package router import ( "bytes" "encoding/json" "io" "net/http" "github.com/julienschmidt/httprouter" ) // Context is passed to handlers and middlewares type Context struct { router *Router Request *http.Request Response http.ResponseWriter Param func(string) string store map[string]interface{} } func newContext(router *Router, res http.ResponseWriter, req *http.Request, param httprouter.Params) *Context { return &Context{router, req, res, param.ByName, make(map[string]interface{})} } // QueryParam returns the specified parameter from the query string. // Returns an empty string if it doesn't exist. Returns the first parameter if multiple instances exist func (c *Context) QueryParam(param string) string { params := c.Request.URL.Query()[param] if params == nil { return `` } return params[0] } // Redirect sends a redirect to the client func (c *Context) Redirect(code int, url string) error { http.Redirect(c.Response, c.Request, url, code) return nil } // Bytes returns the given status code and writes the bytes to the body func (c *Context) Bytes(code int, b []byte) error { c.Response.WriteHeader(code) _, err := c.Response.Write(b) return err } // String returns the given status code and writes the string to the body func (c *Context) String(code int, s string) error { c.Response.Header().Set(`Content-Type`, `text/plain`) c.Response.WriteHeader(code) _, err := c.Response.Write([]byte(s)) return err } // StatusText returns the given status code with the matching status text func (c *Context) StatusText(code int) error { return c.String(code, http.StatusText(code)) } // NoContent returns the given status code without writing anything to the body func (c *Context) NoContent(code int) error { c.Response.WriteHeader(code) return nil } // JSON returns the given status code and writes JSON to the body func (c *Context) JSON(code int, data interface{}) error { c.Response.Header().Set(`Content-Type`, `application/json`) c.Response.WriteHeader(code) return json.NewEncoder(c.Response).Encode(data) // TODO: Encode to buffer first to prevent partial responses on error } // Render renders a templating using the Renderer set in router func (c *Context) Render(code int, template string, data interface{}) error { if c.router.Renderer == nil { panic(`Cannot call render without a renderer set`) } var b bytes.Buffer err := c.router.Renderer.Render(&b, template, data, c) if err != nil { return err } c.Response.Header().Set(`Content-Type`, `text/html`) c.Response.WriteHeader(code) _, _ = io.Copy(c.Response, &b) return nil } // Set sets a value in the context. Set is not safe to be used concurrently func (c *Context) Set(key string, value interface{}) { c.store[key] = value } // Get retrieves a value from the context. func (c *Context) Get(key string) interface{} { return c.store[key] }