Before installing Wagtail, it is necessary to install the **libjpeg** and **zlib** libraries, which provide support for working with JPEG, PNG, and GIF images (via the Python **Pillow** library).
Generally, in Wagtail, each page type, or content type, is represented by a single app. However, different apps can be aware of each other and access each other's data. All of the apps need to be registered within the `INSTALLED_APPS` section of the `base.py` file in the `mysite/settings` directory. Look at this file to see how the `start` command has listed them in there.
This command ensures that the tables in your database are matched to the models in your project. Every time you alter your model (for example you may add a field to a model) you will need to run this command to update the database.
This will prompt you to create a new superuser account with full permissions. Note the password text won’t be visible when typed, for security reasons.
![Browser screenshot of "Welcome to your new Wagtail site!" page, with teal egg above the title, and links to different resources. The page is shown inside a browswer tab, with browser URL bar at the top](../_static/images/tutorial/tutorial_1.png)
Throughout this tutorial we will use `http://127.0.0.1:8000` but depending on your setup, this could be `http://localhost:8000/` or a different IP address or port. Please read the console output of `manage.py runserver` to determine the correct url for your local site.
![Screenshot of Wagtail’s dashboard, with "Welcome to the mysite Wagtail CMS" heading, 1 page, 0 images, 0 documents. Underneath is a "Your most recent edits" section, with the Home page listed](../_static/images/tutorial/tutorial_2.png)
Out of the box, the "home" app defines a blank `HomePage` model in `models.py`, along with a migration that creates a homepage and configures Wagtail to use it.
Edit `home/models.py` as follows, to add a `body` field to the model:
`body` is defined as `RichTextField`, a special Wagtail field. When `blank=True`,
it means that this field is not required and can be empty. You
can use any of the [Django core fields](https://docs.djangoproject.com/en/stable/ref/models/fields). `content_panels` define the
capabilities and the layout of the editing interface. When you add fields to `content_panels`, it enables them to be edited on the Wagtail interface. [More on creating Page models](../topics/pages).
# Executes the migrations and updates the database with your model changes.
python manage.py migrate
```
You must run the above commands each time you make changes to the model definition.
You can now edit the homepage within the Wagtail admin area (on the side bar go to _Pages_ and click the edit button beside _Homepage_) to see the new body field. Enter some text into the body field, and publish the page by selecting _Publish_ at the bottom of the page editor, rather than _Save Draft_.
`home/home_page.html`). This template file can exist in any location recognised by
[Django's template rules](https://docs.djangoproject.com/en/stable/intro/tutorial03/#write-views-that-actually-do-something); conventionally it is placed under a `templates` folder within the app.
Edit `home/templates/home/home_page.html` to contain the following:
`base.html` refers to a parent template and must always be the first template tag used in a template. Extending from this template saves you from rewriting code and allows pages across your app to share a similar frame (by using block tags in the child template, you can override specific content within the parent template).
![Screenshot of an almost empty page – white background, "Welcome to our new site!" in the top left, and Wagtail logo in circled cyan in the bottom right](../_static/images/tutorial/tutorial_3.png)
(unless we override it) will be `blog_index_page.html`. Django will look for a template whose name matches the name of your Page model within the templates directory in your blog app folder. This default behaviour can be overridden if needed.
To create a template for the `BlogIndexPage` model, create a file at the location `blog/templates/blog/blog_index_page.html`.
```{note}
You may need to create the folders `templates/blog` within your `blog` app folder
```
In your `blog_index_page.html` file enter the following content:
Create a new template file at the location `blog/templates/blog/blog_page.html`. Now add the following content to your newly created `blog_page.html` file:
All we've done here is retrieve the original context, create a custom QuerySet,
add it to the retrieved context, and return the modified context back to the view.
You'll also need to modify your `blog_index_page.html` template slightly.
Change:
`{% for post in page.get_children %}` to `{% for post in blogpages %}`
Now try unpublishing one of your posts - it should disappear from the blog index
page. The remaining posts should now be sorted with the most recently published
posts first.
