Adding new bulk actions

Often for user convenience it is useful to perfom the same action across a number of similar metadata items. Aristotle-MDR provides a bulk action API that allows developers to create new discoverable action types that are shown to users in certain item lists, such as search results or workgroup item listings.

Registering a bulk action

The BULK_ACTIONS setting in the in the ARISTOTLE_SETTINGS dictionary stores the register of bulk actions used for generating lists of actions. Adding the qualified path to the form is sufficient to register a new bulk action. For example this set in ARISTOTLE_SETTINGS would register an action int Python module module.forms.MyBulkAction:

'BULK_ACTIONS': [
    'module.forms.MyBulkActionForm',
]

Writing a functional bulk action

A bulk action form is just a specialised Django form for acting on multiple Aristotle-MDR concepts, with a few small additions that come from inheriting from aristotle_mdr.forms.bulk_actions.BulkActionForm.

After inheriting to make a form function some properties should exist.

  • action_text - This is the name for an action shown in lists to users. Default is based on the class name.
  • classes - A string of HTML classes that will be applied to each item. Default empty. Currently these are used for inserting ‘Font Awesome’ icons for each action.
  • confirm_page - An optional template name used to render between a user clicking the action and completing it. By adding extra fields to a form, with this template a bulk action can get additional inforamtion from a user before continuing. No default, if this is empty no confirmation is requested.
  • items_label - An optional override of the label for the list of items the action form acts on. Defaults to “Select some items”

There are two additional methods that complete the class:

  • can_use - A classmethod that provides a boolean response indicating if a certain user has permission to use this action in any context - note this permission does not have knowledge of the items selected. Default is true, so if this is not overriden all users will see the action in their list.
  • make_changes - Performs that actual action of the form, this is called once the user invokes a bulk action (after confirmation is required). No default, not including a make_changes method will cause your action to fail. Any text returned from this method will be shown to a user via the django messages framework.

An example bulk action form

Below is an example bulk action that is only visible for staff users, and deletes the items requested by a user.:

mymodule.forms.StaffDeleteActionForm
from django import forms
from aristotle_mdr.forms.bulk_actions import BulkActionForm
from django.utils.translation import ugettext_lazy as _


class StaffDeleteActionForm(BulkActionForm):
    action_text = _('Delete')
    classes="fa-trash"
    confirm_page = "confirm_delete.html"
    items_label="Items to delete",

    safe_to_delete = forms.BooleanField(required=True, label="Tick to confirm deletion")

    @classmethod
    def can_use(cls, user):
        return user.is_staff

    def make_changes(self):
        if not self.user.is_staff:
            raise PermissionDenied
        else:
            self.cleaned_data['items'].delete()
        return "Items deleted"


confirm_delete.html
{% extends "aristotle_mdr/base.html" %}

{% block title %}Delete items{% endblock %}
{% block content %}
{{ form.media }}
<form method="post" action="{% url 'aristotle:bulk_action' %}?next={{next}}">{% csrf_token %}
    <p>
        Use this page to confirm you wish to delete the following items.
    </p>
    <input type="hidden" name="bulkaction" value="{{action}}"/>
    <table>
        {{ form.as_table }}
    </table>
    <div>
        <a class="btn btn-default" href="{{ next }}">Cancel</a>
        <button type="submit" name="confirmed" class="btn btn-primary" value="Delete">Delete</button>
    </div>
</form>
{% include 'autocomplete_light/static.html' %}
{% endblock %}

This will produce a button wherever other bulk actions are available, similar to the ‘Delete’ button available on the right in the image below.

A list of items with bulk actions available.