I'm inspecting a dynamic html webpage. There is an element that looks like this:
<span id="x">3</span>
It's value constantly changes based on some variable. So for example if the variable changes to 10, the text inside the span element will also change to 10 like this:
<span id="x">10</span>
I want to find where this variable is that is causing this change. Where in inspect element can I find this variable and manipulate it?
Try the sources tab of the Dev Tools.
If can't find it in the elements tab, try the sources tab:
For example this is looking at some JavaScript of github.com:
Look for the JavaScript that may be manipulating this element, I have no idea what it could be, but I'd first look for something along the lines of:
var [VARIBALE_NAME] = document.getElementById("x")
Though on many dynamic web pages it can be very difficult to find something like that. This is because many web pages are dynamically created and tend not to be very human-readable.
You should go to script tags in the inspect page and search where it is getting this element. i.e, somewhere in the script there will be something like this;
document.getElementById('x').innerHTML = that-variable-which-you-are-finding; // as the id of the span is x.
In this way you will get the name of the variable. Then in the script tags, search for that variable on other positions and you will get where it is getting updated.
Related
I have a node application and I have a pug template that are coded up, the pug template represents one project, and within that are shown related targets (so a one to many relationship - one project can have many targets).
What I want to do, is have a user be able to click on the DOM element representing a target, and it open up a modal form or something similar, and allow it to be edited. I'm not sure of the best way to do this. So this is my pug template element for each:
each target in project.targets
.target__card
.target__avatar
h6.target__title= target.title
input#targetId(type='hidden' value=`${target._id}`)
So I've got my hidden id in there and it's all peachy. I want to be able to click on it and it open a form that can edit it and then submit to my endpoint. But if I have a javascript function like this:
const targetCard = document.querySelector('.target__card')
if (targetCard) {
targetCard.addEventListener('click', async (e) => {
const target = document.getElementById('targetId').value
console.log('target is ', target)
})
}
then this is only going to work for the first DOM element. But do I really need to loop through again, in my javascript, or something like that? I'm already looping in the template, and the information is ' just sitting there' already, I can see it. It seems wasteful to loop through it again in a js function, even if I did know the best way to do that (which I'm not sure I do). Is there something obvious that I'm missing? Can I embed a form in each element that can simply be hidden and unhidden? That seems a bit wasteful too.
I have a div that will appear on the page at a separate point. It doesn't always appear on the page and can be added via a CMS if needed. There's a line of text that will appear within the body. If the user has decided to have this div added, it would need to be moved into position via jquery. So, I have this text:
<p><strong>Key Facts:</strong></p>
I want to find it using jquery, then move the other div in front of it. I tried a couple of different ways to select this text then move the div in front of it and haven't had any luck. The best way I found to find the text was to do this:
var foundin = $('*:contains("<p><strong>Key Facts:</strong></p>")');
From that point, to move the div into position, I thought I could something like this:
$('#DivIWantToMove').insertBefore($foundin);
That didn't work, though. I also looked at this:
$( $foundin ).before( $('#DivIWantToMove') );
AS you might imagine, since you're reading this, that didn't work either. So, I'm asking you, is it possible to do what I want? I'm fairly constrained by the CMS that we are using. The DIV I need to move will always be someplace on the page and I have to move it. The client doesn't want to have to add a class to <p><strong>Key Facts:</strong></p> so I'm let with this. If I could have a class on <p> then it would be super easy. I've already done it. The client doesn't like having an extra step. Any ideas?
I think contains selector only looks for text, not html tags. so you have to modify your contains selector. if your html is like this -
<div>
<p><strong>Key Facts:</strong>
</p>
</div>
<div id="move">something something</div>
and you want to move your <div id='move'> in front of p, then try this -
var foundin = $('p:contains("Key Facts")');
var divtomove = $('div#move');
foundin.before(divtomove);
Demo
Update also look into this QA: jQuery :contains with html. Instead of using contains you can use one of the methods from there.
I'm making my own WYSIWYG. I've got two buttons: "Visualize" and Show Source.
I've got an iframe (rich text editor) that contains a huge piece of HTML code. First time it's loaded it shows all the elements visually. Once Show Source is pressed the innerHTML text (of the visualized html) is shown. But how can I make the HTML text visual again, when the Visualize button is pressed?
content.document.body.innerText holds the HTML that needs to be visualized.
