ngamux

name	ngamux
description	Build and modify web services using ngamux, a simple HTTP router for Go. Define routes, apply middleware, handle requests, and send responses efficiently.

When to use this skill

Use this skill when the user needs to:

• Define HTTP endpoints: Create new routes for various HTTP methods (e.g., mux.Get("/users/:id", getUserHandler)) including dynamic path segments (/users/{id}) and wildcards (/files/*filePath).
• Implement request preprocessing/postprocessing: Add global middlewares (e.g., for authentication, logging, CORS) or group-specific middlewares to handle requests before they reach the main handler or after they are processed. For example, mux.Use(authMiddleware) or apiGroup.Use(loggingMiddleware).
• Extract incoming data from requests:
  • URL Parameters: Retrieve values from dynamic path segments (e.g., req.Params("id")).
  • Query Parameters: Access query string values (e.g., req.Query("name", "Guest")).
  • Form Data: Parse application/x-www-form-urlencoded or multipart/form-data (e.g., req.FormValue("username"), req.FormFile("image")).
  • JSON Payloads: Decode application/json request bodies into Go structs (e.g., req.JSON(&user)).
• Construct and send various response types:
  • JSON Responses: Send structured data as JSON (e.g., ngamux.Res(rw).Status(http.StatusOK).Json(data)).
  • Text Responses: Send plain text (e.g., ngamux.Res(rw).Status(http.StatusOK).Text("Hello, World!")).
  • HTML Responses: Render HTML templates (e.g., ngamux.Res(rw).Status(http.StatusOK).HTML("template.html", data)).
  • Custom Status Codes: Set specific HTTP status codes for responses.
• Configure router behavior: Adjust global settings like automatically removing trailing slashes (ngamux.WithTrailingSlash()), setting the logging verbosity (ngamux.WithLogLevel(slog.LevelDebug)), or providing custom json.Marshal/json.Unmarshal functions for specific serialization needs.
• Organize routes with grouping: Create nested route groups to apply common path prefixes and middlewares to a set of routes (e.g., /api/v1).
• Debug routing or handler issues: Inspect route definitions, middleware chains, request context, and logging output to diagnose and resolve problems.

Key Functionality

• Route Definition: ngamux provides methods like mux.Get(), mux.Post(), mux.Put(), mux.Delete(), mux.Patch(), mux.Head(), and mux.All() to register http.HandlerFuncs for specific HTTP methods and paths. It supports path parameters (e.g., /{id}) and wildcards (/*filePath). Routes are efficiently stored and matched using a tree-like structure, leveraging the mapping package for optimized key-value storage.
• Middleware Application: The mux.Use() method allows global middleware registration, while mux.Group() and mux.With() enable group-specific middlewares. Middlewares are MiddlewareFunc types that wrap http.HandlerFuncs, allowing for a chain of responsibility pattern. The WithMiddlewares utility from common.go handles the functional chaining.
• Request Handling: The Request struct (wrapped *http.Request) offers convenience methods:
  • Req().Params(key string): Retrieves URL path parameters parsed during routing.
  • Req().Query(key string, fallback ...string): Accesses URL query string parameters.
  • Req().QueriesParser(data any): Automatically binds query parameters to a Go struct using query tags and reflection.
  • Req().FormValue(key string): Gets form field values.
  • Req().FormFile(key string, maxFileSize ...int64): Handles file uploads from multipart forms.
  • Req().JSON(store any): Decodes JSON request bodies into a provided Go interface.
  • Req().Locals(key any, value ...any): Manages request-scoped data in the context.
• Response Handling: The Response struct (wrapped http.ResponseWriter) provides a fluent API for crafting responses:
  • Res(rw).Status(code int): Sets the HTTP status code.
  • Res(rw).Text(data string): Sends text/plain content.