We Keep Coding

Document.querySelector returns a NULL value - script is at bottom of page

I am trying to get the patientNumber (ClinicA100-PF-TR1-P1) using querySelector. I keep getting a NULL value. The patientNumber is at the top of the page and the script is at the bottom. Even after the page is loaded, I click a button that runs the function and it still returns a NULL value.
Here is a screenshot of the selectors (https://recordit.co/IypXuuXib0)
<script type="text/javascript">
function getPatientNumber(){
var patientNumber = document.querySelector("patientNumber");
console.log(patientNumber);
console.log("hello");
return patientNumber;
}
var patientNumber = getPatientNumber();
console.log(patientNumber);
_kmq.push(['identify', patientNumber]);
</script>
Thank you for any help you can provide.
ADDITIONAL HTML INFORMATION:
I am using Caspio (database management software) to create this HTML code. I don't know if that may be the cause of the issue. Here is the HTML CODE.
<p class="sponsorName" id="sponsorNameID">[#authfield:User_List_Sponsor_Name]</p>
<p class="clinicNumber" id="clinicNumberID">[#authfield:User_List_Site_Number]</p>
<p class="protocolNumber" id="protocolNumberID">[#authfield:User_List_Protocol_Number]</p>
<p class="patientNumber" id="patientNumberID">[#authfield:User_List_Patient_Number]</p>

You are missing a dot.
var patientNumberNode = document.querySelector(".patientNumber");
var patientNumber = patientNumberNode.innerText;

if you select the item with class".", if you select with id, you should use"#".
var patientNumber = document.querySelector(".patientNumber"); // class select
var patientNumber = document.querySelector("#patientNumber"); // id select

Your selector is incorrect. It should be
var patientNumber = document.querySelector(".patientNumber");
Why is it failing:
When you use patientNumber as the selector, JavaScript looks for an element with a name of patientNumber. Since that's not the case, and you are looking for an element with a class of patientNumber, you need to use the . notation.
Addon Suggestion (can be ignored):
Since you are also using IDs, consider using document.getElementById() as it is faster than using document.querySelector().
Note that if you use document.getElementById(), your .patientNumber selector won't work. You need to write it as
document.getElementById('patientNumberID');
//ID based on the screenshot of the DOM you've shared

While the code is at the bottom of the page, and the element is at the top, it is not loaded asynchronously as it comes from a third party database. i put a delay in the getPatientNumber() and it works now.

Remove any specific html code using javascript

In the past I used Google Developer Console to delete some specific divs on a page. I could do it manually of course but in some cases where the divs where many I had to use the console. I had a single line code that did the job (I found it while searching the internet) but I lost my note.
So how can I delete using javascript any html code (by copy pasting the code).
Something like:
elements = $('<div ... </div>');
elements.remove();
OR
$('<div ... </div>').remove();
Any ideas? I am not an expert in javascript (obviously) and I've been searching stackoverflow for hours without finding anything that works.
UPDATE: I think some people might get confused with my question. Google developer console accepts javascript command lines. So even though I ask for javascript I will use the code on the google developer console.
UPDATE 2 :
Here is an example of a div I need to delete. Keep in mind I want to copy paste the entire code in the javascript code. Not just identify the div.
<div class="entry-status-overlay" data-entry-status="declined">
<div class="entry-status-overlay__inner">
<span class="entry-status-overlay__title">Declined</span>
</div>
</div>
It's the data-entry-status="declined" that makes that div unique so I can't just identify the div using an id selector or a class selector. I need to put the entrire thing there and remove it.
I tried:
$('<div class="entry-status-overlay" data-entry-status="declined"><div class="entry-status-overlay__inner"><span class="entry-status-overlay__title">Declined</span></div></div>').remove();
It didn't remove the div.

