BedSheet is a platform for delivering web applications written in Fantom. It provides a rich middleware mechanism for the routing and delivery of content over HTTP.
- An IoC Container - BedSheet applications are IoC applications
- Proxy Mode - Never (manually) restart your application again!
- Routing - Map URLs to Fantom methods
- Route Handlers - Map URLs to file system and pod resources
- Error Handling - Customised error handling and detailed error reporting
- Status Pages - Customise 404 and 500 pages
BedSheet is built on top of IoC and Wisp, and was inspired by Java's Tapestry5 and Ruby's Sinatra.
Install BedSheet
with the Fantom Pod Manager ( FPM ):
C:\> fpm install afBedSheet
Or install BedSheet
with fanr:
C:\> fanr install -r http://eggbox.fantomfactory.org/fanr/ afBedSheet
To use in a Fantom project, add a dependency to build.fan
:
depends = ["sys 1.0", ..., "afBedSheet 1.5"]
Full API & fandocs are available on the Eggbox - the Fantom Pod Repository.
-
Create a text file called
Example.fan
: using afIoc using afBedSheetclass HelloPage { Text hello(Str name, Int iq := 666) { return Text.fromPlain("Hello! I'm $name and I have an IQ of $iq!") } }
const class AppModule { @Contribute { serviceType=Routes# } Void contributeRoutes(Configuration conf) { conf.add(Route(
/index
, Text.fromHtml("Welcome to BedSheet!"))) conf.add(Route(/hello/*/*
, HelloPage#hello)) } }class Example { Int main() { BedSheetBuilder(AppModule#).startWisp(8080) } }
-
Run
Example.fan
as a Fantom script from the command line: C:> fan Example.fan -env development[info] [afBedSheet] Found mod 'Example_0::AppModule' [info] [afBedSheet] Starting Bed App 'Example_0' on port 8080 [info] [web] http started on port 8080 [info] [afIoc] Adding module afIoc::IocModule [info] [afIoc] Adding module Example_0::AppModule [info] [afIoc] Adding module afBedSheet::BedSheetModule [info] [afIoc] Adding module afIocConfig::IocConfigModule [info] [afIoc] Adding module afBedSheet::BedSheetEnvModule [info] [afIoc] Adding module afConcurrent::ConcurrentModule [info] [afIocEnv] Setting from cmd line argument '-env' : development ...
24.32% of services were built on startup (9/37)
___ __ _____ _
/ _ | / /_____ _____ / / / /_____ __ __ / _ | / // / -|/ _ /===/ __// _ / / __/ _ / __|/ // / // ||////_|//// // _,/__/_/// _, / Alien-Factory BedSheet v1.5.0, IoC v3.0.0 //
[info] [afIoc] IoC Registry built in 91ms and started up in 96ms
Bed App 'Example_0' listening on http://localhost:8080/
-
Visit
Welcome to BedSheet!localhost
to hit the web application: C:> curl http://localhost:8080/indexC:> curl http://localhost:8080/hello/Traci/69 Hello! I'm Traci and I have an IQ of 69!
C:> curl http://localhost:8080/hello/Luci Hello! I'm Luci and I have an IQ of 666!
Wow! That's awesome! But what just happened!?
Every BedSheet application has an AppModule
that configures IoC services. Here we told the Routes
service to return some plain text in response to /index
and to call the HelloPage#hello
method for all requests that start with /hello
. Route converts URL path segments into method arguments, or in our case, to Str name
and to an optional Int iq
.
Route handlers are typically what we, the application developers, write. They perform logic processing and render responses. Our HelloPage
route handler simply returns a plain Text response, which BedSheet sends to the client via an appropriate ResponseProcessor.
You can start BedSheet manually, as we did in the Quick Start example, or you can start BedSheet from the command line. Just tell it where to find an AppModule
and the port to run on:
C:\> fan afBedSheet [-port <port>] [-env <env>] [-proxy] <qualified-appModule-name>
For example:
C:\> fan afBedSheet -port 8069 myWebApp::AppModule
Every Bed App (BedSheet Application) has an AppModule
class that defines and configures your IoC services. It is an IoC concept that allows you centralise your application's configuration in one place. It is the AppModule
that defines your Bed App and is central everything it does.
