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Matt Westcott cf0ee13b49 Remove Python 3.6 support

2021-12-09 16:36:29 +00:00

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Your first Wagtail site

.. note::
   This tutorial covers setting up a brand new Wagtail project.
   If you'd like to add Wagtail to an existing Django project instead, see :doc:`integrating_into_django`.

Install and run Wagtail

Install dependencies

Wagtail supports Python 3.7, 3.8, 3.9 and 3.10.

To check whether you have an appropriate version of Python 3:

$ python3 --version

If this does not return a version number or returns a version lower than 3.7, you will need to install Python 3.

.. important::
   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).
   The way to do this varies by platform—see Pillow's
   `platform-specific installation instructions <https://pillow.readthedocs.org/en/latest/installation.html#external-libraries>`_.

Create and activate a virtual environment

We recommend using a virtual environment, which isolates installed dependencies from other projects. This tutorial uses venv, which is packaged with Python 3.

On Windows (cmd.exe):

> python3 -m venv mysite\env
> mysite\env\Scripts\activate.bat

On GNU/Linux or MacOS (bash):

$ python3 -m venv mysite/env
$ source mysite/env/bin/activate

For other shells see the venv documentation.

.. note::

   If you're using version control (e.g. git), ``mysite`` will be the directory for your project.
   The ``env`` directory inside of it should be excluded from any version control.

Install Wagtail

Use pip, which is packaged with Python, to install Wagtail and its dependencies:

$ pip install wagtail

Generate your site

Wagtail provides a start command similar to django-admin startproject. Running wagtail start mysite in your project will generate a new mysite folder with a few Wagtail-specific extras, including the required project settings, a "home" app with a blank HomePage model and basic templates, and a sample "search" app.

Because the folder mysite was already created by venv, run wagtail start with an additional argument to specify the destination directory:

$ wagtail start mysite mysite

.. note::

   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 ``settings`` file. Look at this file to see how the ``start`` command has listed them in there.

Install project dependencies

$ cd mysite
$ pip install -r requirements.txt

This ensures that you have the relevant versions of Wagtail, Django, and any other dependencies for the project you have just created.

Create the database

If you haven't updated the project settings, this will be a SQLite database file in the project directory.

$ python manage.py migrate

This command ensures that the tables in your database are matched to the models in your project. Every time you alter your model (eg. you may add a field to a model) you will need to run this command in order to update the database.

Create an admin user

$ python manage.py createsuperuser

When logged into the admin site, a superuser has full permissions and is able to view/create/manage the database.

Start the server

$ python manage.py runserver

If everything worked, http://127.0.0.1:8000 will show you a welcome page:

You can now access the administrative area at http://127.0.0.1:8000/admin

Extend the HomePage model

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:

from django.db import models

from wagtail.core.models import Page
from wagtail.core.fields import RichTextField
from wagtail.admin.edit_handlers import FieldPanel


class HomePage(Page):
    body = RichTextField(blank=True)

    content_panels = Page.content_panels + [
        FieldPanel('body', classname="full"),
    ]

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. 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.

Run python manage.py makemigrations (this will create the migrations file), then python manage.py migrate (this executes the migrations and updates the database with your model changes). 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 (go to Pages, Homepage, then Edit) 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.

The page template now needs to be updated to reflect the changes made to the model. Wagtail uses normal Django templates to render each page type. By default, it will look for a template filename formed from the app and model name, separating capital letters with underscores (e.g. HomePage within the 'home' app becomes home/home_page.html). This template file can exist in any location recognised by Django's template rules; conventionally it is placed under a templates folder within the app.

Edit home/templates/home/home_page.html to contain the following:

{% extends "base.html" %}

{% load wagtailcore_tags %}

{% block body_class %}template-homepage{% endblock %}

{% block content %}
    {{ page.body|richtext }}
{% endblock %}

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 are able to override specific content within the parent template).

wagtailcore_tags must also be loaded at the top of the template and provide additional tags to those provided by Django.

