onmouseover problems with JavaScript (rendered using django and django-imagekit)
I'm using Imagekit. View.py includes:
def pics(request):
p = Photo.objects.all()
return render_to_response('Shots.html',
{'p': p})
The following simple code in the template will generate associated images:
{% for p in p %}
&l开发者_运维百科t;img src = "{{ p.display.url }}">
<img src = "{{ p.thumbnail_image.url }}">
{% endfor %}
I'm attempting to generate a series of thumbnails {{ p.thumbnail_image.url }} which, when mouseover'd, will generate the slightly larger version of the image, {{ p.display.url }} via Javascript. The following code in the template attempts to do so:
<html>
<head>
<HEAD>
<script
language="Javascript">
{ image1 = new Image
image2 = new Image
image1.src = {{ p.thumbnail_image.url }}
image2.src = {{ p.display.url }}
</script>
</head>
<body>
{% for p in p %}
<a href=""
onMouseOver="document.rollover.src=
image2.src
onMouseOut="document.rollover.src=
image1.src">
<img src="{{ p.thumbnail_image.url }}" border=0 name="rollover"></a>
{% endfor %}
</body>
</html>
This will display the series of thumbnails, but the larger image will not display when mouseover'd. I believe it has to do with how I'm specifying the variable {{ p.display.url }}.
I cleaned up your code, but as @fish2000 mentioned, this is still a dirty way of doing it. I came up with the following:
<html>
<head>
<script>
var thumbs = [];
var hovers = [];
{% for p in p %}
thumbs.push(new Image());
thumbs[thumbs.length - 1].src = p.thumbnail_image.url;
hovers.push(new Image());
hovers[hovers.length - 1].src = p.display.url;
{% endfor %}
</script>
</head>
<body>
{% for idx, p in enumerate(p) %}
<a href="">
<img src="{{ p.thumbnail_image.url }}" border=0 name="rollover" onmouseover="this.src = window.hovers[{{ idx }}].src" onmouseout="this.src = window.thumbs[{{ idx }}].src">
</a>
{% endfor %}
</body>
</html>
I wrote up a basic example over at JSFiddle to try and mock what your Python code will produce: http://jsfiddle.net/TeEHU/
To explain a little bit what I did, I setup a couple of JavaScript arrays in the beginning to hold both the thumbnails and the hovers. Initially, I was just going to make them arrays of strings referencing the URLs but followed suit the way you did using the Image object to preload the image hovers.
From here, I got rid of the event handler attributes you defined in the anchor tag and moved it to the image tag so we could have direct access to the image attributes when the user moused over on it.
I generally don't condone the use of generating dynamic JavaScript from the server-side but I was just trying to stay consistent with your code.
It looks like your JavaScript is a little gnarly in general -- some specific e.g.'s:
- you're using the depreciated
languageparam in the<script>tag; - you have what looks like an unclosed bracket at the top of your first script block
- I don't know if you can reference variables you've declared in
onmouseover/onmouseouttags, as you're doing;
Often, you have line breaks in the middle of things like tags or param values, which those may be legal (I'm not sure) but they're of questionable value, at least to me; they are keeping me from understanding what you are doing. Consider removing them.
Also: generally, your use of quotes is a mess... Trust me, if you clean them up, you'll understand your own code much better.
However THE MAIN THING in your case should be: look at the code as rendered to the browser to solve your JavaScript problems. First and foremost. That'll narrow down whether or not the particular bug you seek to squash is due to your template syntax/logic/etc, vs. your client JavaScript. In any case, it's not specifically a django issue per se.
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