<qualified-appModule-name>
may be replaced with just <pod-name>
as long as your pod's build.fan
defines the following meta:
meta = [
...
...
"afIoc.module" : "<qualified-appModule-name>"
]
This allows BedSheet to look up your AppModule
from the pod. Example:
C:\> fan afBedSheet -port 8069 myWebApp
Note that the AppModule
class is named so out of convention but may be called anything you like.
See Development Proxy for info on the -proxy
option.
BedSheet is an IoC container. That is, it creates and looks after a Registry
instance, using it to create classes and provide access to services.
BedSheet Web applications are multi-threaded; each web request is served on a different thread. For that reason BedSheet defines a threaded scope called request
.
By default const services are matched to the root scope and non-const services are matched the to request scope. But it it better to be explicit and set which scopes a service is available on when it is defined.
class AppModule {
Void defineServices(RegistryBuilder bob) {
bob.addService(MyService1#).withScope("root")
bob.addService(MyService2#).withScope("httpRequest")
}
}
In IoC's default root
scope, only one instance of the service is created for the entire application. It is how you share data and services between requests and threads. Root scoped services need to be const
classes.
In BedSheet's httpRequest
scope a new instance of the service will be created for each thread / web request. BedSheet's WebReq
and WebRes
are good examples this. Note in some situations this per thread object creation could be considered wasteful. In other situations, such as sharing database connections, it is not even viable.
Writing const
services (for the root scope) may be off-putting - because they're constant and can't hold mutable data, right!? ** Wrong! ** Const classes can hold mutable data. See the Maps and Lists in Alien-Factory's Concurrent pod for examples. The article From One Thread to Another... explains the principles in more detail.
The smart ones may be thinking that root
scoped services can only hold other root
scoped services. Well, they would be wrong too! Using IoC's active scope and the magic of IoC's Lazy Funcs, request
scoped services may be injected into root
scoped services. See IoC's Lazy Funcs for more info.
The Routes
service maps HTTP request URLs to response objects and handler methods. It is where you would typically define how requests are handled. You configure the Routes
service by contributing instances of Route. Example:
using afIoc
using afBedSheet
class AppModule {
@Contribute { serviceType=Routes# }
Void contributeRoutes(Configuration config) {
config.add(Route(`/home`, HttpRedirect.movedTemporarily(`/index`)))
config.add(Route(`/index`, IndexPage#service))
config.add(Route(`/work`, WorkPage#service, "POST"))
}
}
Route objects take a matching glob
and a response object. A response object is any object that BedSheet knows how to process or a Method
to be called. If a method is given, then request URL path segments are matched to the method parameters. See Route for more details.
Note that Route
is actually a mixin, so you can create custom instances that match on anything, not just URLs.
Routing lesson over.
(...you Aussies may stop giggling now.)
Route Handler is the name given to a class or method that is processed by a Route
. They process logic and generally don't pipe anything to the HTTP response stream. Instead they return a Response Object for further processing. For example, the Quick Start HelloPage
route handler returns a Text response object.
Route handlers are written by the application developer, but a couple of common use-cases are bundled with BedSheet:
- FileHandler: Maps request URLs to files on the file system.
- PodHandler : Maps request URLs to pod file resources.
See the FileHandler documentation for examples on how to serve up static files. If no configuration is given to FileHandler
then it defaults to serving files from the etc/web-static/
directory.
See the PodHandler documentation for examples on how to serve up static pod files, including Fantom generated Javascript.
(Note that, as of BedSheet 1.4.10, FileHandler
and PodHandler
are actually processed by Asset Middleware and not Routes.)
Response Objects are returned from Route Handlers. It is then the job of Response Processors to process these objects, converting them into data to be sent to the client. Response Processors may themselves return Response Objects, which will be handled by another Response Processor.
You can define Response Processors and process Response Objects yourself; but by default, BedSheet handles the following:
Void
/null
/false
: Processing should fall through to the next Route match.true
: No further processing is required.- Asset : The asset is piped to the client.
- ClientAsset : Caching and identity headers are set and the asset piped to the client.
- Err : An appropriate response object is selected from contributed Err responses. (See Error Processing.)
- Field : The field value is returned for further processing. (*)
- File : The file is piped to the client.
- Func : The function is called, using IoC to inject the parameters. The return value is treated as a new reposonse object for further processing.