Wagtail template tags

In addition to Django's template tags and filters, Wagtail provides a number of its own template tags & filters which can be loaded by including {% load wagtailcore_tags %} at the top of your template file.

In this tutorial, we use the richtext filter to escape and print the contents of a RichTextField:

{% load wagtailcore_tags %}
{{ page.body|richtext }}

Produces:

<p>
    <b>Welcome</b> to our new site!
</p>

Note: You'll need to include {% load wagtailcore_tags %} in each template that uses Wagtail's tags. Django will throw a TemplateSyntaxError if the tags aren't loaded.

A basic blog

We are now ready to create a blog. To do so, run python manage.py startapp blog to create a new app in your Wagtail site.

Add the new blog app to INSTALLED_APPS in mysite/settings/base.py.

Blog Index and Posts

Lets start with a simple index page for our blog. In blog/models.py:

from wagtail.core.models import Page
from wagtail.core.fields import RichTextField
from wagtail.admin.edit_handlers import FieldPanel


class BlogIndexPage(Page):
    intro = RichTextField(blank=True)

    content_panels = Page.content_panels + [
        FieldPanel('intro', classname="full")
    ]

Run python manage.py makemigrations and python manage.py migrate.

Since the model is called BlogIndexPage, the default template name (unless we override it) will be blog/templates/blog/blog_index_page.html. Create this file with the following content:

{% extends "base.html" %}

{% load wagtailcore_tags %}

{% block body_class %}template-blogindexpage{% endblock %}

{% block content %}
    <h1>{{ page.title }}</h1>

    <div class="intro">{{ page.intro|richtext }}</div>

    {% for post in page.get_children %}
        <h2><a href="{% pageurl post %}">{{ post.title }}</a></h2>
        {{ post.specific.intro }}
        {{ post.specific.body|richtext }}
    {% endfor %}

{% endblock %}

Most of this should be familiar, but we'll explain get_children a bit later. Note the pageurl tag, which is similar to Django's url tag but takes a Wagtail Page object as an argument.

In the Wagtail admin, create a BlogIndexPage as a child of the Homepage, make sure it has the slug "blog" on the Promote tab, and publish it. You should now be able to access the url /blog on your site (note how the slug from the Promote tab defines the page URL).

Now we need a model and template for our blog posts. In blog/models.py:

from django.db import models

from wagtail.core.models import Page
from wagtail.core.fields import RichTextField
from wagtail.admin.edit_handlers import FieldPanel
from wagtail.search import index


# Keep the definition of BlogIndexPage, and add:


class BlogPage(Page):
    date = models.DateField("Post date")
    intro = models.CharField(max_length=250)
    body = RichTextField(blank=True)

    search_fields = Page.search_fields + [
        index.SearchField('intro'),
        index.SearchField('body'),
    ]

    content_panels = Page.content_panels + [
        FieldPanel('date'),
        FieldPanel('intro'),
        FieldPanel('body', classname="full"),
    ]

In the model above, we import index as this makes the model searchable. You can then list fields that you want to be searchable for the user.

Run python manage.py makemigrations and python manage.py migrate.

Create a template at blog/templates/blog/blog_page.html:

{% extends "base.html" %}

{% load wagtailcore_tags %}

{% block body_class %}template-blogpage{% endblock %}

{% block content %}
    <h1>{{ page.title }}</h1>
    <p class="meta">{{ page.date }}</p>

    <div class="intro">{{ page.intro }}</div>

    {{ page.body|richtext }}

    <p><a href="{{ page.get_parent.url }}">Return to blog</a></p>

{% endblock %}

Note the use of Wagtail's built-in get_parent() method to obtain the URL of the blog this post is a part of.

Now create a few blog posts as children of BlogIndexPage. Be sure to select type "Blog Page" when creating your posts.

