BedSheetUser Guide

Overview

BedSheet is a Fantom framework for delivering web applications.

Built on top of Ioc and Wisp, BedSheet provides a rich middleware mechanism for the routing and delivery of content over HTTP.

BedSheet is inspired by Java's Tapestry5, Ruby's Sinatra and Fantom's Draft.

Install

Install BedSheet with the Fantom Repository Manager:

C:\> fanr install -r http://repo.status302.com/fanr/ afBedSheet

To use in a Fantom project, add a dependency to its build.fan:

depends = ["sys 1.0", ..., "afBedSheet 1.3+"]

Quick Start

1). Create a text file called Example.fan:

using afIoc
using afBedSheet

class HelloPage {
  Text hello(Str name, Int iq := 666) {
    return Text.fromPlain("Hello! I'm $name and I have an IQ of $iq!")
  }
}

class AppModule {
  @Contribute { serviceType=Routes# }
  static Void contributeRoutes(OrderedConfig conf) {
    conf.add(Route(`/index`, Text.fromPlain("Welcome to BedSheet!")))
    conf.add(Route(`/hello/**`, HelloPage#hello))
  }
}

class Example {
  Int main() {
    afBedSheet::Main().main([AppModule#.qname, "8080"])
  }
}

2). Run Example.fan as a Fantom script from the command line:

C:\> fan Example.fan -env development
...
BedSheet v1.2 started up in 323ms

C:\> curl http://localhost:8080/index
Welcome to BedSheet!

C:\> 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 URI path segments into method arguments, or in our case, to Str name and to an optional Int iq.

Request handlers are typically what we, the application developers, write. They perform logic processing and render responses. Our HelloPage request handler simply returns a plain Text response, which BedSheet sends to the client via an appropriate ResponseProcessor.

Starting BedSheet

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.

To start BedSheet from the command line, you need to tell it where to find the AppModule and which port to run on:

C:\> fan afBedSheet -env development <fully-qualified-app-module-name> <port-number>

For example:

C:\> fan afBedSheet -env development myWebApp::AppModule 8069

TIP: Should your AppModule grow too big, break logical chunks out into their own classes using the @SubModule facet.

<fully-qualified-app-module-name> may be replaced with just <pod-name> as long as your pod's build.fan defines the following meta:

meta = [
    ...
    ...
    "afIoc.module" : "<fully-qualified-app-module-name>"
]

This allows BedSheet to look up your AppModule from the pod. Example:

C:\> fan afBedSheet -env development myWebApp 8069

Note that AppModule is named so out of convention but the class may be called anything you like.

Request Routing

The Routes service maps HTTP request URIs 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# }
    static Void contributeRoutes(OrderedConfig conf) {

        conf.add(Route(`/home`,  Redirect.movedTemporarily(`/index`)))
        conf.add(Route(`/index`, IndexPage#service))
    }
}

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 URI path segments are matched to the method parameters. See Route for more details.

Draft Routes

If you prefer the draft style of routing, that's no problem, you can use Draft Routes in BedSheet!

Add BedSheetDraft and draft as dependencies in your build.fan and you can contribute Draft Route objects to the Routes service.

Routing lesson over.

(...you Aussies may stop giggling now.)

Request Handling

Request Handler is the name given to a method that is called 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 request handler returns a Text object.

Request handlers are usually written by the application developer, but a couple of common use-cases are bundled with BedSheet:

• FileHandler: Maps request URIs to files on file system.
• PodHandler : Maps request URIs to pod file resources.

Response Objects

Response Objects are returned from Request 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 a Response Object, 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.
• File : The file is streamed to the client.
• HttpStatus : Sets the HTTP response status and renders a mini html page. (See HTTP Status Processing.)
• InStream : The InStream is piped to the client. The InStream is guarenteed to be closed.
• MethodCall : The method is called and the return value used for further processing.
• Redirect : 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.

Template Rendering

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:

• Slim for rendering HTML,
• Pillow for integrating afEfanXtra components (may be used with Slim!),
• BedSheetEfan for basic efan (Embedded Fantom) integration, and
• BedSheetMoustache for integrating Mustache templates.