- HttpStatus : An appropriate response object is selected from contributed HTTP status responses. (See HTTP Status Processing.)
- InStream : The
InStream
is piped to the client. TheInStream
is guaranteed to be closed. - MethodCall : The method is called and the return value used for further processing. (*)
- HttpRedirect : Sends a 3xx redirect response to the client.
- Text : The text (be it plain, json, xml, etc...) is sent to the client with a corresponding
Content-Type
.
Because of the nature of response object processing it is possible, nay normal, to chain multiple response objects together. Example:
- If a Route returns or throws an
Err
, ErrProcessor
looks up its responses and returns aFunc
,FuncProcessor
calls a handler method which returns aText
,TextProcessor
serves content to the client and returnstrue
.
Note that response object processing is extensible, just contribute your own Response Processor.
(*) If the slot is not static, then if the parent class:
- is a service then it is retrieved from IoC,
- is
const
then a single instance is created, used, and cached for future use, - is not
const
then an instance is created, used, and discarded.
Templating, or formatting text (HTML or otherwise) is left for other 3rd party libraries and is not a conern of BedSheet. That said, there a couple templating libraries out there and integrating them into BedSheet is relatively simple. For instance, Alien-Factory provides the following libraries:
- efan for basic templating,
- Slim for concise HTML templating, and
- Pillow for integrating efanXtra components (may be used with Slim!)
Taking Slim as an example, simply inject the Slim service into your Route Handler and use it to return a Text
response object:
using afIoc::Inject
using afBedSheet::Text
using afSlim::Slim
class IndexPage {
@Inject Slim? slim
Text render() {
html := slim.renderFromFile(`xmas.html.slim`.toFile)
return Text.fromHtml(html)
}
}
When a HTTP request is received, it is passed through a pipeline of BedSheet Middleware; this is a similar to Java Servlet Filters. If the request reaches the end of the pipeline without being processed, a 404 is returned.
Middleware bundled with BedSheet include:
RequestLoggers
: For logging HTTP request / responses.Routes
: Performs the standard request routing
You can define your own middleware to address cross cutting concerns such as authentication and authorisation. See the FantomFactory article Basic HTTP Authentication With BedSheet for working examples.
When BedSheet catches an Err it scans through a list of contributed response objects to find one that can handle the Err. If no matching response object is found then the default err response object is used. This default response object displays BedSheet's extremely verbose Error 500 page. It displays (a shed load of) debugging information and is highly customisable:
The BedSheet Err page is great for development, but not so great for production - stack traces tend to scare Joe Public! So note that in a production environment (see IocEnv) a simple HTTP status page is displayed instead.
ALIEN-AID: BedSheet defaults to production mode, so to see the verbose error page you must switch to development mode.
The easiest way to do this is to set an environment variable called ENV
with the value development
. See IocEnv details.
To handle a specific Err, contribute a response object to ErrResponses
:
@Contribute { serviceType=ErrResponses# }
Void contributeErrResponses(Configuration config) {
config[ArgErr#] = MethodCall(MyErrHandler#process).toImmutableFunc
}
Note that in the above example, ArgErr
and all subclasses of ArgErr
will be processed by MyErrHandler.process()
. A contribution for just Err
will act as a capture all and be used should a more precise match not be found.
You can also replace the default err response object:
@Contribute { serviceType=ApplicationDefaults# }
Void contributeApplicationDefaults(Configuration config) {
config[BedSheetConfigIds.defaultErrResponse] = Text.fromHtml("<html><b>Oops!</b></html>")
}
When processing an Err, note that the thrown Err
is stored in HttpRequest.stash
. It may be retrieved by handlers with the following:
err := (Err) httpRequest.stash["afBedSheet.err"]
HttpStatus
objects are handled by a ResponseProcessor that selects a contributed response object that corresponds to the HTTP status code. If no specific response object is found then the default http status response object is used. This default response object displays BedSheet's HTTP Status Code page. This is what you see when you receive a 404 Not Found
error.
To set your own 404 Not Found
page contribute a response object to the HttpStatusResponses
service with the status code 404
:
@Contribute { serviceType=HttpStatusResponses# }
Void contribute404Response(Configuration config) {
config[404] = MethodCall(Error404Page#process).toImmutableFunc
}
In the above example, all 404 status codes will be processed by Error404Page.process()
.