### Images
Let's add the ability to attach an image gallery to our blog posts. While it's possible to simply insert images into the `body` rich text field, there are several advantages to setting up our gallery images as a new dedicated object type within the database - this way, you have full control of the layout and styling of the images on the template, rather than having to lay them out in a particular way within the rich text field. It also makes it possible for the images to be used elsewhere, independently of the blog text - for example, displaying a thumbnail on the blog index page.
Run `python manage.py makemigrations` and `python manage.py migrate`.
There are a few new concepts here, so let's take them one at a time:
Inheriting from `Orderable` adds a `sort_order` field to the model, to keep track of the ordering of images in the gallery.
The `ParentalKey` to `BlogPage` is what attaches the gallery images to a specific page. A `ParentalKey` works similarly to a `ForeignKey`, but also defines `BlogPageGalleryImage` as a "child" of the `BlogPage` model, so that it's treated as a fundamental part of the page in operations like submitting for moderation, and tracking revision history.
`image` is a `ForeignKey` to Wagtail's built-in `Image` model, where the images themselves are stored. This appears in the page editor as a pop-up interface for choosing an existing image or uploading a new one. This way, we allow an image to exist in multiple galleries - effectively, we've created a many-to-many relationship between pages and images.
Specifying `on_delete=models.CASCADE` on the foreign key means that if the image is deleted from the system, the gallery entry is deleted as well. (In other situations, it might be appropriate to leave the entry in place - for example, if an "our staff" page included a list of people with headshots, and one of those photos was deleted, we'd rather leave the person in place on the page without a photo. In this case, we'd set the foreign key to `blank=True, null=True, on_delete=models.SET_NULL`.)
Finally, adding the `InlinePanel` to `BlogPage.content_panels` makes the gallery images available on the editing interface for `BlogPage`.
After editing `blog/models.py` you should see a _Gallery images_ field with an option to upload images and provide a caption for it when editing a blog page in your Wagtail admin area.
Make sure to upload some images when editing the blog page on your Wagtail admin if you want them to be displayed after editing your blog page template.
Here we use the `{% image %}` tag (which exists in the `wagtailimages_tags` library, imported at the top of the template) to insert an `<img>` element, with a `fill-320x240` parameter to indicate that the image should be resized and cropped to fill a 320x240 rectangle. You can read more about using images in templates in the [docs](../topics/images).
Since our gallery images are database objects in their own right, we can now query and re-use them independently of the blog post body. Let's define a `main_image` method, which returns the image from the first gallery item (or `None` if no gallery items exist):
Let's add a category system to our blog. Unlike tags, where a page author can bring a tag into existence simply by using it on a page, our categories will be a fixed list, managed by the site owner through a separate area of the admin interface.
First, we define a `BlogCategory` model. A category is not a page in its own right, and so we define it as a standard Django `models.Model` rather than inheriting from `Page`. Wagtail introduces the concept of "snippets" for reusable pieces of content that need to be managed through the admin interface, but do not exist as part of the page tree themselves; a model can be registered as a snippet by adding the `@register_snippet` decorator. All the field types we've used so far on pages can be used on snippets too - here we'll give each category an icon image as well as a name. Add to `blog/models.py`:
```python
from wagtail.snippets.models import register_snippet
Note that we are using `panels` rather than `content_panels` here - since snippets generally have no need for fields such as slug or publish date, the editing interface for them is not split into separate 'content' / 'promote' / 'settings' tabs as standard, and so there is no need to distinguish between 'content panels' and 'promote panels'.
Migrate this change by running `python manage.py makemigrations` and `python manage.py migrate`. Create a few categories through the Snippets area which now appears in the admin menu.
We can now add categories to the `BlogPage` model, as a many-to-many field. The field type we use for this is `ParentalManyToManyField` - this is a variant of the standard Django `ManyToManyField` which ensures that the chosen objects are correctly stored against the page record in the revision history, in much the same way that `ParentalKey` replaces `ForeignKey` for one-to-many relations.To add categories to the `BlogPage`, modify `models.py` in your blog app folder:
Here we're making use of the `widget` keyword argument on the `FieldPanel` definition to specify a checkbox-based widget instead of the default multiple select box, as this is often considered more user-friendly.
Finally, we can update the `blog_page.html` template to display the categories: