Kitten is a micro-framework built on top of the HTTP.jl library.
- Straightforward routing
- Real-time Metrics Dashboard
- Auto-generated swagger documentation
- Out-of-the-box JSON serialization & deserialization (customizable)
- Type definition support for path parameters
- Request Extractors
- Multiple Instance Support
- Multithreading support
- Websockets, Streaming, and Server-Sent Events
- Cron Scheduling (on endpoints & functions)
- Middleware chaining (at the application, router, and route levels)
- Static & Dynamic file hosting
- Templating Support
- Plotting Support
- Protocol Buffer Support
- Route tagging
- Repeat tasks
pkg> add Kitten
Create a web-server with very few lines of code
using Kitten
using HTTP
@get "/greet" function(req::HTTP.Request)
return "hello world!"
end
# start the web server
serve()
Handlers are used to connect your code to the server in a clean & straightforward way. They assign a url to a function and invoke the function when an incoming request matches that url.
- Handlers can be imported from other modules and distributed across multiple files for better organization and modularity
- All handlers have equivalent macro & function implementations and support
do..end
block syntax - The type of first argument is used to identify what kind of handler is being registered
- This package assumes it's a
Request
handler by default when no type information is provided
There are 3 types of supported handlers:
Request
HandlersStream
HandlersWebsocket
Handlers
using HTTP
using Kitten
# Request Handler
@get "/" function(req::HTTP.Request)
...
end
# Stream Handler
@stream "/stream" function(stream::HTTP.Stream)
...
end
# Websocket Handler
@websocket "/ws" function(ws::HTTP.WebSocket)
...
end
They are just functions which means there are many ways that they can be expressed and defined. Below is an example of several different ways you can express and assign a Request
handler.
@get "/greet" function()
"hello world!"
end
@get("/gruessen") do
"Hallo Welt!"
end
@get "/saluer" () -> begin
"Bonjour le monde!"
end
@get "/saludar" () -> "ยกHola Mundo!"
@get "/salutare" f() = "ciao mondo!"
# This function can be declared in another module
function subtract(req, a::Float64, b::Float64)
return a - b
end
# register foreign request handlers like this
@get "/subtract/{a}/{b}" subtract
More Handler Docs
Request handlers are used to handle HTTP requests. They are defined using macros or their function equivalents, and accept a HTTP.Request
object as the first argument. These handlers support both function and do-block syntax.
- The default Handler when no type information is provided
- Routing Macros:
@get
,@post
,@put
,@patch
,@delete
,@route
- Routing Functions:
get()
,post()
,put()
,patch()
,delete()
,route()
Stream handlers are used to stream data. They are defined using the @stream
macro or the stream()
function and accept a HTTP.Stream
object as the first argument. These handlers support both function and do-block syntax.
@stream
andstream()
don't require a type definition on the first argument, they assume it's a stream.Stream
handlers can be assigned with standard routing macros & functions:@get
,@post
, etc- You need to explicitly include the type definition so Kitten can identify this as a
Stream
handler
Websocket handlers are used to handle websocket connections. They are defined using the @websocket
macro or the websocket()
function and accept a HTTP.WebSocket
object as the first argument. These handlers support both function and do-block syntax.
@websocket
andwebsocket()
don't require a type definition on the first argument, they assume it's a websocket.Websocket
handlers can also be assigned with the@get
macro orget()
function, because the websocket protocol requires aGET
request to initiate the handshake.- You need to explicitly include the type definition so Kitten can identify this as a
Websocket
handler
There are two primary ways to register your request handlers: the standard routing macros or the routing functions which utilize the do-block syntax.
