We Keep Coding

how to get div content by role javascript

I'm trying to get feed content from facebook dom.
<div role="feed">
so i did that:
querySelectorAll($("div[role='feed']"))
like this:
get div by role
but it returns undifend result.
I tried some more similar way but still get undifend.
It is possible to get this data?
thanks

Please remove $. It's not needed and might throw an undefined error. Are you running after the page has loaded? Are you using .innerHTML to get the HTML contents? This works for me:
<div role="feed">Hello</div>
<script>
console.log(document.querySelector('div[role="feed"]').innerHTML);
</script>
In case, if you aren't running after your page has loaded, put your code inside onload event of window object.
You should change your code this way:
<script>
// Loading script before element.
window.onload = function () {
console.log(document.querySelector('div[role="feed"]').innerHTML);
}
</script>
<div role="feed">Hello</div>
This works if you are loading script before element.

You are mixing JavaScript and jQuery.
You don't need $() to do that with .querySelectorAll()
You don't need .querySelectorAll() to do that with $()
You can do any of the following to select the div with role="feed":
let divs_js = document.querySelectorAll("div[role='feed']");
console.log('Elements matched:', divs_js.length);
let divs_jq = $("div[role='feed']");
console.log('Elements matched:', divs_jq.length);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div role="feed"></div>
<div role="not-feed"></div>
<div role="feed"></div>
<div role="feed"></div>
<div role="not-feed"></div>
⋅
⋅
⋅
Here is an example of what you can do to get the content, then:
console.log("Using JS:");
let divs_js = document.querySelectorAll("div[role='feed']");
divs_js.forEach(function(elm){
console.log(elm.innerHTML); // or .innerText, according to your needs
});
// ----------------------
console.log("---------");
console.log("Using jQ:");
let divs_jq = $("div[role='feed']");
$(divs_jq).each(function(){
console.log($(this).html()); // or .text(), according to your needs
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div role="feed">feed 1</div>
<div role="not-feed">not feed 1</div>
<div role="feed">feed 2</div>
<div role="feed">feed 3</div>
<div role="not-feed">not feed 2</div>
Hope it helps.

With jQuery you don't need querySelectorAll() to get the DOM you can achieve this with $("div[role='feed']"). Since you are using querySelectorAll(), it accept string which must be a valid CSS selector string; if it's not, a SyntaxError exception is thrown. Since you are using wrong syntax, it returns undefined.
And you need text() function to get content of div in jQuery. text() get the combined text contents of each element in the set of matched elements, including their descendants, or set the text contents of the matched elements.
console.log($("div[role='feed']").text());
console.log($("div[role='feed']"));
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div role="feed">
so i did that:
</div>

Copy and paste text from a div to another [jQuery]

I am trying to do a thing that seems easy to me but I'm not very familiar with javascript language and I can't find any documentation to do what I want.
Let's say I have a code like this:
<div id="sourceA">Text</div>
<div id="sourceB">Another</div>
<div id="destination"></div>
Let's say I click on the "sourceA" div, the text contained in it should go in the "destination" div.
Unfortunately, I have no idea how to do it. Can you help me? And maybe also suggest me somewhere I can go and learn something more about this code?

Read more about JavaScript and jQuery events. What you need here is a .click() event on sourceA to handle your behaviour as follows:
$("#sourceA").click(function() {
$("#destination").html($(this).html());
});

HTML:
<div id="sourceA" class="source">Text</div>
<div id="sourceB" class="source">Another</div>
<div id="destination"></div>
JS:
$('.source').click(function(e) {
$('#destination').text($(e.currentTarget).text())
});

Take a look at this example
var copyContentToDestinationClickHandler = function(event) {
$('#destination').empty();
$('#destination').append($(event.target).text());
}
$('#sourceA').click(copyContentToDestinationClickHandler);
$('#sourceB').click(copyContentToDestinationClickHandler);
https://jsfiddle.net/7v5a6bsu/

Newbie to jQuery and get function

I am completely new to jQuery. I can't find any good documentation on the get function and was wondering if I could get some help.
I have an HTML page called me.html with just a single div called me. I want to use the following page to get the contents within the div. Even a google in the right direction would help. Thanks so much
<head>
<script src="http://code.jquery.com/jquery-latest.js"></script>
<script type="text/javascript" src="data.js"></script>
</head>
<body>
<form id="form" runat="server">
<div>
<div id="me">
</div>
</div>
</form>
</body>
</html>

you don't need to use get(). This simple script should do it
<script>
var contentsOfMe = $('#me').html();
</script>

get is used for loading data from an url. You seem to be wanting to get the contents of a div
as in $("#me").text()

What about using the great documentation provided at http://api.jquery.com/jQuery.get/
EDIT. If you want to just get the text, use var myText=$('#me').html();, and if the html, use var myHtml=$('#me').html();

You will find the documentation for the function get here : http://api.jquery.com/jQuery.get/
But get is to perform an ajax request get on your server so I don't think that's what you need.
In jquery, most of the time you will "select" an element using jquery selector : $("#id")
This will select $(), this will say you are selecting an element using his id $("#name_of_the_id").
Then, you will have an object which will represent the selected element.
If you want to get all the html inside this element do :
function getHtmlFromElementId(id)
{
var element = $("#" + id);
var html = element.html();
return html;
}
Printing the return of this function will print all html code inside the element selected.
If you are seaching for a good tutorial on jquery, the w3schools' one is really good:
http://www.w3schools.com/jquery/jquery_examples.asp

Get onClick element to return to the main element?

