ginapi

Shared Gin utilities for building consistent REST APIs across multiple Go projects.

Why?

When you have multiple services (doujins, hentai0, etc.) that need consistent API behavior, this library provides:

• Response formatting - Stripe-style JSON envelopes so all APIs return the same structure
• Pagination - Offset/limit binding with sensible defaults
• Language detection - Middleware that detects user language from query params, URL path, cookies, or Accept-Language headers
• Language redirects - Helpers for routes without a language prefix (e.g., /galleries) that need to 302 redirect to a concrete language (e.g., /en/galleries) based on user preference

Instead of copy-pasting this boilerplate into each project, import it once.

Install

go get github.com/doujins-org/ginapi

Response Format

{"object": "artist", "id": "123", "name": "..."}

{"object": "list", "data": [...], "total": 100, "limit": 20, "offset": 0, "has_more": true}

{"object": "error", "error": {"type": "not_found_error", "message": "..."}}

Pagination

params := pagination.BindDefault(c)  // ?limit=20&offset=0
response.ListResponse(c, items, total, params.Limit, params.Offset)

Language Middleware

Detects language from: query param → URL path → cookie → Accept-Language → default.

router.Use(middleware.Language(middleware.LanguageConfig{
    Supported: []string{"en", "ja", "ko"},
    Default:   "en",
}))

lang := middleware.GetLanguage(c)

Language Redirect (NoRoute)

Redirects /galleries → /en/galleries based on user preference.

r.NoRoute(func(c *gin.Context) {
    if middleware.HandleLanguageRedirect(c, middleware.LanguageRedirectConfig{
        Supported: []string{"en", "ja", "ko"},
        Default:   "en",
    }) {
        return
    }
    serveIndexHTML(c)
})

Reference

Function	Description
GetLanguage(c)	Get detected language from gin context
LanguageFromContext(ctx)	Get language from request context
SetLanguageCookie(c, lang)	Set 1-year language cookie
ExtractLanguageFromPath(path)	Extract lang prefix from URL
ParseAcceptLanguage(header, supported)	Parse Accept-Language header