I am currently exploring the use of a textarea form field that involves implementing some custom JavaScript code to count and restrict the character limit. The maximum length and size of the textarea are dynamic, meaning these attributes can be changed after creating the model.
To integrate this functionality into the Django form textarea widget, I believe I need to create a custom widget. However, I am unsure how to incorporate the JavaScript code within the template effectively. To adjust the textarea size, I assume I would pass a variable from the view to generate an instance of the textarea widget in the form creation process.
For now, I opt for creating the inputs directly using HTML/JS in the template and then submitting the POST data to the Django view. Subsequently, I retrieve the data using getitem and save it directly to the models. While this method works, it does not fully align with Django's best practices and may expose vulnerabilities without leveraging Django's built-in validation and clean data functions.
Therefore, I have two main inquiries: (a) If I develop a custom Django form widget, how can I implement my JavaScript function for the textarea fields in the template (including "onkeypress=jstextcounter...")? And (b) If I continue extracting the post data in the view without utilizing a Django form, what security risks exist and how can I ensure thorough data validation? (Note that the page already requires user login and is not a public comment box).
Perhaps someone has previously created a similar custom form widget and can share a helpful snippet?
Cheers...
EDIT Thanks to MovieYoda's assistance, I managed to make this setup work while researching more about dynamic forms in Django. By using %d substitution, I can dynamically modify the maxChars attribute for my JavaScript function.
In forms.py, the code looks like:
text=forms.CharField(max_length = 1000, widget=forms.widgets.Textarea())
def __init__(self, *args, **kwargs):
size = kwargs.pop('size')
maxChars = kwargs.pop('maxChars')
super(MyForm, self).__init__(*args, **kwargs)
self.fields['text'].widget.attrs['onkeypress'] = 'return textCounter(this, this.form.counter, %d);' % maxChars
self.fields['text'].widget.attrs['rows'] = size
self.fields['text'].widget.attrs['cols'] = '40'
The JavaScript function 'textCounter' in the template enforces the character limit based on the maxChars variable provided.
<script type="text/javascript">
function textCounter( field, countfield, maxLimit) {
if ( field.value.length > maxLimit )
{
field.value = field.value.substring( 0, maxLimit );
return false;
}
else
{
countfield.value = maxLimit - field.value.length;
}
}
</script>
In the view, the form is instantiated with the specified kwargs inputs:
FormInstance = MyForm(size=1, maxChars=5)