https://github.com/google/CallBuilder

Make a Java builder by defining one function.
https://github.com/google/CallBuilder

Last synced: about 2 months ago
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Make a Java builder by defining one function.

• Host: GitHub
• URL: https://github.com/google/CallBuilder
• Owner: google
• License: apache-2.0
• Archived: true
• Created: 2015-04-02T00:45:33.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2018-01-12T23:47:34.000Z (over 6 years ago)
• Last Synced: 2024-06-27T14:43:03.993Z (3 months ago)
• Language: Java
• Homepage:
• Size: 257 KB
• Stars: 103
• Watchers: 18
• Forks: 30
• Open Issues: 6
• Metadata Files:
  • Readme: README.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE

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• awesome-bazel - CallBuilder

README

        
# CallBuilder

Make a builder by defining one function.  

(_beta_: be ready for breaking API changes)

*CallBuilder* is a Java code generator that finally makes it easy to make a

builder class. Builders are great when you have a constructor or method with

many parameters. They are even helpful when you have two or more arguments of

the same type, since the order is easy to mix up.

Builders are usually hard to write. You will probably need around 4 lines for

every field, and if it's an inner class, it makes the file long and cumbersome

to navigate. This discourages many people from writing builders, and those

people give up and learn to live with brittle, and hard-to-read code. If you

want to add multiple setters for a field (common for lists that may have add and

addAll), your builder will quickly become a chore to write and a burden to

maintain.

CallBuilder changes that. To use it, you can simply write the method or

constructor as you normally would, but add the `@CallBuilder` annotation:

```java

public class Person {

  @CallBuilder

  Person(

      String familyName,

      String givenName,

      List addressLines,

      @Nullable Integer age) {

    // ...

  }

}

```

Now you will have access to a `PersonBuilder` class in the same package!

```java

Person friend = new PersonBuilder()

    .setAddressLines(Arrays.asList("1123 Easy Street", "Townplace, XZ"))

    .setAge(22)

    .setGivenName("John")

    .setFamilyName("Doe")

    .build();

```

With the field styles feature, you can define custom behavior for the fields

that are of a certain type. This can make the API more natural and look more

like a manually-written builder:

```java

public class Person {

  @CallBuilder

  Person(

      String familyName,

      String givenName,

      @BuilderField(style = ArrayListAdding.class) ArrayList addressLines,

      @Nullable Integer age) {

    // ...

  }

}

```

This can be used like:

```java

Person friend = new PersonBuilder()

    .addToAddressLines("1123 Easy Street")

    .addToAddressLines("Townplace, XZ")

    .setAge(22)

    .setGivenName("John")

    .setFamilyName("Doe")

    .build();

```