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On Saturday, you can write and deploy a web application. It's an online poll where visitors can view choices (a bit of text, plus an image) and vote the option up and down.
 
== My notes about this ==
 
* Based on http://www.wiki.devchix.com/index.php?title=Rails_3_Curriculum and http://docs.djangoproject.com/en/dev/intro/tutorial01/
 
== Overview ==
 
'''Note''': This is one ''long'' page. It will take most of the afternoon to go through it.
Line 14 ⟶ 8:
 
This is based ''heavily'' on the official tutorial for the Django web programming framework.
 
This page should say what you should actually expect to know. It is okay that you don't understand everything you are typing in. After a lot more learning, you will be able to. The first time, though, it's okay if you don't. Will and Katie have feedback for this page.
 
== Writing your first Django app, part 1 ==
Line 19 ⟶ 15:
Let’s learn by example.
 
Throughout thisThis tutorial, we’ll walkwalks you through the creation of a basic poll application.
 
It’ll consist of two parts:
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=== Look at the files ===
 
Let’s look at files are in the project:
 
workshop_mysite/
public/
README.mediawiki
__init__.py
manage.py
Line 54 ⟶ 52:
These files are:
 
* README.mediawiki: Many projects come with ''README'' files that, well, you should read. This one does, too.
* __init__.py: An empty file that tells Python that this directory should be considered a Python package. (Read more about packages in the official Python docs if you're a Python beginner.)
* public/: This directory contains files the instructors put together so you can easily deploy your web app to Alwaysdata.com.
* __init__.py: An empty file that tells Python that this directory should be considered a Python module. Because of the __init__.py file, you can use ''import'' to ''import workshop_mysite''.
* manage.py: A command-line utility that lets you interact with this Django project in various ways. You can read all the details about manage.py in django-admin.py and manage.py.
* settings.py: Settings/configuration for this Django project. Django settings will tell you all about how settings work.
Line 61:
=== The development server ===
 
Let's verify this worked. If you haven't already, and runRun the command python manage.py runserver. You'll see the following output on the command line:
 
<pre>
python manage.py runserver
</pre>
 
You'll see the following output on the command line:
 
<pre>
Validating models...
0 errors found.
 
Django version 1.02, using settings 'mysite.settings'
Development server is running at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
</pre>
 
You've started the Django development server, a lightweight Web server written purely in Python. The Django maintainers include this web server, but on a "deployment" like alwaysdata.com, you typically tie Django into an existing server like Apache.
 
Now that the server's running, visit http://127.0.0.1:8000/ with your Web browser. You'll see a "Welcome to Django" page, in pleasant, light-blue pastel. It worked!
 
Exit the server by pressing CONTROL-C on your keyboard.
 
=== Fixing security settings ===
Line 84 ⟶ 94:
=== Database setup ===
 
Keep looking at settings.py: itThe hasDATABASES variable is a dictionary with one key: '''default'''.
 
The value is itself another dictionary with information about the site's default database. You can see from the ''NAME'' that the Django project uses a file called ''database.db'' to store information.
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Here are the things to know:
 
* An ''app'' is component of a website that does something. For example, the ''Django administration'' app is something you'll see later in this tutorial.
* A ''project'' contains one more apps.
* An ''app'' is component of a website that does something. For example, the ''Django administration'' app is something you'll see later in this tutorial
* A ''project'' corresponds to a website: it contains a '''settings.py''' file, so it has a corresponding database.
 
Line 154 ⟶ 163:
In our simple poll app, we'll create two models: polls and choices. A poll has a question and a publication date. A choice has two fields: the text of the choice and a vote tally. Each choice is associated with a poll. (FIXME: Add image to Choice.)
 
These concepts are represented by simple Python classes. Edit the polls/models.py file so it looks like this:
 
from django.db import models
Line 160 ⟶ 169:
class Poll(models.Model):
question = models.CharField(max_length=200)
pub_date = models.DateTimeField('date published')
class Choice(models.Model):
Line 166 ⟶ 175:
choice = models.CharField(max_length=200)
votes = models.IntegerField()
 
Save the models.py file.
 
All models in Django code are represented by a class that subclasses django.db.models.Model. Each model has a number of class variables, each of which represents a database field in the model.
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Each field is represented by an instance of a Field class -- e.g., CharField for character fields and DateTimeField for datetimes. This tells Django what type of data each field holds.
 
