Django : customizing FileField value while editing a model

Question

I\'ve got a model, with FileField. When I edit this model in a view, I want to change the \"current\" value of FileField which gets displayed in the vi

Answer 1

You need to override the ClearableFileInput that is currently used, to change the way it's displayed.

Here is the code of the new ShortNameFileInput which inherit from the default ClearableFileInput with just a change on the 19th line to only show the file name:

from django.forms.widgets import ClearableFileInput
import os
# missing imports
from django.utils.safestring import mark_safe
from cgi import escape
from django.utils.encoding import force_unicode

class ShortNameClarableFileInput(ClearableFileInput):
    def render(self, name, value, attrs=None):
        substitutions = {
            'initial_text': self.initial_text,
            'input_text': self.input_text,
            'clear_template': '',
            'clear_checkbox_label': self.clear_checkbox_label,
        }
        template = u'%(input)s'
        substitutions['input'] = super(ClearableFileInput, self).render(name, value, attrs)

        if value and hasattr(value, "url"):
            template = self.template_with_initial
            substitutions['initial'] = (u'%s'
                                        % (escape(value.url),
                                           escape(force_unicode(os.path.basename(value.url))))) # I just changed this line
            if not self.is_required:
                checkbox_name = self.clear_checkbox_name(name)
                checkbox_id = self.clear_checkbox_id(checkbox_name)
                substitutions['clear_checkbox_name'] = conditional_escape(checkbox_name)
                substitutions['clear_checkbox_id'] = conditional_escape(checkbox_id)
                substitutions['clear'] = CheckboxInput().render(checkbox_name, False, attrs={'id': checkbox_id})
                substitutions['clear_template'] = self.template_with_clear % substitutions

        return mark_safe(template % substitutions)

To use it in your form, you'll have to manually set the widget you want to use :

class DemoVar_addform(ModelForm):
    ...
    class Meta:
        model = DemoVar_model
        widgets = {
            'Welcome_sound': ShortNameClarableFileInput,
        }                    

That should do the trick.