XSL-FO page-master-alternatives 有时会用尽答案

【问题标题】：XSL-FO page-master-alternatives sometimes exhaustedXSL-FO page-master-alternatives 有时会用尽
【发布时间】：2016-04-19 09:15:12
【问题描述】：

我有一些强大的书籍样式表。目前，我无法弄清楚问题可能出在哪里。我的样式表有时有效，有时无效，具体取决于 TOC 的长度，我可以根据我想要包含在其中的级别数动态更改它。

我的样式表是这样工作的（我的意图是）：

Imprints 部分从 Title-Page 开始，到偶数页结束，如果 TOC 的最后一页是奇数，则在后面放一个空白页它：

        <fo:page-sequence-master master-name="Imprints">
            <fo:repeatable-page-master-alternatives>
                <fo:conditional-page-master-reference master-reference="PageMaster.Blank" blank-or-not-blank="blank" page-position="any"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Title-Page" odd-or-even="odd" page-position="first"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.CopyRight-Page" odd-or-even="even" page-position="rest"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.TOC" odd-or-even="odd" page-position="rest"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.TOC" odd-or-even="even" page-position="rest"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.TOC" odd-or-even="odd" page-position="last"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.TOC" odd-or-even="even" page-position="last"/>
            </fo:repeatable-page-master-alternatives>
        </fo:page-sequence-master>

让主体部分，Content-Pages，从 TOC 之后的第一个奇数页（或它之后的空白页）开始，让每一章都从上一章之后的奇数页开始（最后一页或空白）并在偶数页结束。如果最后一页很奇怪，请强制空白页（我想这可能是问题，因为我使用整个部分以及特定章节）：

        <fo:page-sequence-master master-name="Content-Pages">
            <fo:repeatable-page-master-alternatives>
                <fo:conditional-page-master-reference master-reference="PageMaster.Page-Right.First" odd-or-even="odd" page-position="first"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Blank" blank-or-not-blank="blank" page-position="any"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Page-Left" odd-or-even="even" page-position="rest"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Page-Right" odd-or-even="odd" page-position="rest"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Page-Left" odd-or-even="even" page-position="last"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Page-Right" odd-or-even="odd" page-position="last"/>
            </fo:repeatable-page-master-alternatives>
        </fo:page-sequence-master>

我这样称呼它们（我不确定force-page-count="even" 和force-page-count="end-on-even" 之间有什么区别。我检查了一些文档，但我仍然不清楚）：

    <fo:page-sequence master-reference="Imprints" force-page-count="even">
        <fo:flow flow-name="xsl-region-body">
            <fo:block>
                <xsl:apply-templates select="//tei:TEI/tei:teiHeader" mode="draft"/>
            </fo:block>
        </fo:flow>
    </fo:page-sequence>
    <fo:page-sequence master-reference="PageMaster.CopyRight-Page">
        <fo:flow flow-name="xsl-region-body">
            <fo:block xsl:use-attribute-sets="p">
                © Copyright!
            </fo:block>
        </fo:flow>
    </fo:page-sequence>
    <fo:page-sequence master-reference="PageMaster.TOC">
        <fo:flow flow-name="xsl-region-body">
            <fo:block>
                <xsl:apply-templates select="//tei:TEI/tei:text" mode="toc"/>
            </fo:block>
        </fo:flow>
    </fo:page-sequence>
    <xsl:for-each select="//tei:div[@n='1']">
        <fo:page-sequence master-reference="Content-Pages" force-page-count="end-on-even">
            <fo:static-content flow-name="Region-Before-Left">
                <fo:block xsl:use-attribute-sets="running-header-left">
                    <fo:inline xsl:use-attribute-sets="running-header-pageno-left">
                        <fo:page-number/>
                    </fo:inline>
                </fo:block>
            </fo:static-content><!-- Running header right -->
            <fo:static-content flow-name="Region-Before-Right">
                <fo:block xsl:use-attribute-sets="running-header-right">
                    <fo:inline xsl:use-attribute-sets="running-header-pageno-right">
                        <fo:page-number/>
                    </fo:inline>
                </fo:block>
            </fo:static-content>
            <fo:static-content flow-name="xsl-footnote-separator">
                <fo:block>
                    <fo:leader xsl:use-attribute-sets="footnote-separator"/>
                </fo:block>
            </fo:static-content>
            <fo:flow flow-name="xsl-region-body">
                <xsl:apply-templates select="."/>
            </fo:flow>
        </fo:page-sequence>
    </xsl:for-each>

