change README to Markdown to simplify things (#104)

I'm not planning on doing a Sphinx site, so let's use Markdown to make the documentation easier to maintain.

Part of #94

Makefile

@@ -52,11 +52,10 @@ resetdb: ## Delete and then recreate the dev sqlite database
 	python $(MANAGE) migrate --noinput
 	python $(MANAGE) loaddata sample_data
 
-.PHONY: build
-build: ## Build a full set of Docker images
-build: build/2.2.6 build/2.1.13 build/2.0.13 build/1.11.25 build/1.10.8 build/1.9.13 build/1.8.18
+docker/build: ## Build a full set of Docker images
+docker/build: docker/build/2.2.6 docker/build/2.1.13 docker/build/2.0.13 docker/build/1.11.25 docker/build/1.10.8 docker/build/1.9.13 docker/build/1.8.18
 
-build/%:
+docker/build/%:
 	docker build --build-arg DJANGO_VERSION=$* \
 	  -t $(IMAGE):$$(echo "$*" | cut -f 1-2 -d.) .
 

README.md

@@ -0,0 +1,238 @@
+Django Object Actions
+=====================
+
+[![Build Status](https://travis-ci.org/crccheck/django-object-actions.svg?branch=master)](https://travis-ci.org/crccheck/django-object-actions)
+
+If you've ever tried making admin object tools you may have thought, "why can't
+this be as easy as making Django Admin Actions?" Well now they can be.
+
+
+Quick-Start Guide
+-----------------
+
+Install Django Object Actions:
+
+```shell
+$ pip install django-object-actions
+```
+
+Add `django_object_actions` to your `INSTALLED_APPS` so Django can find
+our templates.
+
+In your admin.py:
+
+```python
+from django_object_actions import DjangoObjectActions
+
+class ArticleAdmin(DjangoObjectActions, admin.ModelAdmin):
+    def publish_this(self, request, obj):
+        publish_obj(obj)
+    publish_this.label = "Publish"  # optional
+    publish_this.short_description = "Submit this article"  # optional
+
+    change_actions = ('publish_this', )
+```
+
+Usage
+-----
+
+Defining new &*tool actions* is just like defining regular [admin actions]. The
+major difference is the functions for `django-object-actions` will take an
+object instance instead of a queryset (see *Re-using Admin Actions* below).
+
+*Tool actions* are exposed by putting them in a `change_actions` attribute in
+your `admin.ModelAdmin`. You can also add *tool actions* to the main changelist
+views too. There, you'll get a queryset like a regular [admin action][admin actions]:
+
+```python
+from django_object_actions import DjangoObjectActions
+
+class MyModelAdmin(DjangoObjectActions, admin.ModelAdmin):
+    def toolfunc(self, request, obj):
+        pass
+    toolfunc.label = "This will be the label of the button"  # optional
+    toolfunc.short_description = "This will be the tooltip of the button"  # optional
+
+    def make_published(modeladmin, request, queryset):
+        queryset.update(status='p')
+
+    change_actions = ('toolfunc', )
+    changelist_actions = ('make_published', )
+```
+
+Just like admin actions, you can send a message with `self.message_user`.
+Normally, you would do something to the object and return to the same url, but
+if you return a `HttpResponse`, it will follow it (hey, just like [admin
+actions]!).
+
+If your admin modifies `get_urls`, `change_view`, or `changelist_view`,
+you'll need to take extra care because `django-object-actions` uses them too.
+
+### Re-using Admin Actions
+
+If you would like a preexisting admin action to also be an *object action*, add
+the `takes_instance_or_queryset` decorator to convert object instances into a
+queryset and pass querysets:
+
+```python
+from django_object_actions import DjangoObjectActions, takes_instance_or_queryset
+
+class RobotAdmin(DjangoObjectActions, admin.ModelAdmin):
+    # ... snip ...
+
+    @takes_instance_or_queryset
+    def tighten_lug_nuts(self, request, queryset):
+        queryset.update(lugnuts=F('lugnuts') - 1)
+
+    change_actions = ['tighten_lug_nuts']
+    actions = ['tighten_lug_nuts']
+```
+
+[admin actions]: https://docs.djangoproject.com/en/stable/ref/contrib/admin/actions/
+
+### Customizing *Object Actions*
+
+To give the action some a helpful title tooltip, add a
+`short_description` attribute, similar to how admin actions work:
+
+```python
+def increment_vote(self, request, obj):
+    obj.votes = obj.votes + 1
+    obj.save()
+increment_vote.short_description = "Increment the vote count by one"
+```
+
+By default, Django Object Actions will guess what to label the button
