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Technical Notes

Formatting HTML

AH Formatter V7.0 can format HTML designed for the Web (except for HTML that uses a frame). However, there may be few HTML documents that achieve a good result without needing adjustment after formatting. The reasons are as follows:

For example, if the HTML can be printed from a Web browser without overflowing the right-hand side of the page, then formatting with AH Formatter V7.0 will produce a reasonable result. However, in order to achieve a better result, the HTML must be designed both for the browser and for printing. The CSS for printing may be precisely defined using rules such as: 

@media print { ... }
@page { ... }

Moreover, there are big differences in the CSS implementations of current Web browsers. If the HTML contains grammar mistakes by being designed for a particular browser, or the HTML uses incorrect CSS, it is unlikely that a good result could be obtained.

Many (X)HTML documents on the Web use only generic fonts. (This is desirable considering the characteristics of the Web.) Since the font settings for every script in the Option Setting File always apply in AH Formatter V7.0 GUI on Windows, suitable fonts will be used. However, this applies only to AH Formatter V7.0 GUI and only on Windows. When using the Command-line Interface, set appropriate <script-font> values in the Option Setting File and specify the Option Setting File when formatting.

CAUTION: Since AH Formatter V7.0 formats the document for print media, @media screen is ignored even when viewing documents on-screen with the GUI.

Cascading Order of CSS

The cascading order of the CSS is defined in the CSS2 Specification as follows.

  1. user agent declarations
  2. user normal declarations
  3. author normal declarations
  4. author important declarations
  5. user important declarations

AH Formatter V7.0 corresponds to the following.

Default CSS for HTML

Default CSS for HTML is used as the first stylesheet (user agent declarations) when formatting (X)HTML. This is html.css, which is placed in the directory indicated by the environment variable, AHF70_DEFAULT_HTML_CSS or AHF70_64_DEFAULT_HTML_CSS. (When html.css does not exist, it is formatted as all the elements are inline.)

This stylesheet is created based on the display of a web browser, the style specified by CSS, etc. However, there may be specification which cannot be well displayed depending on the environment. Probably, there is also a difference of taste. Users are required to optimize the default CSS according to their own environment etc. Some examples are shown below.

Detection of Formatting Type

When the formatting starts by setting the detection of formatting type automatically, the formatting type will be determined in the following procedures.

  1. When MIME is specified, AH Formatter V7.0 will follow its settings. That is, if text/html is specified, it will be detected as HTML. When application/xhtml+xml is specified, it will be detected as XHTML.
  2. When auto-formatter-type="html" is specified in the Option Setting File and the extension of the input document is known, AH Formatter V7.0 will follow its setting. That is, when the extension is for HTML such as .htm or .html, it will be detected as HTML. If the extension is for XHTML, such as .xht or .xhtml, it will be detected as XHTML.
  3. When there is no XML declaration and DOCTYPE is for HTML, it will be detected as HTML. If it is for XHTML, it will be detected as XHTML.
  4. When auto-formatter-type="xhtml" is specified in the Option Setting File and the name space is for XHTML, it will be detected as XHTML.
  5. When there is no XML declaration and name space does not exist and the root element is <HTML> with case insensitive, it will be detected as HTML.
  6. When CSS, which is not XSLT, is specified (to the internal or external document), it will be detected as XML+CSS.
  7. When the name space is for XSL-FO, it will be detected as XSL-FO.
  8. Other than these will be detected as XML+CSS.

Although the document does not need to be XML if it's HTML formatting, it is required except HTML that the document should be well formed XML.

Difference in Formatting with AH Formatter V6.6

There are some differences in formatting between AH Formatter V7.0 and AH Formatter V6.6 as listed below.

Difference in Formatting with AH Formatter V6.5

There are some differences in formatting between AH Formatter V6.6 and AH Formatter V6.5 as listed below.

Difference in Formatting with AH Formatter V6.3

There are some differences in formatting between AH Formatter V6.4 and AH Formatter V6.3 as listed below.