当它失败并抛出Subsequences exhausted in page-sequence-master "Content-Pages", cannot recover. (No context info available) 时，它有助于更改force-page-count 或添加另一个对PageMaster.Page-Right.First 的引用并使其在even 页面上成为可能。有了这些章节，有时会从奇数页开始，但有页码（他们不应该这样做）。真的很混乱。

甚至添加：

<fo:conditional-page-master-reference master-reference="PageMaster.Page-Right.First" odd-or-even="odd" page-position="rest"/>

……没有帮助。

我使用最新的 Saxon HE 和 Apache FOP 1.1。

更新

根据@Tony_Graham 的进展：

        <fo:page-sequence-master master-name="Imprints">
            <fo:repeatable-page-master-alternatives>
                <fo:conditional-page-master-reference master-reference="PageMaster.Title-Page" odd-or-even="odd" page-position="first"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.CopyRight-Page" odd-or-even="even" page-position="rest"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.TOC"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Blank" blank-or-not-blank="blank"/>
            </fo:repeatable-page-master-alternatives>
        </fo:page-sequence-master>
        <fo:page-sequence-master master-name="Content-Pages">
            <fo:repeatable-page-master-alternatives>
                <fo:conditional-page-master-reference master-reference="PageMaster.Page-Right.First" odd-or-even="odd" page-position="first"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Page-Left" odd-or-even="even" page-position="rest"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Page-Right" odd-or-even="odd" page-position="rest"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Page-Left" odd-or-even="even" page-position="last"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Page-Right" odd-or-even="odd" page-position="last"/>
                <fo:conditional-page-master-reference master-reference="PageMaster.Blank" blank-or-not-blank="blank"/>
            </fo:repeatable-page-master-alternatives>

其余的：

<fo:page-sequence master-reference="Imprints" force-page-count="end-on-even">
...

<fo:page-sequence master-reference="PageMaster.CopyRight-Page" initial-page-number="auto-odd">
...

【问题讨论】：

标签： xsl-fo

【解决方案1】：

将force-page-count="end-on-even" 放在fo:page-sequence 之前，每个fo:page-sequence 要在奇数页上开始。或者，在fo:page-sequence 上设置initial-page-number="auto-odd"。见https://www.w3.org/TR/xsl11/#initial-page-number

force-page-count="even" 表示如果页面序列从偶数页开始，它将在奇数页结束以使其成为偶数页，反之亦然，如果它从奇数页开始。 force-page-count="end-on-even" 将在奇数页上结束，无论页面序列是从奇数页还是偶数页开始。（AH Formatter 具有以“双偶数”结尾的扩展名，此外还有更多，并强制整个文档的页数以偶数页结尾，等等。请参阅https://www.antennahouse.com/product/ahf63/ahf-ext.html#axf.force-page-count）但是，很可能initial-page-number会做你需要的。

还有：

您无需使用两个不同的odd-or-even 重复fo:conditional-page-master-reference 来选择相同的页面主控。这与没有odd-or-even 的fo:conditional-page-master-reference 相同，因为默认值为any。见https://www.w3.org/TR/xsl11/#odd-or-even。
您可以删除显式 page-position="any"，因为无论如何这是默认设置。
“印记”有两个 'odd-or-even="even" page-position="rest"'，因此永远不会使用第二个。
为奇数/偶数和余数/尾数选择相同的“PageMaster.TOC”可以减少到仅page-position="any"。