+based on the name of the function. You can override this with a `label`
+attribute:
+
+```python
+def increment_vote(self, request, obj):
+    obj.votes = obj.votes + 1
+    obj.save()
+increment_vote.label = "Vote++"
+```
+
+If you need even more control, you can add arbitrary attributes to the buttons
+by adding a Django widget style
+[attrs](https://docs.djangoproject.com/en/stable/ref/forms/widgets/#django.forms.Widget.attrs)
+attribute:
+
+```python
+def increment_vote(self, request, obj):
+    obj.votes = obj.votes + 1
+    obj.save()
+increment_vote.attrs = {
+    'class': 'addlink',
+}
+```
+
+### Programmatically Disabling Actions
+
+You can programmatically disable registered actions by defining your own
+custom `get_change_actions()` method. In this example, certain actions
+only apply to certain object states (e.g. You should not be able to
+close an company account if the account is already closed):
+
+```python
+def get_change_actions(self, request, object_id, form_url):
+    actions = super(PollAdmin, self).get_change_actions(request, object_id, form_url)
+    actions = list(actions)
+    if not request.user.is_superuser:
+        return []
+
+    obj = self.model.objects.get(pk=object_id)
+    if obj.question.endswith('?'):
+        actions.remove('question_mark')
+
+    return actions
+```
+
+The same is true for changelist actions with `get_changelist_actions`.
+
+### Alternate Installation
+
+You don't have to add this to `INSTALLED_APPS`, all you need to to do
+is copy the template `django_object_actions/change_form.html` some place
+Django's template loader [will find
+it](https://docs.djangoproject.com/en/stable/ref/settings/#template-dirs).
+
+If you don't intend to use the template customizations at all, don't
+add `django_object_actions` to your `INSTALLED_APPS` at all and use
+`BaseDjangoObjectActions` instead of `DjangoObjectActions`.
+
+
+More Examples
+-------------
+
+Making an action that links off-site:
+
+```python
+def external_link(self, request, obj):
+    from django.http import HttpResponseRedirect
+    return HttpResponseRedirect(f'https://example.com/{obj.id}')
+```
+
+
+Limitations
+-----------
+
+1.  `django-object-actions` expects functions to be methods of the model
+    admin. While Django gives you a lot more options for their admin
+    actions.
+2.  If you provide your own custom `change_form.html`, you'll also need
+    to manually copy in the relevant bits of [our change form
+    ](./django_object_actions/templates/django_object_actions/change_form.html).
+3.  Security. This has been written with the assumption that everyone in
+    the Django admin belongs there. Permissions should be enforced in
+    your own actions irregardless of what this provides. Better default
+    security is planned for the future.
+
+
+Demo Admin & Docker images
+--------------------------
+
+You can try the demo admin against several versions of Django with these Docker
+images: https://hub.docker.com/r/crccheck/django-object-actions/tags
+
+This runs the example Django project in `./example_project` based on the "polls"
+tutorial. `admin.py` demos what you can do with this app.
+
+
+Development
+-----------
+
+Getting started *(with virtualenvwrapper)*:
+
+```shell
+# get a copy of the code
+git clone git@github.com:crccheck/django-object-actions.git
+cd django-object-actions
+# set up your virtualenv (with virtualenvwrapper)
+mkvirtualenv django-object-actions
+# Install requirements
+make install
+# Hack your path so that we can reference packages starting from the root
+add2virtualenv .
+make test  # run test suite
+make quickstart  # runs 'make resetdb' and some extra steps
+```
+
+This will install whatever the latest stable version of Django is. You
+can also install a specific version of Django and
+`pip install -r requirements.txt`.
+
+Various helpers are available as make commands. Type `make help` and
+view the `Makefile` to see what other things you can do.
+
+
+Similar Packages
+----------------
+
+If you want an actions menu for each row of your changelist, check out [Django
+Admin Row Actions](https://github.com/DjangoAdminHackers/django-admin-row-actions).
+
+Django Object Actions is very similar to
+[django-object-tools](https://github.com/praekelt/django-object-tools), but does
+not require messing with your urls.py, does not do anything special with
+permissions, and uses the same patterns as making [admin actions].