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Attribute / Link

Syntax

An attribute or link definition is composed of the following elements :

  • name

  • ":" (separator)

  • type (basic attribute type or referenced entity for a link)

  • further information (optional) defined between "{" and "}"

    • annotations (optional)

    • tags (optional)

  • ";" (end of definition)

Syntax :

name : type { annotations and tags } ;

An attribute or link definition can span multiple lines. Example :

name : type { 
            annotations 
            tags } ;

Name

The name can be composed of : letters, numbers and "_" (underscore). Other characters are not allowed. By convention the name usually starts with a lower case character.

Each name must be unique in the entity.

Examples of valid attribute names :

  • age

  • firstName

  • first_name

  • flag12

Examples of invalid attribute names :

  • flag#12 ( "#" not allowed )

  • first-name ( "-" not allowed )

  • $code ( "$" not allowed )

Attribute type

An attribute is a simple and unitary piece of data such as a string, a number, etc. Its type is defined by a "neutral type" independent of any programming language. Each "neutral type" will be converted into the target language type during generation. Telosys offers automatic conversion for most used languages (Java, C#, etc).

Available neutral types :

  • binary (to store a sequence of bytes)

  • boolean (to store "true"/"false" value)

  • byte (8-bit integer, range: -128 to +127)

  • date (to store a date with only year, month and day)

  • decimal (arbitrary precision decimal number, not limited to 32 or 64 bits like float or double)

  • double (double-precision 64-bit IEEE 754 floating point)

  • float (single-precision 32-bit IEEE 754 floating point)

  • int (32-bit integer , range: -2,147,483,648 to +2,147,483,647)

  • long (64-bit integer, range: -9,223,372,036,854,775,808 to +9,223,372,036,854,775,807)

  • short (16-bit integer, range: -32,768 to +32,767)

  • string (standard "string" type)

  • time (to store a time with hour, minute, second, and optionally nanosecond - without time zone)

  • timestamp (to store a date and time - without time zone)

Link type

A link is a reference to another entity. It's a relationship with a cardinality (one to many, many to one, etc). So the type is the referenced entity name. Of course, the referenced entity must exist in the model (at least the entity file). To reference a collection of entities just add "[ ]" after the entity name.

Examples :

  • Driver (to reference a single Driver instance, "0..1" cardinality)

  • Driver[ ] (to reference a collection of Driver instances, "0..N" cardinality)

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