For each routing macro, we now have a an equivalent routing function
@get -> get()
@post -> post()
@put -> put()
@patch -> patch()
@delete -> delete()
@route -> route()
The only practical difference between the two is that the routing macros are called during the precompilation stage, whereas the routing functions are only called when invoked. (The routing macros call the routing functions under the hood)
# Routing Macro syntax
@get "/add/{x}/{y}" function(request::HTTP.Request, x::Int, y::Int)
x + y
end
# Routing Function syntax
get("/add/{x}/{y}") do request::HTTP.Request, x::Int, y::Int
x + y
end
Kitten, by default, automatically identifies the Content-Type of the return value from a request handler when building a Response. This default functionality is quite useful, but it does have an impact on performance. In situations where the return type is known, It's recommended to use one of the pre-existing render functions to speed things up.
Here's a list of the currently supported render functions:
html
, text
, json
, file
, xml
, js
, css
, binary
Below is an example of how to use these functions:
using Kitten
get("/html") do
html("<h1>Hello World</h1>")
end
get("/text") do
text("Hello World")
end
get("/json") do
json(Dict("message" => "Hello World"))
end
serve()
In most cases, these functions accept plain strings as inputs. The only exceptions are the binary
function, which accepts a Vector{UInt8}
, and the json
function which accepts any serializable type.
- Each render function accepts a status and custom headers.
- The Content-Type and Content-Length headers are automatically set by these render functions
Path parameters are declared with braces and are passed directly to your request handler.
using Kitten
# use path params without type definitions (defaults to Strings)
@get "/add/{a}/{b}" function(req, a, b)
return parse(Float64, a) + parse(Float64, b)
end
# use path params with type definitions (they are automatically converted)
@get "/multiply/{a}/{b}" function(req, a::Float64, b::Float64)
return a * b
end
# The order of the parameters doesn't matter (just the name matters)
@get "/subtract/{a}/{b}" function(req, b::Int64, a::Int64)
return a - b
end
# start the web server
serve()
Query parameters can be declared directly inside of your handlers signature. Any parameter that isn't mentioned inside the route path is assumed to be a query parameter.
- If a default value is not provided, it's assumed to be a required parameter
@get "/query" function(req::HTTP.Request, a::Int, message::String="hello world")
return (a, message)
end
Alternatively, you can use the queryparams()
function to extract the raw values from the url as a dictionary.
@get "/query" function(req::HTTP.Request)
return queryparams(req)
end
Use the formdata()
function to extract and parse the form data from the body of a request. This function returns a dictionary of key-value pairs from the form
using Kitten
# Setup a basic form
@get "/" function()
html("""
<form action="/form" method="post">
<label for="firstname">First name:</label><br>
<input type="text" id="firstname" name="firstname"><br>
<label for="lastname">Last name:</label><br>
<input type="text" id="lastname" name="lastname"><br><br>
<input type="submit" value="Submit">
</form>
""")
end
# Parse the form data and return it
@post "/form" function(req)
data = formdata(req)
return data
end
serve()
All objects are automatically deserialized into JSON using the JSON3 library
using Kitten
using HTTP
@get "/data" function(req::HTTP.Request)
return Dict("message" => "hello!", "value" => 99.3)
end
# start the web server
serve()
Kitten provides some out-of-the-box serialization & deserialization for most objects but requires the use of StructTypes when converting structs
using Kitten
using HTTP
using StructTypes
struct Animal
id::Int
type::String
name::String
end
# Add a supporting struct type definition so JSON3 can serialize & deserialize automatically
StructTypes.StructType(::Type{Animal}) = StructTypes.Struct()
@get "/get" function(req::HTTP.Request)
# serialize struct into JSON automatically (because we used StructTypes)
return Animal(1, "cat", "whiskers")
end
@post "/echo" function(req::HTTP.Request)
# deserialize JSON from the request body into an Animal struct
animal = json(req, Animal)
# serialize struct back into JSON automatically (because we used StructTypes)
return animal
end
# start the web server
serve()
Kitten comes with several built-in extractors designed to reduce the amount of boilerplate required to serialize inputs to your handler functions. By simply defining a struct and specifying the data source, these extractors streamline the process of data ingestion & validation through a uniform api.