Wagtail gives you full control over what kinds of content can be created under various parent content types. By default, any page type can be a child of any other page type.

Publish each blog post when you are done editing.

You should now have the very beginnings of a working blog. Access the /blog URL and you should see something like this:

Titles should link to post pages, and a link back to the blog's homepage should appear in the footer of each post page.

Parents and Children

Much of the work you'll be doing in Wagtail revolves around the concept of hierarchical "tree" structures consisting of nodes and leaves (see Theory). In this case, the BlogIndexPage is a "node" and individual BlogPage instances are the "leaves".

Take another look at the guts of blog_index_page.html:

{% for post in page.get_children %}
    <h2><a href="{% pageurl post %}">{{ post.title }}</a></h2>
    {{ post.specific.intro }}
    {{ post.specific.body|richtext }}
{% endfor %}

Every "page" in Wagtail can call out to its parent or children from its own position in the hierarchy. But why do we have to specify post.specific.intro rather than post.intro? This has to do with the way we defined our model:

class BlogPage(Page):

The get_children() method gets us a list of instances of the Page base class. When we want to reference properties of the instances that inherit from the base class, Wagtail provides the specific method that retrieves the actual BlogPage record. While the "title" field is present on the base Page model, "intro" is only present on the BlogPage model, so we need .specific to access it.

To tighten up template code like this, we could use Django's with tag:

{% for post in page.get_children %}
    {% with post=post.specific %}
        <h2><a href="{% pageurl post %}">{{ post.title }}</a></h2>
        <p>{{ post.intro }}</p>
        {{ post.body|richtext }}
    {% endwith %}
{% endfor %}

When you start writing more customized Wagtail code, you'll find a whole set of QuerySet modifiers to help you navigate the hierarchy.

# Given a page object 'somepage':
MyModel.objects.descendant_of(somepage)
child_of(page) / not_child_of(somepage)
ancestor_of(somepage) / not_ancestor_of(somepage)
parent_of(somepage) / not_parent_of(somepage)
sibling_of(somepage) / not_sibling_of(somepage)
# ... and ...
somepage.get_children()
somepage.get_ancestors()
somepage.get_descendants()
somepage.get_siblings()

For more information, see: Page QuerySet reference

Overriding Context

There are a couple of problems with our blog index view:

Blogs generally display content in reverse chronological order
We want to make sure we're only displaying published content.

To accomplish these things, we need to do more than just grab the index page's children in the template. Instead, we'll want to modify the QuerySet in the model definition. Wagtail makes this possible via the overridable get_context() method. Modify your BlogIndexPage model like this:

class BlogIndexPage(Page):
    intro = RichTextField(blank=True)

    def get_context(self, request):
        # Update context to include only published posts, ordered by reverse-chron
        context = super().get_context(request)
        blogpages = self.get_children().live().order_by('-first_published_at')
        context['blogpages'] = blogpages
        return context

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.

Add a new BlogPageGalleryImage model to models.py:

from django.db import models

# New imports added for ParentalKey, Orderable, InlinePanel, ImageChooserPanel

from modelcluster.fields import ParentalKey

from wagtail.core.models import Page, Orderable
from wagtail.core.fields import RichTextField
from wagtail.admin.edit_handlers import FieldPanel, InlinePanel
from wagtail.images.edit_handlers import ImageChooserPanel
from wagtail.search import index


# ... (Keep the definition of BlogIndexPage, and update BlogPage:)


class BlogPage(Page):
    date = models.DateField("Post date")
    intro = models.CharField(max_length=250)
    body = RichTextField(blank=True)

    search_fields = Page.search_fields + [
        index.SearchField('intro'),
        index.SearchField('body'),
    ]

    content_panels = Page.content_panels + [
        FieldPanel('date'),
        FieldPanel('intro'),
        FieldPanel('body', classname="full"),
        InlinePanel('gallery_images', label="Gallery images"),
    ]


class BlogPageGalleryImage(Orderable):
    page = ParentalKey(BlogPage, on_delete=models.CASCADE, related_name='gallery_images')
    image = models.ForeignKey(
        'wagtailimages.Image', on_delete=models.CASCADE, related_name='+'
    )
    caption = models.CharField(blank=True, max_length=250)

    panels = [
        ImageChooserPanel('image'),
        FieldPanel('caption'),
    ]

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 comes with a dedicated panel type, ImageChooserPanel, which provides 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.

