Question

Currently I have a heading with a downwards pointing icon. If the header is clicked, I want the image to change to an upwards one.

I have tried using the “?” operator to query if it is, but I am not 100% sure how it works. I’m using this code at the moment.

// Toggle message_body
$(".message_head").click(function(){
    var id = $(this).attr("id");
    $(this).next(".message_body").slideToggle(500);
    $(".icon[id=" + id + "]").attr("src", "../images/admin/Symbol_Down.png" ? : "../images/admin/Symbol_Up.png");
    return false;
});

I know this code does not work. Could someone please show me how? Thanks!

Answer 1

This will do the trick. Note that you need to do the comparison within the terenary operator. If you just do "something" ? "blah" : "result, it will always be true, because non-null values are always true.

var up = "../images/admin/Symbol_Up.png";
var down = "../images/admin/Symbol_Down.png";
$(".message_head").click(function(){
    var icon = $(".icon[id=" + $(this).attr("id") + "]");
    $(this).next(".message_body").slideToggle(500);        
    icon.attr("src", this.attr("src") == up ? down : up);
});

I just realized one fundamental issue with your HTML if your JavaScript css selector is accurate. You are asking for .icon[id=x] and using the ID attribute from the .message_head class to find the ID of the icon. For this to work, you would have to have the same ID for both, which is invalid HTML. What I imagine your HTML looks like is this:

<div class="message_head" id="1">
  <img class="icon" src="up.jpg" id="1"/>
</div>

This is a nono. What you can do is this:

<div class="message_head" id="1">
  <img class="icon" src="up.jpg" />
</div>

var up = "../images/admin/Symbol_Up.png";
var down = "../images/admin/Symbol_Down.png";
$(".message_head").click(function(){
    var icon = $('.icon', this);
    $(this).next(".message_body").slideToggle(500);        
    icon.attr("src", this.attr("src") == up ? down : up);
});