Try to search the dom by its outerHTML.
function deleteDomByHtml(html){
html=html.replace(/\s/g,'');
$("*").each(function(){
if(this.outerHTML.replace(/\s/g,'')===html){
$(this).remove();
}
});
}
And try this line on this page:
deleteDomByHtml(`<span class="-img _glyph">Stack Overflow</span>`);

You cannot do by simply pasting the code. That will remove all the div element.
You may need a specific selector like id,class or child to specific parent to remove the element from the dom.
Consider this case the divs have common class but the data-entry-status is different. So you can get the dom using a selector and then check the dataset property.
For demo I have put it inside setTimeout to show the difference. In application you can avoid it
setTimeout(function() {
document.querySelectorAll('.entry-status-overlay').forEach(function(item) {
let getStatus = item.dataset.entryStatus;
if (getStatus === 'declined') {
item.remove()
}
})
}, 2000)
<div class="entry-status-overlay" data-entry-status="declined">
<div class="entry-status-overlay__inner">
<span class="entry-status-overlay__title">Declined</span>
</div>
</div>
<div class="entry-status-overlay" data-entry-status="accepted">
<div class="entry-status-overlay__inner">
<span class="entry-status-overlay__title">accepted</span>
</div>
</div>

Just add any attribute with [] and it will remove the element.
$('[class="entry-status-overlay"]').remove();
/*OR*/
$('[data-entry-status="declined"]').remove();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<div class="entry-status-overlay" data-entry-status="declined">
<div class="entry-status-overlay__inner">
<span class="entry-status-overlay__title">Declined</span>
</div>
</div>

function del(){
var h = document.body.outerHTML;
h = h.match('<div>...</div>');
h.length--;
return h;
}
I guess this will work just give it a try... i tried on browser console and it worked, this way you can match the exact you want.

I might as well add my take on this. Try running this in your console and see the question vanish.
// convert the whole page into string
let thePage = document.body.innerHTML,
string = [].map.call( thePage, function(node){
return node.textContent || node.innerText || "";
}).join("");
// I get some string. in this scenario the Question or you can set one yourself
let replacableCode = document.getElementsByClassName('post-layout')[0].innerHTML,
string2 = [].map.call( replacableCode, function(node){
return node.textContent || node.innerText || "";
}).join("");
// replace whole page with the removed innerHTML string with blank
document.body.innerHTML = thePage.replace(replacableCode,'');

If you want to identify divs with that particular data attribute, you can use a data-attribute selector. In the example below, I've used a button and click event to make the demo more visual, but in the console the only line you'd need would be:
$('div[data-entry-status="declined"]').remove();
$(function() {
$("#testbutton").click(function() {
$('div[data-entry-status="declined"]').remove();
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="entry-status-overlay" data-entry-status="declined">
<div class="entry-status-overlay__inner">
<span class="entry-status-overlay__title">Declined</span>
</div>
</div>
<div id="x">Some other div</div>
<button type="button" id="testbutton">Click me to test removing the div</button>
See https://api.jquery.com/category/selectors/attribute-selectors/ for documentation of attribute selectors.
P.S. Your idea to paste some raw HTML into the jQuery constructor and then execute "remove" on it cannot work - you're telling jQuery to create an object based on a HTML string, which is, as far as it's concerned, a new set of HTML. It does not try to match that to something existing on the page, even if that exact HTML is in the DOM somewhere, it pays it no attention. It treats what you just gave it as being totally independent. So then when you run .remove() on that new HTML...that HTML was never added to the page, so it cannot be removed. Therefore .remove() has no effect in that situation.

copy html block with tags script

I have such html code:
<div>
<div id="text">text></div>
<script>$("#text").val('some value');</script>
</div>
I copy this html through .clone() and edit html inside. Result:
<div>
<div id="1-text">text></div>
<script>$("#text").val('some value');</script>
</div>
I want to change id inside tags script. $("#1-text").val('other value');
How can I do it?

You can simply add a variable to the outside that dynamically tells you what to select. so if you were to iterate through your values using a loop you can do something like this:
$("#text_"+i).val('other value');
You could also set a counter and as new divs are added the i increments. So it is flexible.
I'm not exactly sure what your end goal is but I wouldn't recommend this methodology if you're attempting to manipulate the javascript in the <script> tag. As I believe that would be cumbersome.

If you want to copy entire html block, you should bind your inline javascript code to this block as a container. Not id. So when you move or copy the block your script will be able to find any elements related to container.
<div id="containerOne" class="js-container">
<div class="js-text" data-text="some value">some value</div>
<script>
var $el = $("script").last().closest(".js-container").find(".js-text");
$el.text($el.data("text"));
</script>
</div>
Hereby you obtain access to elements by class not id. Note using "js-" prefix is just for javascript manipulation not for css styling.
Also you don't need to change script itself. You can change values via "data-" attributes.
In your external script you can encapsulate any clone logic by various methods. For example:
var myModule = {
clone: function(containerSelector) {
var $donorEl = $(containerSelector);
var $donorScript = $donorEl.find('script');
$script = $("<script />");
$script.text($donorScript.text());
$recipientEl = $donorEl.clone();
$recipientEl.attr('id', 'containerTwo');
var newValue = 'other value';
$('.js-text', $recipientEl).data('text', newValue);
$('body').append($recipientEl);
$('script', $recipientEl).replaceWith($script);
}
};
myModule.clone('#containerOne');
You can see the working example.

