π§ Ctx
Acceptsβ
Checks if the specified extensions or content types are acceptable.
Based on the requestβs Accept HTTP header.
func (c fiber.Ctx) Accepts(offers ...string) string
func (c fiber.Ctx) AcceptsCharsets(offers ...string) string
func (c fiber.Ctx) AcceptsEncodings(offers ...string) string
func (c fiber.Ctx) AcceptsLanguages(offers ...string) string
app.Get("/", func(c fiber.Ctx) error {
c.Accepts("html") // "html"
c.Accepts("text/html") // "text/html"
c.Accepts("json", "text") // "json"
c.Accepts("application/json") // "application/json"
c.Accepts("text/plain", "application/json") // "application/json", due to quality
c.Accepts("image/png") // ""
c.Accepts("png") // ""
// ...
})
// Accept: text/html, text/*, application/json, */*; q=0
app.Get("/", func(c fiber.Ctx) error {
c.Accepts("text/plain", "application/json") // "application/json", due to specificity
c.Accepts("application/json", "text/html") // "text/html", due to first match
c.Accepts("image/png") // "", due to */* with q=0 is Not Acceptable
// ...
})
Media-Type parameters are supported.
// Accept: text/plain, application/json; version=1; foo=bar
app.Get("/", func(c fiber.Ctx) error {
// Extra parameters in the accept are ignored
c.Accepts("text/plain;format=flowed") // "text/plain;format=flowed"
// An offer must contain all parameters present in the Accept type
c.Accepts("application/json") // ""
// Parameter order and capitalization do not matter. Quotes on values are stripped.
c.Accepts(`application/json;foo="bar";VERSION=1`) // "application/json;foo="bar";VERSION=1"
})
// Accept: text/plain;format=flowed;q=0.9, text/plain
// i.e., "I prefer text/plain;format=flowed less than other forms of text/plain"
app.Get("/", func(c fiber.Ctx) error {
// Beware: the order in which offers are listed matters.
// Although the client specified they prefer not to receive format=flowed,
// the text/plain Accept matches with "text/plain;format=flowed" first, so it is returned.
c.Accepts("text/plain;format=flowed", "text/plain") // "text/plain;format=flowed"
// Here, things behave as expected:
c.Accepts("text/plain", "text/plain;format=flowed") // "text/plain"
})
Fiber provides similar functions for the other accept headers.
// Accept-Charset: utf-8, iso-8859-1;q=0.2
// Accept-Encoding: gzip, compress;q=0.2
// Accept-Language: en;q=0.8, nl, ru
app.Get("/", func(c fiber.Ctx) error {
c.AcceptsCharsets("utf-16", "iso-8859-1")
// "iso-8859-1"
c.AcceptsEncodings("compress", "br")
// "compress"
c.AcceptsLanguages("pt", "nl", "ru")
// "nl"
// ...
})
Appβ
Returns the *App reference so you can easily access all application settings.
func (c fiber.Ctx) App() *App
app.Get("/stack", func(c fiber.Ctx) error {
return c.JSON(c.App().Stack())
})
Appendβ
Appends the specified value to the HTTP response header field.
If the header is not already set, it creates the header with the specified value.
func (c fiber.Ctx) Append(field string, values ...string)
app.Get("/", func(c fiber.Ctx) error {
c.Append("Link", "http://google.com", "http://localhost")
// => Link: http://google.com, http://localhost
c.Append("Link", "Test")
// => Link: http://google.com, http://localhost, Test
// ...
})
Attachmentβ
Sets the HTTP response Content-Disposition header field to attachment
.
func (c fiber.Ctx) Attachment(filename ...string)
app.Get("/", func(c fiber.Ctx) error {
c.Attachment()
// => Content-Disposition: attachment
c.Attachment("./upload/images/logo.png")
// => Content-Disposition: attachment; filename="logo.png"
// => Content-Type: image/png
// ...
})
AutoFormatβ
Performs content-negotiation on the Accept HTTP header. It uses Accepts to select a proper format.
The supported content types are text/html
, text/plain
, application/json
, and application/xml
.
For more flexible content negotiation, use Format.
If the header is not specified or there is no proper format, text/plain is used.
func (c fiber.Ctx) AutoFormat(body any) error
app.Get("/", func(c fiber.Ctx) error {
// Accept: text/plain
c.AutoFormat("Hello, World!")
// => Hello, World!
// Accept: text/html
c.AutoFormat("Hello, World!")
// => <p>Hello, World!</p>
type User struct {
Name string
}
user := User{"John Doe"}
// Accept: application/json
c.AutoFormat(user)
// => {"Name":"John Doe"}
// Accept: application/xml
c.AutoFormat(user)
// => <User><Name>John Doe</Name></User>
// ..
})
BaseURLβ
Returns the base URL (protocol + host) as a string
.
func (c fiber.Ctx) BaseURL() string
// GET https://example.com/page#chapter-1
app.Get("/", func(c fiber.Ctx) error {
c.BaseURL() // "https://example.com"
// ...
})
Bindβ
Bind is a method that supports bindings for the request/response body, query parameters, URL parameters, cookies, and much more. It returns a pointer to the Bind struct which contains all the methods to bind the request/response data.