Taking Slim as an example, simply inject the service in your Request Handler and use it to return a Text object:

using afIoc
using afBedSheet
using afSlim

class IndexPage {
    @Inject Slim? slim

    Text render() {
        xhtml := slim.renderFromFile(`xmas.xhtml.slim`.toFile)
        return Text.fromXhtml(xhtml)
    }
}

BedSheet Middleware

When a HTTP request is received, it is passed through a pipeline of BedSheet Middleware; this is a similar to Java Servlet Filters. One piece of middleware is the standard Routes service, and the terminating middleware at the end of the pipeline simply returns a 404. Middleware bundled with BedSheet include:

• Routes : Performs the standard request routing
• RequestLog: Generates request logs in the standard W3C Extended Log File Format.

You can define your own middleware to address cross cutting concerns such as authentication and authorisation. See Middleware for further details.

Error Processing

When BedSheet catches an Err it scans through a list of contributed ErrProcessors to find one that can handle the Err. ErrProcessors take an Err and return a Response Object for further processing (for example, Text). Or it may return true if the error has been completely handled and no further processing is required.

If no matching ErrProcessor is found then BedSheet displays its default Err500 page - which is extremely verbose, displays (a shed load of) debugging information and is highly customisable.

The default 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 set an environment variable called ENV with the value development to ensure you continue to see the BedSheet's verbose Err500 page. See this Fantom-Factory article for more details.

To add a custom error page, contribute an ErrProcessor to ErrProcessors:

@Contribute { serviceType=ErrProcessors# }
static Void contributeErrProcessors(MappedConfig conf) {

  conf[Err#] = conf.autobuild(MyErrHandler#)
}

HTTP Status Processing

HttpStatus responses are handled by HttpStatusProcessors which select a contributed processor dependent on the HTTP status code. If none are found, a default catch all processor sets the HTTP status code and sends a mini html page to the client. This is the default page you see when you receive a 404 Not Found error.

To set your own 404 Not Found page, contribute a HttpStatusProcessor to the HttpStatusProcessors service for the status code 404:

@Contribute { serviceType=HttpStatusProcessors# }
static Void contributeHttpStatusProcessors(MappedConfig conf) {

  conf[404] = conf.autobuild(My404Handler#)
}

Config Injection

BedSheet uses IocConfig to give injectable @Config values. @Config values are essesntially 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 contibuting to the ApplicationDefaults service.

@Contribute { serviceType=ApplicationDefaults# }
static Void contributeApplicationDefaults(MappedConfig 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

To inject config values in your services, use the @Config facet with conjunction with Ioc's @Inject:

@Inject @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.

Request Logging

BedSheet can generate standard HTTP request logs in the W3C Extended Log File Format.

To enable, just configure the directory where the logs should be written and (optionally) set the log filename, or filename pattern for log rotation:

@Contribute { serviceType=ApplicationDefaults# }
static Void contributeApplicationDefaults(MappedConfig conf) {

  conf[BedSheetConfigIds.requestLogDir]             = `/my/log/dir/`
  conf[BedSheetConfigIds.requestLogFilenamePattern] = "bedSheet-{YYYY-MM}.log"
}

Ensure the log dir ends in a trailing /slash/.

The fields writen to the logs may be set by configuring BedSheetConfigIds.requestLogFields, but default to looking like:

2013-02-22 13:13:13 127.0.0.1 - GET /doc - 200 222 "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) etc" "http://localhost/index"

Development Proxy

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 when a pod is updated:

C:\> fan afBedSheet -proxy <mypod> <port>

The proxy sits on <port> and starts your real app on <port>+1, forwarding all requests to it.

Client <--> Proxy (port) <--> Web App (port+1)

A problem other (Fantom) web development proxies suffer from is that, when the proxy dies, your real web app is left hanging around; requiring you to manually kill it.

Client <-->   ????????   <--> Web App (port+1)

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 BedSheetConfigIds.proxyPingInterval for more details.

Gzip

By default, BedSheet compresses HTTP responses with gzip where it can.(1) But it doesn't do this willy nilly, oh no! There are many hurdles to overcome...

Disable All

Gzip, although enabled by default, can be disabled for the entire web app by setting the following config property:

config[BedSheetConfigIds.gzipDisabled] = true

Disable per Response

Gzip can be disabled on a per request / response basis by calling the following:

httpResponse.disableGzip()

Gzip'able Mime Types

Not everything should be gzipped. For example, text files gzip very well and yield high compression rates. JPG images on the other hand, because they're already compressed, don't gzip well and can end up bigger than the original! For this reason you must contribute to the GzipCompressible service to enable gzip for specified Mime Types:

config["text/funky"] = true

(Note: The GzipCompressible contrib type is actually sys::MimeType - Ioc kindly coerces the Str to MimeType for us.)

