jwg

JSON wrapper generator or json web go.

Description

jwg can generate Web API friendly struct.

We need a lowerCamelCase property name, not a UpperCamelCase. jwg generate json tag with lower camel case automatically.

Another case, We need a access control of struct property in web app.

type User struct {
	Name              string
	EncryptedPassword string // I want to hide this field!
}

user := &User {
	"go-chan",
	"5ch",
}
builder := NewUserJSONBuilder()
builder.AddAll()
builder.Remove(builder.EncryptedPassword)
json, _ := builder.Marshal(user)
// emit `{"name":"go-chan"}`
fmt.Println(string(json))

Example

from:

type Sample struct {
	Foo string
}

to:

// generated!
type SampleJSON struct {
	Foo string `json:"foo,omitempty"`
}

usage:

src := &Sample{"Foo!"}

builder := NewSampleJSONBuilder() // generated!
builder.AddAll()
var jsonStruct *SampleJSON = builder.Convert(src)

json, err := json.Marshal(jsonStruct)

other example.

With go generate

$ ls -la .
total 16
drwxr-xr-x@ 4 vvakame  staff   136  1 27 17:27 .
drwxr-xr-x@ 6 vvakame  staff   204  1 27 13:14 ..
-rw-r--r--@ 1 vvakame  staff   366  1 27 17:27 model.go
$ cat model.go
//go:generate jwg -output model_json.go .

package d

// test for struct with tagged comment

// +jwg
type Sample struct {
	A string `json:"foo!" datastore:"-"`
	B string `json:",omitempty" datastore:",noindex" endpoints:"req"`
}
$ go generate
$ ls -la .
total 16
drwxr-xr-x@ 4 vvakame  staff   136  1 27 17:27 .
drwxr-xr-x@ 6 vvakame  staff   204  1 27 13:14 ..
-rw-r--r--@ 1 vvakame  staff   366  1 27 17:27 model.go
-rw-r--r--@ 1 vvakame  staff  1549  1 27 17:27 model_json.go

Installation

$ go get github.com/favclip/jwg/cmd/jwg
$ jwg
Usage of jwg:
	jwg [flags] [directory]
	jwg [flags] files... # Must be a single package
Flags:
  -output="": output file name; default srcdir/<type>_string.go
  -type="": comma-separated list of type names; must be set

Command sample

Model with type specific option.

$ cat misc/fixture/a/model.go
package a

// test for basic struct definition

type Sample struct {
	Foo string
}
$ jwg -type Sample -output misc/fixture/a/model_json.go misc/fixture/a

Model with tagged comment.

$ cat misc/fixture/d/model.go
package d

// test for struct with tagged comment

// +jwg
type Sample struct {
	A string `json:"foo!" datastore:"-"`
	B string `json:",omitempty" datastore:",noindex" endpoints:"req"`
}

type IgnoredSample struct {
	A string `json:"foo!" datastore:"-"`
	B string `json:",omitempty" datastore:",noindex" endpoints:"req"`
}
$ jwg -output misc/fixture/d/model_json.go misc/fixture/d