|
|
| Line 5: |
Line 5: |
| | ([http://docwiki.embarcadero.com/RADStudio/XE6/en/Overview_of_Attributes Attributes reference], [http://delphi.about.com/od/oopindelphi/a/delphi-attributes-understanding-using-attributes-in-delphi.htm tutorial]) | | ([http://docwiki.embarcadero.com/RADStudio/XE6/en/Overview_of_Attributes Attributes reference], [http://delphi.about.com/od/oopindelphi/a/delphi-attributes-understanding-using-attributes-in-delphi.htm tutorial]) |
| | | | |
| − | This page describes a proposal for property attributes created in 2007 (thus predating the Delphi syntax).
| + | Property attributes are a part of FPC trunk. Please refer to [[Custom_Attributes]] for further information. |
| − | | |
| − | As of 2014, no released version of FPC supports attributes.
| |
| − | | |
| − | According to Sven Barth ([http://free-pascal-general.1045716.n5.nabble.com/Property-attributes-tp5718442p5718444.html Feb 2014]):
| |
| − | | |
| − | <blockquote>
| |
| − | There is a branch which already supports class attributes. Property
| |
| − | attributes (or any other kind of attributes) are not supported yet. Also
| |
| − | they are implemented Delphi compatible (with attributes being in front
| |
| − | of the class instead of after it).
| |
| − | </blockquote>
| |
| − | | |
| − | The rest of this page describes the older, proposed syntax, and not any current or planned implementation.
| |
| − | | |
| − | | |
| − | == Syntax Diagram ==
| |
| − | | |
| − | PropertyDeclaration ::= PROPERTY Identifier [PropertyInterface] [PropertySpecifiers] [Directives]<br>
| |
| − | PropertySpecifiers ::= [ ... ]
| |
| − | [ ... ]
| |
| − | [ATTRIBUTES AttributesArray]<br>
| |
| − | AttributesArray ::= '[' (AttributeDeclaration [, AttributeDeclaration]) ']'<br>
| |
| − | AttributeDeclaration ::= ''''<string>':'<string>''''<br>
| |
| − | | |
| − | == Declaration Examples ==
| |
| − | | |
| − | <syntaxhighlight>
| |
| − | TmenuItem = class(...)
| |
| − | ...
| |
| − | property Detachable: Boolean read FDetachable write SetDetachable attributes
| |
| − | ['widgetsets:qt,gtk,win32', 'implementor:Vasya Pupkin', 'creation-date:01.01.2007'];
| |
| − | ...
| |
| − | end;
| |
| − | </syntaxhighlight>
| |
| − | | |
| − | <syntaxhighlight>
| |
| − | TxxxDatabase = class(...)
| |
| − | ...
| |
| − | property TransactionModel: TTransactionModel read FtransactionModel write
| |
| − | SetTransactionModel attributes ['engines:firebird,oracle,sybase-asa'];
| |
| − | ...
| |
| − | end;
| |
| − | </syntaxhighlight>
| |
| − | | |
| − | == How to store additional info ==
| |
| − | | |
| − | There were two suggestions about the place for the property attributes:
| |
| − | | |
| − | #RTTI. Advantage - easier access from application. Disadvantage - bigger final executable.
| |
| − | #PPU. Advantage - info will not be added to executable. Disadvantage - more complicated way of accessing data.
| |
| − | | |
| − | As a result of the discussion PPU storage has been selected. This happened somewhere in 2008 looking at this article's revision history.
| |
| | | | |
| | [[Category:FPC]] | | [[Category:FPC]] |
| − | [[Category:Proposals]]
| |