The name of each Field instance (e.g. question or pub_date ) is the field's name, in machine-friendly format. You'll use this value in your Python code, and your database will use it as the column name.
 
The ''pub_date'' field has something unique about it: a human-readable name, "date published". One feature of Django Field classes is that if you pass in a first argument for most fields, Django will use this in a couple of introspective parts of Django, and it doubles as documentation. If the human-readable isn't provided, Django will use the machine-readable name. In this example, we've only defined a human-readable name for Poll.pub_date. For all other fields in this model, the field's machine-readable name will suffice as its human-readable name.
 
Some Field classes have required elements. CharField, for example, requires that you give it a max_length. That's used not only in the database schema, but in validation, as we'll soon see.
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'polls',
)
 
Save the settings.py file.
 
Now Django knows to include the polls app.
Line 215 ⟶ 226:
 
Read the django-admin.py documentation for full information on what the manage.py utility can do.
 
=== Playing with the database ===
 
During Friday setup, you installed SQLite Manager into your system's Firefox. Now's a good time to open it up.
 
* FIXME
 
=== Playing with the API ===
Line 276 ⟶ 281:
[<Poll: Poll object>]
 
Wait a minute. <Poll: Poll object> is, an utterly, an unhelpful representation of this object. Let's fix that by editing the polls model (in the polls/models.py file) and adding a __unicode__() method to both Poll and Choice:
Use your '''text editor''' to open the polls/models.py file and adding a __unicode__() method to both Poll and Choice:
 
class Poll(models.Model):
Line 302 ⟶ 308:
 
Note the addition of import datetime to reference Python's standard datetime module.
FIXME: add explanation of why we did this
 
Save these changes to the models.py file, and then start a new Python interactive shell by running python manage.py shell again:
 
>>> from polls.models import Poll, Choice
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If you want to search your database, you can do it using the '''filter''' method on the ''objects'' attribute of Poll. For example:
 
>>> ppolls = Poll.objects.filter(question="What's up?")
>>> ppolls
[<Poll: What's up?>]
>>> ppolls[0].id
1
 
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Right now, we have a Poll in the database, but it has no Choices. See:
 
>>> p = Poll.objects.get(pkid=1)
>>> p.choice_set.all()
[]
Line 347 ⟶ 354:
<Choice: The sky>
>>> c = p.choice_set.create(choice='Just hacking again', votes=0)
>>> c
<Choice: Just hacking again>
 
Line 363 ⟶ 371:
=== Visualize the database in SQLite Manager ===
 
When you call ''.save()'' on a model instance, Django saves that to the database. (Remember, Django is a web programming framework built around the idea of saving data in a SQL database.)
* FIXME
 
Where ''is'' that database? Take a look at '''settings.py''' in your text editor. You can see that ''database.db'' is the filename. In '''settings.py''' Python calculates the path to the current file.
 
So now:
 
* Open up Firefox
* Find SQLite Manager in '''Tools'''->'''SQLite Manager'''
* In the SQLite Manager menus, choose: '''Database'''->'''Connect Database'''
* Find the '''workshop_mysite/database.db''' file.
 
Browse your tables! This is another way of looking at the data you just created.
 
'''Note''': In order to find the ''database.db'' file, you might need to ask SQLite Manager to show you all files, not just the ''*.sqlite'' files.
 
I (the author of this tutorial) think it's really important that you be able to find this database file. So go ahead and do this step. Browse around! Hooray.
 
When you're satisfied with your Poll data, you can close it.
 
=== Save and share our work ===
 
We've done something! Let's share it with the world.
 
We'll do that with ''git'' and ''Github''. On your own computer, get to a Terminal or a GitBash.
 
Use '''cd''' to get into the '''workshop_mysite''' directory. If it's a fresh Terminal, this is what you'll do:
 
cd Desktop
cd django_projects
cd workshop_mysite
 
Use ''git add'' to add the content of your files to git:
 
git add polls/*.py
 
And use ''git commit'' to ''commit'' those files:
 
git commit -m "I made these files and this is a message describing them"
 
Finally, use ''git push'' to push those up to your Github repository:
 
git push
 
Go to your Github account. Find the ''workshop_mysite'' repository. Do you see your files?
 
