29. label

29. label
	Chapter 5. Content objects

label(key, value, ..., key, value)

Inserts in generated content the value of specified attribute or XPath expression.

Difference with standard construct attr() and with extension xpath():

	Difference with standard construct attr() and with extension xpath():
xpath() and attr() are evaluated once and this happens when the view of the element is built. This means that in some cases, manually refreshing the view of the element after a change in the document will be needed (use Select → Redraw (Ctrl+L)). Unlike xpath() and attr(), label() is automatically updated when the document is modified. For efficiency reasons, the update of label(xpath, `XPath_expression`) is delayed until the editing context changes.

xpath() and attr() are evaluated once and this happens when the view of the element is built. This means that in some cases, manually refreshing the view of the element after a change in the document will be needed (use Select → Redraw (Ctrl+L)).

Unlike xpath() and attr(), label() is automatically updated when the document is modified.

For efficiency reasons, the update of label(xpath, XPath_expression) is delayed until the editing context changes.

Key	Value	Default	Description
async	Boolean: yes\|no, 1\|0, "true"\|"false", "on"\|"off"	no	Evaluate XPath expression in a worker thread. This option is supported only when xpath has been specified. It may be ignored depending on the value of user preference `asyncLabelLoading` in XMLmind XML Editor - Online Help.
attribute	Qualified name of an attribute of the element which is the target of the rule	No default. One of attribute or xpath must be specified.	Display the value of this attribute as styled text.
dimmed	Boolean: yes\|no, 1\|0, "true"\|"false", "on"\|"off"	no	Render the generated label using a dimmed variant of foreground color.
word-wrap	Boolean: yes\|no, 1\|0, "true"\|"false", "on"\|"off"	no	If needed too, wrap the words contained in the generated label. This option is supported only when xpath has been specified. It is ignored when attribute has been specified.
xpath	Literal string specifying an XPath expression using the target of the rule as its context node	No default. One of attribute or xpath must be specified.	Display the value of this XPath expression as styled text.

Key, value, ..., key, value may also specify style parameters.

XHTML examples:

p.msg:before {
    content: label(attribute, title,
                   text-decoration, underline);
    display: marker;
}

a.showtarget {
    content: icon(pop-right)
             label(xpath, "//a[@name = substring-after(current()/@href, '#')]",
                   text-decoration, underline);
}

caption.formal:before {
    content: "Table " 
             label(xpath, "1 + count(../preceding::table[caption])") 
             ": ";
    display: inline;
}


28. image-viewport		30. list