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GoFiler Legato Script Reference

 

Legato v 1.4j

Application v 5.22b

  

 

Chapter ElevenSGML Functions (continued)

11.3.7 Parameters and Properties

Attributes and properties are generally known as parameters and are colloquially referred to as such. Generally, a script can read, write and delete parameters within the SGML element class.

Parameters are processed either as simple string data or as pvalues (see Section 11.1 Introduction to SGML Support for more information on pvalues).

It is important to understand that the parse and element load process can result in a refined or corrected version of SGML parameters. This is particularly true of CSS properties. A good example would be attempting to read the CSS property ‘margin’. Because margin is a shorthand, the actual properties that would be available to read would be ‘margin-top’, ‘margin-right’, ‘margin-bottom’ and ‘margin-left’ with appropriate values loaded according to CSS rules. The same would be true to an even greater extent with the ‘border’ shorthand. Likewise, when a script sets (writes) parameters it does not concern itself with shorthand. Rather, the primitive values are written and latter automatically combined as shorthand CSS when written.

HTML attributes can also be promoted to CSS if the element class is normalized for CSS. The normalization process depends on the HTML element. For example, the ALIGN attribute is generally promoted to the CSS property ‘text-align’ except when used in the context of a table or image tag. This make ready SGML much easier and more predictable. When attempting to determine the alignment a DIV, one must only get the ‘text-align’ parameter.

When referencing a parameter, the programmer has the luxury of either using token values as defined in the DTD or schema and, optionally for HTML and some XML, use values defined in the SDK. For example, the attribute ‘text-align’ can be reference by string or as CP_TEXT_ALIGN. The later is mildly more efficient which can be considered when processing large amounts of data.

Finally, parameters are generally referenced by their respective token or name value. However, on a low-level, a parameter entry can be examined to gather additional information such as whether the source information was quoted or the physical position of the parameter within a tag.

Low-Level Entries

Element Class Control Functions

Parameter Access Functions