Difference in Formatting with AH Formatter V6.2

There are some differences in formatting between AH Formatter V6.3 and AH Formatter V6.2 as listed below.

Difference in Formatting with AH Formatter V6.1

There are some differences in formatting between AH Formatter V6.2 and AH Formatter V6.1 as listed below.

Difference in Formatting with AH Formatter V6.0

There are some differences in formatting between AH Formatter V6.1 and AH Formatter V6.0 as listed below.

Difference in Formatting with AH Formatter V5

There are some differences in formatting between AH Formatter V6.0 and AH Formatter V5 as listed below.

Difference in Formatting with XSL Formatter V4

There are some differences in formatting between AH Formatter V5 and XSL Formatter V4 as listed below.

Incompatibility of XSL 1.0 and XSL 1.1

Some incompatible changes from XSL 1.0 are made to XSL 1.1.

Shorthand

Since the shorthand in the property of XSL has succeeded the definition of CSS, the value is evaluated like CSS. That is, 

margin="0pt -10pt"

is evaluated as two values instead of one formula. However, when it's not a shorthand, this is evaluated as one formula. For example, the following is one formula. 

margin-left="0pt -10pt"

AH Formatter V7.0 processes such an ambiguous expression by the shorthand as follows.

In FO, when using a formula in the shorthand, it can be enclosed with parentheses, etc.

With CSS, when a function of calc() is written as calc(10pt-5pt), “-” is evaluated as a operator.

Property Value Syntax

We briefly explain a part of property value syntax in the XSL/CSS Extensions. This notation conforms to that in CSS. See also Value Definition Syntax for more details.

Unicode

AH Formatter V7.0 supports Unicode 10.0. Newly added characters may not be treated correctly. In addition, it's impossible to treat the character of unsupported script correctly (☞ Scripts and Languages). See unicode-bidi-rev in the Option Setting File for the BIDI control characters.

BIDI Algorithm Implementation Restrictions

When an algorithm that is not compatible with V6.6 is selected in unicode-bidi-rev, the BIDI level may not be resolved as specified.

As shown in the following example, if the character before the break is a character such as a space whose BIDI level depends on the subsequent text, or text that changes the BIDI level depending on the presence of the corresponding character, such as parentheses or “isolate” if present, the text in multiple elements must be combined to determine the BIDI level. At this time, the BIDI level is not evaluated correctly if there is an element within the range that the text is converted depending on the evaluation result of the property. The BIDI level is obtained for the text before the property is applied. 

<fo:block>xxxx <fo:inline property="xxxx">bbbbb</fo:inline> ...</fo:block>
<fo:block>(xxxx<fo:inline property="xxxx">bbbbb</fo:inline> ...)</fo:block>

As shown in the following example, when the element is backward referenced, the text obtained in the evaluation result is assumed to be “Neutral”, the BIDI level is obtained once, and after the text is obtained, the BIDI processing is performed only with that text. 

<p>xxxx<span ref="#yyy" style="content:target-text(attr(ref, url));"></span>zzzz</p>
<p><span id="yyy">ref</span></p>

If you want to place the page number that changes the writing direction of the index reader at the left edge of the page, we recommend that you place a space in front of the reader and change the writing direction with unicode-bidi as shown in the following example, rather than giving control characters to “content”. 

a::before {
	content: leader(dotted) " " target-counter(attr(ref, url),page);
	unicode-bidi: embed;
	direction: rtl;
}

<toc>حول xxxx <a ref="#yyy"></a></toc>

Unicode Range

To express the Unicode range as a property value in the Font Configuration File, Option Setting File, etc., use the following format: 

[ <urange> | <string> ]# | all

<urange> is a hexadecimal number with the preceding U+ and one of the following. Hexadecimal is case insensitive. (In the Unicode specification, the code point must be 4 to 6 digits, but here it is allowed to represent less than 4 digits for notation.)