Set div background color without using ID

Is possible change color of background my div using JavaScript without using ID? And how?
Html code is:
<div class="post" onmouseover="test(this)">
JS code is:
function test(item){
alert("Hi :-)");
}

Have you tried
function test(item){
item.style.backgroundColor = "red";
}
Since item is the actual div you're triggering this event on you won't need an ID to style the element.
A really easy (inline) solution would be the one below.
<div class="post" onmouseover="javascript:style.backgroundColor = 'red';">
Content blabla
</div>
I would personally rather do all of this inside a JS file but hey this works too.

You can loop through the DOM with JavaScript, but you'll have a better time of it if you're using JQuery. You'll want to invest some time learning about selectors:
http://api.jquery.com/category/selectors/
http://www.w3schools.com/jquery/jquery_ref_selectors.asp.
You'll be looking for something like:
function test(){
var element = $('div');
}
As people have shared in the comments, without a unique identifier, you'll have a rough time, especially as new elements are added to the page.

HTML DOM manipulation : properly replace tag by heading tag

I want to replace some tag-inside-a-paragraph-tag by a heading-tag-enclosed-by-a-paragraph tag. This would result in proper W3C coding, but it seems that jQuery is not able to manipulate the DOM in the right way!? I tried several ways of (jQuery) coding, but i can't get it to work ..
Original code:
<p>some text <span>replace me</span> some more text</p>
Desired code:
<p>some text</p><h2>my heading</h2><p>some more text</p>
Resulting code by jQuery replaceWith():
<p>some text<p></p><h2>my heading</h2><p></p>some more text</p>
Demo: http://jsfiddle.net/foleox/J43rN/4/
In this demo, look at "make H2 custom" : i expect this to work (it's a logical replace statement), but it results in adding two empty p-tags .. The other 2 functions ("make code" and "make H2 pure") are for reference.
Officially the W3C definition states that any heading tag should not be inside a paragraph tag - you can check this by doing a W3C validation. So, why does jQuery add empty paragraph tags? Does anybody know a way to achieve this? Am i mistaken somehow?

You can achieve this with this code. However it's pretty ugly:
$('.replaceMe').each(function() {
var $parent = $(this).parent(),
$h2 = $(this).before('$sep$').wrap('<h2>').parent().insertAfter($parent);
var split = $parent.html().split('$sep$');
$parent.before('<p>' + split[0] + '</p>');
$h2.after('<p>' + split[1] + '</p>');
$parent.remove();
});
http://jsfiddle.net/J43rN/5/

If you read the jQuery docs, you will find:
When the parameter has a single tag (with optional closing tag or
quick-closing) — $("<img />") or $("<img>"), $("<a></a>") or $("<a>")
— jQuery creates the element using the native JavaScript
createElement() function.
So that is exactly what it is doing. And as I said in my comment, you can't change a parent node from a child node, you're altering the DOM here, not HTML code. So you'll need to either use replaceWith on the parent node and replace everything or use something like remove and append to split it up in multiple elements which you append after each other.

Try this:
var temp = "<p>some text <span>replace me</span> some more text</p>";
temp.replace(/(\<span\>replace me\<\/span\>)/gi, '</p><h2>my heading</h2><p>');
This will do a case insensitive replace for multiple occurences as well.
Read more about capturing groups here
Original credit to this question!

Please try this I have updated the http://jsfiddle.net/J43rN/6/ example by the below java script function please check I hope it will work for you
function fnMakeCode() {
$('#myP #replaceMe').html("<code id='replaceMe'>My Code</code>");
}
function fnMakeH2pure() {
$('#myP #replaceMe').html("<h2 id='replaceMe'>My H2 pure</h2>");
}
function fnMakeH2custom() {
$('#replaceMe').html("<p></p>").html("<h2>My H2 custom</h2>");
}