For detailed information, check the Bind documentation.
func (c fiber.Ctx) Bind() *Bind
app.Post("/", func(c fiber.Ctx) error {
user := new(User)
// Bind the request body to a struct:
return c.Bind().Body(user)
})
Bodyβ
As per the header Content-Encoding
, this method will try to perform a file decompression from the body bytes. In case no Content-Encoding
header is sent, it will perform as BodyRaw.
func (c fiber.Ctx) Body() []byte
// echo 'user=john' | gzip | curl -v -i --data-binary @- -H "Content-Encoding: gzip" http://localhost:8080
app.Post("/", func(c fiber.Ctx) error {
// Decompress body from POST request based on the Content-Encoding and return the raw content:
return c.Send(c.Body()) // []byte("user=john")
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
BodyRawβ
Returns the raw request body.
func (c fiber.Ctx) BodyRaw() []byte
// curl -X POST http://localhost:8080 -d user=john
app.Post("/", func(c fiber.Ctx) error {
// Get raw body from POST request:
return c.Send(c.BodyRaw()) // []byte("user=john")
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
ClearCookieβ
Expires a client cookie (or all cookies if left empty).
func (c fiber.Ctx) ClearCookie(key ...string)
app.Get("/", func(c fiber.Ctx) error {
// Clears all cookies:
c.ClearCookie()
// Expire specific cookie by name:
c.ClearCookie("user")
// Expire multiple cookies by names:
c.ClearCookie("token", "session", "track_id", "version")
// ...
})
Web browsers and other compliant clients will only clear the cookie if the given options are identical to those when creating the cookie, excluding Expires
and MaxAge
. ClearCookie
will not set these values for you - a technique similar to the one shown below should be used to ensure your cookie is deleted.
app.Get("/set", func(c fiber.Ctx) error {
c.Cookie(&fiber.Cookie{
Name: "token",
Value: "randomvalue",
Expires: time.Now().Add(24 * time.Hour),
HTTPOnly: true,
SameSite: "lax",
})
// ...
})
app.Get("/delete", func(c fiber.Ctx) error {
c.Cookie(&fiber.Cookie{
Name: "token",
// Set expiry date to the past
Expires: time.Now().Add(-(time.Hour * 2)),
HTTPOnly: true,
SameSite: "lax",
})
// ...
})
ClientHelloInfoβ
ClientHelloInfo
contains information from a ClientHello message in order to guide application logic in the GetCertificate
and GetConfigForClient
callbacks.
You can refer to the ClientHelloInfo struct documentation for more information on the returned struct.
func (c fiber.Ctx) ClientHelloInfo() *tls.ClientHelloInfo
// GET http://example.com/hello
app.Get("/hello", func(c fiber.Ctx) error {
chi := c.ClientHelloInfo()
// ...
})
Contextβ
Context
returns a context implementation that was set by the user earlier or returns a non-nil, empty context if it was not set earlier.
func (c fiber.Ctx) Context() context.Context
app.Get("/", func(c fiber.Ctx) error {
ctx := c.Context()
// ctx is context implementation set by user
// ...
})
Cookieβ
Sets a cookie.
func (c fiber.Ctx) Cookie(cookie *Cookie)
type Cookie struct {
Name string `json:"name"` // The name of the cookie
Value string `json:"value"` // The value of the cookie
Path string `json:"path"` // Specifies a URL path which is allowed to receive the cookie
Domain string `json:"domain"` // Specifies the domain which is allowed to receive the cookie
MaxAge int `json:"max_age"` // The maximum age (in seconds) of the cookie
Expires time.Time `json:"expires"` // The expiration date of the cookie
Secure bool `json:"secure"` // Indicates that the cookie should only be transmitted over a secure HTTPS connection
HTTPOnly bool `json:"http_only"` // Indicates that the cookie is accessible only through the HTTP protocol
SameSite string `json:"same_site"` // Controls whether or not a cookie is sent with cross-site requests
Partitioned bool `json:"partitioned"` // Indicates if the cookie is stored in a partitioned cookie jar
SessionOnly bool `json:"session_only"` // Indicates if the cookie is a session-only cookie
}
app.Get("/", func(c fiber.Ctx) error {
// Create cookie
cookie := new(fiber.Cookie)
cookie.Name = "john"
cookie.Value = "doe"
cookie.Expires = time.Now().Add(24 * time.Hour)
// Set cookie
c.Cookie(cookie)
// ...
})
Partitioned cookies allow partitioning the cookie jar by top-level site, enhancing user privacy by preventing cookies from being shared across different sites. This feature is particularly useful in scenarios where a user interacts with embedded third-party services that should not have access to the main site's cookies. You can check out CHIPS for more information.
app.Get("/", func(c fiber.Ctx) error {
// Create a new partitioned cookie
cookie := new(fiber.Cookie)
cookie.Name = "user_session"
cookie.Value = "abc123"
cookie.Partitioned = true // This cookie will be stored in a separate jar when it's embedded into another website
// Set the cookie in the response
c.Cookie(cookie)
return c.SendString("Partitioned cookie set")
})
Cookiesβ
Gets a cookie value by key. You can pass an optional default value that will be returned if the cookie key does not exist.
func (c fiber.Ctx) Cookies(key string, defaultValue ...string) string
app.Get("/", func(c fiber.Ctx) error {
// Get cookie by key:
c.Cookies("name") // "john"
c.Cookies("empty", "doe") // "doe"
// ...
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
Downloadβ
Transfers the file from the given path as an attachment
.
Typically, browsers will prompt the user to download. By default, the Content-Disposition header filename=
parameter is the file path (this typically appears in the browser dialog).
Override this default with the filename parameter.
func (c fiber.Ctx) Download(file string, filename ...string) error
app.Get("/", func(c fiber.Ctx) error {
return c.Download("./files/report-12345.pdf")
// => Download report-12345.pdf
return c.Download("./files/report-12345.pdf", "report.pdf")
// => Download report.pdf
})
Formatβ
Performs content-negotiation on the Accept HTTP header. It uses Accepts to select a proper format from the supplied offers. A default handler can be provided by setting the MediaType
to "default"
. If no offers match and no default is provided, a 406 (Not Acceptable) response is sent. The Content-Type is automatically set when a handler is selected.
If the Accept header is not specified, the first handler will be used.
func (c fiber.Ctx) Format(handlers ...ResFmt) error
// Accept: application/json => {"command":"eat","subject":"fruit"}
// Accept: text/plain => Eat Fruit!
