Running headers and footers are to the text that appears in the top and bottom margins of each page to help with navigation through the paginated document. They typically include information such as page numbers, chapter title, and such. The running headers and footers are formatted using tables. Each table is a single row with three cells, for left, center, and right aligned text.
The default content for running headers is as follows:
For double-sided output in a book, the center header is the current section name.
For single-sided output, or double-sided not in a book, the center header is the title of the element that starts the page sequence, which could be article, chapter or appendix title.
Title page headers are blank.
Headers on the first page of a page sequence are blank.
draft.mode parameter is set to
yes, then the left and right headers show the word "Draft" in
the appropriate language.
The default content for footers is as follows:
For double-sided output, the page number appears in the outside corner (right footer on right-hand pages, left footer on left-hand pages).
For single-sided output, the page number appears in the center footer.
Title page footers are blank.
The content for running headers is defined in a stylesheet template named
header.content. Likewise, the footers are defined in a template named
footer.content. You see the default versions in
fo/pagesetup.xsl. To customize the headers and footers, you redefine these templates in your customization layer.
header.content template is called three times for each page-sequence, once each for left, center, and right header cells. It should select and return the appropriate text to fill each cell. The same is true for the
The header and footer content is considered
static-content in FO, which means it is repeated in the same place on each page in a page sequence. However, the text itself can vary to show the current section title or page number. The static content is declared at the beginning of each different page sequence that is started during the processing of the document. Within a page sequence, FO supports variations for where a given page-master appears in the sequence, such as for odd- or even-numbered pages.
Table 12.4. Header/footer content examples
|Inserts the current page number.|
|Inserts the title of the current chapter, appendix, or other component.|
|Inserts the titleabbrev of the current chapter, appendix, or other component, if it is available. Otherwise it inserts the regular title.|
|Inserts the chapter title with chapter number label. Likewise for appendices.|
|Used to retrieve the current section name.|
|Inserts the value of the first |
<xsl:call-template name="datetime.format"> <xsl:with-param ...
|Inserts a date timestamp. Seethe section “Adding a date timestamp”.|
|Inserts the |
|Inserts a graphical image. See the section “Graphic in header or footer” for details.|
footer.content template is called with the element that starts the page sequence as the context node. This means you can select elements to appear in the content using XPaths relative to that element. An example below adds
corpauthor to a header.
footer.content template is also called with several parameters that you can use in your logic for deciding what should appear in each position. There are also global parameters that can be included in the decision making. The parameters each template is called with include the following:
There is a specific
pageclass value for each type of page design that might be needed. For example, an index might be two-column layout while the rest of the book is single column. Each pageclass has a set of FO simple-page-masters defined for it. The following pageclass values are available by default, but this list could be extended by adding custom page masters.
titlepage Division title page, including set, book, part. lot Page with a list of titles, including book table of contents, list of figures, etc. front Front matter pages, including preface, dedication body Main content pages back Back matter pages, including appendix, glossary, etc. index Alphabetical book-style index
Within a pageclass, the sequence of pages can have different page designs. For example, the first page of sequence might omit the running header so it won't detract from the main title. The enumerated sequence values are:
first First page of a page class. odd Odd-numbered pages in the page class. even Even-numbered pages. blank Blank page at end of sequence, to even out page count.
If the output format is single-sided, then odd and even pages should have the same design, and the blank page is not called upon.
The location of text cell within the header or footer. The values are:
left center right
Some pages need to have a title generated for them, such as
Table of Contents or
Index. Since these titles need to appear in the language of the document, they are designated using a
gentext-key, such as
TableofContents. These keys appear in the localization files such as
common/en.xml to identify a particular generated text string.
<l:gentext key="TableofContents" text="Table of Contents"/>
In addition to these passed parameters, you can use these global parameters to select header/footer content.
This parameter indicates whether the formatted document is to be marked as Draft. This condition might be marked in the header or footer. See the section “Draft mode” for a description of how draft mode is turned on.
A customized version of the
header.content template is typically a big
xsl:choose structure where each
xsl:when states its conditions for choosing the text for a particular header or footer cell. It only has to cover the cells that might have content. Here is a complete example.