If so, proceed!
 
=== Enough databases for now ===
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ROOT_URLCONF = 'workshop_mysite.urls'
 
That means that the default URLconf inis workshop_mysite/urls.py.
 
Time for an example. Edit mysitethe file workshop_mysite/urls.py so it looks like this:
 
<pre>
from django.conf.urls.defaults import *
 
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(r'^polls/(\d+)/vote/$', 'polls.views.vote'),
)
</pre>
 
This is worth a review. When somebody requests a page from your Web site -- say, "/polls/23/", Django will load the ''urls.py'' Python module, because it's pointed to by the ROOT_URLCONF setting. It finds the variable named urlpatterns and traverses the regular expressions in order. When it finds a regular expression that matches -- r'^polls/(\d+)/$' -- it loads the function detail() from polls/views.py. Finally, it calls that detail() function like so:
 
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return HttpResponse("Hello, world. You're at the poll index.")
 
This is the simplest view possible. GoSave the views.py file, then go to "/polls/" in your browser, and you should see your text.
 
Now letslet's add a few more views by adding to the views.py file. These views are slightly different, because they take an argument (which, remember, is passed in from whatever was captured by the regular expression in the URLconf):
 
def detail(request, poll_id):
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return HttpResponse("You're voting on poll %s." % poll_id)
 
TakeSave the views.py file. Now take a look in your browser, at "/polls/34/". It'll run the detail() method and display whatever ID you provide in the URL. Try "/polls/34/results/" and "/polls/34/vote/" too -- these will display the placeholder results and voting pages.
 
=== Write views that actually do something ===
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All Django wants is that HttpResponse. Or an exception.
 
Most of the Django views in the world use Django's own database API, which we covered in Tutorial 1. Let's do that, too. Here's one stab at the index() view, which displays the latest 5 poll questions in the system, separated by commas, according to publication date. Continue editing the file views.py:
 
from polls.models import Poll
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return HttpResponse(output)
 
Now go to "http://localhost:8000/polls/" in your Web browser. You should see the text of the first poll. There's a problem here, though: The page's design is hard-coded in the view. If you want to change the way the page looks, you'll have to edit this Python code. So let's use Django's template system to separate the design from Python:
 
from django.shortcuts import render_to_response
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</pre>
 
Load the page in"http://localhost:8000/polls/" into your Web browser again, and you should see a bulleted-list containing the "What's up" poll from Tutorial 1. The link points to the poll's detail page.
 
=== Raising 404 ===
 
Now, let's tackle the poll detail view -- the page that displays the question for a given poll. Continue editing the ''views.py'' file. This view uses Python ''exceptions'':
 
from django.http import Http404
Line 556 ⟶ 610:
def detail(request, poll_id):
try:
p = Poll.objects.get(pkid=poll_id)
except Poll.DoesNotExist:
raise Http404
Line 563 ⟶ 617:
The new concept here: The view raises the Http404 exception if a poll with the requested ID doesn't exist.
 
If you'd like to quickly get the above example working, just create a new template file and name it ''detail.html''. Enter in it just one line of code:
 
<pre>
Line 569 ⟶ 623:
</pre>
 
willto get you started for now.
 
Does your detail view work? Try it: http://127.0.0.1:8000/polls/1/
Add it to a new template file that you create, ''detail.html''.
 
DoesYou yourcan detailalso viewtry work?to Tryload ita poll page that does not exist, just to test out the pretty 404 error: http://127.0.0.1:8000/polls/detail/132/
 
=== Adding more detail ===
Line 593 ⟶ 647:
 
Method-calling happens in the {% for %} loop: poll.choice_set.all is interpreted as the Python code poll.choice_set.all(), which returns a sequence of Choice objects and is suitable for use in the {% for %} tag.
 
Load the new detail page in your browser: http://127.0.0.1:8000/polls/1/ The poll choices now appear.
 
=== Adding some style ===
Line 599 ⟶ 655:
 
FIXME: CSS
 
== Part 2.5: Deploy your web app! ==
 
You've done a lot of work. It's time to share it with the world.
 
This workshop follows a workflow very similar to what I personally use in my professional Django projects: using ''git'' to store the history of my project on my computer, and using that to synchronize with a web server other people can see.
 
* ?
 