更新

您可以将当前的fo:page-sequence-masters 更改为：

    <fo:page-sequence-master master-name="Imprints">
        <fo:repeatable-page-master-alternatives>
            <fo:conditional-page-master-reference master-reference="PageMaster.Blank" blank-or-not-blank="blank"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.Title-Page" page-position="first"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.CopyRight-Page" odd-or-even="even" page-position="rest"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.TOC"/>
        </fo:repeatable-page-master-alternatives>
    </fo:page-sequence-master>
    <fo:page-sequence-master master-name="Content-Pages">
        <fo:repeatable-page-master-alternatives>
            <fo:conditional-page-master-reference master-reference="PageMaster.Blank" blank-or-not-blank="blank"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.Page-Right.First" page-position="first"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.Page-Left" odd-or-even="even"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.Page-Right" odd-or-even="odd"/>
        </fo:repeatable-page-master-alternatives>

在fo:repeatable-page-master-alternatives 中，“条件从子序列的开头开始按顺序进行测试”，因此您希望将最不可能的替代方案放在首位。（请参阅https://www.w3.org/TR/xsl11/#fo_repeatable-page-master-alternatives）您还希望在最后有一个包罗万象的替代方案，但您已经做到了。

但是，当版权页面和 ToC 都位于引用特定页面母版的单独页面序列中时，我不明白为什么“印记”包括“PageMaster.CopyRight-Page”和“PageMaster.TOC”。你可能想要更多类似的东西：

    <fo:page-sequence-master master-name="Imprints">
        <fo:repeatable-page-master-alternatives>
            <fo:conditional-page-master-reference master-reference="PageMaster.Blank" blank-or-not-blank="blank"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.Title-Page"/>
        </fo:repeatable-page-master-alternatives>
    </fo:page-sequence-master>
    <fo:page-sequence-master master-name="TOC">
        <fo:repeatable-page-master-alternatives>
            <fo:conditional-page-master-reference master-reference="PageMaster.Blank" blank-or-not-blank="blank"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.TOC"/>
        </fo:repeatable-page-master-alternatives>
    </fo:page-sequence-master>
    <fo:page-sequence-master master-name="CopyRight-Page">
        <fo:repeatable-page-master-alternatives>
            <fo:conditional-page-master-reference master-reference="PageMaster.Blank" blank-or-not-blank="blank"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.CopyRight-Page"/>
        </fo:repeatable-page-master-alternatives>
    </fo:page-sequence-master>
    <fo:page-sequence-master master-name="Content-Pages">
        <fo:repeatable-page-master-alternatives>
            <fo:conditional-page-master-reference master-reference="PageMaster.Blank" blank-or-not-blank="blank"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.Page-Right.First" page-position="first"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.Page-Left" odd-or-even="even"/>
            <fo:conditional-page-master-reference master-reference="PageMaster.Page-Right" odd-or-even="odd"/>
        </fo:repeatable-page-master-alternatives>
...
<fo:page-sequence master-reference="Imprints">
...
<fo:page-sequence master-reference="CopyRight-Page" initial-page-number="auto-odd">
...
<fo:page-sequence master-reference="PageMaster.TOC" initial-page-master="auto-odd">
...
<xsl:for-each select="//tei:div[@n='1']">
    <fo:page-sequence master-reference="Content-Pages" initial-page-number="auto-odd">

【讨论】：

坦克很多！但是，我仍然无法让它发挥作用。如果我不指定页面是否应该有特定的page-position，它会起作用。如果是这样，则生成 pdf，但忽略第一页的规则。我将force-page-count="end-on-even" 设置为Imprints 部分，将initial-page-number="auto-odd 添加到Content-Pages，根据您的建议缩短了Imprints 部分。还是筋疲力尽。我有点困惑如何为文档的其余部分重新排列母版。我还用改进的代码更新了问题。
谢谢，看来真的可以了！至于印记，其目的是结构应该始终相同，没有任何变化——一个标题页（奇数）、一个版权页（偶数）、灵活长度的目录（偶数/奇数/空白）。
所以标题页的页序列只需要引用“PageMaster.Title”，版权页的页序列到“PageMaster.CopyRight-Page”。然后，您可以删除“印记”和“CopyRight-Page”fo:page-sequence-master。