Example 12.11. Customized header.content template
<xsl:template name="header.content"> <xsl:param name="pageclass" select="''"/> <xsl:param name="sequence" select="''"/> <xsl:param name="position" select="''"/> <xsl:param name="gentext-key" select="''"/> <xsl:variable name="candidate"> <!-- sequence can be odd, even, first, blank --> <!-- position can be left, center, right --> <xsl:choose> <xsl:when test="$sequence = 'odd' and $position = 'left'"> <fo:retrieve-marker retrieve-class-name="section.head.marker" retrieve-position="first-including-carryover" retrieve-boundary="page-sequence"/> </xsl:when> <xsl:when test="$sequence = 'odd' and $position = 'center'"> <xsl:call-template name="draft.text"/> </xsl:when> <xsl:when test="$sequence = 'odd' and $position = 'right'"> <fo:page-number/> </xsl:when> <xsl:when test="$sequence = 'even' and $position = 'left'"> <fo:page-number/> </xsl:when> <xsl:when test="$sequence = 'even' and $position = 'center'"> <xsl:call-template name="draft.text"/> </xsl:when> <xsl:when test="$sequence = 'even' and $position = 'right'"> <xsl:apply-templates select="." mode="titleabbrev.markup"/> </xsl:when> <xsl:when test="$sequence = 'first' and $position = 'left'"> </xsl:when> <xsl:when test="$sequence = 'first' and $position = 'right'"> </xsl:when> <xsl:when test="$sequence = 'first' and $position = 'center'"> <xsl:value-of select="ancestor-or-self::book/bookinfo/corpauthor"/> </xsl:when> <xsl:when test="$sequence = 'blank' and $position = 'left'"> <fo:page-number/> </xsl:when> <xsl:when test="$sequence = 'blank' and $position = 'center'"> <xsl:text>This page intentionally left blank</xsl:text> </xsl:when> <xsl:when test="$sequence = 'blank' and $position = 'right'"> </xsl:when> </xsl:choose> </xsl:variable> <!-- Does runtime parameter turn off blank page headers? --> <xsl:choose> <xsl:when test="$sequence='blank' and $headers.on.blank.pages=0"> <!-- no output --> </xsl:when> <!-- titlepages have no headers --> <xsl:when test="$pageclass = 'titlepage'"> <!-- no output --> </xsl:when> <xsl:otherwise> <xsl:copy-of select="$candidate"/> </xsl:otherwise> </xsl:choose> </xsl:template>
Tentatively put content into a variable, and then decide at end whether to output it, depending on other conditions.
This built-in template returns the appropriately translated “Draft” label, but only if the conditions for printing it have been met. See the section “Draft mode” for a description of how draft mode is turned on.
This applies templates to the current element using
You can include empty clauses in case you want to add something later.
If this page sequence is part of a book that has a
This entry generates the phrase “This page intentionally left blank” for generated blank pages. These occur when a double-sided chapter ends on an odd page, which generates a blank even page after it. This phrase is in English only, however, so adding a gentext template for multiple languages would probably be more flexible. See the
Certain special cases turn off the header entirely. Sometimes the logic is simpler to check for these at the end. In this case, it does not output the candidate text if such conditions are met.
Otherwise the contents of the candidate variable is copied out to be returned to the calling template to fill in that header cell.
As you can see from the example, there is quite a bit of flexibility in what can appear in a given header or footer location. You can use static text, or dynamic content. You can also include graphics.
Keep in mind that the sequence name
odd does not include the sequence
first, even though the first page may be an odd page. If you specify something for odd pages, you may also want to specify it for the first page too, as for example:
<xsl:when test="$double.sided != 0 and ($sequence = 'odd' or $sequence = 'first') and $position='right'">
It is a common feature to put the current section title in the running header or footer. This is possible with XSL-FO, using the
fo:retrieve-marker elements. The stylesheet automatically inserts the
fo:marker elements, and you specify the
fo:retrieve-marker element in your header or footer content.
You can control which levels of sections are included in the running section titles. Often only the first or second levels are important enough to warrant inclusion. The stylesheet parameter
marker.section.level sets the maximum section level to be used.