To replace all status code responses, replace the default HTTP status response object:
@Contribute { serviceType=ApplicationDefaults# }
Void contributeApplicationDefaults(Configuration config) {
config[BedSheetConfigIds.defaultHttpStatusResponse] = Text.fromHtml("<html>Error</html>")
}
HttpStatus
objects are stored in the HttpRequest.stash
map and may be retrieved by handlers with the following:
httpStatus := (HttpStatus) httpRequest.stash["afBedSheet.httpStatus"]
BedSheet uses IoC Config to give injectable @Config
values. @Config
values are essentially a map of Str to immutable / constant values that may be set and overriden at application start up. (Consider config values to be immutable once the app has started).
BedSheet sets the initial config values by contributing to the FactoryDefaults
service. An application may then override these values by contributing to the ApplicationDefaults
service.
@Contribute { serviceType=ApplicationDefaults# }
Void contributeApplicationDefaults(Configuration conf) {
...
conf["afBedSheet.errPrinter.noOfStackFrames"] = 100
...
}
All BedSheet config keys are listed in BedSheetConfigIds meaning the above can be more safely rewriten as:
conf[BedSheetConfigIds.noOfStackFrames] = 100
Use the @Config
facet to inject config values:
@Config { id="afBedSheet.errPrinter.noOfStackFrames" }
Int noOfStackFrames
The config mechanism is not just for BedSheet, you can use it too when creating 3rd Party libraries! Contributing initial values to FactoryDefaults
gives users of your library an easy way to override your values.
BedSheet can be used to create RESTful applications. The general approach is to use Routes
to define the URLs and HTTP methods that your app responds to.
For example, for a POST
method:
class RestAppModule {
@Contribute { serviceType=Routes# }
Void contributeRoutes(Configuration conf) {
conf.add(Route(`/restAPI/*`, RestService#post, "POST"))
}
}
The routes then delegate to methods on a RouteHandler
service:
using afIoc
using afBedSheet
class RestService {
@Inject HttpRequest httpRequest
@Inject HttpResponse httpResponse
new make(|This| in) { in(this) }
Text post(Int id) {
// use the request body to get submitted data as...
// a [Str:Str] form map or
form := httpRequest.body.form
// as JSON objects
json := httpRequest.body.jsonMap
// return a different status code, e.g. 201 - Created
httpResponse.statusCode = 201
// return plain text or JSON objects to the client
return Text.fromPlainText("OK")
}
}
File uploading can be pretty horrendous in other languages, but here in Fantom land it's pretty easy.
First create your HTML, here's a form snippet:
<form action="/uploadFile" method="POST" enctype="multipart/form-data">
<input name="theFile" type="file" />
<input type="submit" value="Upload File" />
</form>
A Route
should then service the /uploadFile
URL:
class RestAppModule {
@Contribute { serviceType=Routes# }
Void contributeRoutes(Configuration conf) {
conf.add(Route(`/uploadFile`, UploadService#uploadFile, "POST"))
}
}
The UploadService
uses HttpRequest.parseMultiPartForm()
to gain access to the uploaded data and save it as a file:
using afIoc
using afBedSheet
class UploadService {
@Inject HttpRequest? httpRequest
Text uploadFile() {
httpRequest.parseMultiPartForm |Str inputName, InStream in, Str:Str headers| {
// this closure is called for each input in the form
if (inputName == "theFile") {
quoted := headers["Content-Disposition"].split(';').find { it.startsWith("filename") }.split('=')[1]
filename := WebUtil.fromQuotedStr(quoted)
// save file to temp dir
file := Env.cur.tempDir.createFile(filename)
in.pipe(file.out)
file.out.close
}
}
return Text.fromPlain("OK")
}
}
BedSheet has a hook for logging HTTP requests. Just implement RequestLogger and contribute it to the RequestLoggers
service. This service ensures the loggers are able to log what gets sent to the browser, without interruption from the error handling framework.
