Engine.dcl 3.52 KB
Newer Older
1 2 3 4
definition module iTasks.Engine
/**
* This module provides the iTasks engine.
* This is the primary function that creates the complete
5
* environment in which tasks can be executed.
6 7 8 9
*/

from Data.Maybe      import :: Maybe
from System.FilePath import :: FilePath
10
from System.Time     import :: Timespec
11
from Internet.HTTP   import :: HTTPRequest
12 13 14

import iTasks.WF.Definition

15 16 17 18 19 20 21 22 23 24
/*
* There are two ways tasks can be started:
* Interactively when a user requests it through the web,
* or directly when the application (server) is started,
*/
:: StartableTask
  = WebTask !WebTask
  | StartupTask !StartupTask

:: WebTask =
25
	{ path :: !String
26 27 28 29 30 31 32 33 34 35 36 37
	, task :: !WebTaskWrapper
	}

:: StartupTask =
	{ attributes :: !TaskAttributes 
	, task       :: !TaskWrapper
	}

:: WebTaskWrapper = E.a: WebTaskWrapper (HTTPRequest -> Task a) & iTask a
:: TaskWrapper = E.a: TaskWrapper (Task a) & iTask a

//Utility functions for creating collections of startable tasks
38 39
onRequest :: String (HTTPRequest -> Task a) -> StartableTask | iTask a
onStartup :: TaskAttributes (Task a) -> StartableTask | iTask a
40

41
publish :== onRequest //Backwards compatibility
42 43 44 45 46 47 48 49 50 51 52

class Startable a
where
	toStartable :: !a -> [StartableTask]

instance Startable (Task a) | iTask a //Default as web task
instance Startable (HTTPRequest -> Task a) | iTask a //As web task
instance Startable StartableTask
instance Startable [StartableTask]


53 54 55 56 57 58
:: EngineOptions =
	{ appName 		:: String
	, appPath		:: FilePath // Location of the application's executable
	, appVersion    :: String
	, serverPort	:: Int
    , serverUrl     :: String
59 60
	, keepaliveTime :: Timespec
    , sessionTime   :: Timespec
61
    , persistTasks  :: Bool
Bas Lijnse's avatar
Bas Lijnse committed
62
	, autoLayout    :: Bool
63 64 65 66 67
	, timeout       :: Maybe Int // The timeout
	, webDirPath 	:: FilePath  // Location of public files that are served by the iTask webserver
	, storeDirPath 	:: FilePath  // Location of the application's persistent data files 
	, tempDirPath 	:: FilePath  // Location for temporary files used in tasks
	, saplDirPath   :: FilePath  // Location of the application's sapl files (client-side code)
68 69 70
	}

/**
71
* Executes the task framework with a collection of startable task definitions.
72 73 74 75 76
*
* @param Tasks to start
* @param The world
* @return The world
*/
77 78
doTasks :: a !*World -> *World | Startable a
startEngine :== doTasks //Backwards compatibility
79 80 81 82 83 84 85 86 87 88 89 90 91

/**
* Starts the task engine with options and a list of published task definitions.
*
* @param Tasks to start
* @param An initialization function to set the engine options with:
      @param The command line arguments
      @param The default options
	  @return Maybe the engine options, in case of Nothing, the engine is not started
      @return A message that is printed to the console when the engine is started
* @param The world
* @return The world
*/
92 93 94 95
doTasksWithOptions :: ([String] EngineOptions -> (!Maybe EngineOptions,![String])) a !*World
	-> *World | Startable a

startEngineWithOptions :== doTasksWithOptions
96 97 98 99 100

/**
* The function that takes the 'standard' command line options of an itask engine and
* shows the default help and startup message
*
101
* Essentially: doTasks = doTasksWithOptions defaultEngineCLIOptions 
102 103 104 105 106 107 108 109

* @param The command line arguments
* @param The default options
* @return Maybe the engine options, in case of Nothing, the engine is not started
* @return A message that is printed to the console when the engine is started
*/
defaultEngineCLIOptions :: [String] EngineOptions -> (!Maybe EngineOptions,![String])

110 111 112 113
/**
* Determines the default options for an application
*/
defaultEngineOptions :: !*World -> (!EngineOptions,!*World)