The default value is 2, so only sections at levels 1 and 2 are
considered for the running titles. Set the parameter to 1 if you only
want top-level sections, or set it to a higher number to include more
levels. When the stylesheet processes your document, it inserts the
following hidden marker for each section that meets the parameter
My section title</fo:marker>
The content of the element is the title to be displayed, if it is selected. The marker name
section.head.marker is the same for all section levels by default. If you want to display both the first and second section levels on the same page, you would need to customize the stylesheet to output different marker names for the different levels.
When the pages are being laid out by the FO processor, each hidden marker is placed on the page within its section block. A section's block starts with the section title and extends as far as the section's content goes. That may be over more than one page. Then when the header or footer includes a
fo:retrieve-marker, the processor looks for markers with the matching name. Which one it selects depends on the attributes on the
fo:retrieve-marker element. This example shows the typical attributes for running section titles:
<fo:retrieve-marker retrieve-class-name="section.head.marker" retrieve-position="first-including-carryover" retrieve-boundary="page-sequence"/>
retrieve-class-name attribute identifies the group of markers to select from. The
retrieve-position="first-including-carryover" attribute picks up the first matching marker on the current page, or from a section carried over from a previous page if there is no marker on the current page. The
retrieve-boundary="page-sequence" attribute sets the boundary for selecting a previous marker as the current page-sequence, as opposed to the whole document. That prevents carryover from the previous chapter.
Your page design may call for putting a graphical image in headers or footers. The overall process is the same as for other header or footer content. You just add the appropriate XSL-FO markup in the right place in your customized
footer.content template, which are described in the section “Changing the header or footer text”.
Here is an example of the XSL-FO markup as it might appear in the template:
... <xsl:when test="$position = 'center'"> <fo:external-graphic content-height="1.2cm"> <xsl:attribute name="src"> <xsl:call-template name="fo-external-image"> <xsl:with-param name="filename" select="$header.image.filename"/> </xsl:call-template> </xsl:attribute> </fo:external-graphic> </xsl:when> ...
fo:external-graphic element is used in XSL-FO to specify a graphical file to include in your output. The
content-height attribute sets the height, to make sure it will fit within the allocated height for the header or footer. See the section “Allocating height for headers and footers” for details on adjusting the height to fit the graphic.
The image filename itself is specified here using a parameter value
$header.image.filename. This is not a DocBook XSL parameter, but one that you could add to your stylesheet. A parameter that is specified at the top of the stylesheet makes it easier to change the filename without searching through code in your customization. But why does it call a template named
fo-external-image instead of just adding a literal
src attribute? Because different XSL-FO processors handle slightly different syntax for the file reference. That template handles generating the right syntax for each processor.
Some page designs cram more information into the headers or footers by stacking it onto multiple lines. For example, you could have the chapter title on the first line and the running section title on the second. There are two approaches to achieving this effect, using multiple blocks or customizing the layout table.
If you just need to stack two pieces of information into one location in the header or footer, then using two blocks is the easiest customization. In the appropriate
xsl:when clause in your customization of the
footer.content template, use two
fo:block elements. The following example uses two stacked blocks:
... <xsl:when test="$sequence = 'odd' and $position = 'left'"> <fo:block> <xsl:apply-templates select="." mode="titleabbrev.markup"/> </fo:block> <fo:block> <fo:retrieve-marker retrieve-class-name="section.head.marker" retrieve-position="first-including-carryover" retrieve-boundary="page-sequence"/> </fo:block> </xsl:when> ...
In this example, the first block would contain the chapter title, and the second block would contain the section title.
If your header or footer design uses stacked information in more than one position, then you may want to use the second method, which is customizing the layout table. Using multiple rows in a layout table ensures that the different information will align vertically.
header.table template in
fo/pagesetup.xsl lays out the table
rows and cells in the page header. Likewise the
footer.table lays out the footer area. You can customize either template to write
a table to display whatever combination of rows and cells and spans you
want, expressed in XSL-FO table elements.