Example, this simple logger generates standard HTTP request log files in the W3C Extended Log File Format.
using webmod
const class W3CLogger : RequestLogger {
private const LogMod logMod
new make() {
logMod = LogMod {
it.dir = File.os("C:\\temp\\logs\\") // note the trailing slash!
it.filename = "afBedSheet-{YYYY-MM}.log"
it.fields = "date time c-ip cs(X-Real-IP) cs-method cs-uri-stem cs-uri-query sc-status time-taken cs(User-Agent) cs(Referer) cs(Cookie)"
}
logMod.onStart
}
override Void logOutgoing() {
logMod.onService
}
}
To enable, add the W3CLogger
to the RequestLoggers
service
@Contribute { serviceType=RequestLoggers# }
Void contributeRequestLoggers(Configuration config) {
config.add(MyRequestLogger())
}
The log files will then look something like the following, see webmod::LogMod for more details.
2013-02-22 13:13:13 127.0.0.1 - GET /doc - 200 222 "Mozilla/5.0" "http://localhost/index"
BedSheet ships with a basic default logger that times each request. To enable, turn on BedSheet debug logging. You can do this in code with:
Log.get("afBedSheet").level = LogLevel.debug
Or you can enable it for the environment by adding the following to %FAN_HOME%\etc\sys\log.props
afBedSheet = debug
Then you should see output like this in your console:
[debug] [afBedSheet] GET /about --------------------------------------------------> 200 (in 21ms)
[debug] [afBedSheet] GET /coldFeet/nx6lXQ==/css/website.min.css ------------------> 200 (in 6ms)
[debug] [afBedSheet] GET /pods ---------------------------------------------------> 200 (in 52ms)
[debug] [afBedSheet] GET /pods/whoops --------------------------------------------> 404 (in 28ms)
BedSheet compresses HTTP responses with gzip where it can for HTTP optimisation. Gzipping in BedSheet is highly configurable.
Gzip may be disabled for the entire web app by setting the following config property:
@Contribute { serviceType=ApplicationDefaults# }
Void contributeApplicationDefaults(Configuration config) {
config[BedSheetConfigIds.gzipDisabled] = true
}
Or Gzip can be disabled on a per request / response basis by calling:
HttpResponse.disableGzip()
Text files gzip very well and yield high compression rates, but not everything should be gzipped. For example, JPG images are already compressed when gzip'ed often end up larger than the original! For this reason only Mime Types contributed to the GzipCompressible
service will be gzipped.
Most standard compressible types are already contributed to GzipCompressible
including html, css, javascript, json, xml and other text responses. You may contribute your own with:
@Contribute { serviceType=GzipCompressible# }
Void configureGzipCompressible(Configuration config) {
config[MimeType("text/funky")] = true
}
Guaranteed that someone, somewhere is still using Internet Explorer 3.0 - or some other client that can't handle gzipped content from the server. As such, and as per RFC 2616 HTTP1.1 Sec14.3, the response is only gzipped if the appropriate HTTP request header was set.
Gzip is great when compressing large files, but if you've only got a few bytes to squash... then the compressed version is going to be bigger than the original - which kinda defeats the point compression! For that reason the response data must reach a minimum size / threshold before it gets gzipped. See gzipThreshold for more details.
If a Content-Length
header was not supplied then BedSheet attempts to calculate it by buffering HttpResponse.out
. When the response stream is closed, it writes the Content-Length
and pipes the buffer to the real HTTP response. This is part of HTTP optimisation.
Response buffering may be disabled on a per request / response basis by calling:
HttpResponse.disableBuffering()
A threshold can be set, whereby if the buffer size exeeds that value, all content is streamed directly to the client. See responseBufferThreshold for more details.
Never (manually) restart your app again!
Use the -proxy
option when starting BedSheet to create a development Proxy and your app will auto re-start whenever a pod is updated:
C:\> fan afBedSheet -port <port> -proxy <appModule>
The proxy sits on (port)
and starts the real app on (port+1)
, forwarding all requests to it.
Each time the web browser makes a request, it connects to the proxy which forwards it to the real web app.
. |---> Web App (port+1)
Proxy (port) <-->|
|<--- Web Browser
On each request, the proxy scans the pod files in the Fantom environment, and should any of them be updated, it restarts the web application.
. |<--> RESTART
Proxy (port) <-->|
|<--> Web Browser
Note that the proxy is intelligent enough to only scan those pods used by the web application. If need be, use the -watchAllPods option to watch all pods.
