By default, the JSON:API returns all the available data for an object in its response. Using JSON:API sparse fieldsets you can increase the performance of your consumer application by reducing the fields in the returned response object to just those that you need.
In this tutorial, we will learn how to reduce the output to get exactly the information that we need from the API.
This is one of the most important features of modern APIs like JSON:API.
By the end of this tutorial, you'll know what sparse fieldsets are, the role they fulfill, and how to use them when requesting data from a JSON:API server.
Whenever we need our consumer application to change the contents of an entity we will need to issue a PATCH request. The JSON:API module will process that request and update the entity with the provided values.
In this tutorial, we'll:
- Define the appropriate HTTP headers for a PATCH request
- Construct the JSON object used to update an entity
- Issue a PATCH request that will update an entity in our Drupal backend
By the end of this tutorial, you should know how to update content via the JSON:API.
In the last several years REST has been the de facto standard for web services. However, there are several common problems when developing websites and digital experiences with the traditional REST implementations. Luckily, those issues have solutions, either complete or partial.
Modern web service specifications like JSON:API and GraphQL implement those solutions, although they differ slightly in their implementation.
In this tutorial we will learn about:
- The problems of traditional REST implementations
- Common solutions to those problems, and how JSON:API and GraphQL deal with them
By the end of this tutorial you'll be able to explain some of the common pitfalls of REST-based APIs, and how JSON:API and GraphQL address those issues.
In the previous tutorials, we learned to install and configure the Simple OAuth module. We also learned how to generate authentication tokens using different grants. In this tutorial, we will learn how to use a token to authenticate a request for a given Drupal user, and:
- Check if a particular route supports a specific type of authentication,
oauth2in particular - Send an authentication token, like the ones we acquired in the previous tutorial in order to prove to Drupal that the request is made by a specific user
By the end of this tutorial you should be able to make authenticated requests, as a specific user, to your API.
In order to authenticate a request against the API server, we need to send an authentication token along with the request. For that we need to first obtain the token from the server. The various ways we can get a token from the server are called grants. Using one of them, we will obtain an access token and a refresh token.
In this tutorial we will:
- Learn how OAuth 2 grants work
- Learn how to generate and request authentication tokens
- Learn how to generate and request refresh tokens
By the end of this tutorial you should be able to exchange a user name and password for OAuth 2 authentication and refresh tokens so that your API client can make authenticated requests.
The Simple OAuth module can be used to configure Drupal as an OAuth 2 authentication provider. Doing so will allow third-party applications to authenticate users using any of the OAuth flows, and validate their roles and permissions.
If you're creating applications that access Drupal's data and need to act like a logged-in user you'll want to use OAuth for authentication. There are 2 steps to accomplishing this: first, you'll need to set up Drupal to act as an authentication provider (this tutorial). Second, you'll need to make the appropriate HTTP requests to obtain an access token, which is covered in the next tutorial, Make an Authenticated Request Using OAuth 2.
In this tutorial we will:
- Learn how to install the Simple OAuth Drupal module
- Configure the Simple OAuth module so we can generate tokens that can authenticate users in Drupal
- Demonstrate what the responses generated by the Simple OAuth module look like
By the end of this tutorial you should know how to install and configure the Simple OAuth module.
The term web services has been around for quite a while. Given that web services is such a broad topic, let's define what web services are and how we are going to refer to them throughout this series so we are all on the same page.
This tutorial is an introduction to web services that will help you:
- Learn what a web service is.
- Understand that this series focuses on HTTP web services, and mostly on REST principles.
- Get some examples of APIs in the wild and what type of consumers they have.
By the end of this tutorial, you'll be able to define what web services are, and how we'll use the term in the context of these tutorials.
When running migrations you can use the highwater_mark source plugin configuration option to influence which rows are considered for import on subsequent migration runs. This allows you to do things like only look at new rows added to a large dataset. Or to reimport records that have changed since the last time the migration was run. The term, highwater mark, comes from water line marks found on structures in areas where water level changes are common. In running migrations, you can think of a highwater mark as a line that denotes how far the migration has progressed, and saying, "from now one, we only care about data created after this line".
Another common use case for highwater marks is when you're importing a large dataset and the system runs out of resources. Usually this will look like a migration failing because it timed out, or the process ran out of memory. A highwater mark should allow you to pickup from where you left off.
In this tutorial we'll:
- Define what a highwater mark is, and how you can use them to limit the rows considered for importing each time a migration is executed.
- Demonstrate how highwater marks can be used to reimport source records that have been modified since the previous time the migration was executed.
- Introduce the
track_changesoption.