As you will see in the original template, each
fo:table-cell must have a call to the
header.content template, and
it must communicate that cell's location in the table using the
right values are just strings that are matched in
header.content template. You can add your own position values
row1col2, as long as you match it with a selection in your customized
You can change the font family, size, style, and other attributes of the headers or footers by customizing the default attribute-sets. You can put FO properties into the
header.content.properties attribute set to change the running header
style, or into the
footer.content.properties attribute-set to change the running footer
style. For example:
<xsl:attribute-set name="header.content.properties"> <xsl:attribute name="font-family">Helvetica</xsl:attribute> <xsl:attribute name="font-size">9pt</xsl:attribute> </xsl:attribute-set>
The rule lines in the headers and footers can be changed or turned off. If you want to change the style of the rule line, you can customize the following two templates that are found in
<xsl:template name="head.sep.rule"> <xsl:if test="$header.rule != 0"> <xsl:attribute name="border-bottom-width">0.5pt</xsl:attribute> <xsl:attribute name="border-bottom-style">solid</xsl:attribute> <xsl:attribute name="border-bottom-color">black</xsl:attribute> </xsl:if> </xsl:template> <xsl:template name="foot.sep.rule"> <xsl:if test="$footer.rule != 0"> <xsl:attribute name="border-top-width">0.5pt</xsl:attribute> <xsl:attribute name="border-top-style">solid</xsl:attribute> <xsl:attribute name="border-top-color">black</xsl:attribute> </xsl:if> </xsl:template>
If you want to change which page classes have these rule lines, then you will need to customize the template files that create the tables that format the headers or footers. These templates are named
footer.table, and they are located in
The header or footer is laid out using a single row three-cell table for the left, center, and right positions. Text in the left cell is left-aligned, text in the middle cell is centered, and text in the right cell is right-aligned. By default, all three cell positions are assigned the same width. But you may need to adjust the relative widths to fit your pattern of text. A page number requires very little space, while a long chapter title may need more than a third of the page width.
You can use the
footer.column.widths parameters to adjust the relative widths. Each
takes three numbers separated by white space. Each number represents
its proportion of the sum of the three numbers. For example:
<xsl:param name="header.column.widths">1 2 1</xsl:param>
The first number represents the relative width of the left position, the second number the relative width of the middle position, and the third number the relative width of the right position. That is for single-sided output. For double-sided output, a mirrored design is assumed, so the first number represents the inside position, and the third number represents the outside position. So in this example, the middle position is twice as wide as either of the other two positions.
Here are some guidelines for setting these width values:
The numbers don't have to be integers, but there must be three of them, and they must not be negative.
Each column's relative width is taken as its value divided by the sum of the three numbers. So the left position in the above example is 1 divided by 4, or 25% of the available width.
If you use the middle position and want to keep it centered, then the first and third numbers must be equal to each other. Otherwise the middle position won't be centered (which may be ok in your design).
You can set any of the numbers to zero, and the stylesheet will then allocate the space among the remaining numbers. For example, using
1 0 3 means the left postion is 25% and the right position is 75%. Using
0 0 1 means the right position is 100%. Just be sure your
header.content template doesn't attempt to put content into a zero-width position, or you will likely generate errors.
If some content is longer than the allocated width, then the text will try to wrap to a second line within the cell. If the cell height is not tall enough, you may lose part of your text. See the section “Allocating height for headers and footers” to fix that.
If you find the table layout used in headers and footer to be too restrictive, you can always replace the header or footer table with your own XSL-FO layout. You'll need to customize the template named
fo/pagesetup.xsl. You can keep the same template name and template parameters, but you can customize how the information is used within the header or footer space.
If you plan to put more in the headers or footers than just short bits of text, then you need to provide sufficient space. The header text is positioned within the top margin using three parameters, as described in the section “Top and bottom margins”, with similar parameters for the footer text in the bottom margin.
The parameter that sets the height of the header area is
region.before.extent. It gets that name from the XSL-FO standard
(enough said). The default height is 0.4 inches, which is about 29
points. Since the default line-height is 12 points, there is room for
two lines of text. That's helpful when you carry running titles in
the header, because some titles may be long enough to wrap to a
If you increase the header font size and line height by setting attributes in the
header.content.properties attribute-set, you may also need to increase
region.before.extent parameter. Remember that the header area has to fit
within the top margin area, though, so you may also need to increase
those two margin parameters as well, to give it more space and to
adjust its position. If you are changing the footer size, then it is
region.after.extent and the bottom margin parameters that would
If you add a graphic to the header or footer content, be sure its
content-height property fits within the appropriate region extent.
