add ash_tutorial
This commit is contained in:
Chang CL
277
ash_tutorial/customizing_actions.livemd
Normal file
277
ash_tutorial/customizing_actions.livemd
Normal file
@@ -0,0 +1,277 @@
|
||||
# Ash: 5 - Customizing Actions
|
||||
|
||||
```elixir
|
||||
Application.put_env(:ash, :validate_domain_resource_inclusion?, false)
|
||||
Application.put_env(:ash, :validate_domain_config_inclusion?, false)
|
||||
Mix.install([{:ash, "~> 3.0"}], consolidate_protocols: false)
|
||||
```
|
||||
|
||||
## Customizing Actions
|
||||
|
||||
<div class="flex items-center w-full flex-start justify-between rounded-xl p-4" style="background-color: #f0f5f9; color: #61758a;">
|
||||
<div class="flex">
|
||||
<i class="ri-arrow-left-fill"></i>
|
||||
<a class="flex ml-2" style="color: #61758a;" href="attributes.livemd">Attributes</a>
|
||||
</div>
|
||||
<div class="flex">
|
||||
<i class="ri-home-fill"></i>
|
||||
<a class="flex ml-2" style="color: #61758a;" href="overview.livemd">Home</a>
|
||||
</div>
|
||||
<div class="flex">
|
||||
<a class="flex mr-2" style="color: #61758a;" href="relationships.livemd">Relationships</a>
|
||||
<i class="ri-arrow-right-fill"></i>
|
||||
</div>
|
||||
</div>
|
||||
|
||||
### In this tutorial you will add custom Actions on the Ticket resource
|
||||
|
||||
Create 2 custom actions, `:open` and `:close`.
|
||||
|
||||
Custom actions allow you to attach *semantics* to actions.
|
||||
|
||||
* Instead of *Creating* a ticket, you can *Open* a ticket.
|
||||
* Instead of *Updating* the status on a ticket you can *Close* it.
|
||||
|
||||
In addition, you can customize the behaviour of these actions. For example, closing a ticket only sets the status to `:closed`.
|
||||
|
||||
It also allows you to define what attributes can be set when calling that action. For example for the `:open` action, you can only allow the `:subject` and `:description` to be set.
|
||||
It does not make sense to set the `:status` in this case as it should always be `:open`. For the closing action you won't allow any attributes to be set.
|
||||
|
||||
Custom actions go inside the `actions do ... end` block.
|
||||
|
||||
To define the `:open` action, open a `do end` block like so:
|
||||
|
||||
<!-- livebook:{"force_markdown":true} -->
|
||||
|
||||
```elixir
|
||||
create :open do
|
||||
|
||||
end
|
||||
```
|
||||
|
||||
Same for the `:close` action, but instead of `create`, use `update`.
|
||||
|
||||
You then can define the accepted attributes like so:
|
||||
|
||||
`accept [:subject, :description]`
|
||||
|
||||
Or in the case of the `:close` action:
|
||||
|
||||
`accept []`
|
||||
|
||||
Then for the `:close` action define a `change`:
|
||||
|
||||
`change set_attribute(:status, :closed)`
|
||||
|
||||
That's it, you defined your first custom actions.
|
||||
|
||||
<details class="rounded-lg my-4" style="background-color: #96ef86; color: #040604;">
|
||||
<summary class="cursor-pointer font-bold p-4"></i>Show Solution</summary>
|
||||
<div class="p-4">
|
||||
|
||||
```elixir
|
||||
defmodule Tutorial.Support.Ticket do
|
||||
use Ash.Resource,
|
||||
domain: Tutorial.Support,
|
||||
data_layer: Ash.DataLayer.Ets
|
||||
|
||||
actions do
|
||||
defaults [:read]
|
||||
|
||||
create :open do
|
||||
# By default you can provide all public attributes to an action
|
||||
# This action should only accept the subject
|
||||
accept [:subject, :description]
|
||||
end
|
||||
|
||||
update :close do
|
||||
# We don't want to accept any input here
|
||||
accept []
|
||||
|
||||
change set_attribute(:status, :closed)
|
||||
# A custom change could be added like so:
|
||||
#
|
||||
# change MyCustomChange
|
||||
# change {MyCustomChange, opt: :val}
|
||||
end
|
||||
end
|
||||
|
||||
attributes do
|
||||
uuid_primary_key :id
|
||||
|
||||
attribute :subject, :string, allow_nil?: false
|
||||
attribute :description, :string
|
||||
attribute :status, :atom do
|
||||
constraints [one_of: [:open, :closed]]
|
||||
default :open
|
||||
allow_nil? false
|
||||
end
|
||||
|
||||
create_timestamp :created_at
|
||||
update_timestamp :updated_at
|
||||
end
|
||||
end
|
||||
|
||||
defmodule Tutorial.Support do
|
||||
use Ash.Domain
|
||||
|
||||
resources do
|
||||
resource Tutorial.Support.Ticket
|
||||
end
|
||||
end
|
||||
```
|
||||
|
||||
</div>
|
||||
</details>
|
||||
|
||||
### Enter your solution
|
||||
|
||||
```elixir
|
||||
defmodule Tutorial.Support.Ticket do
|
||||
use Ash.Resource,
|
||||
domain: Tutorial.Support,
|
||||
data_layer: Ash.DataLayer.Ets
|
||||
|
||||
actions do
|
||||
defaults [:read]
|
||||
|
||||
# <-- Add the :open and :close action
|
||||
end
|
||||
|
||||
attributes do
|
||||
uuid_primary_key(:id)
|
||||
|
||||
attribute :subject, :string, allow_nil?: false
|
||||
attribute :description, :string
|
||||
|
||||
attribute :status, :atom do
|
||||
constraints one_of: [:open, :closed]
|
||||
default :open
|
||||
allow_nil? false
|
||||
end
|
||||
|
||||
create_timestamp :created_at
|
||||
update_timestamp :updated_at
|
||||
end
|
||||
end
|
||||
|
||||
defmodule Tutorial.Support do
|
||||
use Ash.Domain
|
||||
|
||||
resources do
|
||||
resource Tutorial.Support.Ticket
|
||||
end
|
||||
end
|
||||
```
|
||||
|
||||
## Open a Ticket
|
||||
|
||||
Open a ticket.
