问题
I have to add title attribute to options of the ModelChoiceField. Here is my admin code for that:
class LocModelForm(forms.ModelForm):
def __init__(self,*args,**kwargs):
super(LocModelForm,self).__init__(*args,**kwargs)
self.fields['icons'] = forms.ModelChoiceField(queryset = Photo.objects.filter(galleries__title_slug = "markers"))
self.fields['icons'].widget.attrs['class'] = 'mydds'
class Meta:
model = Loc
widgets = {
'icons' : forms.Select(attrs={'id':'mydds'}),
}
class Media:
css = {
"all":("/media/css/dd.css",)
}
js=(
'/media/js/dd.js',
)
class LocAdmin(admin.ModelAdmin):
form = LocModelForm
I can add any attribute to select widget, but i don't know how to add attributes to option tags. Any idea ?
回答1:
First of all, don't modify fields in __init__, if you want to override widgets use Meta inner class, if you want to override form fields, declare them like in a normal (non-model) form.
If the Select widget does not do what you want, then simply make your own. Original widget uses render_option method to get HTML representation for a single option — make a subclass, override it, and add whatever you want.
class MySelect(forms.Select):
def render_option(self, selected_choices, option_value, option_label):
# look at the original for something to start with
return u'<option whatever>...</option>'
class LocModelForm(forms.ModelForm):
icons = forms.ModelChoiceField(
queryset = Photo.objects.filter(galleries__title_slug = "markers"),
widget = MySelect(attrs = {'id': 'mydds'})
)
class Meta:
# ...
# note that if you override the entire field, you don't have to override
# the widget here
class Media:
# ...
回答2:
I had a similar problem, where I needed to add a custom attribute to each option dynamically. But in Django 2.0, the html rendering was moved into the Widget base class, so modifying render_option no longer works. Here is the solution that worked for me:
from django import forms
class CustomSelect(forms.Select):
def __init__(self, *args, **kwargs):
self.src = kwargs.pop('src', {})
super().__init__(*args, **kwargs)
def create_option(self, name, value, label, selected, index, subindex=None, attrs=None):
options = super(CustomSelect, self).create_option(name, value, label, selected, index, subindex=None, attrs=None)
for k, v in self.src.items():
options['attrs'][k] = v[options['value']]
return options
class CustomForm(forms.Form):
def __init__(self, *args, **kwargs):
src = kwargs.pop('src', {})
choices = kwargs.pop('choices', ())
super().__init__(*args, **kwargs)
if choices:
self.fields['custom_field'].widget = CustomSelect(attrs={'class': 'some-class'}, src=src, choices=choices)
custom_field = forms.CharField(max_length=100)
Then in views, render a context with {'form': CustomForm(choices=choices, src=src)} where src is a dictionary like this: {'attr-name': {'option_value': 'attr_value'}}.
回答3:
Here's a class I made that inherits from forms.Select (thanks to Cat Plus Plus for getting me started with this). On initialization, provide the option_title_field parameter indicating which field to use for the <option> title attribute.
from django import forms
from django.utils.html import escape
class SelectWithTitle(forms.Select):
def __init__(self, attrs=None, choices=(), option_title_field=''):
self.option_title_field = option_title_field
super(SelectWithTitle, self).__init__(attrs, choices)
def render_option(self, selected_choices, option_value, option_label, option_title=''):
print option_title
option_value = forms.util.force_unicode(option_value)
if option_value in selected_choices:
selected_html = u' selected="selected"'
if not self.allow_multiple_selected:
# Only allow for a single selection.
selected_choices.remove(option_value)
else:
selected_html = ''
return u'<option title="%s" value="%s"%s>%s</option>' % (
escape(option_title), escape(option_value), selected_html,
forms.util.conditional_escape(forms.util.force_unicode(option_label)))
def render_options(self, choices, selected_choices):
# Normalize to strings.
selected_choices = set(forms.util.force_unicode(v) for v in selected_choices)
choices = [(c[0], c[1], '') for c in choices]
more_choices = [(c[0], c[1]) for c in self.choices]
try:
option_title_list = [val_list[0] for val_list in self.choices.queryset.values_list(self.option_title_field)]
if len(more_choices) > len(option_title_list):
option_title_list = [''] + option_title_list # pad for empty label field
more_choices = [(c[0], c[1], option_title_list[more_choices.index(c)]) for c in more_choices]
except:
more_choices = [(c[0], c[1], '') for c in more_choices] # couldn't get title values
output = []
for option_value, option_label, option_title in chain(more_choices, choices):
if isinstance(option_label, (list, tuple)):
output.append(u'<optgroup label="%s">' % escape(forms.util.force_unicode(option_value)))
for option in option_label:
output.append(self.render_option(selected_choices, *option, **dict(option_title=option_title)))
output.append(u'</optgroup>')
else: # option_label is just a string
output.append(self.render_option(selected_choices, option_value, option_label, option_title))
return u'\n'.join(output)
class LocModelForm(forms.ModelForm):
icons = forms.ModelChoiceField(
queryset = Photo.objects.filter(galleries__title_slug = "markers"),
widget = SelectWithTitle(option_title_field='FIELD_NAME_HERE')
)
回答4:
Here is a solution if you want to use the instance to set the attribute value.
class IconSelectWidget(forms.Select):
def create_option(self, name, value, *args, **kwargs):
option = super().create_option(name, value, *args, **kwargs)
if value:
icon = self.choices.queryset.get(pk=value) # get icon instance
option['attrs']['title'] = icon.title # set option attribute
return option
class LocModelForm(forms.ModelForm):
icons = forms.ModelChoiceField(
queryset=Photo.objects.filter(galleries__title_slug='markers'),
widget=IconSelectWidget
)
回答5:
From django 1.11 and above the render_option method was removed. see this link: https://docs.djangoproject.com/en/1.11/releases/1.11/#changes-due-to-the-introduction-of-template-based-widget-rendering
Here is a solution that worked for me different than Kayoz's. I did not adapt the names as in the example but i hope it is still clear. In the model form I overwrite the field:
class MyForm(forms.ModelForm):
project = ProjectModelChoiceField(label=_('Project'), widget=ProjectSelect())
Then I declare the classes from above and one extra, the iterator:
class ProjectModelChoiceIterator(django.forms.models.ModelChoiceIterator):
def choice(self, obj):
# return (self.field.prepare_value(obj), self.field.label_from_instance(obj)) #it used to be like this, but we need the extra context from the object not just the label.
return (self.field.prepare_value(obj), obj)
class ProjectModelChoiceField(django.forms.models.ModelChoiceField):
def _get_choices(self):
if hasattr(self, '_choices'):
return self._choices
return ProjectModelChoiceIterator(self)
class ProjectSelect(django.forms.Select):
def create_option(self, name, value, label, selected, index, subindex=None, attrs=None):
context = super(ProjectSelect, self).create_option(name, value, label, selected, index, subindex=None, attrs=None)
context['attrs']['extra-attribute'] = label.extra_attribute #label is now an object, not just a string.
return context
来源：https://stackoverflow.com/questions/6477856/how-to-add-attributes-to-option-tags-in-django