- The serialized data is accessible through the
payload
property - Can be used alongside other parameters and extractors
- Default values can be assigned when defined with the
@kwdef
macro - Includes both global and local validators
- Struct definitions can be deeply nested
Supported Extractors:
Path
- extracts from path parametersQuery
- extracts from query parameters,Header
- extracts from request headersForm
- extracts form data from the request bodyBody
- serializes the entire request body to a given type (String, Float64, etc..)ProtoBuffer
- extracts theProtoBuf
message from the request body (available through a package extension)Json
- extracts json from the request bodyJsonFragment
- extracts a "fragment" of the json body using the parameter name to identify and extract the corresponding top-level key
In this example we show that the Path
extractor can be used alongside regular path parameters. This Also works with regular query parameters and the Query
extractor.
struct Add
b::Int
c::Int
end
@get "/add/{a}/{b}/{c}" function(req, a::Int, pathparams::Path{Add})
add = pathparams.payload # access the serialized payload
return a + add.b + add.c
end
Default values can be setup with structs using the @kwdef
macro.
@kwdef struct Pet
name::String
age::Int = 10
end
@post "/pet" function(req, params::Json{Pet})
return params.payload # access the serialized payload
end
On top of serializing incoming data, you can also define your own validation rules by using the validate
function. In the example below we show how to use both global
and local
validators in your code.
- Validators are completely optional
- During the validation phase, Kitten will call the
global
validator before running alocal
validator.
import Kitten: validate
struct Person
name::String
age::Int
end
# Define a global validator
validate(p::Person) = p.age >= 0
# Only the global validator is ran here
@post "/person" function(req, newperson::Json{Person})
return newperson.payload
end
# In this case, both global and local validators are ran (this also makes sure the person is age 21+)
# You can also use this sytnax instead: Json(Person, p -> p.age >= 21)
@post "/adult" function(req, newperson = Json{Person}(p -> p.age >= 21))
return newperson.payload
end
You can interpolate variables directly into the paths, which makes dynamically registering routes a breeze
(Thanks to @anandijain for the idea)
using Kitten
operations = Dict("add" => +, "multiply" => *)
for (pathname, operator) in operations
@get "/$pathname/{a}/{b}" function (req, a::Float64, b::Float64)
return operator(a, b)
end
end
# start the web server
serve()
The router()
function is an HOF (higher order function) that allows you to reuse the same path prefix & properties across multiple endpoints. This is helpful when your api starts to grow and you want to keep your path operations organized.
Below are the arguments the router()
function can take:
router(prefix::String; tags::Vector, middleware::Vector, interval::Real, cron::String)
tags
- are used to organize endpoints in the autogenerated docsmiddleware
- is used to setup router & route-specific middlewareinterval
- is used to support repeat actions (calling a request handler on a set interval in seconds)cron
- is used to specify a cron expression that determines when to call the request handler.
using Kitten
# Any routes that use this router will be automatically grouped
# under the 'math' tag in the autogenerated documenation
math = router("/math", tags=["math"])
# You can also assign route specific tags
@get math("/multiply/{a}/{b}", tags=["multiplication"]) function(req, a::Float64, b::Float64)
return a * b
end
@get math("/divide/{a}/{b}") function(req, a::Float64, b::Float64)
return a / b
end
serve()
Kitten comes with a built-in cron scheduling system that allows you to call endpoints and functions automatically when the cron expression matches the current time.
When a job is scheduled, a new task is created and runs in the background. Each task uses its given cron expression and the current time to determine how long it needs to sleep before it can execute.
The cron parser in Kitten is based on the same specifications as the one used in Spring. You can find more information about this on the Spring Cron Expressions page.
The following is a breakdown of what each parameter in our cron expression represents. While our specification closely resembles the one defined by Spring, it's not an exact 1-to-1 match.