// Accept: application/xml => Not Acceptable
app.Get("/no-default", func(c fiber.Ctx) error {
return c.Format(
fiber.ResFmt{"application/json", func(c fiber.Ctx) error {
return c.JSON(fiber.Map{
"command": "eat",
"subject": "fruit",
})
}},
fiber.ResFmt{"text/plain", func(c fiber.Ctx) error {
return c.SendString("Eat Fruit!")
}},
)
})
// Accept: application/json => {"command":"eat","subject":"fruit"}
// Accept: text/plain => Eat Fruit!
// Accept: application/xml => Eat Fruit!
app.Get("/default", func(c fiber.Ctx) error {
textHandler := func(c fiber.Ctx) error {
return c.SendString("Eat Fruit!")
}
handlers := []fiber.ResFmt{
{"application/json", func(c fiber.Ctx) error {
return c.JSON(fiber.Map{
"command": "eat",
"subject": "fruit",
})
}},
{"text/plain", textHandler},
{"default", textHandler},
}
return c.Format(handlers...)
})
FormFileβ
MultipartForm files can be retrieved by name, the first file from the given key is returned.
func (c fiber.Ctx) FormFile(key string) (*multipart.FileHeader, error)
app.Post("/", func(c fiber.Ctx) error {
// Get first file from form field "document":
file, err := c.FormFile("document")
// Save file to root directory:
return c.SaveFile(file, fmt.Sprintf("./%s", file.Filename))
})
FormValueβ
Form values can be retrieved by name, the first value for the given key is returned.
func (c fiber.Ctx) FormValue(key string, defaultValue ...string) string
app.Post("/", func(c fiber.Ctx) error {
// Get first value from form field "name":
c.FormValue("name")
// => "john" or "" if not exist
// ..
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
Freshβ
When the response is still fresh in the client's cache true is returned, otherwise false is returned to indicate that the client cache is now stale and the full response should be sent.
When a client sends the Cache-Control: no-cache request header to indicate an end-to-end reload request, Fresh
will return false to make handling these requests transparent.
Read more on https://expressjs.com/en/4x/api.html#req.fresh
func (c fiber.Ctx) Fresh() bool
Getβ
Returns the HTTP request header specified by the field.
The match is case-insensitive.
func (c fiber.Ctx) Get(key string, defaultValue ...string) string
app.Get("/", func(c fiber.Ctx) error {
c.Get("Content-Type") // "text/plain"
c.Get("CoNtEnT-TypE") // "text/plain"
c.Get("something", "john") // "john"
// ..
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
GetReqHeadersβ
Returns the HTTP request headers as a map. Since a header can be set multiple times in a single request, the values of the map are slices of strings containing all the different values of the header.
func (c fiber.Ctx) GetReqHeaders() map[string][]string
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
GetRespHeaderβ
Returns the HTTP response header specified by the field.
The match is case-insensitive.
func (c fiber.Ctx) GetRespHeader(key string, defaultValue ...string) string
app.Get("/", func(c fiber.Ctx) error {
c.GetRespHeader("X-Request-Id") // "8d7ad5e3-aaf3-450b-a241-2beb887efd54"
c.GetRespHeader("Content-Type") // "text/plain"
c.GetRespHeader("something", "john") // "john"
// ..
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
GetRespHeadersβ
Returns the HTTP response headers as a map. Since a header can be set multiple times in a single request, the values of the map are slices of strings containing all the different values of the header.
func (c fiber.Ctx) GetRespHeaders() map[string][]string
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
GetRouteURLβ
Generates URLs to named routes, with parameters. URLs are relative, for example: "/user/1831"
func (c fiber.Ctx) GetRouteURL(routeName string, params Map) (string, error)
app.Get("/", func(c fiber.Ctx) error {
return c.SendString("Home page")
}).Name("home")
app.Get("/user/:id", func(c fiber.Ctx) error {
return c.SendString(c.Params("id"))
}).Name("user.show")
app.Get("/test", func(c fiber.Ctx) error {
location, _ := c.GetRouteURL("user.show", fiber.Map{"id": 1})
return c.SendString(location)
})
// /test returns "/user/1"
Hostβ
Returns the host derived from the Host HTTP header.
In a network context, Host
refers to the combination of a hostname and potentially a port number used for connecting, while Hostname
refers specifically to the name assigned to a device on a network, excluding any port information.
func (c fiber.Ctx) Host() string
// GET http://google.com:8080/search
app.Get("/", func(c fiber.Ctx) error {
c.Host() // "google.com:8080"
c.Hostname() // "google.com"
// ...
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
Hostnameβ
Returns the hostname derived from the Host HTTP header.
func (c fiber.Ctx) Hostname() string
// GET http://google.com/search
app.Get("/", func(c fiber.Ctx) error {
c.Hostname() // "google.com"
// ...
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
IPβ
Returns the remote IP address of the request.
func (c fiber.Ctx) IP() string
app.Get("/", func(c fiber.Ctx) error {
c.IP() // "127.0.0.1"
// ...
})
When registering the proxy request header in the Fiber app, the IP address of the header is returned (Fiber configuration)
app := fiber.New(fiber.Config{
ProxyHeader: fiber.HeaderXForwardedFor,
})
IPsβ
Returns an array of IP addresses specified in the X-Forwarded-For request header.
func (c fiber.Ctx) IPs() []string
// X-Forwarded-For: proxy1, 127.0.0.1, proxy3
app.Get("/", func(c fiber.Ctx) error {
c.IPs() // ["proxy1", "127.0.0.1", "proxy3"]
// ...
})
Improper use of the X-Forwarded-For header can be a security risk. For details, see the Security and privacy concerns section.
Isβ
Returns the matching content type, if the incoming requestβs Content-Type HTTP header field matches the MIME type specified by the type parameter.
If the request has no body, it returns false.
func (c fiber.Ctx) Is(extension string) bool
// Content-Type: text/html; charset=utf-8
app.Get("/", func(c fiber.Ctx) error {
c.Is("html") // true
c.Is(".html") // true
c.Is("json") // false
// ...
