django form: how to check out checkbox state in te

问题:

I have a form with checkboxes that works fine, but when the user submits the form with errors and my checkbox is checked I need to change div class which holds the checkbox. So I was experimenting with {{ form.mycheckbox.data }} in the template and it says False on page load. Now when user is click on a checkbox and the form has errors, it says on. So I tried:

{{ if form.mycheckbox.data == True }} doesn't work

{{ if form.mycheckbox.data != False }} doesn't work

{{ if form.mycheckbox.data == 'on' }} doesn't work

{{ if form.mycheckbox.data == on }} doesn't work

回答1:

Use {% if form.mycheckbox.value %}. This will evaluate to true if the box is checked. For the opposite behavior, use {% if not form.mycheckbox.value %}.

Note the syntax is {% if ... %}, not {{ if ...}}. Percent-brackets are for commands, double-brackets are for outputting variables.

回答2:

In models.py:

class Article:
    published = BooleanField()
    (...)

In the template:

 <input type="checkbox" name="published" {% if article.published %}checked{% endif %} />

回答3:

Work for me:

{% for foo in form.tags %}
  <label class="publication-tag">
    <input class="publication-tag__checkbox"
      {% if foo.choice_value in foo.value %}checked="checked"{% endif %}
      type="checkbox" 
      name="{{ foo.name }}"
      value="{{ foo.choice_value }}">
{% endfor %}

That:

{% if foo.choice_value in foo.value %}checked="checked"{% endif %}

回答4:

While, first you should use BooleanField in your model, not the CharField. Then, there are two accesses:

• just put {{form.yourField}} in your template (preferred)

• or, use {% if form.yourFiled.value %} checked {%endif%}

回答5:

Django templates are evaluated on the server-side.

I think you want to look into JavaScript to check the state of your check boxes. Doing it with the templating language (especially the one included with Django) is a really bad idea.

Any processing / calculation should be done in the view function / class.