The string has six single space-separated time and date fields:
โโโโโโโโโโโโโโ second (0-59)
โ โโโโโโโโโโโโโโ minute (0 - 59)
โ โ โโโโโโโโโโโโโโ hour (0 - 23)
โ โ โ โโโโโโโโโโโโโโ day of the month (1 - 31)
โ โ โ โ โโโโโโโโโโโโโโ month (1 - 12) (or JAN-DEC)
โ โ โ โ โ โโโโโโโโโโโโโโ day of the week (1 - 7)
โ โ โ โ โ โ (Monday is 1, Tue is 2... and Sunday is 7)
โ โ โ โ โ โ
* * * * * *
Partial expressions are also supported, which means that subsequent expressions can be left out (they are defaulted to '*'
).
# In this example we see only the `seconds` part of the expression is defined.
# This means that all following expressions are automatically defaulted to '*' expressions
@cron "*/2" function()
println("runs every 2 seconds")
end
The router()
function has a keyword argument called cron
, which accepts a cron expression that determines when an endpoint is called. Just like the other keyword arguments, it can be reused by endpoints that share routers or be overridden by inherited endpoints.
# execute at 8, 9 and 10 o'clock of every day.
@get router("/cron-example", cron="0 0 8-10 * * *") function(req)
println("here")
end
# execute this endpoint every 5 seconds (whenever current_seconds % 5 == 0)
every5 = router("/cron", cron="*/5")
# this endpoint inherits the cron expression
@get every5("/first") function(req)
println("first")
end
# Now this endpoint executes every 2 seconds ( whenever current_seconds % 2 == 0 ) instead of every 5
@get every5("/second", cron="*/2") function(req)
println("second")
end
In addition to scheduling endpoints, you can also use the new @cron
macro to schedule functions. This is useful if you want to run code at specific times without making it visible or callable in the API.
@cron "*/2" function()
println("runs every 2 seconds")
end
@cron "0 0/30 8-10 * * *" function()
println("runs at 8:00, 8:30, 9:00, 9:30, 10:00 and 10:30 every day")
end
When you run serve()
or serveparallel()
, all registered cron jobs are automatically started. If the server is stopped or killed, all running jobs will also be terminated. You can stop the server and all repeat tasks and cron jobs by calling the terminate()
function or manually killing the server with ctrl+C
.
In addition, Kitten provides utility functions to manually start and stop cron jobs: startcronjobs()
and stopcronjobs()
. These functions can be used outside of a web server as well.
Repeat tasks provide a simple api to run a function on a set interval.
There are two ways to register repeat tasks:
- Through the
interval
parameter in arouter()
- Using the
@repeat
macro
It's important to note that request handlers that use this property can't define additional function parameters outside of the default HTTP.Request
parameter.
In the example below, the /repeat/hello
endpoint is called every 0.5 seconds and "hello"
is printed to the console each time.
The router()
function has an interval
parameter which is used to call
a request handler on a set interval (in seconds).
using Kitten
taskrouter = router("/repeat", interval=0.5, tags=["repeat"])
@get taskrouter("/hello") function()
println("hello")
end
# you can override properties by setting route specific values
@get taskrouter("/bonjour", interval=1.5) function()
println("bonjour")
end
serve()
Below is an example of how to register a repeat task outside of the router
@repeat 1.5 function()
println("runs every 1.5 seconds")
end
# you can also "name" a repeat task
@repeat 5 "every-five" function()
println("runs every 5 seconds")
end
When the server is ran, all tasks are started automatically. But the module also provides utilities to have more fine-grained control over the running tasks using the following functions: starttasks()
, stoptasks()
, and cleartasks()
In some advanced scenarios, you might need to spin up multiple web severs within the same module on different ports. Kitten provides both a static and dynamic way to create multiple instances of a web server.
As a general rule of thumb, if you know how many instances you need ahead of time it's best to go with the static approach.
Kitten provides a new macro which makes it possible to setup and run multiple instances. It generates methods and binds them to a new internal state for the current module.
