Template customization

Overview

goctl code generation is go based on template to implement data drive. While currently goctl code generation meets some of the code successes, the template custom can enrich code generation.

Template instructions can be consulted goctl template

Sample

Scenes

Implementing unified body response, following：

{
  "code": 0,
  "msg": "OK",
  "data": {} // ①
}

① Actual Response Data

tip

go-zerogenerated code not handled

Preparation

我们提前在 module 为 greet 的工程下的 response 包中写一个 Response 方法，目录树类似如下：

greet
├── response
│   └── response.go
└── xxx...

Code:

package response
import (
    "net/http"
    "github.com/zeromicro/go-zero/rest/httpx"
)
type Body struct {
    Code int         `json:"code"`
    Msg  string      `json:"msg"`
    Data interface{} `json:"data,omitempty"`
}
func Response(w http.ResponseWriter, resp interface{}, err error) {
    var body Body
    if err != nil {
        body.Code = -1
        body.Msg = err.Error()
    } else {
        body.Msg = "OK"
        body.Data = resp
    }
    httpx.OkJson(w, body)
}

Edit handler template

$ vim ~/.goctl/${goctl_version}/api/handler.tpl

Replace the template with the following

package handler
import (
    "net/http"
    "greet/response"// ①
    {{.ImportPackages}}
)
func {{.HandlerName}}(svcCtx *svc.ServiceContext) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        {{if .HasRequest}}var req types.{{.RequestType}}
        if err := httpx.Parse(r, &req); err != nil {
            httpx.Error(w, err)
            return
        }{{end}}
        l := logic.New{{.LogicType}}(r.Context(), svcCtx)
        {{if .HasResp}}resp, {{end}}err := l.{{.Call}}({{if .HasRequest}}&req{{end}})
        {{if .HasResp}}response.Response(w, resp, err){{else}}response.Response(w, nil, err){{end}}//②
    }
}

① Replace with your realresponsepackage name, information

② Custom Template Content

::tip 1. If you don’t have~/.goctl/${goctl版本号}/api/handler.tplfile you can initialize the template initialization commandgoctl template format ininitialize
: :::

Compare the template before and after

• Modify before

func GreetHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        var req types.Request
        if err := httpx.Parse(r, &req); err != nil {
            httpx.Error(w, err)
            return
        }
        l := logic.NewGreetLogic(r.Context(), svcCtx)
        resp, err := l.Greet(&req)
        // 以下内容将被自定义模板替换
        if err != nil {
            httpx.Error(w, err)
        } else {
            httpx.OkJson(w, resp)
        }
    }
}

• Modified

func GreetHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        var req types.Request
        if err := httpx.Parse(r, &req); err != nil {
            httpx.Error(w, err)
            return
        }
        l := logic.NewGreetLogic(r.Context(), svcCtx)
        resp, err := l.Greet(&req)
        response.Response(w, resp, err)
    }
}

Modify response body comparison before and after template

• Modify before

{
  "message": "Hello go-zero!"
}

• Modified

{
  "code": 0,
  "msg": "OK",
  "data": {
    "message": "Hello go-zero!"
  }
}

Template Custom Rules

1. Modify within valid data range provided by goctl, i.e. external variables are not supported
2. Adding template file is not supported
3. Variable changes not supported

References

• goctl template
• text/template