Deriving Property Values
Property settings for an element can be specified in several ways:
• The property value is set depending on the element's context (where it is located in the document).
• Properties can be set explicitly (applied directly to the element itself). Explicit properties cannot be affected by any other source.
• Properties can be applied via a property set, which is a named collection of property values that can be applied to many different elements.
• A property value can be inherited from an ancestor of the current element, if it’s not set for the current element. For example, a para element in a listitem may be formatted in a blue font because the orderedlist element's font value was set to blue.
• An element can be set to derive its value from another source (see below).
When you publish your document with a stylesheet, the publishing process takes into account all of the sources of property values that could affect the format of each element, and derives the final format for the element according to the relative precedence of the source.
Property values can be derived from the following sources:
• Property sets - Contexts, conditions, and property sets can obtain property values from property sets. See
Working with Property Sets for further information.
• Conditions - Contexts can obtain property values from conditions. See
Working with Conditions for further information.
• Base properties - You can choose to set properties for specific types of output (uses) by selecting a use from the Outputs to edit field. If you have not applied output specific values for a context or condition, the values set for Base (all uses) will be used.
• Ancestor contexts - Values not specified by the context of an element can be obtained from the context of parent or ancestor elements.
• Arbortext Styler defaults - Arbortext Styler applies default values when property values are not set anywhere else in the process.
Derivation Chain
Derivation often involves a chain of sources, referred to as the derivation chain. Following are some examples of derivation chains:
• A context derives from a condition that derives from a property set.
• A proper value is derived from a property set applied to a condition of the context.
• A context has the Arbortext Styler default setting, derived from the parent context of its parent context.
• Base properties values derived from a property set that is set to derive from an original property set are applied to an element whose parent context derives its properties from its parent context, where the grandparent context derives its properties from a condition that has the original property set assigned.
The Arbortext Styler property categories use tool tips, colored labels, and a variety of shortcut menus to assist you in determining this chain of property sources.
Deriving Properties from Ancestors
Most element's properties will be affected by, or inherited from, their ancestors. Therefore, it is not necessary to explicitly set all properties for each element's contexts. Arbortext Styler can derive property values for a context from the context of its parent (or another ancestor) element in the document being published. Some properties can derive values from ancestors, while others cannot. When Arbortext Styler has derived a context's properties, properties that have not been set can derive their values from ancestors. If a context cannot derive its value from an ancestor, it derives its value from a Arbortext Styler default.
For example, you may want to specify several values, such as font and line spacing, for the context of the document's root element. These values will be inherited by most of the document's child elements, making it unnecessary to set them all explicitly.
Arbortext Styler can derive the following properties from an element's ancestors:
• All properties in the Text category.
• Line spacing properties in the Spacing category.
• Word breaking and Language properties in the Breaks category, and the widow and orphan controls in the Keeps category.
Properties that Cannot be Derived from Ancestors
Properties that cannot be derived from ancestors are listed in the following tables, along with their default values.
Spacing properties that cannot be derived from ancestors
|
Property
|
Default value
|
|
Spacing before
|
0pt
|
|
Spacing after
|
0pt
|
|
Space before Precedence
|
none
|
|
Space before Minimum
|
<Derive>
|
|
Space before Maximum
|
<Derive>
|
|
Keep space before at top of column or page
|
Not selected
|
|
Space after Precedence
|
none
|
|
Spacing after Minimum
|
<Derive>
|
|
Space after Maximum
|
<Derive>
|
Breaks properties that cannot be derived from ancestors
|
Property
|
Default value
|
|
Structure type
|
Inline
|
|
Number of columns
|
No change
|
|
Start new
|
Blank
|
|
Landscape page body for duration of element
|
Not selected
|
|
Page set
|
No change
|
|
Page number
|
Continue
|
Gentext properties that cannot be derived from ancestors
|
Property
|
Default value
|
|
Before-text
|
Blank
|
|
After-text
|
Blank
|
|
Marker
|
None
|
Deriving Property Sets from Ancestors
Sometimes several contexts need to use the same property settings, but Arbortext Styler cannot derive the property values from ancestors. For example, titles in a document often share font properties that are different from the font properties of their parent elements. You can use property sets to modularize property settings in such situations. You might create a Title Font property set that sets values for the Font, Bold, and Color properties in the Text category, and then several different title contexts can reference this property set.
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|
To make them easier to use, property sets should only affect a few closely related properties. For example, the Title Font property set should not set spacing or alignment properties.
|
Deriving Properties from Base Properties
You can use base properties (Base (All Uses) in the Properties to Edit list) to set common properties for all of the available types of output (uses).
For example, you may want titles for all uses to be bold and Arial, but you want title color and point size to be black and 18pt respectively for Print/PDF and blue and 24pt for all other uses. To specify these settings:
1. Select the title in chapter element (or other title in context) in the Elements list.
2. Choose Base (All Uses) from the Outputs to edit list.
3. In the Text category, set Font family to Arial, Bold to Yes, Text color to blue, and Font size to 24pt. The labels on each of these fields change to blue and bold when you make these explicit settings.
4. Choose Print/PDF from the Outputs to edit list.
5. In the Text category, select black as the Text color and 18pt as the Font size. Note that Font family is set to Arial and Bold is set to Yes because these properties are derived from Base (All Uses) (if you place your cursor over the Font family or Bold fields, the tool tip indicates that the property is Derived from Base (All Uses)).
Derivation Exceptions
• The Property Sets category displays the property sets configured for the stylesheet (Available property sets), and the property sets referenced by the current object (Used property sets). However, when you resolve a context with a property set applied, the derived values do not display on the Edit Property Set dialog box.
• Generated text applied to a specific output (using the Properties to Edit list) sets all of the generated text for that context or condition explicitly. For example, if you add generated text after the para in listitem context for Print/PDF output, Arbortext Styler automatically sets the Repeating titles and Add Before generated text options explicitly. If you choose the Derive option from any shortcut menu on the Generated text category, all of the generated text settings will be set to Derive.
• Generated text applied to multiple conditions on an element cannot be combined. If a specific element matches more than one condition, the generated text associated with the last condition in the Element list will be applied. For example, if one condition sets generated text before the element and another condition sets generated text after the element, then if both conditions apply, only the generated text setting from the last condition applies.
