go-j2s

A tool for generating Go source code from json data file.

It saves your time for writing nested corresponding struct/slice according to in-coming json data. The generated struct/slice also has field tag added. It also can work on multiple json files at once.

Contents:

1. Installation
2. Usage
3. Go Code
4. Field Name
5. Scalability
6. Go Generate

Installation

$ go get -u github.com/liangrog/go-j2s/...    

Usage

For help, run option -h or --help

$ go-j2s -h

To specify the base directory to search for all the json files, use -in option. It defaults to current directory.

$ go-j2s -in /tmp

By default, go-j2s only searchs default or the directory specified in -in. To search recursively, use -r.

$ go-j2s -in /tmp -r 

For excluding directory from the search, use -excl. go-j2s will check if searching directory contains the exluding directory string.

$ go-j2s -excl /tmp/test       

You can specify multiple.

$ go-j2s -excl /tmp/test -excl /tmp/data

To specify a source json file to convert, use -from option. It will make -in option obsolete.

$ go-j2s -from /home/user/data.json

You can also have multiple source json files.

$ go-j2s -from /home/user/data.json -from /tmp/test.json

By default, the generated Go file will be saved to the current directory. To change it, use -out.

$ go-j2s -out /home/user/project

j2s is the default generated Go file name. You can change it by using -name.

$ go-j2s -name model

The generated Go code uses main as package. You can specify the package by using -pkg.

$ go-j2s -pkg config

Go Code

The generated Go code follows the Go "encoding/json" unmarshal rules. Those are:

bool, for JSON booleans
float64, for JSON numbers
string, for JSON strings
[]interface{}, for JSON arrays
map[string]interface{}, for JSON objects
nil for JSON null

Field Name

The struct field name is in camel case, converting from original json field name. - and _ get removed. For example, field_name coverts to FieldName.

Scalability

go-j2s unmarshals all found json files concurrently, providing quick conversion time.

Go Generate

You can also use go-j2s in conjuntion with go generate. Drop below line in any of your existing Go file for example:

//go:generate go-j2s -in /tmp/ -r 

Then simply run:

$ go generate