U+4?? is equivalent to U+400-4FF. U+??? is equivalent to U+000-FFF. Unicode up to U+10FFFF is effective. Even if a range greater than U+10FFFF is specified, it is disregarded.

<string> is any string enclosed with quotation marks. For example, U+0028-0029 can be written as '()'.

“all” is considered as U+0-10FFFF is specified.

URI

<uri-specification> in the XSL specification is supposed to specify the character string which fulfills IRI (RFC3987) specification in url(). IRI is called URI for convenience in this document.

CAUTION: In the XSL specification, it is not necessary to enclose a string in url() with quotation marks. However, it may be difficult to accurately recognize url( corresponding to ), such as when the string contains parentheses. We strongly recommend to enclose a string in url() with quotation marks.

Schemes which can actually be specified in AH Formatter V7.0 are as follows:

It's possible to specify a correct absolute URI that includes the scheme name without using url(). For example, the following two are the same. 

<fo:external-graphic src="url('http://localhost/image.png')"/>
<fo:external-graphic src="http://localhost/image.png"/>

Moreover, it's possible to specify a relative URI without specifying the scheme name. 

<fo:external-graphic src="url('image.png')"/>
<fo:external-graphic src="image.png"/>

AH Formatter V7.0 allows specifying the file name on a local file system instead of URI for user's convenience. However, generally there is no compatibility between URI and a local file name. For example, while a white space is not allowed for URI, a white space may be available for a local file name. Moreover, since the direct use of the % may be available to use, a character string called foo%20bar.png will point to a different resource between the two cases, evaluating as URI and evaluating as a local file name.

AH Formatter V7.0 solves this problem as follows:

The relative URI is combined with base-uri and transformed into the absolute URI. All local file names are transformed into a file scheme at this time. For example, in the Windows environment, when base-uri is C:\dir\, it is transformed as follows:

foobar.pngfile:///C:/dir/foobar.png
url('foobar.png')file:///C:/dir/foobar.png
url('url(foobar.png)')file:///C:/dir/url(foobar.png)
subdir\foobar.pngfile:///C:/dir/subdir/foobar.png
url('subdir\foobar.png')file:///C:/dir/subdir%5Cfoobar.png
url('subdir/foobar.png')file:///C:/dir/subdir/foobar.png
foo bar.pngfile:///C:/dir/foo%20bar.png
url('foo bar.png')file:///C:/dir/foo%20bar.png
foo%20bar.pngfile:///C:/dir/foo%2520bar.png
url('foo%20bar.png')file:///C:/dir/foo%20bar.png
foo%%20bar.pngfile:///C:/dir/foo%25%2520bar.png
url('foo%%20bar.png')file:///C:/dir/foo%25%2520bar.png
foo#bar.pngfile:///C:/dir/foo#bar.png
url('foo#bar.png')file:///C:/dir/foo#bar.png
foo%23bar.pngfile:///C:/dir/foo%2523bar.png
url('foo%23bar.png')file:///C:/dir/foo%23bar.png

A local file name cannot be written directly into url(). For example: 

url('C:\My Document\foobar.png')

The string above will not operate as expected. Specify a local file name without surrounding by url().

“#” is a fragment separator. In file:///C:/dir/foo#bar.png, the resource actually accessed is file:///C:/dir/foo. Specify url('foo%23bar.png') to access a resource called foo#bar.png.

UNC (Universal Naming Convention) in Windows, for example, \\host\My Document\foobar.png is transformed into file://host/My%20Document/foobar.png. Also, //host/My Document/foobar.png will be transformed into http://host/My%20Document/foobar.png when base-uri is http:. (The same applies to https:.) In non-Windows environments, file://host/... is not supported.

The format of the data scheme defined in RFC2397 is: 

"data:" [ mediatype ] [ ";base64" ] "," data
Note that a semicolon “;” is required when specifying base64, and a data delimiter is a comma “,”.

The jar scheme defined in JarURLConnection can be specified. This is effective to JAR or ZIP and possible to specify the entry in it. 

jar:http://www.foo.com/bar/baz.jar!/COM/foo/Quux.png

What is specified from after the first separator “!/” is considered as the entry specification. The nest of JAR or ZIP is not supported.