Adjust your blog page template to include the images:

{% extends "base.html" %}

{% load wagtailcore_tags wagtailimages_tags %}

{% block body_class %}template-blogpage{% endblock %}

{% block content %}
    <h1>{{ page.title }}</h1>
    <p class="meta">{{ page.date }}</p>

    <div class="intro">{{ page.intro }}</div>

    {{ page.body|richtext }}

    {% for item in page.gallery_images.all %}
        <div style="float: left; margin: 10px">
            {% image item.image fill-320x240 %}
            <p>{{ item.caption }}</p>
        </div>
    {% endfor %}

    <p><a href="{{ page.get_parent.url }}">Return to blog</a></p>

{% endblock %}

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.

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):

class BlogPage(Page):
    date = models.DateField("Post date")
    intro = models.CharField(max_length=250)
    body = RichTextField(blank=True)

    def main_image(self):
        gallery_item = self.gallery_images.first()
        if gallery_item:
            return gallery_item.image
        else:
            return None

    search_fields = Page.search_fields + [
        index.SearchField('intro'),
        index.SearchField('body'),
    ]

    content_panels = Page.content_panels + [
        FieldPanel('date'),
        FieldPanel('intro'),
        FieldPanel('body', classname="full"),
        InlinePanel('gallery_images', label="Gallery images"),
    ]

This method is now available from our templates. Update blog_index_page.html to include the main image as a thumbnail alongside each post:

{% load wagtailcore_tags wagtailimages_tags %}

...

{% for post in blogpages %}
    {% with post=post.specific %}
        <h2><a href="{% pageurl post %}">{{ post.title }}</a></h2>

        {% with post.main_image as main_image %}
            {% if main_image %}{% image main_image fill-160x100 %}{% endif %}
        {% endwith %}

        <p>{{ post.intro }}</p>
        {{ post.body|richtext }}
    {% endwith %}
{% endfor %}

Tagging Posts

Let's say we want to let editors "tag" their posts, so that readers can, e.g., view all bicycle-related content together. For this, we'll need to invoke the tagging system bundled with Wagtail, attach it to the BlogPage model and content panels, and render linked tags on the blog post template. Of course, we'll need a working tag-specific URL view as well.

First, alter models.py once more:

from django.db import models

# New imports added for ClusterTaggableManager, TaggedItemBase, MultiFieldPanel

from modelcluster.fields import ParentalKey
from modelcluster.contrib.taggit import ClusterTaggableManager
from taggit.models import TaggedItemBase

from wagtail.core.models import Page, Orderable
from wagtail.core.fields import RichTextField
from wagtail.admin.edit_handlers import FieldPanel, InlinePanel, MultiFieldPanel
from wagtail.images.edit_handlers import ImageChooserPanel
from wagtail.search import index


# ... (Keep the definition of BlogIndexPage)


class BlogPageTag(TaggedItemBase):
    content_object = ParentalKey(
        'BlogPage',
        related_name='tagged_items',
        on_delete=models.CASCADE
    )


class BlogPage(Page):
    date = models.DateField("Post date")
    intro = models.CharField(max_length=250)
    body = RichTextField(blank=True)
    tags = ClusterTaggableManager(through=BlogPageTag, blank=True)

    # ... (Keep the main_image method and search_fields definition)

    content_panels = Page.content_panels + [
        MultiFieldPanel([
            FieldPanel('date'),
            FieldPanel('tags'),
        ], heading="Blog information"),
        FieldPanel('intro'),
        FieldPanel('body'),
        InlinePanel('gallery_images', label="Gallery images"),
    ]

Run python manage.py makemigrations and python manage.py migrate.

