Transcript Component Step by Step
Here we describe how to build the Transcript component already specified. See Transcript Component Specification
1 Create the Implementation class TranscriptImpl
1.1 Create TranscriptImpl
For each client function interface, we should have an instance variable. Here, there is no client interface.
Object subclass: #TranscriptImpl
instanceVariableNames: ''
classVariableNames: ''
poolDictionaries: ''
category: 'FracTalkTutorial-Chat'
1.2 Define TranscriptImpl methods
For each operation available in server functional interfaces, we should have a method with the same selector
TranscriptImpl>>cr
"print a carriage-return into a Transcript"
Transcript cr
TranscriptImpl>>show: aString
"print aString into a Transcript"
Transcript show: aString
2 Create the maker class TranscriptMaker
2.1 Define the maker class
The TranscriptMaker, as every maker, must inherit from AbstractComponentMaker.
AbstractComponentMaker subclass: #TranscriptMaker
instanceVariableNames: ''
classVariableNames: ''
poolDictionaries: ''
category: 'FracTalkTutorial-Chat'
2.2 Define the behavior
There is 3 essential methods that must be redefined for each new component maker:
- fcContentDescription: set the content description to use, i.e. the object that implement the services, also named poso.
- fcControllerDescription: set the Template Controller to use (here we have a primitive component so it will be TemplateControllerDescription primitive)
- functionalComponentType: it creates the functional component type by creating all the client and server interfaces gathered into a Set.
2.3 Define the interfaces
Each interface has a signature that tells what operations will be provided (in case of a server interface) or asked for (in case of a client interface). Here we have only one server interface:
TranscriptMaker>>createShowFunctionalType
| server |
server := typeFactory
createFcItfType: #show
signature: ((FcSignature newNamed: #message)
addSelector: #show:;
addSelector: #cr;
yourself)
client: false
optional: false
collection: false.
^server
3 Use the Transcript Component
3.1 Create a Transcript Component
transcriptCmp := self new newComponent.
(transcriptCmp getFcInterface: #'lifecycle-controller') startFc.
3.2 Retreive the Functional Server Interface 'show'
transcriptItf := transcriptCmp getFcInterface: #show.
3.3 Send Messages to the Interface 'show'
transcriptItf show: 'Coucou'.
3.4 So one can write the following class method:
TranscriptMaker class>>transcriptExample
"TranscriptMaker transcriptExample"
| transcriptCmp transcriptItf |
transcriptCmp := self new newComponent.
(transcriptCmp getFcInterface: #'lifecycle-controller') startFc.
transcriptItf := transcriptCmp getFcInterface: #show.
transcriptItf show: 'Coucou'.
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