When accessing HTTP or HTTPS via a proxy in non-Windows environments, it's necessary to specify the proxy address with the HTTP_PROXY or HTTPS_PROXY environment variable.

When the root certificate is necessary in non-Windows environments, it's necessary to specify the file of the root certificate with the SSL_CERT environment variable.

Supports Multi-domain Certificates.

Table Auto Layout

The table (fo:table) has the attribute, table-layout="fixed" and table-layout="auto". The former specifies the fixed layout which has the fixed column width, and the latter is a specification of the automatic layout which calculates the column width automatically. When the value is omitted, the default value is table-layout="auto". In the XSL specification, the automatic layout serves as implementation-independent. We will explain the implementation of AH Formatter V7.0 in this document.

An automatic layout can take a lot of time for calculating the width of columns. Specify table-layout="fixed" if high-speed formatting is desired.

In AH Formatter V7.0, the processing method of the table differs between the specification of table-layout and the specification of the width to fo:table. When the width of all columns is specified, even if table-layout="auto" is specified, it is treated as table-layout="fixed". Moreover, proportional-column-width() is supposed to be available to specify only in the case of table-layout="fixed" according to the XSL specification. In AH Formatter V7.0, when a column with proportional-column-width() and a column without the width specification are intermingled, it is considered that column-width="proportional-column-width(1)" is specified to the column without the width specification. In addition, it is considered and processed that table-layout="fixed" is specified. That is, in such case, all columns will have the width specification.

table-layoutWidth of fo:tableProcessing Method
fixedYes The width is divided equally and assigned to the column as which width is not specified. When the content exceeds the width, it will overflow.
No The table width becomes 100%. The width is divided equally and assigned to the column where the width is not specified. When the content exceeds the width, it will overflow.
autoYes The content of the column are calculated and the width is assigned to the column where the width is not specified. When the table width exceeds its specified width even if the minimum width of a column is adopted, the table width expands to the exceeded width.
No The content of the column are calculated and the width is assigned to the column where the width is not specified. When the table width does not fill to 100% even if the maximum width of a column is adopted, it will become the table width. When the table width exceeds 100% even if the width of a column is adopted, it will become the table width. Otherwise, the width of a table becomes 100%.

When table-layout="auto" is specified, the content of the column where the width is not specified are investigated. More desirable column width can be determined if all rows are investigated, but it takes too much time for a big table. AH Formatter V7.0 usually investigates the contents only to the column for 100 rows at the maximum and determines the width of a column. This number of rows can be changed by table-auto-layout-limit of Option Setting File.

When table-layout="fixed" is specified, since the contents of the column are not investigated, the processing speed is always high.

CAUTION: The column width of the table cell whose contents are generated by fo:retrieve-table-marker is not automatically calculated.

Line Breaking

AH Formatter V7.0 processes two types of line breaking. One is to break lines into the line width at appropriate points at the end of every line, and the other is a processing according to the line breaking algorithm by Knuth-Plass's “Breaking Paragraphs into Lines”. (Hereinafater referred to as BPIL.) BPIL determines the break position considering the balance of the whole block.

Candidates for line breaking positions are determined by the processing of UAX#14: Line Breaking Properties. The UAX#14 processing is somewhat different from the Unicode specification as follows:

BPIL is applied to the following blocks:

The language of the block is specified by xml:lang or the language property, or specified by default-lang in the Option Setting File. However, BPIL is not always applied to all situations. In the following cases, BPIL is not applied, but the line breaking is performed at the end of every line.

The following are restrictions.

Hyphenation

This section explains the behavior of the page (or column) break when hyphenation-keep="page" (or "column") is specified. Suppose there is the following sentence with hyphenation-keep="page" specified. 

xxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxx
xxxxxxxxxxx abc-
def xxxxxxx ghi-
jkl mnopqr.