In the example below, two simple servers are defined within modules A and B and are started in the parent module. Both modules contain all of the functions exported from Kitten which can be called directly as shown below.
module A
using Kitten; @oxidise
get("/") do
text("server A")
end
end
module B
using Kitten; @oxidise
get("/") do
text("server B")
end
end
try
# start both instances
A.serve(port=8001, async=true)
B.serve(port=8002, async=false)
finally
# shut down if we `Ctrl+C`
A.terminate()
B.terminate()
end
The instance
function helps you create a completely independent instance of an Kitten web server at runtime. It works by dynamically creating a julia module at runtime and loading the Kitten code within it.
All of the same methods from Kitten are available under the named instance. In the example below we can use the get
, and serve
by simply using dot syntax on the app1
variable to access the underlying methods.
using Kitten
######### Setup the first app #########
app1 = instance()
app1.get("/") do
text("server A")
end
######### Setup the second app #########
app2 = instance()
app2.get("/") do
text("server B")
end
######### Start both instances #########
try
# start both servers together
app1.serve(port=8001, async=true)
app2.serve(port=8002)
finally
# clean it up
app1.terminate()
app2.terminate()
end
For scenarios where you need to handle higher amounts of traffic, you can run Kitten in a multithreaded mode. In order to utilize this mode, julia must have more than 1 thread to work with. You can start a julia session with 4 threads using the command below
julia --threads 4
serveparallel()
Starts the webserver in streaming mode and handles requests in a cooperative multitasking approach. This function uses Threads.@spawn
to schedule a new task on any available thread. Meanwhile, @async is used inside this task when calling each request handler. This allows the task to yield during I/O operations.
using Kitten
using StructTypes
using Base.Threads
# Make the Atomic struct serializable
StructTypes.StructType(::Type{Atomic{Int64}}) = StructTypes.Struct()
x = Atomic{Int64}(0);
@get "/show" function()
return x
end
@get "/increment" function()
atomic_add!(x, 1)
return x
end
# start the web server in parallel mode
serveparallel()
Kitten includes an extension for the ProtoBuf.jl package. This extension provides a protobuf()
function, simplifying the process of working with Protocol Buffers in the context of web server. For a better understanding of this package, please refer to its official documentation.
This function has overloads for the following scenarios:
- Decoding a protobuf message from the body of an HTTP request.
- Encoding a protobuf message into the body of an HTTP request.
- Encoding a protobuf message into the body of an HTTP response.
using HTTP
using ProtoBuf
using Kitten
# The generated classes need to be created ahead of time (check the protobufs)
include("people_pb.jl");
using .people_pb: People, Person
# Decode a Protocol Buffer Message
@post "/count" function(req::HTTP.Request)
# decode the request body into a People object
message = protobuf(req, People)
# count the number of Person objects
return length(message.people)
end
# Encode & Return Protocol Buffer message
@get "/get" function()
message = People([
Person("John Doe", 20),
Person("Alice", 30),
Person("Bob", 35)
])
# seralize the object inside the body of a HTTP.Response
return protobuf(message)
end
The following is an example of a schema that was used to create the necessary Julia bindings. These bindings allow for the encoding and decoding of messages in the above example.
syntax = "proto3";
message Person {
string name = 1;
sint32 age = 2;
}
message People {
repeated Person people = 1;
}
Kitten is equipped with several package extensions that enhance its plotting capabilities. These extensions make it easy to return plots directly from request handlers. All operations are performed in-memory using an IOBuffer and return a HTTP.Response
Supported Packages and their helper utils:
- CairoMakie.jl:
png
,svg
,pdf
,html
- WGLMakie.jl:
html
- Bonito.jl:
html
using CairoMakie: heatmap
using Kitten
@get "/cairo" function()
fig, ax, pl = heatmap(rand(50, 50))
png(fig)
end
serve()
using Bonito
using WGLMakie: heatmap
using Kitten
using Kitten: html # Bonito also exports html
@get "/wgl" function()
fig = heatmap(rand(50, 50))
html(fig)
end
serve()
using Bonito
using WGLMakie: heatmap
using Kitten
using Kitten: html # Bonito also exports html
@get "/bonito" function()
app = App() do
return DOM.div(
DOM.h1("Random 50x50 Heatmap"),
DOM.div(heatmap(rand(50, 50)))
)
end
return html(app)
end
serve()
Rather than building an internal engine for templating or adding additional dependencies, Kitten
provides two package extensions to support Mustache.jl
and OteraEngine.jl
templates.
