[javascript] JavaScript hide/show element

How could I hide the 'Edit'-link after I press it? and also can I hide the "lorem ipsum" text when I press edit?

<script type="text/javascript">
function showStuff(id) {
  document.getElementById(id).style.display = 'block';
}
</script>


<td class="post">

  <a href="#" onclick="showStuff('answer1'); return false;">Edit</a>
  <span id="answer1" style="display: none;">
    <textarea rows="10" cols="115"></textarea>
  </span>

  Lorem ipsum Lorem ipsum Lorem ipsum Lorem ipsum 
</td>

you can use hidden property of element:

document.getElementById("test").hidden=true;
document.getElementById("test").hidden=false

Though this question has been answered many times before, I thought I would add to it with a more complete and solid answer for future users. The main answer does solve the problem, but I believe it may be better to know/understand the some of various ways to show/hide things.

.

Changing display using css()

This is the way I used to do it until I found some of these other ways.

Javascript:

$("#element_to_hide").css("display", "none");  // To hide
$("#element_to_hide").css("display", "");  // To unhide

Pros:

• Hides and unhides. That's about it.

Cons:

• If you use the "display" attribute for something else, you will have to hardcode the value of what it was prior to hiding. So if you had "inline", you would have to do $("#element_to_hid").css("display", "inline"); otherwise it will default back to "block" or whatever else that it will be forced into.
• Lends itself to typos.

Example: https://jsfiddle.net/4chd6e5r/1/

.

Changing display using addClass()/removeClass()

While setting up the example for this one, I actually ran into some flaws on this method that make it very very unreliable.

Css/Javascript:

.hidden {display:none}
$("#element_to_hide").addClass("hidden");  // To hide
$("#element_to_hide").removeClass("hidden");  // To unhide

Pros:

• It hides....sometimes. Refer to p1 on the example.
• After unhiding, it will return back to using the previous display value....sometimes. Refer to p1 on the example.
• If you want to grab all hidden objects, you just need to do $(".hidden").

Cons:

• Does not hide if the display value was set directly on the html. Refer to p2 on the example.
• Does not hide if the display is set in javascript using css(). Refer to p3 on the example.
• Slightly more code because you have to define a css attribute.

Example: https://jsfiddle.net/476oha8t/8/

.

Changing display using toggle()

Javascript:

$("element_to_hide").toggle();  // To hide and to unhide

Pros:

• Always works.
• Allows you to not have to worry about which state it was prior to switching. The obvious use for this is for a....toggle button.
• Short and simple.

Cons:

• If you need to know which state it is switching to in order to do something not directly related, you will have to add more code (an if statement) to find out which state it is in.
• Similar to the previous con, if you want to run a set of instructions that contains the toggle() for the purpose of hiding, but you don't know if it is already hidden, you have to add a check (an if statement) to find out first and if it is already hidden, then skip. Refer to p1 of the example.
• Related to the previous 2 cons, using toggle() for something that is specifically hiding or specifically showing, can be confusing to others reading your code as they do not know which way they will toggle.

Example: https://jsfiddle.net/cxcawkyk/1/

.

Changing display using hide()/show()

Javascript:

$("#element_to_hide").hide();  // To hide
$("#element_to_hide").show();  // To show

Pros:

• Always works.
• After unhiding, it will return back to using the previous display value.
• You will always know which state you are swapping to so you:
  1. don't need to add if statements to check visibility before changing states if the state matters.
  2. won't confuse others reading your code as to which state you are switching to if, if the state matters.
• Intuitive.

Cons:

• If you want to imitate a toggle, you will have to check the state first and then switch to the other state. Use toggle() instead for these. Refer to p2 of the example.

Example: https://jsfiddle.net/k0ukhmfL/

.

Overall, I would say the best to be hide()/show() unless you specifically need it to be a toggle. I hope you found this information to be helpful.