})
IsFromLocalβ
Returns true
if the request came from localhost.
func (c fiber.Ctx) IsFromLocal() bool
app.Get("/", func(c fiber.Ctx) error {
// If request came from localhost, return true; else return false
c.IsFromLocal()
// ...
})
IsProxyTrustedβ
Checks the trustworthiness of the remote IP.
If TrustProxy
is false
, it returns true
.
IsProxyTrusted
can check the remote IP by proxy ranges and IP map.
func (c fiber.Ctx) IsProxyTrusted() bool
app := fiber.New(fiber.Config{
// TrustProxy enables the trusted proxy check
TrustProxy: true,
// TrustProxyConfig allows for configuring trusted proxies.
// Proxies is a list of trusted proxy IP ranges/addresses
TrustProxyConfig: fiber.TrustProxyConfig{
Proxies: []string{"0.8.0.0", "1.1.1.1/30"}, // IP address or IP address range
},
})
app.Get("/", func(c fiber.Ctx) error {
// If request came from trusted proxy, return true; else return false
c.IsProxyTrusted()
// ...
})
JSONβ
Converts any interface or string to JSON using the encoding/json package.
JSON also sets the content header to the ctype
parameter. If no ctype
is passed in, the header is set to application/json
.
func (c fiber.Ctx) JSON(data any, ctype ...string) error
type SomeStruct struct {
Name string
Age uint8
}
app.Get("/json", func(c fiber.Ctx) error {
// Create data struct:
data := SomeStruct{
Name: "Grame",
Age: 20,
}
return c.JSON(data)
// => Content-Type: application/json
// => {"Name": "Grame", "Age": 20}
return c.JSON(fiber.Map{
"name": "Grame",
"age": 20,
})
// => Content-Type: application/json
// => {"name": "Grame", "age": 20}
return c.JSON(fiber.Map{
"type": "https://example.com/probs/out-of-credit",
"title": "You do not have enough credit.",
"status": 403,
"detail": "Your current balance is 30, but that costs 50.",
"instance": "/account/12345/msgs/abc",
}, "application/problem+json")
// => Content-Type: application/problem+json
// => "{
// => "type": "https://example.com/probs/out-of-credit",
// => "title": "You do not have enough credit.",
// => "status": 403,
// => "detail": "Your current balance is 30, but that costs 50.",
// => "instance": "/account/12345/msgs/abc",
// => }"
})
JSONPβ
Sends a JSON response with JSONP support. This method is identical to JSON, except that it opts-in to JSONP callback support. By default, the callback name is simply callback
.
Override this by passing a named string in the method.
func (c fiber.Ctx) JSONP(data any, callback ...string) error
type SomeStruct struct {
Name string
Age uint8
}
app.Get("/", func(c fiber.Ctx) error {
// Create data struct:
data := SomeStruct{
Name: "Grame",
Age: 20,
}
return c.JSONP(data)
// => callback({"Name": "Grame", "Age": 20})
return c.JSONP(data, "customFunc")
// => customFunc({"Name": "Grame", "Age": 20})
})
Linksβ
Joins the links followed by the property to populate the responseβs Link HTTP header field.
func (c fiber.Ctx) Links(link ...string)
app.Get("/", func(c fiber.Ctx) error {
c.Links(
"http://api.example.com/users?page=2", "next",
"http://api.example.com/users?page=5", "last",
)
// Link: <http://api.example.com/users?page=2>; rel="next",
// <http://api.example.com/users?page=5>; rel="last"
// ...
})
Localsβ
A method that stores variables scoped to the request and, therefore, are available only to the routes that match the request. The stored variables are removed after the request is handled. If any of the stored data implements the io.Closer
interface, its Close
method will be called before it's removed.
This is useful if you want to pass some specific data to the next middleware. Remember to perform type assertions when retrieving the data to ensure it is of the expected type. You can also use a non-exported type as a key to avoid collisions.
func (c fiber.Ctx) Locals(key any, value ...any) any
// keyType is an unexported type for keys defined in this package.
// This prevents collisions with keys defined in other packages.
type keyType int
// userKey is the key for user.User values in Contexts. It is
// unexported; clients use user.NewContext and user.FromContext
// instead of using this key directly.
var userKey keyType
app.Use(func(c fiber.Ctx) error {
c.Locals(userKey, "admin") // Stores the string "admin" under a non-exported type key
return c.Next()
})
app.Get("/admin", func(c fiber.Ctx) error {
user, ok := c.Locals(userKey).(string) // Retrieves the data stored under the key and performs a type assertion
if ok && user == "admin" {
return c.Status(fiber.StatusOK).SendString("Welcome, admin!")
}
return c.SendStatus(fiber.StatusForbidden)
})
An alternative version of the Locals
method that takes advantage of Go's generics feature is also available. This version allows for the manipulation and retrieval of local values within a request's context with a more specific data type.
func Locals[V any](c fiber.Ctx, key any, value ...V) V
app.Use(func(c fiber.Ctx) error {
fiber.Locals[string](c, "john", "doe")
fiber.Locals[int](c, "age", 18)
fiber.Locals[bool](c, "isHuman", true)
return c.Next()
})
app.Get("/test", func(c fiber.Ctx) error {
fiber.Locals[string](c, "john") // "doe"
fiber.Locals[int](c, "age") // 18
fiber.Locals[bool](c, "isHuman") // true
return nil
})
Make sure to understand and correctly implement the Locals
method in both its standard and generic form for better control over route-specific data within your application.
Locationβ
Sets the response Location HTTP header to the specified path parameter.
func (c fiber.Ctx) Location(path string)
app.Post("/", func(c fiber.Ctx) error {
c.Location("http://example.com")
c.Location("/foo/bar")
return nil
})
Methodβ
Returns a string corresponding to the HTTP method of the request: GET
, POST
, PUT
, and so on.
