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4. Running code generation

Now that we have both a schema and a query file, it's time to run code generation. To run code generation run the following command in Terminal from your project directory:

Bash
1./apollo-ios-cli generate

You should now see a new RocketReserverAPI folder in your project directory which contains the Swift package containing your generated source code.

Generated swift package folder

Add the generated SPM package to your project

With the code generated, next we need to add the generated SPM package to the project.

The default configuration for code generation creates a new Swift package for the schema module and operations. For more information on code generation such as different module types you can generate or different ways to run code generation see the documentation.

  1. In Xcode go to File > Add Packages..., in the Add Package dialog select Add Local...

Add local package

  1. Select the RocketReserverAPI folder in the file dialog, then click Add Package

Add local package browser

  1. You should now see the RocketReserverAPI package included in your project

Package in project hierarchy

  1. Next, in Xcode select the project, then the RocketReserver target, and go to Build Phases. Under the Link Binary With Libraries section click the + sign

Link binary with libraries

  1. In the dialog that pops up, select the RocketReserverAPI library and click Add

Link binary with libraries dialog

Examine the generated code

In the Xcode project hierarchy, navigate to RocketReserver/Packages/RocketReseverAPI/Sources/Operations/Queries/LaunchListQuery.graphql.swift. It defines a root class, LaunchListQuery, with many nested structs below it. If you compare the structs to the JSON data returned in Sandbox Explorer, you see that the structure matches. These structs include properties only for the fields that your query requests.

Try commenting out the id property in LaunchList.graphql using a #, saving, then running code generation again. When the code generation completes, the innermost Launch now only includes the built-in __typename and the requested site property.

Uncomment id in LaunchList.graphql and re-run code generation to restore the property.

Now that you've generated code and had a chance to see what's in there, it's time to get everything working end to end! Next, you will Execute your first query.