By the end of this tutorial you should be able to define what a highwater_mark is and how to use them to speed up the import of large datasets or force the migration to reimport records when the source data is changed.
You should also be aware of the track_changes feature which is a slower, but more dynamic, method of checking for changes in source data and reimporting records when a change is found.
If you need to write a migration that is capable of being executed multiple times and picking up changes to previously imported data, you can use the track_changes configuration option of most source plugins. This will tell the migration to keep a hash of each source row, and on subsequent runs of the same migration it will compare the previous hash to the current one. If they don't match this means the source data has changed, and Drupal will reimport that record and update the existing destination record with new data.
Using track_changes differs from calling drush migrate:import --update in that using --update will force every record to be re-imported regardless of whether the source data has changed or not.
In this tutorial we'll:
- Learn how change tracking works to detect changes in your source data
- Use the
track_changesoption in a migration
Note that progress of a migration can also be tracked using highwater marks if the source data has something like a last_updated timestamp column. Using highwater marks in this case is likely more efficient than using track_changes. It's a good idea to understand how both features work, and then choose the appropriate one for each migration.
Before you can migrate your Drupal 7 site to the latest version of Drupal you'll need to be able to build the features that make up the current site. Part of this is evaluating all the modules you've got installed, figuring out what you're using them for, and if there's a version that's compatible with the latest version of Drupal along with a migration path.
I usually make a spreadsheet for this. But any list of the modules you’re currently using that allows you to keep track of how you plan to update them will work. You also want to keep track of where you are in the process of figuring that all out. Because it’s likely you’ll have some modules for which the path is clear, and others where it’s pretty murky and requires more in-depth research to find a path forward. Having a list means you can break that up into tasks, and ensure you’re not missing something. It'll also help you define when your migration is done as well as any final quality assurance (QA) tasks.
In this tutorial we'll:
- Start a list of the modules that make up our current site.
- Point to some tools that can help speed up the process of evaluating a module's readiness.
- Provide a set of questions that you can ask about each module you're using as part of your planning process.
By the end of this tutorial you should have a list of all the modules you're currently using, and some tools you can use to help you figure out how to move forward with each one.
If you want to be able to say you're done with your Drupal-to-Drupal migration, first you have to be able to define "done". And part of that is doing a content analysis and inventory. Performing a content analysis and inventory will help you ensure that you don't miss any fields or important records. It also gives you an opportunity to spend some time thinking about the overall information architecture of your site. You're already going to be doing a lot of work to migrate your content, so deciding to shuffle things a bit now might not add any significant extra time. Additionally, the latest Drupal (as of Drupal 10) is a different platform than either Drupal 6 or 7, and as such, there are some new best practices and new ways of doing things that might not have been available before.
In this tutorial we'll:
- Provide a set of questions you can ask yourself about the content of your current site to kick-start your analysis.
- Give an example of how we create a content type inventory in a spreadsheet and use that to help define "done" for our projects.
By the end of this tutorial you should be able to get started analyzing the content and content types of your existing site in order to start planning for your Drupal-to-Drupal migration.
Because current versions of Drupal are so much different from older versions like Drupal 7 upgrading to the latest version requires creating a new site using the latest version of Drupal and then migrating your old site's content and configuration into it.
There is no one right way to tackle a Drupal-to-Drupal migration. Instead, it's like walking down a path and coming to a fork in the trail and then choosing a direction over and over and over. Since every site is different, every path to a finished migration will be different, too. I know nobody wants to hear it, but every migration is its own unique adventure. Every successful migration will require its own custom code, weird shell scripts, and detailed lists of the exact order of things. But that doesn't mean there's no plan to follow.
A successful migration charts a course through the maze, while leveraging existing tools and experience to help find the shortest route and the right path at each fork--with minimal backtracking due to wrong choices.
In this tutorial we'll:
- Look at what makes a Drupal-to-Drupal migration (a major version upgrade) so tricky, and how to think about performing one
- Define 3 high-level approaches to performing a Drupal-to-Drupal migration
- Get a better idea of what the migration work entails, so you go into it with a proper mental model.
By the end of this tutorial you should be able to explain the different approaches to performing a Drupal-to-Drupal migration in broad strokes, and have a better picture of the work that will be involved.
The migration_lookup process plugin allows you to populate entity reference fields when the entity that you want to reference is created by another migration, and you don't yet know what the unique ID will be in the Drupal database. Think of this as being able to answer the question: I have a migration that imports new users from a CSV file, and another that imports articles from a different CSV file. The articles' CSV file has a column that indicates which row from the users' CSV file is the author of this file. But in order to populate the author field for the Drupal node I need to know the ID of the imported user which is an auto-incremented ID that I'm not setting. So, what is the correct ID to use?
