dl

DL(Default Loader)

Overview

DL (Default Loader) is a tool designed to generate and assign default values to fields within Go structs based on tags.

This utility allows you to specify default values for your struct fields using a simple tag syntax, making it easier to initialize structs with predefined values without having to explicitly set them in your code.

defaults.go is forked from creasty/defaults and modified to meet the requirements of this project.

Features

• Tag-based Default Values: Use the default tag to set default values for struct fields.
• Easy Integration: Quickly generate methods to load default values into your structs.
• Efficient Initialization: Simplifies the initialization process of complex structs by automatically setting default values.

Installation

To use DL (Default Loader), first install the tool via:

go install github.com/godcong/dl/cmd@latest

Usage

Step 1: Define Struct with Default Tags

Add the default tag to your struct fields to specify their default values:

// example: demo.go
type Demo struct {
    Name string `default:"demo"`
}

Step 2: Generate Default Value Loading Method

Run DL to generate the necessary loading method for your struct, using the -f flag to specify the file path with filename or directory:

dl -f ./demo.go

This will generate a Default() error method in your struct that initializes the fields with the specified default values.

Below is the generated code example with Demo struct:

// Default loads default values for Demo
func (obj *Demo) Default() error {
	obj.Name = "demo"
	return nil
}

Step 3: Load Default Values

In your code, use dl.Load() to populate your struct with the default values:

func main() {
    demo := &Demo{}
    if err := dl.Load(demo); err != nil {
        panic(err)
    } 
    // Now 'demo' has its fields initialized with default values. 
}