mention that I am VERY new to javascript. Is attribute even the right word to use here? It looks like attribute is a bit of a misnomer as well. It could be an attribute of the object but could also be an attribute of the object.attributes attribute, right? I assume the later is where styling ect., goes and is not what I want to change. Does anyone have some insight as to what I should be doing here?

In jQuery:
$('selector').attr('attribute_name', 'value');
However, you can should only use predefined attributes as creating custom attributes requires additional setup (see this question) that is not necessary in your case.
In your case, you may just want to add a active_onscreen class to the element. Classes are meant to be used to identify elements (and not just for CSS), so they are perfect for this applicaiton. You would use this to add a class to an element:
$('selector').addClass('active_onscreen').
When it is no longer active, you would use this to remove the class:
$('selector').removeClass('active_onscreen').

What you are doing here is adding a property of the DOM object - not an attribute of the element.
Adding an attribute does not necessarily make the property mirror it. Only built-in properties do this.
If you want to set an attribute, but not the property, you can use jQuery's .attr() method.

If you just want to see if a given modal is open, Bootstrap does that for you. You can check the bs.modal data attribute:
$("element").data('bs.modal').isShown;
or a class (but this method is prone to race conditions):
$('#myModal').hasClass('in');

Element duplicates when append

At first, I'm trying to create a basic tcg in jQuery, Ajax and PHP.
The following fiddle is my try to append the card to empty places and change the data attribute value, but When I click in a card, it creates other "cards" and the value doesn't changes.
http://jsfiddle.net/bNB89/1/
The code I tried to use for data changing:
$(this).data('place', 'field');
How can I fix this?

The problem in your code is that you are using append in a class, so the content is being created in every element containing that class. You should instead fetch for the first element with the class, append to it and then remove the class so it won't be selected again. I set up a fiddle demonstrating it http://jsfiddle.net/bNB89/2/

You get other cards because there are multiple .myslot elements and each one will get a copy.
Use a selector that will give you one item to append to. e.g. .myslot:empty:first.
.data() does not change data attributes it uses its own internal mechanism to store the data. If you really want to change the attribute you can use attr.
http://jsfiddle.net/bNB89/3/

How to get original browser set input colors back after changing them with jQuery().css()?

Problem with jQuery:
After changing the border and background color of some input fields in a form that fail the validation i don't know how to get the previous, original colors back as i don't pre-style the inputs but use the browser settings instead. how to handle this?
thanks in advance,
clubnite

This will remove the color from the style element styles, causing the stylesheet to resume control.
$(sel).css('color', '')
Note that this will not restore the color to a value that was explicitly set before. To do that, you'd have to cache the prior values.

Set the value of your modified attributes to inherit

What you should be doing is not changing the CSS attributes, but adding a css class to the element. When the validation fails, remove that CSS class.

I would use a CSS class instead of setting individual properties with jQuery. That way, you can just add and remove the class to apply or remove the style. It's simpler, probably faster, and lets you keep all your style information together in one place. Adding a class also makes it easier to find all the fields that have errors with jQuery selector.
If, for whatever reason, you really want to use .css(), you can remove the properties by setting them to an empty string. For example, if you added a border, you would remove it with
$(selector).css("border", "");

Stick ID to the HTML element (using js) instead of id-attribute?

First post on stackoverflow. Hope everything is right!
I'm thinking of attaching an ID value to the HTML element itself via JavaScript, instead of using the HTML id attribute.
For instance, say that JavaScript variable htmlElement is a div. So htmlElement.cssName would tell us its CSS class.
Now, how about doing
htmlElement.idProperty = "someValue"
in JavaScript instead of doing <div id="someValue">? Then I can use the idProperty in say event handlers.
this.idProperty
That simple!
Is there something wrong in doing so?
EDIT: Thanks for yor answers! Very helpful and instructive. I wish I could check green on all of them!

no, you can do it the way you like it, if you are dynamically creating this item you should use this method, if you are doing this inside html I recommend you to just put the name of the id in html too.
However a small note. Use element.id instead of idProperty.
element.id = 'my-id';

You can use the createAttribute method to add an id to the element like this:
id = document.createAttribute('id');
id.value = "someValue";
htmlElement.setAttributeNode(id);

What you're doing there is adding a runtime property (in your case, called idProperty) to an HTMLElement object instance. You can get away with doing that in your JavaScript code (the Prototype library does it all the time). Makes me uncomfortable, but it does work on all major browsers.
If you want to be able to specify these in HTML markup as well, though, I'd use attributes instead. You can create attributes with any names you want, although to be careful I'd use names like data-xyz (e.g., use a data- prefix) as that's the HTML5 standard way of using your own attributes. Then you use getAttribute to get the value and setAttribute to set/update the value.