Question

I have a django form that first validates its data through calling form.is_valid(). If its not, the form is redisplayed, with an error message regarding the invalid data.
Now if is_valid() is true, I try to save the data in an ldap backend. If the form.cleaned_data is not in correspondance with the ldap data type, I get an Exception from my ldap save method. Now what I would like to do in this case is to redisplay the form with an error message, just like the thing that happens after form.is_valid() returns false.
I tried reading some docs and also some django source, but could not find where I could hook into this.

An alternative would be to carefully build the form of (custom) form fields that would “guarantee” that the data is allready compliant to ldap syntax.
But I would like to make shure that I catch ldap syntax errors and display them in a convenient form. So if I could hook into that form redisplay mechanism would make me a happy little programmer 🙂

Any ideas or hints?

Answer 1

Under your class for the form that extends forms.Form, add one of the following methods, assuming you have a is_valid_ldap_data() defined somewhere:

for a whole form:

def clean(self):
    if !is_valid_ldap_data(self.cleaned_data.get("fieldname")):
        raise forms.ValidationError("Invalid LDAP data type");
    return self.cleaned_data

or for a single field:

def clean_fieldname(self):
    if !is_valid_ldap_data(self.cleaned_data['fieldname'])):
        raise forms.ValidationError("Invalid LDAP data type");
    return self.cleaned_data['fieldname']