Optionally, you can override the method by passing a string.
func (c fiber.Ctx) Method(override ...string) string
app.Post("/override", func(c fiber.Ctx) error {
c.Method() // "POST"
c.Method("GET")
c.Method() // "GET"
// ...
})
MultipartFormβ
To access multipart form entries, you can parse the binary with MultipartForm()
. This returns a *multipart.Form
, allowing you to access form values and files.
func (c fiber.Ctx) MultipartForm() (*multipart.Form, error)
app.Post("/", func(c fiber.Ctx) error {
// Parse the multipart form:
if form, err := c.MultipartForm(); err == nil {
// => *multipart.Form
if token := form.Value["token"]; len(token) > 0 {
// Get key value:
fmt.Println(token[0])
}
// Get all files from "documents" key:
files := form.File["documents"]
// => []*multipart.FileHeader
// Loop through files:
for _, file := range files {
fmt.Println(file.Filename, file.Size, file.Header["Content-Type"][0])
// => "tutorial.pdf" 360641 "application/pdf"
// Save the files to disk:
if err := c.SaveFile(file, fmt.Sprintf("./%s", file.Filename)); err != nil {
return err
}
}
}
return nil
})
Nextβ
When Next is called, it executes the next method in the stack that matches the current route. You can pass an error struct within the method that will end the chaining and call the error handler.
func (c fiber.Ctx) Next() error
app.Get("/", func(c fiber.Ctx) error {
fmt.Println("1st route!")
return c.Next()
})
app.Get("*", func(c fiber.Ctx) error {
fmt.Println("2nd route!")
return c.Next()
})
app.Get("/", func(c fiber.Ctx) error {
fmt.Println("3rd route!")
return c.SendString("Hello, World!")
})
OriginalURLβ
Returns the original request URL.
func (c fiber.Ctx) OriginalURL() string
// GET http://example.com/search?q=something
app.Get("/", func(c fiber.Ctx) error {
c.OriginalURL() // "/search?q=something"
// ...
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
Paramsβ
This method can be used to get the route parameters. You can pass an optional default value that will be returned if the param key does not exist.
Defaults to an empty string (""
) if the param doesn't exist.
func (c fiber.Ctx) Params(key string, defaultValue ...string) string
// GET http://example.com/user/fenny
app.Get("/user/:name", func(c fiber.Ctx) error {
c.Params("name") // "fenny"
// ...
})
// GET http://example.com/user/fenny/123
app.Get("/user/*", func(c fiber.Ctx) error {
c.Params("*") // "fenny/123"
c.Params("*1") // "fenny/123"
// ...
})
Unnamed route parameters (*, +) can be fetched by the character and the counter in the route.
// ROUTE: /v1/*/shop/*
// GET: /v1/brand/4/shop/blue/xs
c.Params("*1") // "brand/4"
c.Params("*2") // "blue/xs"
For reasons of downward compatibility, the first parameter segment for the parameter character can also be accessed without the counter.
app.Get("/v1/*/shop/*", func(c fiber.Ctx) error {
c.Params("*") // outputs the value of the first wildcard segment
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
In certain scenarios, it can be useful to have an alternative approach to handle different types of parameters, not
just strings. This can be achieved using a generic Params
function known as Params[V GenericType](c fiber.Ctx, key string, defaultValue ...V) V
.
This function is capable of parsing a route parameter and returning a value of a type that is assumed and specified by V GenericType
.
func Params[V GenericType](c fiber.Ctx, key string, defaultValue ...V) V
// GET http://example.com/user/114
app.Get("/user/:id", func(c fiber.Ctx) error{
fiber.Params[string](c, "id") // returns "114" as string.
fiber.Params[int](c, "id") // returns 114 as integer
fiber.Params[string](c, "number") // returns "" (default string type)
fiber.Params[int](c, "number") // returns 0 (default integer value type)
})
The generic Params
function supports returning the following data types based on V GenericType
:
- Integer:
int
,int8
,int16
,int32
,int64
- Unsigned integer:
uint
,uint8
,uint16
,uint32
,uint64
- Floating-point numbers:
float32
,float64
- Boolean:
bool
- String:
string
- Byte array:
[]byte
Pathβ
Contains the path part of the request URL. Optionally, you can override the path by passing a string. For internal redirects, you might want to call RestartRouting instead of Next.
func (c fiber.Ctx) Path(override ...string) string
// GET http://example.com/users?sort=desc
app.Get("/users", func(c fiber.Ctx) error {
c.Path() // "/users"
c.Path("/john")
c.Path() // "/john"
// ...
})
Portβ
Returns the remote port of the request.
func (c fiber.Ctx) Port() string
// GET http://example.com:8080
app.Get("/", func(c fiber.Ctx) error {
c.Port() // "8080"
// ...
})
Protocolβ
Contains the request protocol string: http
or https
for TLS requests.
func (c fiber.Ctx) Protocol() string
// GET http://example.com
app.Get("/", func(c fiber.Ctx) error {
c.Protocol() // "http"
// ...
})
Queriesβ
Queries
is a function that returns an object containing a property for each query string parameter in the route.
func (c fiber.Ctx) Queries() map[string]string
// GET http://example.com/?name=alex&want_pizza=false&id=
app.Get("/", func(c fiber.Ctx) error {
m := c.Queries()
m["name"] // "alex"
m["want_pizza"] // "false"
m["id"] // ""
// ...