Kitten provides a simple wrapper api around both packages that makes it easy to render templates from strings,
templates, and files. This wrapper api returns a render
function which accepts a dictionary of inputs to fill out the
template.
In all scenarios, the rendered template is returned inside a HTTP.Response object ready to get served by the api.
By default, the mime types are auto-detected either by looking at the content of the template or the extension name on the file.
If you know the mime type you can pass it directly through the mime_type
keyword argument to skip the detection process.
Please take a look at the Mustache.jl documentation to learn the full capabilities of the package
Example 1: Rendering a Mustache Template from a File
using Mustache
using Kitten
# Load the Mustache template from a file and create a render function
render = mustache("./templates/greeting.txt", from_file=false)
@get "/mustache/file" function()
data = Dict("name" => "Chris")
return render(data) # This will return an HTML.Response with the rendered template
end
Example 2: Specifying MIME Type for a plain string Mustache Template
using Mustache
using Kitten
# Define a Mustache template (both plain strings and mustache templates are supported)
template_str = "Hello, {{name}}!"
# Create a render function, specifying the MIME type as text/plain
render = mustache(template_str, mime_type="text/plain") # mime_type keyword arg is optional
@get "/plain/text" function()
data = Dict("name" => "Chris")
return render(data) # This will return a plain text response with the rendered template
end
Please take a look at the OteraEngine.jl documentation to learn the full capabilities of the package
Example 1: Rendering an Otera Template with Logic and Loops
using OteraEngine
using Kitten
# Define an Otera template
template_str = """
<html>
<head><title>{{ title }}</title></head>
<body>
{% for name in names %}
Hello {{ name }}<br>
{% end %}
</body>
</html>
"""
# Create a render function for the Otera template
render = otera(template_str)
@get "/otera/loop" function()
data = Dict("title" => "Greetings", "names" => ["Alice", "Bob", "Chris"])
return render(data) # This will return an HTML.Response with the rendered template
end
In this example, an Otera template is defined with a for-loop that iterates over a list of names, greeting each name.
Example 2: Running Julia Code in Otera Template
using OteraEngine
using Kitten
# Define an Otera template with embedded Julia code
template_str = """
The square of {{ number }} is {< number^2 >}.
"""
# Create a render function for the Otera template
render = otera(template_str)
@get "/otera/square" function()
data = Dict("number" => 5)
return render(data) # This will return an HTML.Response with the rendered template
end
In this example, an Otera template is defined with embedded Julia code that calculates the square of a given number.
You can mount static files using this handy function which recursively searches a folder for files and mounts everything. All files are loaded into memory on startup.
using Kitten
# mount all files inside the "content" folder under the "/static" path
staticfiles("content", "static")
# start the web server
serve()
Similar to staticfiles, this function mounts each path and re-reads the file for each request. This means that any changes to the files after the server has started will be displayed.
using Kitten
# mount all files inside the "content" folder under the "/dynamic" path
dynamicfiles("content", "dynamic")
# start the web server
serve()
Disabling the internal logger can provide some massive performance gains, which can be helpful in some scenarios.
Anecdotally, i've seen a 2-3x speedup in serve()
and a 4-5x speedup in serveparallel()
performance.
