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Append div only if it does not contain text JQuery

I am creating a social media website and am trying to make a comment textarea appear when users click on a status.
Here is what I have so far:
$(".status").click(function (){
//Check if status div they clicked on contains a textarea already
if($(this).closest('div').innerHTML.indexOf("<textarea name='status_body'>") == -1) {
//Append with textarea
var textarea = "<textarea name='status_body'></textarea>";
$(this).closest('div').append(textarea);
}
});
This was working before I put the if statement in. Of course without the if statement a textarea will be added everytime the user clicks. I would only like for a textarea to appear if there is not one aready.
Another method I tried and failed with is:
if(!$(this).closest('div:contains("<textarea")').length > 0)

You're close, just check for the existence with .length
if ($(this).closest("div").find("textarea").length > 0) {
//contains a text area!
} else {
//Doesnt!
}

Do not search for it as text. You should threat the textarea for what it is, a DOM element.
if($(this).closest('div').find("textarea[name='status_body']").length == 0) {
/*...*/
}

Jquery add using append and remove using .remove

I'm trying to make two buttons that acts as remove and add function first I have this:
HTML
<video id="localVideo" style="background-color:black"></video>
<div id="remoteVideos"></div>
Buttons
<button id="BtnOn">On</button>
<button id="BtnOff">Off</button>
Script:
$(document).ready(function() {
//$("#BtnOn").click(function() {
// $('#A').append("<div id='localVideo'>");
// $('#A').append("<div id='remoteVideos'>");
//});
$("#BtnOff").click(function() {
$("#localVideo").remove();
$("#remoteVideos").remove();
});
});
What I'm trying to do is remove the 2 div's and have the ability to return them, with the condition that you can only add them if they are missing and remove them if they are present, therefore limiting them to 1 add and 1 remove. How can I accomplish this?Any help suggestion is appreciated

You could check if the #localVideo element exists. Also, if they are the only elements in the #A element, you can remove them by calling $('#A').empty();.
$(document).ready(function() {
$('#BtnOn').click(function() {
if ($('#localVideo').length == 0) {
$('#A').append('<video id="localVideo" style="background-color:black"></video><div id="remoteVideos"></div>');
}
});
$('#BtnOff').click(function() {
if ($('#localVideo').length > 0) {
$("#localVideo").remove();
$("#remoteVideos").remove();
}
});
});
You could also consider hiding and showing the video elements, rather than adding and removing them.

Instead of using .append() and .remove(), you can change the CSS display property to none or initial, depending on whether you want the thing to be shown or not.
This way, you can then add an if statement like so:
$("#BtnOff").click(function() {
if('#localvideo').css('display') == 'none'){
//do nothing
} else {
$('#localVideo').css('display','none');
$('#remoteVideos').css('display','none');
}
});

How to check if an element with id exists or not in jQuery?

I'm generating a div dynamically and I've to check whether a dynamically generated div exists or not ? How can I do that?
Currently I'm using the following which does not detects the div generated dynamically. It only detects if there is already an element with the id contained in the HTML template.
$(function() {
var $mydiv = $("#liveGraph_id");
if ($mydiv.length){
alert("HHH");
}
});
How can I detect the dynamically generated div?

If mutation observes aren't an option due to their browser compatibility, you'll have to involve the code that's actually inserting the <div> into the document.
One options is to use a custom event as a pub/sub.
$(document).on('document_change', function () {
if (document.getElementById('liveGraph_id')) {
// do what you need here
}
});
// without a snippet to go on, assuming `.load()` for an example
$('#container').load('/path/to/content', function () {
$(this).trigger('document_change');
});

If it is added dinamically, you have to test again. Let's say, a click event
$("#element").click(function()
{
if($("#liveGraph_id").length)
alert("HHH");
});

How you inserting your dynamic generated div?
It works if you do it in following way:
var div = document.createElement('div');
div.id = 'liveGraph_id';
div.innerHTML = "i'm dynamic";
document.getElementsByTagName('body')[0].appendChild(div);
if ($(div).length > 0) {
alert('exists'); //will give alert
}
if ($('#liveGraph_id').length > 0) {
alert('exists'); //will give alert
}
if ($('#liveGraph_id_extra').length > 0) {
alert('exists'); //wont give alert because it doesn't exist.
}
jsfiddle.

