program

Program

Using Copygen programmatically allows you to implement custom loaders, matchers, and generator functions, or pass .yml files in a similar manner to the command line tool.

Disclaimer

Copygen uses a GPLv3 License. An exception is provided for template and example files, which are licensed under the MIT License. While this allows you to use the generator tool without restriction, proprietary programmatic usage of Copygen requires the purchase of a license exception. In order to purchase a license exception, please contact SwitchUpCB using the Copygen License Exception Inquiry Form. For more information, please read What Can I do?

Standard

The Run() function operates in a similar manner to using copygen -yml path in your command line interface.

Define the Environment

Use an Environment object to specify the .yml Copygen will use.

env := cli.Environment{
    YMLPath: "relative/path/to/yml/",
    Output:  false, // Don't output to standard output.
    Write:   true,  // Write the output to a file.
}

Output

Generate code using Run().

code, err := env.Run()
if err != nil {
    return err
}

fmt.Println(code)

Custom

The Run() function shows the flow of the standard copygen program.

// The configuration file is loaded (.yml)
gen, err := config.LoadYML(e.YMLPath)
if err != nil {
    return "", fmt.Errorf("%w", err)
}

// The data file is parsed (.go)
if err = parser.Parse(gen); err != nil {
    return "", fmt.Errorf("%w", err)
}

// The matcher is run on the parsed data (to create the objects used during generation).
if err = matcher.Match(gen); err != nil {
    return "", fmt.Errorf("%w", err)
}

// The generator is used to generate code.
code, err := generator.Generate(gen, e.Output, e.Write)
if err != nil {
    return "", fmt.Errorf("%w", err)
}

return code, nil

Copygen's standard functions (Parse, Match, Generate) accept a model.Generator. This allows the implementation of any configuration method (including LoadYML) with a Copygen standard function, as long as that method returns a valid model.Generator. In a similar manner, custom Parse, Match, and Generate functions can be used with Copygen standard functions interchangeably.

Configuration

The purpose of the config is to configure the setup, output, and template filepaths of a Generator; along with any GeneratorOptions. For more more information, read the documentation.

Parser

The purpose of the parser is to determine:

1. The code that is kept (Generator.Keep) from the setup file (placed above generated code in the output file).
2. Define the Generator.Functions (which contain fields).

For more information, read the documentation.

Parser Options

Read the documentation.

Matcher

Read the documentation.

Generator

The generator package exports three methods of code generation by default. The easiest way to customize the generator is by using templates. For more information, read the documentation.

Debug

The debug.go file provides helper functions during debugging. To view an Abstract Syntax Tree, use a GoAst Viewer.

PrintFunctionFields

Parser

type models.Account.
      Unpointed Field "models.Account.ID" of Definition "int": Parent "models.Account." Fields[0]
      Unpointed Field "models.Account.Name" of Definition "string": Parent "models.Account." Fields[0]
      Unpointed Field "models.Account.Password" of Definition "string": Parent "models.Account." Fields[0]
      Unpointed Field "models.Account.Email" of Definition "string": Parent "models.Account." Fields[0]
type models.User.
        Unpointed Field "models.User.ID" of Definition "int": Parent "models.User." Fields[0]
        Unpointed Field "models.User.Name" of Definition "int": Parent "models.User." Fields[0]
        Unpointed Field "models.User.UserData" of Definition "string": Parent "models.User." Fields[0]
type *domain.Account.
        Unpointed Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0]
        Unpointed Field "*domain.Account.UserID" of Definition "string": Parent "*domain.Account." Fields[0]
        Unpointed Field "*domain.Account.Name" of Definition "string": Parent "*domain.Account." Fields[0]
        Unpointed Field "*domain.Account.Other" of Definition "string": Parent "*domain.Account." Fields[0]

Matcher

type models.Account.
        From Field "models.Account.ID" of Definition "int": Parent "models.Account." Fields[0]
        From Field "models.Account.Name" of Definition "string": Parent "models.Account." Fields[0]
type models.User.
        From Field "models.User.UserID" of Definition "int": Parent "models.User." Fields[0]
type *domain.Account.
        To Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0]
        To Field "*domain.Account.UserID" of Definition "int": Parent "*domain.Account." Fields[0]
        To Field "*domain.Account.Name" of Definition "string": Parent "*domain.Account." Fields[0]