A problem other web frameworks (cough draft) suffer from is that, when the proxy dies, your real web app is left hanging around; requiring you to manually kill it. Which can be both confusing and annoying.
. |<--> Web App (port+1)
??? |
|<--> Web Browser
BedSheet applications go a step further and, should it be started in proxy mode, it pings the proxy every second to stay alive. Should the proxy not respond, the web app kills itself.
See proxyPingInterval for more details.
To some, BedSheet may look like a behemoth web framework, but it is in fact just a standard Fantom WebMod. This means it can be plugged into a Wisp application along side other all the other standard webmods. Just create an instance of BedSheetWebMod and pass it to Wisp like any other.
For example, the following Wisp application places BedSheet under the path poo/
.
using concurrent
using wisp
using webmod
using afIoc
using afBedSheet
class Example {
Void main() {
bob := BedSheetBuilder(AppModule#.qname)
mod := RouteMod { it.routes = [
"poo" : BedSheetWebMod(bob.build)
]}
WispService { it.port=8069; it.root=mod }.install.start
Actor.sleep(Duration.maxVal)
}
}
** A tiny BedSheet app that returns 'Hello Mum!' for every request.
const class TinyBedAppModule {
@Contribute { serviceType=Routes# }
Void contributeRoutes(Configuration conf) {
conf.add(Route(`/***`, Text.fromPlain("Hello Mum!")))
}
}
When run, a request to http://localhost:8069/
will return a Wisp 404 and any request to http://localhost:8069/poo/*
will invoke BedSheet and return Hello Mum!
.
When running BedSheet under a non-root path, be sure to transform all link hrefs with BedSheetServer.toClientUrl() to ensure the extra path info is added. Similarly, ensure asset URLs are retrieved from the FileHandler service.
Note that mulitple BedSheet instances may be run side by side in the same Wisp application.
BedSheet can also be seemlessly run as SkySpark Web Extension
Following is a SkySpark Web Ext that delegates all web requests to BedSheet.
using skyarcd::Ext
using skyarcd::ExtMeta
using concurrent::AtomicRef
using afIoc
using afBedSheet::MiddlewarePipeline
using web::Weblet
@ExtMeta { name = "myExtensionName" }
const class BedSheetExt : Ext, Weblet {
private const AtomicRef registryRef := AtomicRef(null)
private Registry registry {
get { registryRef.val }
set { registryRef.val = it }
}
private const AtomicRef pipelineRef := AtomicRef(null)
private MiddlewarePipeline pipeline {
get { pipelineRef.val }
set { pipelineRef.val = it }
}
override Void onStart() {
this.registry = RegistryBuilder().addModulesFromPod("afBedSheet").addModule(AppModule#).build
this.pipeline = registry.activeScope.serviceById(MiddlewarePipeline#.qname)
}
override Void onService() {
registry.activeScope.createChild("httpRequest") {
// this is the actual call to BedSheet!
pipeline.service
}
}
override Void onStop() {
registry.shutdown
}
}
onStart()
creates the IoC registry based on your AppModule
and caches BedSheet's MiddlewarePipeline
service. A new IoC web request
scope is created on every web request and the BedSheet pipeline is used to service it.
onStop()
then just shuts down the IoC registry, and hence BedSheet also.
Note that SkySpark will need the BedSheet pod, and all its dependencies, in its /lib/fan/
dir (or some other environment lib dir). How you maintain and distribute these with your SkySpark application is then up to you.
In a hurry to go live? Use Heroku!
The heroku-fantom-buildpack makes it ridiculously to deploy your web app to a live server. Just check in your code and Heroku will build your web app from source and deploy it to a live environment!
See the Fantom Buildpack for Heroku for more details.
In a hurry to go live? Use OpenShift! RedHat's OpenShift Origin is a cloud PaaS with free plans. Just check in your code and OpenShift will build your web app from source and deploy it to a live environment!
See Alien-Factory's Fantom Quickstart for OpenShift template for details on how to deploy your BedSheet application to OpenShift.
All route handlers and processors are built by IoC so feel free to @Inject
DAOs and other services.
BedSheet itself is built with IoC so look at the BedSheet Source for IoC examples.
Even if your route handlers aren't services, if they're const
classes, they're cached by BedSheet and reused on every request.