When the page break occurs at the last line, ghi will be pushed to the next page and results in the following: 

xxxxxxxxxxxxxxxx
xxxxxxxxxxx abc-
def xxxxxxx
---------------- page break
ghijkl mnopqr.

When widows="2" is specified, another 1 line will be pushed to the next page and results in the following: 

xxxxxxxxxxxxxxxx
xxxxxxxxxxx abc-
---------------- page break
def xxxxxxx ghi-
jkl mnopqr.

But it acts against the behavior of hyphenation-keep="page". At that time, AH Formatter V7.0 cannot push only abc and accordingly 1 line will be pushed to the next page. 

xxxxxxxxxxxxxxxx
---------------- page break
xxxxxxxxxxx abc-
def xxxxxxx ghi-
jkl mnopqr.

When the previous line ends with the hyphenation, lines will be pushed line after line. It's better to use together with hyphenation-ladder-count.

In a slightly different case, lines may increase when ghi is pushed as follows: 

xxxxxxxxxxxxxxxx
xxxxxxxxxxx xxxx
xxx xxxxxxx
---------------- page break
ghijkl xxxx mno-
pqr.

When widows="3" is specified, one more line will be pushed. At this time, lines may decrease as follows: 

xxxxxxxxxxxxxxxx
xxxxxxxxxxx xxxx
---------------- page break
xxx xxxxxxx ghi-
jkl xxxx mnopqr.

AH Formatter V7.0 cannot dissolve the widows="3" caused by the side effect. This is the limitation of AH Formatter V7.0. widows="2" never cause such scenario.

Variation Sequence

AH Formatter V7.0 supports the Unicode Character “Variation Sequence”. When the OpenType font has the capability of Variation Sequence (cmap Format14), it is processed appropriately. For example, Variant Sequences can be expressed as follows.

葛&#xE0100;城市
葛城市
葛&#xE0101;飾区
葛飾区

Even when it is applied to a CID font which does not have the capability of Variation Sequence, CID is selected according to the following IVD (UTS#37: Ideographic Variation Database).

&#xE0100;, etc. will be disregarded when it is a font which does not have the capability of Variation Sequence or there is no corresponded variation characters, or the specified Variation Sequence is beyond the range. This indicates that even if the setting is the same, the displayed font face may differ depending on which Variation Sequence the font corresponds to.

CAUTION: Variation Sequences other than Ideographic are not supported.

Font Selection

Fonts in FO or CSS are specified by the font-family property. There are various cases in settings when the candidates of the font are enumerated like font-family="'Courier New', serif", or when there is no specification of font-family, AH Formatter V7.0 determines which font should be applied to a character string as follows.

  1. The character strings in the region are divide into the character strings with the same character by the script information corresponding to the character defined by Unicode, the language specified in FO or CSS, or the script information, etc. and the script of the divided character string is determined. This method of determination is complicated because of the reason that there contains the ambiguous characters to determine if it's a full width character or not in Unicode. Or the language is being unable to determine by kanji only as a character string.

  2. When font-selection-mode="6" is specified in the Option Setting File, each character of this character string is investigated in order whether the font-family specified by FO or CSS has its glyph. Then the font with the first found glyph will be adopted. If these are not specified, each character of this character string is investigated whether the font-family specified by FO or CSS has its glyph, and the font-family supports the Unicode range or script in order. Then the first found supported font will be adopted. When no font-family is specified, it is considered that the generic font family as the standard font family is specified.

In XSL or CSS, the following five can be used as the generic font family.

AH Formatter V7.0 has the information of which font is actually made to correspond to these for every script. Moreover, the default generic font which does not belong to any script can also be defined now. These can be specified in the Font Setting page of the Option Setting dialog in Graphical User Interface, and also can be specified with <script-font> in the Option Setting File.

  1. When the generic font classified by the script corresponding to the script of the target character string is specified, whether it supports the character string is investigated.

  2. When the corresponding generic font classified by the script is not specified, the default generic font is investigated.