Just for interest, you can also use a live collection for this (they are provided as part of the DOM). You can setup a collection of all divs in the page (this can be done in the head even before the body is loaded):
var allDivs = document.getElementsByTagName('div');
Any div with an id is available as a named property of the collection, so you can do:
if (allDivs.someId) {
// div with someId exists
}
If the ID isn't a valid identifier, or it's held in a variable, use square bracket notation. Some play code:
<button onclick="
alert(!!allDivs.newDiv);
">Check for div</button>
<button onclick="
var div = document.createElement('div');
div.id = 'newDiv';
document.body.appendChild(div);
">Add div</button>
Click the Check for div button and you'll get false. Add the div by clicking the Add div button and check again—you'll get true.

is very simple as that
if(document.getElementById("idname")){
//div exists
}
or
if(!document.getElementById("idname")){
// don't exists
}

How do I set the CSS for one instance of a class when the markup has multiple instances

I have a page with a content accordion with 8 items. I also have an h4 tag on the page outside of the accordion. I want to hide which ever content accordion item matches the text inside the h4 tag.
The text inside the h4 tag and the content accordion items might change so I need to use variables (I think).
Here is what I have so far:
var category = $('.leftColumnNav h4').html();
var topic = $('.contentAccordionItemTitle p').html();
if(topic === category){
$(".contentAccordionItemTitle").css("display", "none");
} else {
$(".contentAccordionItemTitle").css("display", "block");
}
What I have sort of works. It successfully hides the .contentAccordionItemTitle. Unfortunately it obviously hides all of them. I just want to hide the one that matches the h4 tag.
If it's needed I can probably create a JSFiddle example.

var category = $('.leftColumnNav h4').text();
$(".contentAccordionItemTitle").each(function() {
if ($(this).text() === category) { $(this).hide() }
})

var topic = $('.contentAccordionItemTitle p').html();
That line means you're getting all the p-tags. If you want to continue down this solution, you could use the jQuery each function -> http://api.jquery.com/each/
$(".contentAccordionItemTitle").css("display", "none");
} else {
$(".contentAccordionItemTitle").css("display", "block");
The $(".contentAccordionItemTitle") also gets all elements with this class.

You should use a loop, like jQuery each:
var category = jQuery('.leftColumnNav h4').html();
jQuery('.contentAccordionItemTitle p').each(function() {
if(jQuery(this).html() === category) {
jQuery(this).parent('.contentAccordionItemTitle').css('display', 'none');
} else {
jQuery(this).parent('.contentAccordionItemTitle').css('display', 'block');
}
This is assuming there is only one element that matches jQuery('.leftColumnNav h4')

Passing parameter to css :not selector

I have a function to hide all divs on the page except one div.
// hide all div exceept div1
function hideAllExcept()
{
$('div:not(#div1)').slideUp(800);
}
or
// hide all div exceept 'thisdiv'
function hideAllExcept()
{
$('div:not("#div1")').slideUp(800);
}
The above works fine (difference is first function doesn't have "" around #div1). However, I would like to pass a parameter in the hideAllExcept function to dynamically specify which div to not hide. So I changed the function to:
// hide all div exceept 'thisdiv'
function hideAllExcept(thisdiv)
{
$('div:not(thisdiv)').slideUp(800);
}
if i call the function using: hideAllExcept('#div1') or hideAllExcept("#div1") it doesn't work. It seems that $('div:not(thisdiv)') still selects all divs, it doesn't exclude thisdiv.
Any ideas? Many thanks

Change it to:
function hideAllExcept(thisdiv) {
$('div:not('+thisdiv+')').slideUp(800);
}

$('div').not(thisdiv).slideUp(800);

var divid='div:not('+thisdiv+')';
$(divid).slideUp(800);