})
// GET http://example.com/?field1=value1&field1=value2&field2=value3
app.Get("/", func (c fiber.Ctx) error {
m := c.Queries()
m["field1"] // "value2"
m["field2"] // "value3"
})
// GET http://example.com/?list_a=1&list_a=2&list_a=3&list_b[]=1&list_b[]=2&list_b[]=3&list_c=1,2,3
app.Get("/", func(c fiber.Ctx) error {
m := c.Queries()
m["list_a"] // "3"
m["list_b[]"] // "3"
m["list_c"] // "1,2,3"
})
// GET /api/posts?filters.author.name=John&filters.category.name=Technology
app.Get("/", func(c fiber.Ctx) error {
m := c.Queries()
m["filters.author.name"] // John
m["filters.category.name"] // Technology
})
// GET /api/posts?tags=apple,orange,banana&filters[tags]=apple,orange,banana&filters[category][name]=fruits&filters.tags=apple,orange,banana&filters.category.name=fruits
app.Get("/", func(c fiber.Ctx) error {
m := c.Queries()
m["tags"] // apple,orange,banana
m["filters[tags]"] // apple,orange,banana
m["filters[category][name]"] // fruits
m["filters.tags"] // apple,orange,banana
m["filters.category.name"] // fruits
})
Queryβ
This method returns a string corresponding to a query string parameter by name. You can pass an optional default value that will be returned if the query key does not exist.
If there is no query string, it returns an empty string.
func (c fiber.Ctx) Query(key string, defaultValue ...string) string
// GET http://example.com/?order=desc&brand=nike
app.Get("/", func(c fiber.Ctx) error {
c.Query("order") // "desc"
c.Query("brand") // "nike"
c.Query("empty", "nike") // "nike"
// ...
})
Returned value is only valid within the handler. Do not store any references.
Make copies or use the Immutable
setting instead. Read more...
In certain scenarios, it can be useful to have an alternative approach to handle different types of query parameters, not
just strings. This can be achieved using a generic Query
function known as Query[V GenericType](c fiber.Ctx, key string, defaultValue ...V) V
.
This function is capable of parsing a query string and returning a value of a type that is assumed and specified by V GenericType
.
Here is the signature for the generic Query
function:
func Query[V GenericType](c fiber.Ctx, key string, defaultValue ...V) V
// GET http://example.com/?page=1&brand=nike&new=true
app.Get("/", func(c fiber.Ctx) error {
fiber.Query[int](c, "page") // 1
fiber.Query[string](c, "brand") // "nike"
fiber.Query[bool](c, "new") // true
// ...
})
In this case, Query[V GenericType](c Ctx, key string, defaultValue ...V) V
can retrieve page
as an integer, brand
as a string, and new
as a boolean. The function uses the appropriate parsing function for each specified type to ensure the correct type is returned. This simplifies the retrieval process of different types of query parameters, making your controller actions cleaner.
The generic Query
function supports returning the following data types based on V GenericType
:
- Integer:
int
,int8
,int16
,int32
,int64
- Unsigned integer:
uint
,uint8
,uint16
,uint32
,uint64
- Floating-point numbers:
float32
,float64
- Boolean:
bool
- String:
string
- Byte array:
[]byte
Rangeβ
Returns a struct containing the type and a slice of ranges.
func (c fiber.Ctx) Range(size int) (Range, error)
// Range: bytes=500-700, 700-900
app.Get("/", func(c fiber.Ctx) error {
r := c.Range(1000)
if r.Type == "bytes" {
for _, rng := range r.Ranges {
fmt.Println(rng)
// [500, 700]
}
}
})
Redirectβ
Returns the Redirect reference.
For detailed information, check the Redirect documentation.
func (c fiber.Ctx) Redirect() *Redirect
app.Get("/coffee", func(c fiber.Ctx) error {
return c.Redirect().To("/teapot")
})
app.Get("/teapot", func(c fiber.Ctx) error {
return c.Status(fiber.StatusTeapot).Send("π΅ short and stout π΅")
})
Renderβ
Renders a view with data and sends a text/html
response. By default, Render
uses the default Go Template engine. If you want to use another view engine, please take a look at our Template middleware.
func (c fiber.Ctx) Render(name string, bind Map, layouts ...string) error
Requestβ
Returns the *fasthttp.Request pointer.
func (c fiber.Ctx) Request() *fasthttp.Request
app.Get("/", func(c fiber.Ctx) error {
c.Request().Header.Method()
// => []byte("GET")
})
RequestCtxβ
Returns *fasthttp.RequestCtx that is compatible with the context.Context
interface that requires a deadline, a cancellation signal, and other values across API boundaries.
func (c fiber.Ctx) RequestCtx() *fasthttp.RequestCtx
Please read the Fasthttp Documentation for more information.
Responseβ
Returns the *fasthttp.Response pointer.
func (c fiber.Ctx) Response() *fasthttp.Response
app.Get("/", func(c fiber.Ctx) error {
c.Response().BodyWriter().Write([]byte("Hello, World!"))
// => "Hello, World!"
return nil
})
Resetβ
Resets the context fields by the given request when using server handlers.
func (c fiber.Ctx) Reset(fctx *fasthttp.RequestCtx)
It is used outside of the Fiber Handlers to reset the context for the next request.
RestartRoutingβ
Instead of executing the next method when calling Next, RestartRouting restarts execution from the first method that matches the current route. This may be helpful after overriding the path, i.e., an internal redirect. Note that handlers might be executed again, which could result in an infinite loop.
func (c fiber.Ctx) RestartRouting() error
app.Get("/new", func(c fiber.Ctx) error {
return c.SendString("From /new")
})
app.Get("/old", func(c fiber.Ctx) error {
c.Path("/new")
return c.RestartRouting()
})
Routeβ
Returns the matched Route struct.
func (c fiber.Ctx) Route() *Route
// http://localhost:8080/hello
app.Get("/hello/:name", func(c fiber.Ctx) error {
r := c.Route()
fmt.Println(r.Method, r.Path, r.Params, r.Handlers)
// GET /hello/:name handler [name]
// ...
