Context

type Context interface {
    GetSetter
    HttpProvider
    App() App
    Next() error
}

id := c.Param("id")           // Route parameter: /users/{id}
page := c.Query("page")       // Query string: ?page=2

body, _ := c.Body()              // Raw form body (map[string][]string)
form, _ := c.Form()              // Parsed form (supports multipart)

file, header, err := c.FormFile("avatar")  // Get uploaded file
if c.HasFile("avatar") {                    // Check if file was uploaded
    // Process file
}

c.HasJSONRequest()              // Content-Type: application/json
c.HasFormDataRequest()          // Content-Type: multipart/form-data
c.HasFormURLEncodedRequest()    // Content-Type: application/x-www-form-urlencoded
c.HasMultiPartRequest()         // Is multipart request?

r := c.Request()              // *http.Request
w := c.ResponseWriter()        // http.ResponseWriter
ctx := c.RequestContext()      // context.Context
method := r.Method
path := r.URL.Path

// Decode JSON body into struct
var input MyInput
if err := c.DecodeJSON(&input); err != nil { ... }

// Parse and validate with httpin tags
if err := c.ParseInput(&input); err != nil { ... }

// One-liner: parse and store in context
result := c.Input(&MyInput{}).(*MyInput)

c.WantsJSON()           // Accept: application/json
c.WantsHTML()           // Accept: text/html
c.WantsXML()            // Accept: application/xml

c.IsReading()           // Is this a GET/HEAD/OPTIONS request?
c.Status()              // Get current response status code

// Set in middleware
c.Set("user", currentUser)

// Get in handler
user := c.Get("user").(*User)

// Read
val := c.Session("key")
str := c.SessionString("key")

// Write
c.PutSession("key", value)

// Read and remove
val := c.PopSession("key")
str := c.PopSessionString("key")

// Read
cookie := c.Cookie("session_id")

// Write
c.SetCookie(&http.Cookie{
    Name:  "preference",
    Value: "dark-mode",
    Path:  "/",
})

// Read
ua := c.Header("User-Agent")

// Write
c.SetHeader("X-Request-Id", requestID)

c.Status()                    // Get current status code
c.SetStatus(http.StatusCreated) // Set status
c.WriteStatus(http.StatusOK)  // Write status to response

return c.JSON(app.M{
    "id":    1,
    "name":  "John",
})

// From a map
return c.XML(app.M{"status": "ok"})

// From a struct
return c.XML(myStruct)

// From a raw string
return c.XML("<status>ok</status>")

return c.HTML([]byte("<h1>Hello</h1>"))

return c.Text([]byte("Hello, World!"))

return c.Redirect("/dashboard")
return c.Back() // redirect to referrer

// Serve a file from the filesystem
return c.File("path/to/file.pdf")

// Serve a file from a storage disk
return c.StorageFile("uploads/report.pdf")

// Download a file with a custom filename
return c.Download("path/to/file.pdf", "report.pdf")

c.Write([]byte("raw data"))

import "github.com/lemmego/api/res"

tmpl := res.NewTemplate(c, "index.page.gohtml")
tmpl = tmpl.WithData(map[string]any{"title": "Hello"})
return c.Render(tmpl)

import "github.com/lemmego/templ"

return c.Templ(components.Hello("World"))

c.Error(status, err)            // Send error with status code

// Typed errors (return these from handlers)
return c.InternalServerError(err)
return c.NotFound()
return c.NotFound(fmt.Errorf("user %d not found", id))
return c.BadRequest(err)
return c.Unauthorized(err)
return c.Forbidden(err)
return c.MethodNotAllowed(err)
return c.PageExpired(err)
return c.UnprocessableEntity(err)
return c.NoContent()              // 204

// Validation error helper
return c.ValidationError(err)

v := c.Validator()
v.Field("email", input.Email).Required().Email()
if err := v.Validate(); err != nil {
    return c.UnprocessableEntity(err)
}

file, err := c.Upload("avatar", "avatars")
// Saves the uploaded file to the configured storage disk
// Returns the created file

// With custom filename:
file, err := c.Upload("avatar", "avatars", "custom-name.jpg")

ref := c.Referer()            // Referer header

func myMiddleware(next app.Handler) app.Handler {
    return func(c app.Context) error {
        // Pre-processing
        err := next(c) // Call the next handler
        // Post-processing
        return err
    }
}

a := c.App()                  // Access the App instance
cfg := a.Config()             // Configuration
sess := a.Session()           // Session manager
fs := a.FileSystem()          // Filesystem manager

type Context interface {
    GetSetter
    HttpProvider
    App() App
    Next() error
}

type GetSetter interface {
    Get(key string) any
    Set(key string, value any)
}

type HttpProvider interface {
    ParamQueryResolver      // Param, Query
    InputDecoder            // ParseInput, Input, DecodeJSON
    BodyParser              // Body, Form, FormFile, HasFile, HasMultiPartRequest,
                            // HasFormDataRequest, HasFormURLEncodedRequest, HasJSONRequest
    RequestBodyValidator    // Validate, Validator
    HeaderGetSetter         // Header, SetHeader
    AcceptHeaderResolver    // WantsJSON, WantsHTML, WantsXML
    RequestGetSetter        // Request, SetRequest
    RequestResponseResolver // Request, ResponseWriter, RequestContext
    CookieGetSetter         // Cookie, SetCookie
    SessionGetSetter        // Session, SessionString, PopSession, PopSessionString, PutSession
    HttpResponder           // JSON, XML, Text, HTML, Redirect, Back, File, StorageFile, Download, Write, Render
    Downloader              // Download
    Uploader                // Upload
    ErrorProvider           // Error, InternalServerError, NotFound, BadRequest,
                            // Unauthorized, Forbidden, PageExpired, MethodNotAllowed,
                            // UnprocessableEntity, NoContent, ValidationError
    IsReading() bool
    Status() int
    SetStatus(code int) HttpResponder
    WriteStatus(code int) HttpResponder
    Referer() string
}