John John - 2 months ago 11
Javascript Question

Using html() method with a symbol in jQuery

I wanted to create an updates list, when you see only the title of the update- unless you click on a down-pointing traingle near the title, and then you will see the full update information + the down-pointing traingle will change to an up-pointing traingle. And after clicking on the up-pointing traingle- you will see only the title of the update again + the triangle will be down-pointing.

So I wrote the following code in order to implement that:

html:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<script type="text/javascript" src="script.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
</head>

<script>
arrowsUpdate();
</script>


<p>
<span class="down-arrow">&#9660;</span>
<br>
<span class="hidden-text">update 1</span>
</p>

<p>
<span class="down-arrow">&#9660;</span>
<br>
<span class="hidden-text">update 2</span>
</p>


</body>
</html>


JS:

function arrowsUpdate(){
$(document).ready(function(){
$(".down-arrow").each(function(){
$(this).click(function(){
$(this).siblings(".hidden-text").slideToggle(0,"linear");
if($(this).html()=="&#9660;")
$(this).html("&#9650;");
else
$(this).html("&#9660;");
});
});
});
}


The problem with this code is that the pointing triangle is allways down-pointing. It seems that there is a problem with the
if
statement- which allways returns false.

I don't understand why that happens, especially when the set code lines (
$(this).html("&#9650;");
and
$(this).html("&#9660;");
) are working as expected (tried using those code lines in a different page- and it works).

Why the condition
$(this).html()=="&#9660;"
returns allways false, if the content of
this
is
&#9660;
?

Answer

You can set html with entities, but when you get it back, it will no longer be entities but characters, that's how entities work.

To be clearer, this line fails every time

if( $(this).html()=="&#9660;" )

because $(this).html() will never return an entity, but the character instead, proof ...

document.body.innerHTML = '&#9660;';
console.log( document.body.innerHTML )

An easier way to create toggle functionality without relying on the markup, would be to just use a flag

function arrowsUpdate() {
  $(".down-arrow").on('click', function() {
    $(this).siblings(".hidden-text").slideToggle(0, "linear");

    var flag = $(this).data('flag');

    $(this).html(flag ? "&#9660;" : "&#9650;").data('flag', !flag);
  });
}