By default BedSheet will compress plain text, css, html, javascript, xml, json and other text responses.

Gzip only when asked

Guaranteed that someone, somewhere is still using Internet Explorer 3.0 and they can't handle gzipped content. As such, and as per RFC 2616 HTTP1.1 Sec14.3, we only gzip the response if the client actually asked for it!

Min content threshold

Gzip is great when compressing large files, but if you've only got a few bytes to squash... the compressed version is going to be bigger, which kinda defeats the point of using gzip in the first place! For that reason the response data must reach a minimum size / threshold before it gets gzipped.

See GzipOutStream and BedSheetConfigIds.gzipThreshold for more details.

Phew! Made it!

If (and only if!) your request passed all the tests above, will it then be lovingly gzipped and sent to the client.

• (1) http://betterexplained.com/articles/how-to-optimize-your-site-with-gzip-compression/

Buffered Response

By default, BedSheet attempts to set the Content-Length HTTP response header.(2) It does this by buffering HttpResponse.out. When the stream is closed, it writes the Content-Length and pipes the buffer to the real HTTP response.

Response buffering can be disabled on a per HTTP response basis.

A threshold can be set, whereby if the buffer exeeds that value, all content is streamed directly to the client.

See BufferedOutStream and BedSheetConfigIds.responseBufferThreshold for more details.

• (2) http://stackoverflow.com/questions/2419281/content-length-header-versus-chunked-encoding

Tips

All request 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 request handlers aren't services, if they're const classes, they're cached by BedSheet and reused on every request.

Go Live with Heroku

In a hurry to go live? Use Heroku!

Heroku and 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!

To have Heroku run your BedSheet web app you have 2 options:

1) Create a Heroku text file called Procfile at the same level as your build.fan with the following line:

web: fan afBedSheet <fully-qualified-app-module-name> $PORT

substituting <fully-qualified-app-module-name> with, err, your fully qualified app module name! Example, MyPod::AppModule. Type $PORT verbatim, as it is.

2) Create a Main class in your app:

using util

class Main : AbstractMain {

  @Arg { help="The HTTP port to run the app on" }
  private Int port

  override Int run() {
    return afBedSheet::Main().main("<fully-qualified-app-module-name> $port".split)
  }
}

Main classes have the advantage of being easy to run from an IDE or cmd line.

See heroku-fantom-buildpack for more details.

Release Notes

v1.3.4

• New: Added fromClientUri() and fromServerFile() to FileHandler.
• New: 404 Not Found page now has contributable sections, just like the Err page.
• New: Ioc Config values, BedSheet Routes and Fantom Pods are now printed on the standard Err page.
• Chg: Added some handy toStr methods to Route and response objects.
• Chg: Pretty printed the Str maps that get logged on Err.

v1.3.2

• New: Added appName to BedSheetMetaData that returns the proj.name from the application's pod meta.
• Chg: Added matchesMethod() and matchesParams() helper methods to RouteResponseFactory.
• Chg: Made ErrPrinterStr and ErrPrinterHtml public, but @NoDoc, as they're useful for emails et al.
• Chg: Made HttpRequestHeaders and HttpResponsetHeaders const classes, backed by WebReq and WebRes.
• Bug: Ensured HttpRequest.modRel always returns a path absolute uri - see Inconsistent WebReq::modRel()
• Bug: Application could NPE on startup if an AppModule could not be found.

v1.3.0

• New: Added HttpCookies service, removed corresponding cookie methods from HttpRequest and HttpResponse. (Breaking change)
• New: Added stash() to HttpRequest
• New: Added fromXhtml(...) to Text
• New: Added contentLength() and cookie() to HttpRequestHeaders
• New: MethodCallresponseProcessor uses Ioc to call methods so that it may inject any dependencies / services as method arguments.
• New: Added StackFrameFilter to filter out lines in stack traces.
• New: Added host to BedSheetConfigIds, mainly for use by 3rd party libraries.
• Chg: Upgraded to afIoc-1.5.2.
• Chg: Removed BedServer and BedClient, they have been moved to Bounce. (Breaking change)
• Chg: Removed @Config, use @afIocConfig::Config instead. (Breaking change)
• Chg: Renamed HttpPipelineFilter -> Middleware and updated the corresponding services. Hardcoded the default BedSheet filters / middleware to the start of the pipeline. (Breaking change)
• Chg: Renamed HttpRequestLogFilter -> RequestLogMiddleware and updated the @Config values. (Breaking change)
• Chg: @NoDoced some services as they're only referenced by @Contribute methods: ErrProcessors, HttpStatusProcessors, ResponseProcessor, ValueEncoder.
• Chg: QualityValues are nullable from HttpRequestHeaders

v1.2.4

• Chg: Upgraded to afIoc-1.5.0.
• Chg: Upgraded to afIocConfig-1.0.0.