If you are using it in a table use this :-

  <script type="text/javascript">
   function showStuff(id, text, btn) {
    document.getElementById(id).style.display = 'table-row';
    // hide the lorem ipsum text
    document.getElementById(text).style.display = 'none';
    // hide the link
    btn.style.display = 'none';
}
</script>


<td class="post">

<a href="#" onclick="showStuff('answer1', 'text1', this); return false;">Edit</a>
<span id="answer1" style="display: none;">
<textarea rows="10" cols="115"></textarea>
</span>

<span id="text1">Lorem ipsum Lorem ipsum Lorem ipsum Lorem ipsum</span>
</td>

I would suggest this to hide elements (as others have suggested):

document.getElementById(id).style.display = 'none';

But to make elements visible, I'd suggest this (instead of display = 'block'):

document.getElementById(id).style.display = '';

The reason is that using display = 'block' is causing additional margin/whitespace next to the element being made visible in both IE (11) and Chrome (Version 43.0.2357.130 m) on the page I'm working on.

When you first load a page in Chrome, an element without a style attribute will appear like this in the DOM inspector:

element.style {
}

Hiding it using the standard JavaScript makes it this, as expected:

element.style {
  display: none;
}

Making it visible again using display = 'block' changes it to this:

element.style {
  display: block;
}

Which is not the same as it originally was. This could very well not make any difference in the majority of cases. But in some cases, it does introduce abnormalities.

Using display = '' does restore it to its original state in the DOM inspector, so it seems like the better approach.

I would like to suggest you the JQuery option.

$("#item").toggle();
$("#item").hide();
$("#item").show();

For example:

$(document).ready(function(){
   $("#item").click(function(event){
     //Your actions here
   });
 });

I recommend Javascript, because its relatively fast and more malleable.

    <script>
function showStuff(id, text, btn) {
document.getElementById(id).style.display = 'block';
// hide the lorem ipsum text
document.getElementById(text).style.display = 'none';
// hide the link
btn.style.display = 'none';
}
</script>


<td class="post">

<a href="#" onclick="showStuff('answer1', 'text1', this); return false;">Edit</a>
<span id="answer1" style="display: none;">
<textarea rows="10" cols="115"></textarea>
</span>

<span id="text1">Lorem ipsum Lorem ipsum Lorem ipsum Lorem ipsum</span>
</td>

Vanilla JS for Classes and IDs

By ID

document.querySelector('#element-id').style.display = 'none';

By Class (Single element)

document.querySelector('.element-class-name').style.display = 'none';

By Class (Multiple elements)

for (const elem of document.querySelectorAll('.element-class-name')) {
    elem.style.display = 'none';
}

You can also use this code to show/hide elements:

document.getElementById(id).style.visibility = "hidden";
document.getElementById(id).style.visibility = "visible";

Note The difference between style.visibility and style.display is when using visibility:hidden unlike display:none, the tag is not visible, but space is allocated for it on the page. The tag is rendered, it just isn't seen on the page.

See this link to see the differences.

You should think JS for behaviour, and CSS for visual candy as much as possible. By changing your HTML a bit :

<td class="post">
    <a class="p-edit-btn" href="#" onclick="showStuff(this.parentNode);return false;">Edit</a>
    <span id="answer1" class="post-answer">
       <textarea rows="10" cols="115"></textarea>
    </span>
    <span class="post-text" id="text1">Lorem ipsum ... </span>
</td>

You'll be able to switch from one view to the other simply using CSS rules :

td.post-editing > a.post-edit-btn,
td.post-editing > span.post-text,
td.post > span.post-answer
{
    display : none;
}

And JS code that switch between the two classes

<script type="text/javascript">
function showStuff(aPostTd) {
    aPostTd.className="post-editing";
}
</script>

Just create hide and show methods yourself for all elements, as follows

Element.prototype.hide = function() {
    this.style.display = 'none';
}
Element.prototype.show = function() {
    this.style.display = '';
}

After this you can use the methods with the usual element identifiers like in these examples:

document.getElementByTagName('div')[3].hide();
document.getElementById('thing').show();

or:

<img src="removeME.png" onclick="this.hide()">