(content = id of the iframe)
$('#Visualize').click(function()
{
// Make HTML visible
});
With the html code that you already have you and to show a preview in a div, correct? Just use the html function.
$('#Visualize').click(function(){
$('#myShowDiv').html(content.document.body.innerText);
});
If you're using an iframe and that iframe is only intended to hold the actual page source being edited, then you're going to need variables on your parent frame that hold the actual source. I would recommend keeping it separate and then use the following to perform switches:
var actualSource = content.document.body.innerHTML;
// just something to initialize it
// You should probably keep it in a global object instead of as a var
$('#Visualize').click(function()
{
actualSource = content.document.body.innerText;
content.document.body.innerHTML = "";
content.document.body.innerHTML= actualSource;
});
I would imagine that you have methods that are capturing the source, but I would imagine you'd want to capture the actual source as it is at that moment. I'm not sure what you're doing with the actual editing piece (is it a div that is editable? is it a text area?), but in order to perform the showing, it should just be a matter of toggling the innerHTML and innerText between the two settings. The real catch will be monitoring the actual controls affected by this change.
Can't seem to get this one to work...
I have a page that hides certain links. When the DOM is loaded, I'm using jQuery to toggle some of those elements. This is driven by using a data attribute like so:
<div class="d_btn" data-usr='48'>
<div class="hidden_button">
Then, I have the code:
$.each($(".d_btn"), function() {
var btn = $(this).data('usr');
if ( btn == '48' ){
$(this).children('.hidden_button').toggle();
}
The above all works as planned. The problem is that I am trying to remove the data-usr from the class .d_btn once the if statement is evaluated. I've tried the following and nothing works (i.e., after the page is loaded, the source still shows the data-usr attribute:
$(this).removeAttr("data-usr");
$(this).removeData("usr");
I've been working on this for a couple of hours now and...nothing! Help is greatly appreciated!
UPDATE
I've tried the great suggestions of setting the data attribute to an empty string but I'm still not getting the desired result.
To explain a little further, The reason I'm trying to remove the attribute is so when an ajax response adds another item to the page, the previously added items would already have the button either shown or hidden. Upon AJAX response, I'm calling the same function once the DOM is loaded.
Currently, when something is added via AJAX, it toggles all the buttons (showing the ones that were hidden and vice versa.) Ugh...
I'm also fully willing to try alternatives to my approach. Thanks!
UPDATE
Well, the light bulb just flashed and I am able to do what I want to do by just using .show() instead of .toggle()
Anyway, I'd still like to find an answer to this question because the page will be potentially checking hundreds of items whenever something is added - this seems horribly inefficient (even for a computer, hahaha.)
Why don't you set the value to a random value or empty variable instead if removeAttr does not work..
$(this).attr("data-usr" , '');
$(this).prop("data-usr" , '');
Changing the DOM doesn't affect the source. It affects the DOM, which you can view with the Inspector/Developer Tools. Right click => View Source will give you the original source of the page, not the actual current source as modified by JavaScript.
Set it to a blank string:
$(this).attr("data-usr", "");
I second what Kolink said: check the DOM, not the source. (Chrome: Ctrl + Shift + i).
As others have stated. Checking the source will only show the original unedited source for the webpage. What you need to do is check the DOM using developer tools.
I've just checked everything in Chrome's inspector on jsfiddle here and the attribute is definitely being removed as well as the data.
I want to give a static javascript block of code to a html template designer, which can be:
either inline or external or both
used once or more in the html template
and each block can determine its position in the template relative to the other javascript code blocks.
An example could be image banners served using javascript. I give code to template designer who places it in two places, once for a horizontal banner in the header and once for a vertical banner. The same code runs in both blocks but knowing their positions can determine if to serve a horizontal or a vertical image banner.
Make sense?
Another example: Say you have the same 2 javascript tags in a web page calling an external script on a server. Can the server and/or scripts determine which javascript tag it belongs to?
NOTE: Can we say this is a challenge? I know that I can avoid this puzzle very easily but I come across this on a regular basis.
JavaScript code can locate all <script> elements on the page and it can probably examine the attributes and the content to check from which element it came from. But that's probably not what you want.
What you want is a piece of JavaScript which replaces tags on the page with ad banners. The usual solution is to add a special element, say a IMG, for this and give that IMG an id or a class or maybe even a custom attribute (like adtype="vertical") and then use JavaScript to locate these elements and replace the content by changing the src attribute.