v1.2.2

• New: Added gzip compression for web fonts.
• New: BedSheet connection details printed on startup.
• Chg: FileHandler now lets non-existant files fall through.
• Chg: FileHandler auto adds Route mappings to the Routes service.
• Chg: Added more info to the BedSheet 404 page in dev.
• Chg: Gave more control over the verbose rendering of the standard BedSheet pages.
• Bug: BedServer generated the wrong info for BedSheetMetaData - required when testing Pillow web apps.

v1.2.0

• New: Route objects may take any response result - not just Methods!
• New: BedSheet now has a dependency on IocEnv
• Chg: HttpRequestLogFilter is now in the Http Pipeline by default - it just needs enabling.
• Chg: The detailed BedSheet Err500 page is disabled in production environments.
• Chg: Rejigged how the default ErrProcessor is used, making it easier to plug in your own. (Breaking change.)
• Chg: BedSheetConfigIds renamed from ConfigIds. (Breaking change.)
• Chg: Removed Route Matching - Routes now only take Route objects. (Breaking change.)
• Chg: Removed IeAjaxCacheBustingFilter with no replacement. (Breaking change.)
• Chg: Removed CorsHandler with no replacement. (Breaking change.)
• Chg: Massaged a lot of the documentation.

v1.1.4

• New: The cause of startup Errs are printed before service shutdown - see this topic.
• Chg: Better Err msg if AppModule type not found on startup.
• Chg: Disabled afIoc service list on startup.
• Bug: BedServer would crash if the app required BedSheetMetaData.

v1.1.2

• New: Added Causes section to Err500 page.
• Chg: Faster startup times when using a proxy
• Chg: Better Err handling on app startup
• Bug: Transitive dependencies have been re-instated.
• Bug: The -noTransDeps startup option now propogates through the proxy.

v1.1.0

• New: Added BedSheetMetaData with information on which AppModule afbedSheet was started with.
• Chg: Renamed RouteHandler -> MethodInvoker. (Breaking change.)
• Chg: Injectable services are now documented with (Service).
• Chg: Moved internal proxy options in Main to their own class.
• Chg: Enabled multi-line quotes.
• Bug: afIocConfig was not always added as a transitive dependency. (Thanks to LightDye for reporting.)

v1.0.16

• New: Added Available Values section to Err500 page, from afIoc::NotFoundErr.
• Chg: Broke @Config code out into its own module: afIocConfig.
• Chg: Added a skull logo to the Err500 page.
• Chg: Rejigged the Err500 section layout and tweaked the source code styling.

v1.0.14

• New: SrcCodeErrs from afPlastic / efan are printed in the default Err500 pages.
• New: Added ConfigSource.getCoerced() method.
• New: Added Template Rendering to fandoc.

v1.0.12

• New: Added IoC Operation Trace section to Err500 page.
• New: Added Moustache Compilation Err section to Err500 page.
• Chg: Moved Moustache out into it's own project.
• Chg: Anyone may now contribute sections to the default verbose Err500 page.
• Bug: Module name was not always found correctly on startup.

v1.0.10

• Bug: This documentation page didn't render.

v1.0.8

• Chg: Updated to use afIoc-1.4.x
• Chg: Overhauled Route to match null values. Thanks go to LightDye.
• Chg: Warnings on startup if an AppModule could not be found - see Issue #1. Thanks go to Jorge Ortiz.
• Chg: Better Err handling when a dir is not mapped to FileHandler
• Chg: Transferred VCS ownership to AlienFactory
• Chg: Test code is no longer distributed with the afBedSheet.pod.

v1.0.6

• Chg: HttpResponse.statusCode is now a field.
• Chg: HttpResponse.disableGzip is now a field.
• Chg: HttpResponse.disableBuffering is now a field.

v1.0.4

• New: Added BedServer and BedClient to test BedSheet apps without using a real web server.

v1.0.2

• New: Initial release