# This is how you disable internal logging in both modes
serve(access_log=nothing)
serveparallel(access_log=nothing)
Kitten provides a default logging format but allows you to customize the format using the access_log
parameter. This functionality is available in both the serve()
and serveparallel()
functions.
You can read more about the logging options here
# Uses the default logging format
serve()
# Customize the logging format
serve(access_log=logfmt"[$time_iso8601] \"$request\" $status")
# Disable internal request logging
serve(access_log=nothing)
Middleware functions make it easy to create custom workflows to intercept all incoming requests and outgoing responses. They are executed in the same order they are passed in (from left to right).
They can be set at the application, router, and route layer with the middleware
keyword argument. All middleware is additive and any middleware defined in these layers will be combined and executed.
Middleware will always be executed in the following order:
application -> router -> route
Now lets see some middleware in action:
using Kitten
using HTTP
const CORS_HEADERS = [
"Access-Control-Allow-Origin" => "*",
"Access-Control-Allow-Headers" => "*",
"Access-Control-Allow-Methods" => "POST, GET, OPTIONS"
]
# https://juliaweb.github.io/HTTP.jl/stable/examples/#Cors-Server
function CorsMiddleware(handler)
return function(req::HTTP.Request)
println("CORS middleware")
# determine if this is a pre-flight request from the browser
if HTTP.method(req)=="OPTIONS"
return HTTP.Response(200, CORS_HEADERS)
else
return handler(req) # passes the request to the AuthMiddleware
end
end
end
function AuthMiddleware(handler)
return function(req::HTTP.Request)
println("Auth middleware")
# ** NOT an actual security check ** #
if !HTTP.headercontains(req, "Authorization", "true")
return HTTP.Response(403)
else
return handler(req) # passes the request to your application
end
end
end
function middleware1(handle)
function(req)
println("middleware1")
handle(req)
end
end
function middleware2(handle)
function(req)
println("middleware2")
handle(req)
end
end
# set middleware at the router level
math = router("math", middleware=[middleware1])
# set middleware at the route level
@get math("/divide/{a}/{b}", middleware=[middleware2]) function(req, a::Float64, b::Float64)
return a / b
end
# set application level middleware
serve(middleware=[CorsMiddleware, AuthMiddleware])
If you don't want to use Kitten's default response serializer, you can turn it off and add your own! Just create your own special middleware function to serialize the response and add it at the end of your own middleware chain.
Both serve()
and serveparallel()
have a serialize
keyword argument which can toggle off the default serializer.
using Kitten
using HTTP
using JSON3
@get "/divide/{a}/{b}" function(req::HTTP.Request, a::Float64, b::Float64)
return a / b
end
# This is just a regular middleware function
function myserializer(handle)
function(req)
try
response = handle(req)
# convert all responses to JSON
return HTTP.Response(200, [], body=JSON3.write(response))
catch error
@error "ERROR: " exception=(error, catch_backtrace())
return HTTP.Response(500, "The Server encountered a problem")
end
end
end
# make sure 'myserializer' is the last middleware function in this list
serve(middleware=[myserializer], serialize=false)
Swagger documentation is automatically generated for each route you register in your application. Only the route name, parameter types, and 200 & 500 responses are automatically created for you by default.
You can view your generated documentation at /docs
, and the schema
can be found under /docs/schema
. Both of these values can be changed to whatever you want using the configdocs()
function. You can also opt out of autogenerated docs entirely by calling the disabledocs()
function
before starting your application.
To add additional details you can either use the built-in mergeschema()
or setschema()
functions to directly modify the schema yourself or merge the generated schema from the SwaggerMarkdown.jl
package (I'd recommend the latter)
Below is an example of how to merge the schema generated from the SwaggerMarkdown.jl
package.
using Kitten
using SwaggerMarkdown
# Here's an example of how you can merge autogenerated docs from SwaggerMarkdown.jl into your api
@swagger """
/divide/{a}/{b}:
get:
description: Return the result of a / b
parameters:
- name: a
in: path
required: true
description: this is the value of the numerator
schema:
type : number
responses:
'200':
description: Successfully returned an number.
