gin

ExampleInitGin shows how to create a Gin engine with no CORS. Pass nil or an empty slice when all cross-origin requests should be blocked.

package main

import (
	"fmt"
	"net/http"

	"github.com/gin-gonic/gin"
	libgin "github.com/phcp-tech/common-library-golang/gin"
)

func main() {
	router := libgin.InitGin(nil)
	router.GET("/health", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{"status": "ok"})
	})
	fmt.Println(router != nil)
}

Output:
true

ExampleInitGin_cors shows how to enable CORS for a list of allowed origins. Exact origins and wildcard patterns (entries containing *) can be mixed. A wildcard * matches exactly one subdomain label (no dots).

package main

import (
	"fmt"
	"net/http"
	"net/http/httptest"

	"github.com/gin-gonic/gin"
	libgin "github.com/phcp-tech/common-library-golang/gin"
)

func main() {
	router := libgin.InitGin([]string{
		"https://app.example.com", // exact origin
		"https://*.example.com",   // wildcard: root + any single subdomain
	})
	router.GET("/api/data", func(c *gin.Context) {
		c.Status(http.StatusOK)
	})

	// Allowed origin receives its own origin in the response header.
	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/api/data", nil)
	req.Header.Set("Origin", "https://app.example.com")
	router.ServeHTTP(w, req)
	fmt.Println(w.Header().Get("Access-Control-Allow-Origin"))

	// Blocked origin receives no CORS header.
	w2 := httptest.NewRecorder()
	req2 := httptest.NewRequest(http.MethodGet, "/api/data", nil)
	req2.Header.Set("Origin", "https://test.com")
	router.ServeHTTP(w2, req2)
	fmt.Println(w2.Header().Get("Access-Control-Allow-Origin"))
}

Output:
https://app.example.com