Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Update contexts.md & mix_tasks.md #4550

Merged
merged 1 commit into from
Oct 21, 2021
Merged

Update contexts.md & mix_tasks.md #4550

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 3 additions & 3 deletions guides/contexts.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -976,7 +976,7 @@ We're almost ready to try out our cart page, but first we need to implement our

We implemented `total_item_price/1` which accepts a `%CartItem{}` struct. To calculate the total price, we simply take the preloaded product's price and multiply it by the item's quantity. We used `Decimal.mult/2` to take our decimal currency struct and multiply it with proper precision. Similarly for calculating the total cart price, we implemented a `total_cart_price/1` function which accepts the cart and sums the preloaded product prices for items in the cart. We again make use of the `Decimal` functions to add our decimal structs together.

Now that we can calculate price totals, let's try it out! Visit [`http://localhost:4000/cart`](http://localhost:4000/cart) and you should already see your first item in the cart. Going back to the same product and clicking "add to cart" will show our upsert in action. Your quantity should now show be two. Nice work!
Now that we can calculate price totals, let's try it out! Visit [`http://localhost:4000/cart`](http://localhost:4000/cart) and you should already see your first item in the cart. Going back to the same product and clicking "add to cart" will show our upsert in action. Your quantity should now be two. Nice work!

Our cart page is almost complete, but submitting the form will yield yet another error.

Expand Down Expand Up @@ -1086,7 +1086,7 @@ We generated a `Orders` context along with HTML controllers, views, etc. We adde

Like we did previously, we gave appropriate precision and scale options for our decimal column which will allow us to store currency without precision loss. We also added a not-null constraint to enforce all orders to have a price.

The orders table alone doesn't hold much information, but we know we'll need to store point-in-time product price information of all the items in the order. For that, we'll add additional struct for this context named `LineItem`. Line items will capture the price of the product *at payment transaction time*. Please run the following command:
The orders table alone doesn't hold much information, but we know we'll need to store point-in-time product price information of all the items in the order. For that, we'll add an additional struct for this context named `LineItem`. Line items will capture the price of the product *at payment transaction time*. Please run the following command:

```console
$ mix phx.gen.context Orders LineItem order_line_items \
Expand Down Expand Up @@ -1261,7 +1261,7 @@ From our requirements alone, we can start to see why a generic `create_order` fu
end
```

We started by mapping the `%ShoppingCart.CartItem{}`'s in our shopping cart into a map of order line items structs. The job of order line item record is to capture the price of the product *at payment transaction time*, so we reference the product's price here. Next, we create a bare order changeset with `Ecto.Changeset.change/2` and associate our user UUID, set our total price calculation, and place our order line items in the changeset. With a fresh order changeset ready to be inserted, we can again make use of `Ecto.Multi` to execute our operations in a database transaction. We start by inserting the order, followed by a `run` operation. The `Ecto.Multi.run/3` function allows us to run any code in the function which must either succeed with `{:ok, result}` or error, which halts and rolls back the transaction. Here, we simply can call into our shopping cart context and ask it to prune all items in a cart. Running the transaction will execute the multi as before and we return the result to the caller.
We started by mapping the `%ShoppingCart.CartItem{}`'s in our shopping cart into a map of order line items structs. The job of the order line item record is to capture the price of the product *at payment transaction time*, so we reference the product's price here. Next, we create a bare order changeset with `Ecto.Changeset.change/2` and associate our user UUID, set our total price calculation, and place our order line items in the changeset. With a fresh order changeset ready to be inserted, we can again make use of `Ecto.Multi` to execute our operations in a database transaction. We start by inserting the order, followed by a `run` operation. The `Ecto.Multi.run/3` function allows us to run any code in the function which must either succeed with `{:ok, result}` or error, which halts and rolls back the transaction. Here, we simply can call into our shopping cart context and ask it to prune all items in a cart. Running the transaction will execute the multi as before and we return the result to the caller.

To close out our order completion, we need to implement the `ShoppingCart.prune_cart_items/1` function in `lib/hello/shopping_cart.ex`:

Expand Down
10 changes: 5 additions & 5 deletions guides/mix_tasks.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -40,7 +40,7 @@ We will cover all Phoenix Mix tasks, except `phx.new`, `phx.new.ecto`, and `phx.

Phoenix offers the ability to generate all the code to stand up a complete HTML resource — Ecto migration, Ecto context, controller with all the necessary actions, view, and templates. This can be a tremendous time saver. Let's take a look at how to make this happen.

The `mix phx.gen.html` task takes a number of arguments, the module name of the context, the module name of the schema, the resource name, and a list of column_name:type attributes. The module name we pass in must conform to the Elixir rules of module naming, following proper capitalization.
The `mix phx.gen.html` task takes the following arguments: the module name of the context, the module name of the schema, the resource name, and a list of column_name:type attributes. The module name we pass in must conform to the Elixir rules of module naming, following proper capitalization.

```console
$ mix phx.gen.html Blog Post posts body:string word_count:integer
Expand Down Expand Up @@ -132,7 +132,7 @@ It will tell us we need to add a line to our router file, but since we skipped t

Phoenix also offers the ability to generate all the code to stand up a complete JSON resource — Ecto migration, Ecto schema, controller with all the necessary actions and view. This command will not create any template for the app.

The `mix phx.gen.json` task takes a number of arguments, the module name of the context, the module name of the schema, the resource name, and a list of column_name:type attributes. The module name we pass in must conform to the Elixir rules of module naming, following proper capitalization.
The `mix phx.gen.json` task takes the following arguments: the module name of the context, the module name of the schema, the resource name, and a list of column_name:type attributes. The module name we pass in must conform to the Elixir rules of module naming, following proper capitalization.

```console
$ mix phx.gen.json Blog Post posts title:string content:string
Expand Down Expand Up @@ -179,7 +179,7 @@ warning: function HelloWeb.Router.Helpers.post_path/3 is undefined or private

If we don't need a complete HTML/JSON resource and only need a context, we can use the `mix phx.gen.context` task. It will generate a context, a schema, a migration and a test case.

The `mix phx.gen.context` task takes a number of arguments, the module name of the context, the module name of the schema, the resource name, and a list of column_name:type attributes.
The `mix phx.gen.context` task takes the following arguments: the module name of the context, the module name of the schema, the resource name, and a list of column_name:type attributes.

```console
$ mix phx.gen.context Accounts User users name:string age:integer
Expand Down Expand Up @@ -211,7 +211,7 @@ $ mix phx.gen.context Admin.Accounts User users name:string age:integer

If we don't need a complete HTML/JSON resource and are not interested in generating or altering a context we can use the `mix phx.gen.schema` task. It will generate a schema, and a migration.

The `mix phx.gen.schema` task takes a number of arguments, the module name of the schema (which may be namespaced), the resource name, and a list of column_name:type attributes.
The `mix phx.gen.schema` task takes the following arguments: the module name of the schema (which may be namespaced), the resource name, and a list of column_name:type attributes.

```console
$ mix phx.gen.schema Accounts.Credential credentials email:string:unique user_id:references:users
Expand Down Expand Up @@ -293,7 +293,7 @@ A more complete walk-through of how to get started with this generator is availa

### `mix phx.gen.channel` and `mix phx.gen.socket`

This task will generate a basic Phoenix channel, the socket to power the channel (if you haven't created one yet), as well a test case for it. It takes the module name for the channel as the only one argument:
This task will generate a basic Phoenix channel, the socket to power the channel (if you haven't created one yet), as well a test case for it. It takes the module name for the channel as the only argument:

```console
$ mix phx.gen.channel Room
Expand Down