== Part 3: Let people vote ==
Line 635 ⟶ 683:
* Since we're creating a POST form (which can have the effect of modifying data), we need to worry about Cross Site Request Forgeries. Thankfully, you don't have to worry too hard, because Django comes with a very easy-to-use system for protecting against it. In short, all POST forms that are targeted at internal URLs should use the {% csrf_token %} template tag.
 
The {% csrf_token %} tag requires information from the request object, which is not normally accessible from within the template context. To fix this, a small adjustment needs to be made to the detail view in the "views.py" file, so that it looks like the following:
 
<pre>
Line 646 ⟶ 694:
</pre>
 
The details of how this works are explained in the [http://docs.djangoproject.com/en/dev/ref/templates/api/#subclassing-context-requestcontext documentation for RequestContext].
 
Now, let's create a Django view that handles the submitted data and does something with it. Remember, in Tutorial 3, we created a URLconf for the polls application that includes this line:
Line 720 ⟶ 768:
Does it work?! If so, show your neighbor!
 
== Part 3.5: Deploy againyour web app! ==
 
You've done a lot of work. It's time to share it with the world.
Well, your app works! Let's push it to the web so you can send a link to all your friends.
 
This workshop follows a workflow very similar to what I personally use in my professional Django projects: using ''git'' to store the history of my project on my computer, and using that to synchronize with a web server other people can see.
 
You've already pushed some work to Github. To get our changes over to alwaysdata. you'll:
 
# Add and commit files on your own computer.
# Push your changes to Github.
# Connect to your alwaysdata.com account via SSH/PuTTY
# Run "git pull" to get the latest version to your Alwaysdata account.
 
So we'll do those steps in order.
 
To do the ''add and commit'', open up your Terminal or GitBash:
 
git add .
git commit -m "More changes"
 
To push:
 
git push
 
Now, open up SSH or PuTTY and connect to your alwaysdata.com account.
 
Finally, in '''that''' terminal:
 
cd workshop_mysite
git pull
 
Okay, not quite finally. You might need to go to https://admin.alwaysdata.com/advanced/processes/ and click ''Restart my applications''.
 
Go to your alwaysdata site's /polls/ page. For me, I'd go to:
 
* http://paulproteus.alwaysdata.com/polls/
 
You should see your poll!
 
== Part 4: Editing your polls in the Django admin interface ==
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* An unnecessary lack of color.
 
Django=== comesBackground: with aDjango's built-in admin interface that lets you add ...===
 
This tutorial begins where Tutorial 1 left off. We’re continuing the Web-poll application and will focus on Django’s automatically-generated admin site.
 
Philosophy
 
Generating admin sites for your staff or clients to add, change and delete content is tedious work that doesn’t require much creativity. For that reason, Django entirely automates creation of admin interfaces for models.
Line 743 ⟶ 822:
 
The admin isn’t necessarily intended to be used by site visitors; it’s for site managers.
 
Activate the admin site¶
=== Activate the admin site ===
 
The Django admin site is not activated by default – it’s an opt-in thing. To activate the admin site for your installation, do these three things:
 
* Open up '''workshop_mysite/settings.py''' and * Addadd "django.contrib.admin" to your INSTALLED_APPS setting.
* Run python manage.py syncdb. Since you have added a new application to INSTALLED_APPS, the database tables need to be updated.
* Edit your mysite'''workshop_mysite/urls.py''' file and uncomment the lines that reference the admin – there are three lines in total to uncomment. This file is a URLconf; we’ll dig into URLconfs in the next tutorial. For now, all you need to know is that it maps URL roots to applications. In the end, you should have a urls.py file that looks like this:
 
=== Start the development server ===
Changed in Django 1.1: The method for adding admin urls has changed in Django 1.1.
 
Let’s make sure the development server is running and explore the admin site.
from django.conf.urls.defaults import *
 
Try going to http://127.0.0.1:8000/admin/. If it does not load, make sure you are still running the development server. You can start the development server like so:
# Uncomment the next two lines to enable the admin:
from django.contrib import admin
admin.autodiscover()
 
python manage.py runserver
urlpatterns = patterns('',
# Example:
# (r'^mysite/', include('mysite.foo.urls')),
 
http://127.0.0.1:8000/admin/ should show you the admin site's login screen.
# Uncomment the admin/doc line below and add 'django.contrib.admindocs'
=== Enter the admin site ===
# to INSTALLED_APPS to enable admin documentation:
# (r'^admin/doc/', include('django.contrib.admindocs.urls')),
 
Now, try logging in. (You created a superuser account earlier, when running ''syncdb'' for the fist time. If you didn't create one or forgot the password you can create another one.) You should see the Django admin index page.
# Uncomment the next line to enable the admin:
(r'^admin/', include(admin.site.urls)),
)
 
You should see a few other types of editable content, including groups, users and sites. These are core features Django ships with by default.
(The bold lines are the ones that needed to be uncommented.)
 
