VideotexMapper Object

The VideotexMapper object is used to drive the Carapace Videotex mapping. The map for a particular Videotex service is defined as as set of page definitions. These are loaded into the VideotexMapper object which then performs the mapping.

VideotexMapper Creation

The create function can be used to create a VideotexMapper object eg.

    (create VideotexMapper)

Once created, this object is tailored using its properties and methods.

VideotexMapper Properties

A VideotexMapper object supports the following properties:

property name property type description

newPageEvent Event an event which page triggers can set when a new page is detected -- this event is usually set through use of the method detectNewPage

screen Screen holds a representation of the current Videotex screen

currentPage VideotexMapPage if non-() holds the definition for the currently matched Videotex page

environment HashTable an environment for use by the mapping triggers which persists across different pages

upload HashTable data available to be uploaded to the Videotex service

property name	property type	description
`newPageEvent`	`Event`	an event which page triggers can set when a new page is detected -- this event is usually set through use of the method `detectNewPage`
`screen`	`Screen`	holds a representation of the current Videotex screen
`currentPage`	`VideotexMapPage`	if non-`()` holds the definition for the currently matched Videotex page
`environment`	`HashTable`	an environment for use by the mapping triggers which persists across different pages
`upload`	`HashTable`	data available to be uploaded to the Videotex service

VideotexMapper Methods

A VideotexMapper object supports the following methods:

method name description

loadPages load page definitions from the supplied file

clearPages remove all the currently loaded page definitions

isCursorAt test if the cursor is at the given location

isCursorOnAt test if the cursor is on and located at the given position

detectNewPage mark the arrival a new Videotex page if the cursor is on at the given position

identifyScreen attempt to identify the current Videotex screen from the loaded page definitions

isComplete test if the current page is complete and ready for mapping

scrapeCurrentPage scrape the data from the current Videotex page according to the current page definition

displayFile display the Videotex stored in the supplied file

mapCurrentPage map the current page

currentPageOptions list the options for the current page

setError record an error within the mapper -- this is typically picked up and processed by a different thread

setLog use the supplied log

method name	description
`loadPages`	load page definitions from the supplied file
`clearPages`	remove all the currently loaded page definitions
`isCursorAt`	test if the cursor is at the given location
`isCursorOnAt`	test if the cursor is on and located at the given position
`detectNewPage`	mark the arrival a new Videotex page if the cursor is on at the given position
`identifyScreen`	attempt to identify the current Videotex screen from the loaded page definitions
`isComplete`	test if the current page is complete and ready for mapping
`scrapeCurrentPage`	scrape the data from the current Videotex page according to the current page definition
`displayFile`	display the Videotex stored in the supplied file
`mapCurrentPage`	map the current page
`currentPageOptions`	list the options for the current page
`setError`	record an error within the mapper -- this is typically picked up and processed by a different thread
`setLog`	use the supplied log

`loadPages`

Load page definitions from the supplied file -- the name of the first page is returned.

Arguments:

filename String

Return type: String

`clearPages`

Remove all the currently loaded page definitions.

Arguments: none

Return type: the empty List ()

`isCursorAt`

Test if the cursor is at the given location.

Arguments:

row Integer

column Integer

Return type: the empty List () is returned if the cursor is not at the supplied position.

`isCursorOnAt`

Test if the cursor is on and located at the given position.

Arguments:

row Integer

column Integer

Return type: the empty List () is returned if the test fails.

`detectNewPage`

Mark the arrival a new Videotex page if the cursor is on at the given position. This is usually used within a trigger -- e.g. a hotPatch trigger, so the function allows for the trigger to be re-enabled on the screen.

Arguments:

row Integer

column Integer

triggerName String

Return type: the empty List ()

`identifyScreen`

Attempt to identify the current Videotex screen from the loaded page definitions -- returns the string unknown or the name of a matching page.

Arguments: none

Return type: String

`isComplete`

Test if the current page is complete and ready for mapping.

Arguments: none

Return type: the empty List () if the page is not complete.

`scrapeCurrentPage`

Scrape the data from the current Videotex page according to the current page definition -- this is stored in the "history" part of the environment unless an argument is supplied.

This uses the extractFields part of the page definition.

Arguments:

(optional) record Object

Return type: HashTable

`displayFile`

Display the Videotex stored in the supplied file.

Arguments:

emulator Dispatch

filename String

Return type: the empty List ()

`mapCurrentPage`

Map the current page. The value returned is that returned by the map method setup for the current page.

Arguments: none

Return type: Object

`currentPageOptions`

List the options for the current page as defined by the page's options statement.

Arguments: none

Return type: List of Strings.

`setError`

Record an error within the mapper -- this is typically picked up and processed by a different thread.

Arguments:

err Error

Return type: the empty List ()

Contents Current topic: videotex Related topics: Carapace Hub