})
Do not rely on c.Route()
in middlewares before calling c.Next()
- c.Route()
returns the last executed route.
func MyMiddleware() fiber.Handler {
return func(c fiber.Ctx) error {
beforeNext := c.Route().Path // Will be '/'
err := c.Next()
afterNext := c.Route().Path // Will be '/hello/:name'
return err
}
}
SaveFileβ
Method is used to save any multipart file to disk.
func (c fiber.Ctx) SaveFile(fh *multipart.FileHeader, path string) error
app.Post("/", func(c fiber.Ctx) error {
// Parse the multipart form:
if form, err := c.MultipartForm(); err == nil {
// => *multipart.Form
// Get all files from "documents" key:
files := form.File["documents"]
// => []*multipart.FileHeader
// Loop through files:
for _, file := range files {
fmt.Println(file.Filename, file.Size, file.Header["Content-Type"][0])
// => "tutorial.pdf" 360641 "application/pdf"
// Save the files to disk:
if err := c.SaveFile(file, fmt.Sprintf("./%s", file.Filename)); err != nil {
return err
}
}
return err
}
})
SaveFileToStorageβ
Method is used to save any multipart file to an external storage system.
func (c fiber.Ctx) SaveFileToStorage(fileheader *multipart.FileHeader, path string, storage Storage) error
storage := memory.New()
app.Post("/", func(c fiber.Ctx) error {
// Parse the multipart form:
if form, err := c.MultipartForm(); err == nil {
// => *multipart.Form
// Get all files from "documents" key:
files := form.File["documents"]
// => []*multipart.FileHeader
// Loop through files:
for _, file := range files {
fmt.Println(file.Filename, file.Size, file.Header["Content-Type"][0])
// => "tutorial.pdf" 360641 "application/pdf"
// Save the files to storage:
if err := c.SaveFileToStorage(file, fmt.Sprintf("./%s", file.Filename), storage); err != nil {
return err
}
}
return err
}
})
Schemaβ
Contains the request protocol string: http
or https
for TLS requests.
Please use Config.TrustProxy
to prevent header spoofing if your app is behind a proxy.
func (c fiber.Ctx) Schema() string
// GET http://example.com
app.Get("/", func(c fiber.Ctx) error {
c.Schema() // "http"
// ...
})
Secureβ
A boolean property that is true
if a TLS connection is established.
func (c fiber.Ctx) Secure() bool
// Secure() method is equivalent to:
c.Protocol() == "https"
Sendβ
Sets the HTTP response body.
func (c fiber.Ctx) Send(body []byte) error
app.Get("/", func(c fiber.Ctx) error {
return c.Send([]byte("Hello, World!")) // => "Hello, World!"
})
Fiber also provides SendString
and SendStream
methods for raw inputs.
Use this if you don't need type assertion, recommended for faster performance.
func (c fiber.Ctx) SendString(body string) error
func (c fiber.Ctx) SendStream(stream io.Reader, size ...int) error
app.Get("/", func(c fiber.Ctx) error {
return c.SendString("Hello, World!")
// => "Hello, World!"
return c.SendStream(bytes.NewReader([]byte("Hello, World!")))
// => "Hello, World!"
})
SendFileβ
Transfers the file from the given path. Sets the Content-Type response HTTP header field based on the file extension or format.
// SendFile defines configuration options when to transfer file with SendFile.
type SendFile struct {
// FS is the file system to serve the static files from.
// You can use interfaces compatible with fs.FS like embed.FS, os.DirFS etc.
//
// Optional. Default: nil
FS fs.FS
// When set to true, the server tries minimizing CPU usage by caching compressed files.
// This works differently than the github.com/gofiber/compression middleware.
// You have to set Content-Encoding header to compress the file.
// Available compression methods are gzip, br, and zstd.
//
// Optional. Default: false
Compress bool `json:"compress"`
// When set to true, enables byte range requests.
//
// Optional. Default: false
ByteRange bool `json:"byte_range"`
// When set to true, enables direct download.
//
// Optional. Default: false
Download bool `json:"download"`
// Expiration duration for inactive file handlers.
// Use a negative time.Duration to disable it.
//
// Optional. Default: 10 * time.Second
CacheDuration time.Duration `json:"cache_duration"`
// The value for the Cache-Control HTTP-header
// that is set on the file response. MaxAge is defined in seconds.
//
// Optional. Default: 0
MaxAge int `json:"max_age"`
}
func (c fiber.Ctx) SendFile(file string, config ...SendFile) error
app.Get("/not-found", func(c fiber.Ctx) error {
return c.SendFile("./public/404.html")
// Disable compression
return c.SendFile("./static/index.html", fiber.SendFile{
Compress: false,
})
})
If the file contains a URL-specific character, you have to escape it before passing the file path into the SendFile
function.
app.Get("/file-with-url-chars", func(c fiber.Ctx) error {
return c.SendFile(url.PathEscape("hash_sign_#.txt"))
})
You can set the CacheDuration
config property to -1
to disable caching.
app.Get("/file", func(c fiber.Ctx) error {
return c.SendFile("style.css", fiber.SendFile{
CacheDuration: -1,
})
})
You can use multiple SendFile
calls with different configurations in a single route. Fiber creates different filesystem handlers per config.
app.Get("/file", func(c fiber.Ctx) error {
switch c.Query("config") {
case "filesystem":
return c.SendFile("style.css", fiber.SendFile{
FS: os.DirFS(".")
})
case "filesystem-compress":
return c.SendFile("style.css", fiber.SendFile{
FS: os.DirFS("."),
Compress: true,
})
case "compress":
return c.SendFile("style.css", fiber.SendFile{
Compress: true,
})
default:
return c.SendFile("style.css")
}
return nil
})
For sending multiple files from an embedded file system, this functionality can be used.
SendStatusβ
Sets the status code and the correct status message in the body if the response body is empty.
You can find all used status codes and messages here.
func (c fiber.Ctx) SendStatus(status int) error
app.Get("/not-found", func(c fiber.Ctx) error {
return c.SendStatus(415)
// => 415 "Unsupported Media Type"
c.SendString("Hello, World!")
return c.SendStatus(415)
// => 415 "Hello, World!"