=== Make the poll app modifiable in the admin ===
Start the development server¶
 
Let’s start the development server and explore the admin site.
 
Recall from Tutorial 1 that you start the development server like so:
 
python manage.py runserver
 
Now, open a Web browser and go to "/admin/" on your local domain -- e.g., http://127.0.0.1:8000/admin/. You should see the admin's login screen:
Django admin login screen
Enter the admin site¶
 
Now, try logging in. (You created a superuser account in the first part of this tutorial, remember? If you didn't create one or forgot the password you can create another one.) You should see the Django admin index page:
Django admin index page
 
You should see a few other types of editable content, including groups, users and sites. These are core features Django ships with by default.
Make the poll app modifiable in the admin¶
 
But where's our poll app? It's not displayed on the admin index page.
Line 795 ⟶ 852:
Just one thing to do: We need to tell the admin that Poll objects have an admin interface. To do this, create a file called admin.py in your polls directory, and edit it to look like this:
 
<pre>
from polls.models import Poll
from django.contrib import admin
 
admin.site.register(Poll)
</pre>
 
You'll need to restart the development server to see your changes. Normally, the server auto-reloads code every time you modify a file, but the action of creating a new file doesn't trigger the auto-reloading logic. You can stop it by typing '''Ctrl-C''' ('''Ctrl-Break''' on Windows); then use the '''up''' arrow on your keyboard to find the command again, and hit enter.
Explore the free admin functionality¶
 
=== Explore the free admin functionality ===
Now that we've registered Poll, Django knows that it should be displayed on the admin index page:
Django admin index page, now with polls displayed
 
Now that we've registered Poll, Django knows that it should be displayed on the admin index page.
Click "Polls." Now you're at the "change list" page for polls. This page displays all the polls in the database and lets you choose one to change it. There's the "What's up?" poll we created in the first tutorial:
Polls change list page
 
Click "Polls." Now you're at the "change list" page for polls. This page displays all the polls in the database and lets you choose one to change it. There's the "What's up?" poll we created in the first tutorial.
Click the "What's up?" poll to edit it:
Editing form for poll object
 
Things to note here:
 
* The form is automatically generated from the Poll model.
* The different model field types (DateTimeField, CharField) correspond to the appropriate HTML input widget. Each type of field knows how to display itself in the Django admin.
* Each DateTimeField gets free JavaScript shortcuts. Dates get a "Today" shortcut and calendar popup, and times get a "Now" shortcut and a convenient popup that lists commonly entered times.
 
The bottom part of the page gives you a couple of options:
 
* Save -- Saves changes and returns to the change-list page for this type of object.
* Save and continue editing -- Saves changes and reloads the admin page for this object.
* Save and add another -- Saves changes and loads a new, blank form for this type of object.
* Delete -- Displays a delete confirmation page.
 
Change the "Date published" by clicking the "Today" and "Now" shortcuts. Then click "Save and continue editing." Then click "History" in the upper right. You'll see a page listing all changes made to this object via the Django admin, with the timestamp and username of the person who made the change:
History page for poll object
Customize the admin form¶
 
=== Adding related objects ===
Take a few minutes to marvel at all the code you didn't have to write. By registering the Poll model with admin.site.register(Poll), Django was able to construct a default form representation. Often, you'll want to customize how the admin form looks and works. You'll do this by telling Django the options you want when you register the object.
 
Let's see how this works by re-ordering the fields on the edit form. Replace the admin.site.register(Poll) line with:
 
class PollAdmin(admin.ModelAdmin):
fields = ['pub_date', 'question']
 
admin.site.register(Poll, PollAdmin)
 
You'll follow this pattern -- create a model admin object, then pass it as the second argument to admin.site.register() -- any time you need to change the admin options for an object.
 
