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MetaProperty


Revision as of 07:36, 15 October 2013 by JKN (Talk | contribs) (Data Types)

Basics

In UBIK®, a MetaProperty describes a single feature of a certain MetaClass. A MetaProperty will never hold own values, but it serves as a definition for a resulting BaseProperty on a derived ContentClass.

For enhanced reuse, MetaProperties can be organized in a Pool and linked to many MetaClasses, using the Systemrelation MetaProperty

Data Types

A MetaProperty needs to have a data type that determines which kind of data should be stored in it. The following data types are supported by UBIK®:

Undefined

Boolean

A boolean value that can be either True or false

ByteStream

A serialized stream of bytes, non human readable.

Source Code

A compressed text value, typically used to store texts with lots of white spaces and formatting information, such as source code.

Date/Time

Date and time in a combined value, where the actual format is depending on the cultural/regional settings of the machine.

Floating point

Double-precision floating-point format, optionally with unit of measurement that can be configured with the setting Unit item.

File reference

A path to a physical file in DOS/Windows- or UNC notation.

Geo Data

Absolute geographic position combined of Longitude, Latitude and Altitude in WGS84 format.

Guid

A pointer to another object, represented with the GUID of the target object.

Integer

An integer number.

Text

A string value.

XML

Markup text in XML format.

Configuration

A MetaProperty can be configured with various additional options which are described in the following.

String Length

Multilanguage

Reference

Selective List

Unit Item

Format

Value Validation

Needs Validation

Default value

The default value of a MetaProperty defines which value will be delivered by a property if it doesn't have an own value set.

Initial value

The initial value of a MetaProperty defines which value will be set to the property initially when a new instance of it is created. Once the value is changed, the initial value is lost for this instance.

Index Keys

Index Count

Index Type

Bytestream Type

Category

Editing a MetaProperty

Once a MetaProperty is used on a single MetaClass editing of properties is restricted to properties that may not effect data validity. The System uses a Rule to validate the edited properties and creates a RuleViolation whenever a "locked" property is edited. Following properties may not be changed/edited for a "used" MetaProperty:

  • Name
  • PropertyType

Released To LiveMode

A MetaProperty is marked as released to live mode when:

Editing a released MetaProperty is restricted to properties that have no effect on the released table structure. The System uses a Rule to validate the edited properties and creates a RuleViolation whenever a "locked" property is edited. Following properties may not be changed/edited for a released MetaProperty:

  • Name
  • PropertyType
  • StringLen
  • Multilanguage
  • Indexcount
  • Serialize
  • NeedsValidation
  • IndexType

See also