Golang : Handle API query by curl with Gorilla Queries example




This is an add on for previous tutorial on how to use Gorilla mux example. One reader emailed and asked me on how to use Gorilla mux to handle curl query or URL that look like this :

http://website.com:8080/api/getDataAPI/v1?name=Boo&job=CEO&age=50

rather than :

http://website.com:8080/person/Boo/CEO/50

Gorilla webtoolkit has the Queries method that you can use to configure your handler to accept input with &. This can be useful in building REST API.

Below is an example for you to compare the way how ProcessPathVariables() versus HandleAPI() functions work. HandleAPI() function uses the Queries() method to break down the variables from the given URL.

 package main

 import (
 "fmt"
 "github.com/gorilla/mux"
 "net/http"
 )

 func Home(w http.ResponseWriter, r *http.Request) {
 w.Write([]byte("use curl command!"))
 }

 func ProcessPathVariables(w http.ResponseWriter, r *http.Request) {

 // break down the variables for easier assignment
 vars := mux.Vars(r)
 name := vars["name"]
 job := vars["job"]
 age := vars["age"]
 w.Write([]byte(fmt.Sprintf("Name is %s ", name)))
 w.Write([]byte(fmt.Sprintf("Job is %s ", job)))
 w.Write([]byte(fmt.Sprintf("Age is %s ", age)))
 }

 func HandleAPI(w http.ResponseWriter, r *http.Request) {

 // Queries will automatically break down the &variables
 // you don't need to worry about the ampersand & in the
 // URL.

 vars := mux.Vars(r)
 version := vars["version"]
 name := vars["name"]
 job := vars["job"]
 age := vars["age"]
 w.Write([]byte(fmt.Sprintf("Version is %s\n", version)))
 w.Write([]byte(fmt.Sprintf("Name is %s \n", name)))
 w.Write([]byte(fmt.Sprintf("Job is %s \n", job)))
 w.Write([]byte(fmt.Sprintf("Age is %s \n", age)))
 }

 func main() {
 mx := mux.NewRouter()

 mx.HandleFunc("/", Home)

 //to handle URL like
 //http://website:8080/person/Boo/CEO/199
 //http://website:8080/person/Boo/CEO/199 <- if age > 199, will cause 404 error

 mx.HandleFunc("/person/{name}/{job}/{age:[0-199]+}", ProcessPathVariables)

 //to handle URL like
 //http://website:8080/api/getDataAPI/v1?name=Boo&job=CEO&age=50

 mx.HandleFunc("/api/getDataAPI/{version}", HandleAPI).Queries("name", "{name}", "job", "{job}", "age", "{age:[0-999]+}")

 http.ListenAndServe(":8080", mx)
 }

Do test out this code with curl and see how it goes.

A sample output :

http://example.com:8080/api/getDataAPI/v1?name=Boo&job=CEO&age=999

Version is v1

Name is Boo

Job is CEO

Age is 999

Reference :

http://www.gorillatoolkit.org/pkg/mux

  See also : Golang : Gorilla mux routing example





By Adam Ng

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