Using jquery to run code when django document is ready
Question
I am building a django admin site and am using javascript and jquery (2.0.3) to add some extra functionality to the forms.
I am importing the scripts into my page like this:
<html>
<head>
<script type="text/javascript" src="/static/admin/js/jquery.js"></script>
<script type="text/javascript" src="/static/admin/js/jquery.init.js"></script>
<script type="text/javascript" src="/static/project/js/project.js"></script>
</head>
<!-- ... -->
</html>
At first I placed the following code at the end of project.js :
function tryCustomiseForm() {
// ...
}
$(document).ready(tryCustomiseForm);
Unfortunately this results in an Uncaught TypeError: undefined is not a function exception on the last line.
I then tried the alternative syntaxes of ready() without any more luck.
Lastly I explored the change_form.html template and found this inline javascript:
<script type="text/javascript">
(function($) {
$(document).ready(function() {
$('form#{{ opts.model_name }}_form :input:visible:enabled:first').focus()
});
})(django.jQuery);
</script>
I was able to modify it to suit my needs and now my project.js ends with:
(function($) {
$(document).ready(function() {
tryCustomiseForm();
});
})(django.jQuery);
While this results in the correct behaviour I don't understand it .
This leads to my question: Why did my first approach fail? And what is the second approach doing?
3 answers
solution1
5 ACCPTED 2014-12-02 07:47:57
It's hard to tell from the code you've posted, but it looks like the $ variable is not assigned to jQuery in your template; hence the $() construct threw the undefined function error.
The reason the latter works is because it puts a closure around your DOMReady handler, which passes in django.jQuery , which I assume to be the noConflict jQuery assigned variable from your template, and assigns it to the $ within the scope of that:
(function($) { // < start of closure
// within this block, $ = django.jQuery
$(document).ready(function() {
tryCustomiseForm();
});
})(django.jQuery); // passes django.jQuery as parameter to closure block
solution2
2 2014-12-02 08:22:53
Django文档解释了这一点 ：jQuery是命名空间，因此您可以使用django.jQuery在管理模板中引用它。
solution3
-1 2014-12-02 07:49:06
try
$(document).ready(function(){
tryCustomiseForm();
});
function tryCustomiseForm() {
// ...
}
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