The DocBook XSL print stylesheet provides a pair of named templates,
format.page.number, that give you complete control over the page numbering style in your document. The default numbering style for a book uses lowercase roman numerals (i, ii, iii, etc.) for the front matter, and then restarts with arabic numeral 1 on the first chapter. But you may want a style that numbers consecutively in arabic numerals without restarting, or that starts with page 1 in the table of contents. instead of the title page.
initial.page.number template to change which parts of your document restart the numbering sequence. That template is called at the start of each page-sequence, which is the only place in XSL-FO where you can change the starting page number. The template works through several
xsl:choose statements and returns a single value for the
initial-page-number property that is added to the
fo:page-sequence output element. If the template returns a literal number such as
1, then the calling page sequence will restart page numbering with that number. If the template returns
auto, then the calling page sequence continues the page numbering from the previous page-sequence. If the template returns
auto-odd, then the calling page sequence continues the page numbering but forces the new page-sequence to start on an odd numbered page (the processor will generate a blank page if needed).
Here is the first part of the original template, which resides in
<xsl:template name="initial.page.number"> <xsl:param name="element" select="local-name(.)"/> <xsl:param name="master-reference" select="''"/> <xsl:choose> <!-- double-sided output --> <xsl:when test="$double.sided != 0"> <xsl:choose> <xsl:when test="$element = 'toc'">auto-odd</xsl:when> <xsl:when test="$element = 'book'">1</xsl:when> <xsl:when test="$element = 'part' and not(preceding::chapter) and not(preceding::part)">1</xsl:when> ...
The table of contents (
When the element is a
When the element is a
As you can see, the template provides complete control over when page numbering restarts. You can copy the template to your customization layer and change whatever parts you like.
If you change the page numbering sequence, you may also want to change the page number format used for different page sequences. Customize the
page.number.format template from
fo/pagesetup.xsl to do that. It returns a value, either
1 that is used in the
format property of the
page-sequence element. Here is the original template:
<xsl:template name="page.number.format"> <xsl:param name="element" select="local-name(.)"/> <xsl:param name="master-reference" select="''"/> <xsl:choose> <xsl:when test="$element = 'toc' and self::book">i</xsl:when> <xsl:when test="$element = 'preface'">i</xsl:when> <xsl:when test="$element = 'dedication'">i</xsl:when> <xsl:otherwise>1</xsl:otherwise> </xsl:choose> </xsl:template>
As you can see, the front matter page sequences use the lowercase roman numeral by default, while all other page sequences use arabic numerals.
If you want a consecutive page numbering style, then the customizations of the two page numbering templates are amazingly simple. Just add these two one-line templates to your customization layer. Then all your pages will be numbered consecutively with arabic numerals:
<xsl:template name="initial.page.number">auto-odd</xsl:template> <xsl:template name="page.number.format">1</xsl:template>
These templates always return the same value, regardless of which page-sequence calls them. The first page sequence will start with
1 even when the value is
auto-odd because the default value for the first page sequence is 1.
Some styles call for putting a chapter number prefix on page numbers and restarting the page count in each chapter. So pages in chapter one would be numbered
1-1, 1-2, 1-3, etc., and those in chapter two would be numbered
2-1, 2-1, 2-3, etc. Currently there is no parameter in the stylesheets that turns on this style of page numbering. However, Jeff Beal has kindly made available a stylesheet customization for Page Number Prefixes that you can download from the DocBook Wiki site.
If you use double-sided output, you have the choice of whether to end the document on an even-numbered page. That is, if the last bit of content lands on an odd-numbered page, should a blank even page be generated? If you are primarily interested in preparing a document to hand to a print vendor, then you probably want to end on an even page. But if you are primarily interested in generating a PDF file, you may not want to. That's because many people print their PDF on a single-sided printer, and a blank last page would just be a waste.
<xsl:template name="force.page.count"> <xsl:param name="element" select="local-name(.)"/> <xsl:param name="master-reference" select="''"/> <xsl:choose> <!-- double-sided output --> <xsl:when test="$double.sided != 0">end-on-even</xsl:when> <!-- single-sided output --> <xsl:otherwise>no-force</xsl:otherwise> </xsl:choose> </xsl:template>
The two choices are:
|DocBook XSL: The Complete Guide - 3rd Edition||PDF version available|
Copyright © 2002-2005 Sagehill Enterprises