hz usage(protobuf)

Create a project based on protobuf IDL

new: Create a new project

Create the protobuf IDL file in the current directory

Note: In order to support api annotations in protobuf, please import the following file in the proto file where the annotation is used

// idl/api.proto; Annotation extension
syntax = "proto2";

package api;

import "google/protobuf/descriptor.proto";

option go_package = "/api";

extend google.protobuf.FieldOptions {
  optional string raw_body = 50101;
  optional string query = 50102;
  optional string header = 50103;
  optional string cookie = 50104;
  optional string body = 50105;
  optional string path = 50106;
  optional string vd = 50107;
  optional string form = 50108;
  optional string go_tag = 51001;
  optional string js_conv = 50109;
}

extend google.protobuf.MethodOptions {
  optional string get = 50201;
  optional string post = 50202;
  optional string put = 50203;
  optional string delete = 50204;
  optional string patch = 50205;
  optional string options = 50206;
  optional string head = 50207;
  optional string any = 50208;
  optional string gen_path = 50301;
  optional string api_version = 50302;
  optional string tag = 50303;
  optional string name = 50304;
  optional string api_level = 50305;
  optional string serializer = 50306;
  optional string param = 50307;
  optional string baseurl = 50308;
}

extend google.protobuf.EnumValueOptions {
  optional int32 http_code = 50401;
}

Main IDL definition

// idl/hello/hello.proto
syntax = "proto3";

package hello;

option go_package = "hertz/hello";

import "api.proto";

message HelloReq {
  string Name = 1[(api.query)="name"];
}

message HelloResp {
  string RespBody = 1;
}

service HelloService {
  rpc Method1(HelloReq) returns(HelloResp) {
    option (api.get) = "/hello";
  }
}

Create a new project

// Execute under GOPATH, if the dependencies of the main IDL and the main IDL are not in the same path, you need to add the "-I" option, its meaning is IDL search path, equivalent to the option "-I" for protoc
hz new -I idl -idl idl/hello/hello.proto

go mod init

// Tidy & get dependencies
go mod tidy

// Execute is not under GOPATH, add go mod name after "-module", if the dependencies of the main IDL and the main IDL are not in the same path, you need to add the "-I" option, its meaning is IDL search path, equivalent to the option "-I" for protoc

hz new -module example/m -I idl -idl idl/hello/hello.proto

// Tidy & get dependencies
go mod tidy

Modify the handler and add your own logic

// handler path: biz/handler/hello/hello_service.go
// where "/hello" is the last level of go_package in protobuf IDL
// "hello_service.go" is the name of the service in protobuf IDL, all methods defined by the service will be generated in this file

// Method1 .
// @router /hello [GET]
func Method1(ctx context.Context, c *app.RequestContext) {
   var err error
   var req hello.HelloReq
   err = c.BindAndValidate(&req)
   if err != nil {
      c.String(400, err.Error())
      return
   }

   resp := new(hello.HelloResp)

   // You can modify the logic of the entire function, not just the current template
   resp.RespBody = "hello," + req.Name // added logic

   c.JSON(200, resp)
}

Compile the project

go build

Run the project and test it

Run the project：

./{{your binary}}

Test：

curl --location --request GET 'http://127.0.0.1:8888/hello?name=hertz'

If it returns {"RespBody":"hello,hertz"}, it works.

update: Update an existing Hertz project

If your protobuf IDL is updated, for example:

// idl/hello/hello.proto
syntax = "proto3";

package hello;

option go_package = "hertz/hello";

import "api.proto";

message HelloReq {
  string Name = 1[(api.query)="name"];
}

message HelloResp {
  string RespBody = 1;
}

message OtherReq {
  string Other = 1[(api.body)="other"];
}

message OtherResp {
  string Resp = 1;
}

service HelloService {
  rpc Method1(HelloReq) returns(HelloResp) {
    option (api.get) = "/hello";
  }
  rpc Method2(OtherReq) returns(OtherResp) {
    option (api.post) = "/other";
  }
}

service NewService {
  rpc Method3(OtherReq) returns(OtherResp) {
    option (api.get) = "/new";
  }
}

Switch to the directory where the new command was executed and update the modified IDL

hz update -I idl -idl idl/hello/hello.proto

As you can see

Add new method under “biz/handler/hello/hello_service.go”
The file “new_service.go” and the corresponding “Method3” method have been added under “biz/handler/hello”

Now let’s develop the “Method2” interface

// Method1 .
// @router /hello [GET]
func Method1(ctx context.Context, c *app.RequestContext) {
   var err error
   var req hello.HelloReq
   err = c.BindAndValidate(&req)
   if err != nil {
      c.String(400, err.Error())
      return
   }

   resp := new(hello.HelloResp)

   // You can modify the logic of the entire function, not just the current template
   resp.RespBody = "hello," + req.Name // added logic

   c.JSON(200, resp)
}

// Method2 .
// @router /other [POST]
func Method2(ctx context.Context, c *app.RequestContext) {
   var err error
   var req hello.OtherReq
   err = c.BindAndValidate(&req)
   if err != nil {
      c.String(400, err.Error())
      return
   }

   resp := new(hello.OtherResp)

   // added logic
   resp.Resp = "Other method: " + req.Other

   c.JSON(200, resp)
}

Compile the project

go build

Run the project and test it

Run the project:

./{{your binary}}

Test：

curl --location --request POST 'http://127.0.0.1:8888/other' \
--header 'Content-Type: application/json' \
--data-raw '{
    "Other": "other method"
}'

If it returns {"Resp":"Other method: other method"}, it works.

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Last modified April 18, 2023 : docs(wip): request context handler (36ea2d4)