Another use case is circular dependencies, like hierarchical taxonomies with parent/child relationships. Or a content type with a field that references other nodes of the same type, like articles that reference other articles.
In this tutorial we'll:
- Learn about the
migration_lookupprocess plugin and its configuration - Provide examples of using the plugin to populate entity reference fields during a migration
- Look at alternatives
By the end of this tutorial you should be able to use the migration_lookup plugin to effectively manage entity relationships across multiple individual migrations.
When a migration is run the Migrate API creates a mapping table that keeps track of what source record was used to create which destination record. A record is automatically added for each successfully migrated row. This mapping table can be used later to:
- See if a row was previously imported
- Look up the ID of the entity created for the row
- Tracking if a source record has changed and needs to be re-imported.
In this tutorial we'll learn:
- What migration map tables are
- Why they exist, and what the Migrate API does with them
By the end of this tutorial you should be able to explain the use case for map tables and describe the data they contain.
Do you know some PHP and want to learn how to create a custom page at a custom URL in Drupal? You're in the right place.
Every web framework has the same job: provide a way for developers to map user-accessible URLs with code that builds the page. Routes, controllers, and responses are what module developers use to create pages at custom URLs in a Drupal site.
In this tutorial, we'll:
- Define what routes, controllers, and responses are.
- Explain the routing workflow that Drupal uses to match a URL to a route.
- Define routing system-related terms like parameter and upcasting.
By the end of this tutorial, you should be able to explain how a developer uses routes, controllers, and responses to create custom pages in a module.
If you want to define a new URL that a user can navigate to, and custom PHP code that will generate the content of the page, you need a route and a controller. Most of the time you'll want to do something more complex than hard code the content of the page. This will require using services in your controller. This can be accomplished in different ways.
In this tutorial we'll:
- Provide the definition for a new route which maps a path to the callback method of a controller class.
- Create a controller that returns a hard coded string.
- Look at examples of using both
ControllerBaseand dependency injection to access services from a controller, and discuss the benefits of both approaches.
By the end of this tutorial, you should be able to define a new route that maps to a controller and displays content on the page as a result of your custom logic.
The routing system can get dynamic values from the URL and pass them as arguments to the controller. This means a single route with a path of /node/{node} can be used to display any node entity. Route parameters can be validated, and upcast to complex data types via parameter conversion. If you ever want to pass arguments to the controller for a route, you'll use parameters to do so.
In this tutorial we'll:
- Define what parameters (slugs, placeholders) are and what they are used for in a route definition.
- Explain how URL parameters are passed to a controller.
- Define parameter upcasting.
By the end of this tutorial, you should be able to explain how to define a route that uses parameters to pass dynamic values to the route controller, and explain how parameter upcasting works.
Every route should define its access control parameters. When you define routes in a module, you can limit who has access to those routes via different access control options. Route-level access control applies to the path. If your route defines a path like /journey/example, the access control configuration will determine whether to show the current user the page at the path defined by the route, or to have Drupal serve an "HTTP 403 Access Denied" message instead.
In this tutorial we'll look at different ways of adding access control to a route including:
- Access based on the current user's roles and permissions
- Access based on custom logic in a callback method
- Logic in an access checker service
By the end of this tutorial, you should be able to add access control logic to your custom routes that will meet any requirement.
When defining a route and subsequently displaying the page, often we need to calculate the page title based on route parameters or other logic. In these cases, we can't just hard code the value into the _title configuration of the route. To set a dynamic title for a page, we'll use the route's _title_callback option, and point to a PHP callback that contains the logic that computes the title of the page.
In this tutorial we'll:
- Learn how to use the
_title_callbackroute configuration option to dynamically set a page title - Explain how arguments are provided to the title callback method
- Update the route and controller from a previous tutorial to use a dynamic title callback
By the end of this tutorial, you should be able to configure a route so that its title can be set dynamically using route parameters, instead of hard-coding the title with a static string of text.
Let's write some code that will allow us to see route parameters in action. We'll define a new route with a path like /journey/42/full but where 42 can be any node ID, and full can be any view mode. When a user accesses the path we'll pass the dynamic parameters from the URL to the controller. The controller will then load the corresponding node and render it using the provided view mode, and return that to display on the page.
By the end of this tutorial you should be able to:
- Use dynamic slugs in a route to pass parameters to the route controller.
- See how Drupal will upcast a value like the node ID, 42, to a
Nodeobject automatically. - Explain what happens when you visit a URL that matches a route but the parameters don't pass validation.
By the end of this tutorial, you should be able to pass dynamic values from the URL to a route's controller.