RTTI controls

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Revision as of 11:33, 21 June 2014 by Minesadorada (talk | contribs) (Added 'Testing Components' section)
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Introduction

This page describes the package RunTimeTypeInfoControls in <lazarusdir>/components/rtticontrols/.

RTTI controls extend many LCL controls by the ability to directly connect to published properties of classes. They greatly reduce writing boring code, by automatically loading/saving data between LCL controls and published properties. In fact, you can create fully functional forms without writing any code at all.

In combination with Streaming components you can reduce the amount of code needed for connecting the program Data with the GUI and the Disk/Network to a minimum.

A good explanation on RTTI for delphi that can apply to freepascal too can be found here: http://www.blong.com/Conferences/BorConUK98/DelphiRTTI/CB140.htm

Testing Components

The RTTI controls are very useful when writing/testing a component.

  • Drop the component onto a form
  • Drop an RTTI conrtol onto the form
  • Set the RTTI component's TIObject property to your component
  • Set the RTTI component's TIPropertyname (from the drop-down list) to the property
  • You can now edit the property interactively and see the effects of your changes at runtime (and sometimes designtime; depending on the component)
  • Each RTTI control will try to invoke the appropriate property editor for your chosen property.

So for instance, if the property is a Stringlist type, the RTTI Button would bring up the stringlist editor, the RTTI Memo would display it - all without writing a line of code!

See Also