For example, using jQuery, you can should your images like so:
<img src="empty.gif" width="..." height="..." class="ad" adtype="..." />
Then you can locate each image with
$('img.ad')
[EDIT] Well, the server obviously knows which script belongs into which script tag because it inserts the script. So this is a no-brainer.
If the script wants to find out where it is in the DOM, add something which it can use to identify itself, say:
<script>var id= '329573485745';
Then you can walk all script tags and check which one contains the value of the variable id.
If you call an external script, then you can do the same but you must add the ID to the script tag as you emit the HTML:
<script id="329573485745" src="..." />
Then the external script can examine the DOM and lookup the element with this id. You will want to use an UUID for this, btw.
This way, a piece of JS can locate the script tag which added itself to the page.
Best thing would probably be to make an insert once function, and then have him insert only the function call where needed.
Like this:
timescalled=0
function buildad(){
var toinsert="" //Code to generate the desired piece of HTML
document.write(toinsert)
timescalled+=1 //So you can tell how many times the function have been called
}
Now a script block calling the function can simply be inserted wherever a banner is needed
<script type="text/javascript">buildad()</script>
Thanks for the tips everyone but I'll be answering my own question.
I figured out several ways of accomplishing the task and I give you the one which works nicely and is easy to understand.
The following chunk of code relies on outputting dummy divs and jQuery.
<script>
// Unique identifier for all dummy divs
var rnd1="_0xDEFEC8ED_";
// Unique identifier for this dummy div
var rnd2=Math.floor(Math.random()*999999);
// The dummy div
var d="<div class='"+rnd1+" "+rnd2+"'></div>";
// Script which :
// Calculates index of THIS dummy div
// Total dummy divs
// Outputs to dummy div for debugging
var f1="<script>$(document).ready(function(){";
var f2="var i=$('."+rnd1+"').index($('."+rnd2+"'))+1;";
var f3="var t=$('."+rnd1+"').length;";
var f4="$('."+rnd2+"').html(i+' / '+t);";
var f5="});<\/script>";
document.write(d+f1+f2+f3+f4+f5);
</script>
Why not not just place the function call on the page instead of the entire code block? This way you can pass in a parameter to tell it what type of advertisement is needed?
BuildAd('Tower');
BuildAd('Banner');
Javascript itself has no clue of it's position in a page. You have to target a control on the page to get it's location.
I don't think it is possible for JavaScript code to know where it was loaded from. It certainly doesn't run at the point it is found, since execution isn't directly tied to the loading process (code usually runs after the whole DOM is loaded). In fact, in the case of externals, it doesn't even make sense, since only one copy of the code will be loaded no matter how many times it is encountered.
It shouldn't be the same code for each banner - there will be a parameter passed to whatever is serving the image banner which will specify the intended size.
Can you give a specific example of what you need this for?
To edit for your recent example: The simple answer is no. I could help you approach the problem from a different direction if you post details of your problem
The term "static block of code" leaves a lot of room for interpretation.
Inline scripts (e.g., ones that rely on document.write and so must be parsed and executed during the HTML parsing phase) cannot tell where they are in the DOM at runtime. You have to tell them (as in one of the first answers you got).
I think you'll probably find that you need to change your approach.
A common way to keep code and markup separate (which is useful when providing tools to HTML designers who aren't coders) is to have them use a script tag like so:
<script defer async type='text/javascript' src='pagestuff.js'></script>
...which then triggers itself when the page is loaded (using window.onload if necessary, but there are several techniques for being triggered earlier than that, which you want because window.onload doesn't trigger until the images have all loaded).
That script then looks for markers in the markup and manipulates the page accordingly. For instance (this example uses Prototype, but you can do the same with raw JavaScript, jQuery, Closure, etc.):
document.observe("dom:loaded", initPage);
function initPage() {
var verticals = $$('div.vertical');
/* ...do something with the array of "vertical" divs in `verticals`,
such as: */
var index;
for (index = 0; index < verticals.length; ++index) {
vertical.update("I'm vertical #" + index);
}
}
The designers can then have blocks on the page that are filled in by code which they flag up in a way that's normal for them (classes or attributes, etc.). The code figures out what it should do based on the classes/attributes of the blocks it finds when it runs.