|
||||
|
||||
Remember, when creating a resource, use a changeset (`Ash.Changeset.for_create/3`), which gets passed to `Ash.create!/1`. But in this case use the `:open` argument instead of `:create`.
|
||||
|
||||
<details class="rounded-lg my-4" style="background-color: #96ef86; color: #040604;">
|
||||
<summary class="cursor-pointer font-bold p-4"></i>Show Solution</summary>
|
||||
<div class="p-4">
|
||||
|
||||
```elixir
|
||||
Tutorial.Support.Ticket
|
||||
|> Ash.Changeset.for_create(:open, %{subject: "My Subject"})
|
||||
|> Ash.create!()
|
||||
```
|
||||
|
||||
</div>
|
||||
</details>
|
||||
|
||||
Try setting the `:status` to `:closed` and see if it works.
|
||||
|
||||
<details class="rounded-lg my-4" style="background-color: #96ef86; color: #040604;">
|
||||
<summary class="cursor-pointer font-bold p-4"></i>Show Solution</summary>
|
||||
<div class="p-4">
|
||||
|
||||
```elixir
|
||||
Tutorial.Support.Ticket
|
||||
|> Ash.Changeset.for_create(:open, %{subject: "My Subject", status: :closed})
|
||||
|> Ash.create!()
|
||||
```
|
||||
|
||||
</div>
|
||||
</details>
|
||||
|
||||
The output when trying to set `:status` should look something like this:
|
||||
|
||||
```
|
||||
** (Ash.Error.Invalid) Input Invalid
|
||||
|
||||
* Invalid value provided for status: cannot be changed.
|
||||
```
|
||||
|
||||
This is because you set the accepted attributes to `:subject` and `:description` only.
|
||||
|
||||
**Enter your solution**
|
||||
|
||||
```elixir
|
||||
|
||||
```
|
||||
|
||||
Create a Ticket and store it in the `ticket` variable.
|
||||
|
||||
<details class="rounded-lg my-4" style="background-color: #96ef86; color: #040604;">
|
||||
<summary class="cursor-pointer font-bold p-4"></i>Show Solution</summary>
|
||||
<div class="p-4">
|
||||
|
||||
```elixir
|
||||
ticket =
|
||||
Tutorial.Support.Ticket
|
||||
|> Ash.Changeset.for_create(:open, %{subject: "My Subject"})
|
||||
|> Ash.create!()
|
||||
```
|
||||
|
||||
</div>
|
||||
</details>
|
||||
|
||||
**Enter your solution**
|
||||
|
||||
```elixir
|
||||
|
||||
```
|
||||
|
||||
## Close a Ticket
|
||||
|
||||
Close the `ticket` you created in the previous section.
|
||||
|
||||
Remember to use `Ash.Changeset.for_update/2` with the `:close` action.
|
||||
|
||||
To update use `Ash.update!/1`.
|
||||
|
||||
<details class="rounded-lg my-4" style="background-color: #96ef86; color: #040604;">
|
||||
<summary class="cursor-pointer font-bold p-4"></i>Show Solution</summary>
|
||||
<div class="p-4">
|
||||
|
||||
```elixir
|
||||
ticket
|
||||
|> Ash.Changeset.for_update(:close)
|
||||
|> Ash.update!()
|
||||
```
|
||||
|
||||
</div>
|
||||
</details>
|
||||
|
||||
```elixir
|
||||
|
||||
```
|
||||
|
||||
<div class="flex items-center w-full flex-start justify-between rounded-xl p-4" style="background-color: #f0f5f9; color: #61758a;">
|
||||
<div class="flex">
|
||||
<i class="ri-arrow-left-fill"></i>
|
||||
<a class="flex ml-2" style="color: #61758a;" href="attributes.livemd">Attributes</a>
|
||||
</div>
|
||||
<div class="flex">
|
||||
<i class="ri-home-fill"></i>
|
||||
<a class="flex ml-2" style="color: #61758a;" href="overview.livemd">Home</a>
|
||||
</div>
|
||||
<div class="flex">
|
||||
<a class="flex mr-2" style="color: #61758a;" href="relationships.livemd">Relationships</a>
|
||||
<i class="ri-arrow-right-fill"></i>
|
||||
</div>
|
||||
</div>
|
||||
Reference in New Issue
Block a user