This particular change above makes the "Publication date" come before the "Question" field:
Fields have been reordered
 
This isn't impressive with only two fields, but for admin forms with dozens of fields, choosing an intuitive order is an important usability detail.
 
And speaking of forms with dozens of fields, you might want to split the form up into fieldsets:
 
class PollAdmin(admin.ModelAdmin):
fieldsets = [
(None, {'fields': ['question']}),
('Date information', {'fields': ['pub_date']}),
]
 
admin.site.register(Poll, PollAdmin)
 
The first element of each tuple in fieldsets is the title of the fieldset. Here's what our form looks like now:
Form has fieldsets now
 
You can assign arbitrary HTML classes to each fieldset. Django provides a "collapse" class that displays a particular fieldset initially collapsed. This is useful when you have a long form that contains a number of fields that aren't commonly used:
 
class PollAdmin(admin.ModelAdmin):
fieldsets = [
(None, {'fields': ['question']}),
('Date information', {'fields': ['pub_date'], 'classes': ['collapse']}),
]
 
Fieldset is initially collapsed
Adding related objects¶
 
OK, we have our Poll admin page. But a Poll has multiple Choices, and the admin page doesn't display choices.
Line 875 ⟶ 891:
There are two ways to solve this problem. The first is to register Choice with the admin just as we did with Poll. That's easy:
 
<pre>
from polls.models import Choice
 
admin.site.register(Choice)
</pre>
 
Now "Choices" is an available option in the Django admin. TheCheck "out the '''Add choice"Choice''' form looks like this:.
Choice admin page
 
In that form, the "Poll" field is a select box containing every poll in the database. Django knows that a ForeignKey should be represented in the admin as a <select> box. In our case, only one poll exists at this point.
Line 890 ⟶ 907:
Remove the register() call for the Choice model. Then, edit the Poll registration code to read:
 
<pre>
class ChoiceInline(admin.StackedInline):
model = Choice
Line 902 ⟶ 920:
 
admin.site.register(Poll, PollAdmin)
</pre>
 
This tells Django: "Choice objects are edited on the Poll admin page. By default, provide enough fields for 3 choices."
 
Load the "Add poll" page to see how that looks, you may need to restart your development server:
Add poll page now has choices on it
 
It works like this: There are three slots for related Choices -- as specified by extra -- and each time you come back to the "Change" page for an already-created object, you get another three extra slots.
 
=== Customize the admin change list ===
One small problem, though. It takes a lot of screen space to display all the fields for entering related Choice objects. For that reason, Django offers a tabular way of displaying inline related objects; you just need to change the ChoiceInline declaration to read:
 
Now that the Poll admin page is looking good, let's make some tweaks to the admin "change list" page -- the one that displays all the polls in the system.
class ChoiceInline(admin.TabularInline):
#...
 
With that TabularInline (instead of StackedInline), the related objects are displayed in a more compact, table-based format:
Add poll page now has more compact choices
Customize the admin change list¶
 
Now that the Poll admin page is looking good, let's make some tweaks to the "change list" page -- the one that displays all the polls in the system.
 
Here's what it looks like at this point:
Polls change list page
 
By default, Django displays the str() of each object. But sometimes it'd be more helpful if we could display individual fields. To do that, use the list_display admin option, which is a tuple of field names to display, as columns, on the change list page for the object:
 
<pre>
class PollAdmin(admin.ModelAdmin):
class PollAdmin(admin.ModelAdmin):
# ...
# ...
list_display = ('question', 'pub_date')
list_display = ('question', 'pub_date')
</pre>
 
Just for good measure, let's also include the was_published_today custom method from Tutorial 1:
 
<pre>
class PollAdmin(admin.ModelAdmin):
# ...
list_display = ('question', 'pub_date', 'was_published_today')
</pre>
 
Now, check out the poll changepolls list page looks like this:.
Polls change list page, updated
 
You can click on the column headers to sort by those values -- except in the case of the was_published_today header, because sorting by the output of an arbitrary method is not supported. Also note that the column header for was_published_today is, by default, the name of the method (with underscores replaced with spaces). But you can change that by giving that method (in models.py) a short_description attribute:
 