  3. When auto-fallback-font="true" is specified in the Option Setting File and any fonts specified in the font-family don't support the target character string, the following fallback processing will be performed.

    1. The font specified to the fallback associated with the corresponding script is investigated.
    2. The font specified to the fallback of the standard generic font is investigated.
    3. Even then any fonts don't support the target character string, the following fonts are investigated in order.
      • Windows version
        1. Lucida Sans Unicode
        2. Microsoft Sans Serif
        3. IPAGothic
        4. Code2000
        5. MS PGothic
        6. Arial Unicode MS
      • Non-Windows version
        1. Helvetica
        2. IPAGothic
        3. Code2000

  4. It is an error even then the font which supports the target character string is not found.

The settings in the Option Setting dialog is reflected on the Option Setting File. For example, it is written like 

<script-font script="Hans" serif="SimSun" sans-serif="SimHei" monospace="SimSun"/>

Since there is no specification of cursive here, cursive in the default generic font is adopted to Hans. Like immediately after the installation, when <script-font script="Hans"/> itself is not specified, it is considered that the default group is specified. The following default group is set up with the Windows version. Only scripts that are specified here are set up. Moreover, it is not set up when the font does not actually exist.

Scriptserifsans-serifcursivefantasymonospace
default Times New Roman Arial Segeo Script or
Comic Sans MS or
Monotype Corsiva 		Impact Courier New
Jpan MS Mincho MS Gothic MS Mincho or
MS Gothic		 MS Mincho or
MS Gothic		 MS Gothic or
MS Mincho
Hans SimSun or
MS Song		 SimHei or
MS Hei or
MS Song		 SimSun or
MS Song		 SimSun or
MS Song		 SimHei or
MS Hei or
MS Song
Hant MingLiU ← ← ← ←
Hang Batang or
BatangChe		 Gulim or
BatangChe		 Batang or
BatangChe		 Batang or
BatangChe		 BatangChe
Ethi no-LT Nyala ← ← ← ←
Arab Arabic Typesetting ← ← ← ←
Syrc no-LT Estrangelo Edessa ← ← ← ←
Hebr FrankRuehl ← ← ← ←
Deva Mangal ← ← ← ←
Beng no-LT Vrinda ← ← ← ←
Guru no-LT Raavi ← ← ← ←
Gujr no-LT Shruti ← ← ← ←
Taml no-LT Latha ← ← ← ←
Telu no-LT Gautami ← ← ← ←
Knda no-LT Tunga ← ← ← ←
Mlym no-LT Kartika ← ← ← ←
Sinh no-LT Iskoola Pota ← ← ← ←
Thai Angsana New ← ← ← ←
Khmr no-LT DaunPenh ← ← ← ←
Laoo no-LT DokChampa ← ← ← ←
Mymr no-LT Myanmar Text ← ← ← ←

The following default group is set up with the Macintosh version.

Scriptserifsans-serifcursivefantasymonospace
default Times or
Times New Roman		 Helvetica or
Arial		 Monaco or
Chalkboard		 Monaco or
Chalkboard		 Courier
Jpan HiraMinPro W3 HiraKakuPro W3 HiraMaruPro W3 or
HiraKakuPro W3		 HiraMaruPro W3 or
HiraKakuPro W3		 HiraKakuPro W3
Hans STXihei
or STSong 		STSong STXihei
or STSong 		STXihei
or STSong 		STSong
Hant LiHeiPro
or LiSongPro 		LiSongPro LiHeiPro
or LiSongPro 		LiHeiPro
or LiSongPro 		LiSongPro
Hang AppleMyungjo AppleGothic AppleMyungjo AppleMyungjo AppleGothic
Arab Geeza Pro ← ← ← ←
Hebr NewPeninimMT ← ← ← ←
Deva DevanagariMT ← ← ← ←
Thai Thonburi ← ← ← ←

The following default group is set up with the other UNIX version.