})
SendStreamβ
Sets the response body to a stream of data and adds an optional body size.
func (c fiber.Ctx) SendStream(stream io.Reader, size ...int) error
app.Get("/", func(c fiber.Ctx) error {
return c.SendStream(bytes.NewReader([]byte("Hello, World!")))
// => "Hello, World!"
})
SendStringβ
Sets the response body to a string.
func (c fiber.Ctx) SendString(body string) error
app.Get("/", func(c fiber.Ctx) error {
return c.SendString("Hello, World!")
// => "Hello, World!"
})
Setβ
Sets the responseβs HTTP header field to the specified key
, value
.
func (c fiber.Ctx) Set(key string, val string)
app.Get("/", func(c fiber.Ctx) error {
c.Set("Content-Type", "text/plain")
// => "Content-Type: text/plain"
// ...
})
SetContextβ
Sets the user-specified implementation for the context.Context
interface.
func (c fiber.Ctx) SetContext(ctx context.Context)
app.Get("/", func(c fiber.Ctx) error {
ctx := context.Background()
c.SetContext(ctx)
// Here ctx could be any context implementation
// ...
})
Staleβ
https://expressjs.com/en/4x/api.html#req.stale
func (c fiber.Ctx) Stale() bool
Statusβ
Sets the HTTP status for the response.
This method is chainable.
func (c fiber.Ctx) Status(status int) fiber.Ctx
app.Get("/fiber", func(c fiber.Ctx) error {
c.Status(fiber.StatusOK)
return nil
})
app.Get("/hello", func(c fiber.Ctx) error {
return c.Status(fiber.StatusBadRequest).SendString("Bad Request")
})
app.Get("/world", func(c fiber.Ctx) error {
return c.Status(fiber.StatusNotFound).SendFile("./public/gopher.png")
})
Stringβ
Returns a unique string representation of the context.
func (c fiber.Ctx) String() string
app.Get("/", func(c fiber.Ctx) error {
c.String() // => "#0000000100000001 - 127.0.0.1:3000 <-> 127.0.0.1:61516 - GET http://localhost:3000/"
// ...
})
Subdomainsβ
Returns a slice of subdomains in the domain name of the request.
The application property subdomain offset
, which defaults to 2
, is used for determining the beginning of the subdomain segments.
func (c fiber.Ctx) Subdomains(offset ...int) []string
// Host: "tobi.ferrets.example.com"
app.Get("/", func(c fiber.Ctx) error {
c.Subdomains() // ["ferrets", "tobi"]
c.Subdomains(1) // ["tobi"]
// ...
})
Typeβ
Sets the Content-Type HTTP header to the MIME type listed here specified by the file extension.
This method is chainable.
func (c fiber.Ctx) Type(ext string, charset ...string) fiber.Ctx
app.Get("/", func(c fiber.Ctx) error {
c.Type(".html") // => "text/html"
c.Type("html") // => "text/html"
c.Type("png") // => "image/png"
c.Type("json", "utf-8") // => "application/json; charset=utf-8"
// ...
})
Varyβ
Adds the given header field to the Vary response header. This will append the header if not already listed; otherwise, it leaves it listed in the current location.
Multiple fields are allowed.
func (c fiber.Ctx) Vary(fields ...string)
app.Get("/", func(c fiber.Ctx) error {
c.Vary("Origin") // => Vary: Origin
c.Vary("User-Agent") // => Vary: Origin, User-Agent
// No duplicates
c.Vary("Origin") // => Vary: Origin, User-Agent
c.Vary("Accept-Encoding", "Accept")
// => Vary: Origin, User-Agent, Accept-Encoding, Accept
// ...
})
ViewBindβ
Adds variables to the default view variable map binding to the template engine.
Variables are read by the Render
method and may be overwritten.
func (c fiber.Ctx) ViewBind(vars Map) error
app.Use(func(c fiber.Ctx) error {
c.ViewBind(fiber.Map{
"Title": "Hello, World!",
})
return c.Next()
})
app.Get("/", func(c fiber.Ctx) error {
return c.Render("xxx.tmpl", fiber.Map{}) // Render will use the Title variable
})
Writeβ
Adopts the Writer
interface.
func (c fiber.Ctx) Write(p []byte) (n int, err error)
app.Get("/", func(c fiber.Ctx) error {
c.Write([]byte("Hello, World!")) // => "Hello, World!"
fmt.Fprintf(c, "%s\n", "Hello, World!") // => "Hello, World!"
})
Writefβ
Writes a formatted string using a format specifier.
func (c fiber.Ctx) Writef(format string, a ...any) (n int, err error)
app.Get("/", func(c fiber.Ctx) error {
world := "World!"
c.Writef("Hello, %s", world) // => "Hello, World!"
fmt.Fprintf(c, "%s\n", "Hello, World!") // => "Hello, World!"
})
WriteStringβ
Writes a string to the response body.
func (c fiber.Ctx) WriteString(s string) (n int, err error)
app.Get("/", func(c fiber.Ctx) error {
return c.WriteString("Hello, World!")
// => "Hello, World!"
})
XHRβ
A boolean property that is true
if the requestβs X-Requested-With header field is XMLHttpRequest, indicating that the request was issued by a client library (such as jQuery).
func (c fiber.Ctx) XHR() bool
// X-Requested-With: XMLHttpRequest
app.Get("/", func(c fiber.Ctx) error {
c.XHR() // true
// ...
})
XMLβ
Converts any interface or string to XML using the standard encoding/xml
package.
XML also sets the content header to application/xml
.
func (c fiber.Ctx) XML(data any) error
type SomeStruct struct {
XMLName xml.Name `xml:"Fiber"`
Name string `xml:"Name"`
Age uint8 `xml:"Age"`
}
app.Get("/", func(c fiber.Ctx) error {
// Create data struct:
data := SomeStruct{
Name: "Grame",
Age: 20,
}
return c.XML(data)
// <Fiber>
// <Name>Grame</Name>
// <Age>20</Age>
// </Fiber>
})