I'm awful with javascript and I'm having a problem with this one.
I'm using this code
<script>
function changeNavigation(id){
document.getElementById('members')
.innerHTML=document.getElementById(id).innerHTML
}
</script>
and HTML
`<span onClick="changeNavigation('members')" >MEMBERS</span>
<span onClick="changeNavigation('help')" >HELP</span>`
<div id="members>...</div>
<div id="help" style="display: none;>...</div>
But I can't get <span onClick="changeNavigation('members')" >MEMBERS</span> to actually go to an element "members" without duplicating everything inside of it in another id.
Is there a way to do this?

This can be done using only standard javascript, but personally I'd recommend going ahead and getting used to using jQuery. Here's an example jsfiddle using jQuery: http://jsfiddle.net/JnvCR/2/
Don't forget to include jQuery in your website:
<script src="http://code.jquery.com/jquery.js"></script>

You need to correct your syntax errors. Use onclick instead of onClick (pedantic). Make sure you close your attributes properly, you are missing a few closing " marks.
updated html
<span onclick="changeNavigation('members')" >MEMBERS</span>
<span onclick="changeNavigation('help')" >HELP</span>`
<div id="members">...</div>
<div id="help" style="display: none;">...</div>
There is also an error with your logic as you are simply replacing the contents of div#members with itself.
Updated JS without syntax errors, but still with dodgy logic
function changeNavigation(id){
document.getElementById('members').innerHTML=document.getElementById(id).innerHTML;
}
Demo fiddle
http://jsfiddle.net/ADGCV/
As far as your actual question goes, can you explain what you would like to happen a bit better??
Here's a possible solution http://jsfiddle.net/ADGCV/1/

Can't fire click event on the elements with same id

Could you help me to understand - where I made the mistake. I have the following html code:
<div id="container">
Info mail.ru
</div>
<div id="container">
Info mail.com
</div>
<div id="container">
Info mail.net
</div>
and the following js code (using jQuery):
$('#getInfo').click(function(){
alert('test!');
});
example here
"Click" event fired only on first link element. But not on others.
I know that each ID in html page should be used only one time (but CLASS can be used a lot of times) - but it only should (not must) as I know. Is it the root of my problem?
TIA!
upd: Big thx to all for explanation!:)

Use a class for this (and return false in your handler, not inline):
<div id="container">
Info mail.ru
</div>
<div id="container">
Info mail.com
</div>
<div id="container">
Info mail.net
</div>
$('.getInfo').click(function(){
alert('test!');
return false;
});
http://jsfiddle.net/Xde7K/2/
The reason you're having this problem is that elements are retrieved by ID using document.getElementById(), which can only return one element. So you only get one, whichever the browser decides to give you.

While you must, according to the W3 specifications, have only one element with a given id within any document, you can bypass this rule, and the issues arising from the consequences if document.getElementById(), if you're using jQuery, by using:
$('a[id="getInfo"]').click(function() {
alert('test!');
return false;
});
JS Fiddle demo.
But, please, don't. Respect the specs, they make everybody's life easier when they're followed. The above is a possibility, but using html correctly is much, much better for us all. And reduces the impact of any future changes within the browser engines, jQuery or JavaScript itself.

It must only be used once or it will be invalid so use a class instead, return false can also be added to your jQuery code as so: -
$('.getInfo').click(function(){
alert('test!');
return false;
});
<a href="#info-mail.net" **class**="getInfo" ....

First id's are for one element only, you should have same id for several divs.
you can make it class instead.
your example changed:
<div class="container">
<a href="#info-mail.ru" class="getInfo" >Info mail.ru</a>
</div>
<div class="container">
<a href="#info-mail.com" class="getInfo" >Info mail.com</a>
</div>
<div class="container">
<a href="#info-mail.net" class="getInfo" >Info mail.net</a>
</div>
$('.getInfo').click(function(ev){
ev.preventDefault(); //this is for canceling your code : onClick="return false;"
alert('test!');
});

You can use the same id for several element (although the page won't validate), but then you can't use the id to find the elements.
The document.getElementById method only returns a single element for the given id, so if you would want to find the other elements you would have to loop through all elements and check their id.
The Sizzle engine that jQuery uses to find the elements for a selector uses the getElementById method to find the element when given a selector like #getInfo.

I know this is an old question and as everyone suggested, there should not be elements with duplicate IDs. But sometimes it cannot be helped as someone else may have written the HTML code.
For those cases, you can just expand the selector used to force jQuery to use querySelectorAll internally instead of getElementById. Here is a sample code to do so:
$('body #getInfo').click(function(){
alert('test!');
});
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
</head>
<body>
<div id="container">
Info mail.ru
</div>
<div id="container">
Info mail.com
</div>
<div id="container">
Info mail.net
</div>
</body>
However as David Thomas said in his answer
But, please, don't. Respect the specs, they make everybody's life easier when they're followed. The above is a possibility, but using html correctly is much, much better for us all. And reduces the impact of any future changes within the browser engines, jQuery or JavaScript itself.