Scriptserifsans-serifcursivefantasymonospace
defaultTimesHelveticaTimesTimesCourier

Upright Rendering of Text in Vertical Writing Mode

There are basically three types of the orientation of text in Japanese or Chinese documents as follows:

In horizontal writing In vertical writing
SVO MVO

Expresses the orientation of text in vertical writing mode with U or R. U is a character displayed upright on the paper. R is a character rotated 90 degrees clockwise on the paper. Then the text orientation in vertical writing mode is as follows:

There is an argument of which characters should be upright or which characters should be rotated 90 degrees at UAX#50: Unicode Vertical Text Layout. Right now only the description of MVO (Mixed Vertical Orientation) is here. However, the description of SVO (Stacked Vertical Orientation) was also included in the past (tr50-6.html). AH Formatter V7.0 implements axf:text-orientation="mixed" complying with MVO, axf:text-orientation="upright" complying with SVO. However, AH Formatter V7.0 uses the one with some modifications (☞ tr50-x.Orientation.txt). This data can be modified arbitrarily in the Option Setting File. See also UAX50.

Usually, the font supporting the vertical writing mode has the glyph for vertical writing for some characters. It is because some are inapplicable to vertical writing simply by rotating the glyph for horizontal writing mode. They are small kana, punctuations, long vowel, etc. In vertical writing mode, if the character has the glyph for vertical writing, it will be used.

The orientation of text (U or R) is decided and expressed as compared to the orientation of the glyph for horizontal writing mode. However some glyphs for vertical writing mode differ from that for horizontal writing mode. The example below shows the glyph of U+3083, U+FF08, and U+2190. U+FF08 and U+2190 have the different orientation between vertical and horizontal writing mode.

Glyph for horizontal writing Glyph for vertical writing

Although “brackets are R” as mentioned above, actually you have to display them as U using the glyph for vertical writing mode. That is, here is a tacit assumption that the glyph for vertical writing mode is designed to have the orientation differently from that for horizontal writing mode. Whether the font has the glyph for vertical writing mode or whether the orientation is the same as that for horizontal writing mode depends on the font. In particular, the difference by a font is remarkable in the orientation of symbols, such as arrows. Since it is impossible to get to know which orientation the glyph is designed, this problem is generally impossible to solve. Therefore, AH Formatter V7.0 controls the orientation of the character according to the major implementations.

Formatting Large Document

When outputting PDF, AH Formatter V7.0 discards pages that have already been formatted, so AH Formatter V7.0 consumes just the memory required for one page when outputting PDF for, for example, a simple FO without <fo:page-number-citation>, no matter how huge the document is (except when formatting from the GUI). However, if a page contains an <fo:page-number-citation> that refers to a following page, we cannot know the page number of the referenced page until that page is actually formatted. For that reason, if a page containing an unresolved <fo:page-number-citation> appears, AH Formatter V7.0 will suspend its output and store the result in memory while continuing formatting. When a document has a table of contents at the start, the table of contents will not be output until all the page numbers appearing in it are resolved. Because of the high memory consumption, there is a limit to the number of formatted pages, so it is not possible to format extremely large documents.

To solve this problem, AH Formatter V7.0 makes it possible to process the document in two formatting passes. In the first pass, the formatting is processed only for resolving <fo:page-number-citation>, and all the required page number information is collected. In the second pass, formatting starts again from the first page. Since all <fo:page-number-citation> are already resolved, AH Formatter V7.0 can discard formatted pages when outputting the document. Although the formatting processing time is increased, the formatting consumes less memory and it is possible to format extremely large documents. But this has no effect on the memory consumption needed for the output.

The following shows how to perform 2-pass formatting:

CAUTION: Two-pass formatting is not available with CSS formatting.
CAUTION: It's not possible to perform two-pass formatting from Graphical User Interface.
CAUTION: Two-pass formatting is not available with AH Formatter V7.0 Lite.

Temporary File

AH Formatter V7.0 does not make a temporary working file if it can be avoided. The following are the cases that AH Formatter V7.0 makes the temporary file for work.

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