This is shaping up well. Let's add some search capability. Add this to '''class PollAdmin''':
def was_published_today(self):
return self.pub_date.date() == datetime.date.today()
class PollAdmin(admin.ModelAdmin):
was_published_today.short_description = 'Published today?'
# ...
 
search_fields = ['question']
Edit your admin.py file again and add an improvement to the Poll change list page: Filters. Add the following line to PollAdmin:
 
list_filter = ['pub_date']
 
That adds a "Filter" sidebar that lets people filter the change list by the pub_date field:
Polls change list page, updated
 
The type of filter displayed depends on the type of field you're filtering on. Because pub_date is a DateTimeField, Django knows to give the default filter options for DateTimeFields: "Any date," "Today," "Past 7 days," "This month," "This year."
 
This is shaping up well. Let's add some search capability:
 
search_fields = ['question']
 
That adds a search box at the top of the change list. When somebody enters search terms, Django will search the question field. You can use as many fields as you'd like -- although because it uses a LIKE query behind the scenes, keep it reasonable, to keep your database happy.
Line 962:
Finally, because Poll objects have dates, it'd be convenient to be able to drill down by date. Add this line:
 
class PollAdmin(admin.ModelAdmin):
date_hierarchy = 'pub_date'
# ...
date_hierarchy = 'pub_date'
 
That adds hierarchical navigation, by date, to the top of the change list page. At top level, it displays all available years. Then it drills down to months and, ultimately, days.
 
That's the basics of the Django admin interface!
Now's also a good time to note that change lists give you free pagination. The default is to display 50 items per page. Change-list pagination, search boxes, filters, date-hierarchies and column-header-ordering all work together like you think they should.
Customize the admin look and feel¶
 
Clearly, having "Django administration" at the top of each admin page is ridiculous. It's just placeholder text.
 
That's easy to change, though, using Django's template system. The Django admin is powered by Django itself, and its interfaces use Django's own template system.
 
Open your settings file (mysite/settings.py, remember) and look at the TEMPLATE_DIRS setting. TEMPLATE_DIRS is a tuple of filesystem directories to check when loading Django templates. It's a search path.
 
By default, TEMPLATE_DIRS is empty. So, let's add a line to it, to tell Django where our templates live:
 
TEMPLATE_DIRS = (
"/home/my_username/mytemplates", # Change this to your own directory.
)
 
Now copy the template admin/base_site.html from within the default Django admin template directory in the source code of Django itself (django/contrib/admin/templates) into an admin subdirectory of whichever directory you're using in TEMPLATE_DIRS. For example, if your TEMPLATE_DIRS includes "/home/my_username/mytemplates", as above, then copy django/contrib/admin/templates/admin/base_site.html to /home/my_username/mytemplates/admin/base_site.html. Don't forget that admin subdirectory.
 
Then, just edit the file and replace the generic Django text with your own site's name as you see fit.
 
This template file contains lots of text like {% block branding %} and {{ title }}. The {% and {{ tags are part of Django's template language. When Django renders admin/base_site.html, this template language will be evaluated to produce the final HTML page. Don't worry if you can't make any sense of the template right now -- we'll delve into Django's templating language in Tutorial 3.
 
Note that any of Django's default admin templates can be overridden. To override a template, just do the same thing you did with base_site.html -- copy it from the default directory into your custom directory, and make changes.
 
Astute readers will ask: But if TEMPLATE_DIRS was empty by default, how was Django finding the default admin templates? The answer is that, by default, Django automatically looks for a templates/ subdirectory within each app package, for use as a fallback. See the template loader documentation for full information.
Customize the admin index page¶
 
On a similar note, you might want to customize the look and feel of the Django admin index page.
 
By default, it displays all the apps in INSTALLED_APPS that have been registered with the admin application, in alphabetical order. You may want to make significant changes to the layout. After all, the index is probably the most important page of the admin, and it should be easy to use.
 
Create a poll! Create some choices. Find your views, and show them to the world.
The template to customize is admin/index.html. (Do the same as with admin/base_site.html in the previous section -- copy it from the default directory to your custom template directory.) Edit the file, and you'll see it uses a template variable called app_list. That variable contains every installed Django app. Instead of using that, you can hard-code links to object-specific admin pages in whatever way you think is best. Again, don't worry if you can't understand the template language -- we'll cover that in more detail in Tutorial 3.
 
== Part 4.5: Deploy again, again! ==
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