"""
@get "/divide/{a}/{b}" function (req, a::Float64, b::Float64)
return a / b
end
# title and version are required
info = Dict("title" => "My Demo Api", "version" => "1.0.0")
openApi = OpenAPI("3.0", info)
swagger_document = build(openApi)
# merge the SwaggerMarkdown schema with the internal schema
mergeschema(swagger_document)
# start the web server
serve()
Below is an example of how to manually modify the schema
using Kitten
using SwaggerMarkdown
# Only the basic information is parsed from this route when generating docs
@get "/multiply/{a}/{b}" function (req, a::Float64, b::Float64)
return a * b
end
# Here's an example of how to update a part of the schema yourself
mergeschema("/multiply/{a}/{b}",
Dict(
"get" => Dict(
"description" => "return the result of a * b"
)
)
)
# Here's another example of how to update a part of the schema yourself, but this way allows you to modify other properties defined at the root of the schema (title, summary, etc.)
mergeschema(
Dict(
"paths" => Dict(
"/multiply/{a}/{b}" => Dict(
"get" => Dict(
"description" => "return the result of a * b"
)
)
)
)
)
@get(path, func)
Parameter | Type | Description |
---|---|---|
path |
string or router() |
Required. The route to register |
func |
function |
Required. The request handler for this route |
Used to register a function to a specific endpoint to handle that corresponding type of request
@route(methods, path, func)
Parameter | Type | Description |
---|---|---|
methods |
array |
Required. The types of HTTP requests to register to this route |
path |
string or router() |
Required. The route to register |
func |
function |
Required. The request handler for this route |
Low-level macro that allows a route to be handle multiple request types
staticfiles(folder, mount)
Parameter | Type | Description |
---|---|---|
folder |
string |
Required. The folder to serve files from |
mountdir |
string |
The root endpoint to mount files under (default is "static") |
set_headers |
function |
Customize the http response headers when returning these files |
loadfile |
function |
Customize behavior when loading files |
Serve all static files within a folder. This function recursively searches a directory and mounts all files under the mount directory using their relative paths.
dynamicfiles(folder, mount)
Parameter | Type | Description |
---|---|---|
folder |
string |
Required. The folder to serve files from |
mountdir |
string |
The root endpoint to mount files under (default is "static") |
set_headers |
function |
Customize the http response headers when returning these files |
loadfile |
function |
Customize behavior when loading files |
Serve all static files within a folder. This function recursively searches a directory and mounts all files under the mount directory using their relative paths. The file is loaded on each request, potentially picking up any file changes.
html(content, status, headers)
Parameter | Type | Description |
---|---|---|
content |
string |
Required. The string to be returned as HTML |
status |
integer |
The HTTP response code (default is 200) |
headers |
dict |
The headers for the HTTP response (default has content-type header set to "text/html; charset=utf-8") |
Helper function to designate when content should be returned as HTML
queryparams(request)
Parameter | Type | Description |
---|---|---|
req |
HTTP.Request |
Required. The HTTP request object |
Returns the query parameters from a request as a Dict()
text(request)
Parameter | Type | Description |
---|---|---|
req |
HTTP.Request |
Required. The HTTP request object |
Returns the body of a request as a string
binary(request)
Parameter | Type | Description |
---|---|---|
req |
HTTP.Request |
Required. The HTTP request object |
Returns the body of a request as a binary file (returns a vector of UInt8
s)
json(request, classtype)
Parameter | Type | Description |
---|---|---|
req |
HTTP.Request |
Required. The HTTP request object |
classtype |
struct |
A struct to deserialize a JSON object into |
Deserialize the body of a request into a julia struct
MIT License, see LICENSE.md for more information.
Migrated from Oxygen.jl and modified to work with JuliaKit project.