PrintFieldGraph

Parser

Unpointed Field "models.Account.ID" of Definition "int": Parent "models.Account." Fields[0]
Unpointed Field "models.Account.Name" of Definition "string": Parent "models.Account." Fields[0]
Unpointed Field "models.Account.Password" of Definition "string": Parent "models.Account." Fields[0]
Unpointed Field "models.Account.Email" of Definition "string": Parent "models.Account." Fields[0]
Unpointed Field "models.User.ID" of Definition "int": Parent "models.User." Fields[0]
Unpointed Field "models.User.Name" of Definition "int": Parent "models.User." Fields[0]
Unpointed Field "models.User.UserData" of Definition "string": Parent "models.User." Fields[0]
Unpointed Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0]
Unpointed Field "*domain.Account.UserID" of Definition "string": Parent "*domain.Account." Fields[0]
Unpointed Field "*domain.Account.Name" of Definition "string": Parent "*domain.Account." Fields[0]
Unpointed Field "*domain.Account.Other" of Definition "string": Parent "*domain.Account." Fields[0]

Matcher

From Field "models.Account.ID" of Definition "int": Parent "models.Account." Fields[0]
From Field "models.Account.Name" of Definition "string": Parent "models.Account." Fields[0]
From Field "models.User.UserID" of Definition "int": Parent "models.User." Fields[0]
To Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0]
To Field "*domain.Account.UserID" of Definition "string": Parent "*domain.Account." Fields[0]
To Field "*domain.Account.Name" of Definition "string": Parent "*domain.Account." Fields[0]

PrintFieldTree

Parser

type Account // domain
    // 0
    ID      int
    Name    string
    Email   string
            // 1
    User    domain.DomainUser
                UserID  int
                Name    string    
type User    // models
    // 0 
    UserID    int
    Name      string
              // 1
    UserData  models.UserData
                  Options map[string]interface{}
                  // 2
                  Data    models.Data
                        ID      int
type Account // models
    // 0
    ID       int
    Name     string
    Password string
    Email    string

Matcher

// depth-level 0 tree
type Account
    ID      int
    Name    string
type User
    UserID  int
type Account
    ID      int
    UserID  int
    Name    string

PrintFieldRelation

Matcher (Unpointed)

To Field To Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0] and From Field From Field "models.Account.ID" of Definition "int": Parent "models.Account." Fields[0] are related to each other.
To Field To Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0] is not related to From Field From Field "models.Account.Name" of Definition "string": Parent "models.Account." Fields[0].
To Field To Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0] is not related to From Field Unpointed Field "models.Account.Password" of Definition "string": Parent "models.Account." Fields[0].
To Field To Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0] is not related to From Field Unpointed Field "models.Account.Email" of Definition "string": Parent "models.Account." Fields[0].
To Field Unpointed Field "*domain.Account.UserID" of Definition "int": Parent "*domain.Account." Fields[0] is not related to From Field From Field "models.Account.ID" of Definition "int": Parent "models.Account." Fields[0].
...

Matcher (Pointed)

To Field To Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0] and From Field From Field "models.Account.ID" of Definition "int": Parent "models.Account." Fields[0] are related to each other.
To Field To Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0] is not related to From Field From Field "models.Account.Name" of Definition "string": Parent "models.Account." Fields[0].
To Field To Field "*domain.Account.UserID" of Definition "int": Parent "*domain.Account." Fields[0] is not related to From Field From Field "models.Account.ID" of Definition "int": Parent "models.Account." Fields[0].
To Field To Field "*domain.Account.UserID" of Definition "int": Parent "*domain.Account." Fields[0] is not related to From Field From Field "models.Account.Name" of Definition "string": Parent "models.Account." Fields[0].
To Field To Field "*domain.Account.Name" of Definition "string": Parent "*domain.Account." Fields[0] is not related to From Field From Field "models.Account.ID" of Definition "int": Parent "models.Account." Fields[0].
To Field To Field "*domain.Account.Name" of Definition "string": Parent "*domain.Account." Fields[0] and From Field From Field "models.Account.Name" of Definition "string": Parent "models.Account." Fields[0] are related to each other.
To Field To Field "*domain.Account.ID" of Definition "int": Parent "*domain.Account." Fields[0] is not related to From Field From Field "models.User.UserID" of Definition "int": Parent "models.User." Fields[0].
To Field To Field "*domain.Account.UserID" of Definition "int": Parent "*domain.Account." Fields[0] and From Field From Field "models.User.UserID" of Definition "int": Parent "models.User." Fields[0] are related to each other.
To Field To Field "*domain.Account.Name" of Definition "string": Parent "*domain.Account." Fields[0] is not related to From Field From Field "models.User.UserID" of Definition "int": Parent "models.User." Fields[0].

CountFields

6