Note the new modelcluster and taggit imports, the addition of a new BlogPageTag model, and the addition of a tags field on BlogPage. We've also taken the opportunity to use a MultiFieldPanel in content_panels to group the date and tags fields together for readability.

Edit one of your BlogPage instances, and you should now be able to tag posts:

To render tags on a BlogPage, add this to blog_page.html:

{% if page.tags.all.count %}
    <div class="tags">
        <h3>Tags</h3>
        {% for tag in page.tags.all %}
            <a href="{% slugurl 'tags' %}?tag={{ tag }}"><button type="button">{{ tag }}</button></a>
        {% endfor %}
    </div>
{% endif %}

Notice that we're linking to pages here with the builtin slugurl tag rather than pageurl, which we used earlier. The difference is that slugurl takes a Page slug (from the Promote tab) as an argument. pageurl is more commonly used because it is unambiguous and avoids extra database lookups. But in the case of this loop, the Page object isn't readily available, so we fall back on the less-preferred slugurl tag.

Visiting a blog post with tags should now show a set of linked buttons at the bottom - one for each tag. However, clicking a button will get you a 404, since we haven't yet defined a "tags" view. Add to models.py:

class BlogTagIndexPage(Page):

    def get_context(self, request):

        # Filter by tag
        tag = request.GET.get('tag')
        blogpages = BlogPage.objects.filter(tags__name=tag)

        # Update template context
        context = super().get_context(request)
        context['blogpages'] = blogpages
        return context

Note that this Page-based model defines no fields of its own. Even without fields, subclassing Page makes it a part of the Wagtail ecosystem, so that you can give it a title and URL in the admin, and so that you can manipulate its contents by returning a QuerySet from its get_context() method.

Migrate this in, then create a new BlogTagIndexPage in the admin. You'll probably want to create the new page/view as a child of Homepage, parallel to your Blog index. Give it the slug "tags" on the Promote tab.

Access /tags and Django will tell you what you probably already knew: you need to create a template blog/blog_tag_index_page.html:

{% extends "base.html" %}
{% load wagtailcore_tags %}

{% block content %}

    {% if request.GET.tag %}
        <h4>Showing pages tagged "{{ request.GET.tag }}"</h4>
    {% endif %}

    {% for blogpage in blogpages %}

          <p>
              <strong><a href="{% pageurl blogpage %}">{{ blogpage.title }}</a></strong><br />
              <small>Revised: {{ blogpage.latest_revision_created_at }}</small><br />
              {% if blogpage.author %}
                <p>By {{ blogpage.author.profile }}</p>
              {% endif %}
          </p>

    {% empty %}
        No pages found with that tag.
    {% endfor %}

{% endblock %}

We're calling the built-in latest_revision_created_at field on the Page model - handy to know this is always available.

We haven't yet added an "author" field to our BlogPage model, nor do we have a Profile model for authors - we'll leave those as an exercise for the reader.

Clicking the tag button at the bottom of a BlogPost should now render a page something like this:

.. _tutorial_categories:

Where next

Read the Wagtail topics and reference documentation
Learn how to implement StreamField for freeform page content
Browse through the advanced topics section and read third-party tutorials

31 KiB Raw Blame History

Your first Wagtail site

Install and run Wagtail

Install dependencies

Create and activate a virtual environment

Install Wagtail

Generate your site

Install project dependencies

Create the database

Create an admin user

Start the server

Extend the HomePage model

Wagtail template tags

A basic blog

Blog Index and Posts

Parents and Children

Overriding Context

Images

Tagging Posts

Categories

Where next

31 KiB

Raw Blame History