repo_zf1/documentation/manual/en/ref/documentation-standard.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Reviewed: no -->
<appendix id="doc-standard">
    <title>Zend Framework Documentation Standard</title>

    <sect1 id="doc-standard.overview">
        <title>Overview</title>

        <sect2 id="doc-standard.overview.scope">
            <title>Scope</title>

            <para>
                This document provides guidelines for creation of the end-user
                documentation found within Zend Framework. It is intended as a
                guide to Zend Framework contributors, who must write
                documentation as part of component contributions, as well as to
                documentation translators. The standards contained herein are
                intended to ease translation of documentation, minimize
                visual and stylistic differences between different documentation
                files, and make finding changes in documentation easier with
                <command>diff</command> tools.
            </para>

            <para>
                You may adopt and/or modify these standards in accordance with the terms of our
                <ulink url="http://framework.zend.com/license">license</ulink>.
            </para>

            <para>
                Topics covered in Zend Framework's documentation standards include documentation
                file formatting and recommendations for documentation quality.
            </para>
        </sect2>
    </sect1>

    <sect1 id="doc-standard.file-formatting">
        <title>Documentation File Formatting</title>

        <sect2 id="doc-standard.file-formatting.xml-tags">
            <title>XML Tags</title>

            <para>
                Each manual file must include the following <acronym>XML</acronym> declarations at
                the top of the file:
            </para>

            <programlisting language="xml"><![CDATA[
<?xml version="1.0" encoding="UTF-8"?>
<!-- Reviewed: no -->
]]></programlisting>

            <para>
                <acronym>XML</acronym> files from translated languages must also include a revision
                tag containing the revision of the corresponding English-language file the
                translation was based on.
            </para>

            <programlisting language="xml"><![CDATA[
<?xml version="1.0" encoding="UTF-8"?>
<!-- EN-Revision: 14978 -->
<!-- Reviewed: no -->
]]></programlisting>
        </sect2>

        <sect2 id="doc-standard.file-formatting.max-line-length">
            <title>Maximum Line Length</title>

            <para>
                The maximum line length, including tags, attributes, and indentation, is not to
                exceed 100 characters. There is only one exception to this rule: attribute and value
                pairs are allowed to exceed the 100 chars as they are not allowed to be separated.
            </para>
        </sect2>

        <sect2 id="doc-standard.file-formatting.indentation">
            <title>Indentation</title>

            <para>Indentation should consist of 4 spaces. Tabs are not allowed.</para>
            <para>Tags which are at the same level must have the same indentation.</para>

            <programlisting language="xml"><![CDATA[
<sect1>
</sect1>

<sect1>
</sect1>
]]></programlisting>

            <para>
                Tags which are one level under the previous tag must be indented with 4 additional
                spaces.
            </para>

            <programlisting language="xml"><![CDATA[
<sect1>
    <sect2>
    </sect2>
</sect1>
]]></programlisting>

            <para>
                Multiple block tags within the same line are not allowed; multiple inline tags are
                allowed, however.
            </para>

            <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED: -->
<sect1><sect2>
</sect2></sect1>

<!-- ALLOWED -->
<para>
    <classname>Zend_Magic</classname> does not exist. <classname>Zend_Acl</classname> does.
</para>
]]></programlisting>
        </sect2>

        <sect2 id="doc-standard.file-formatting.line-termination">
            <title>Line Termination</title>

            <para>
                Line termination follows the Unix text file convention. Lines must end with a
                single linefeed (LF) character. Linefeed characters are represented as ordinal 10,
                or hexadecimal 0x0A.
            </para>

            <para>
                Note: Do not use carriage returns (<acronym>CR</acronym>) as is the convention in
                Apple OS's (0x0D) or the carriage return - linefeed combination
                (<acronym>CRLF</acronym>) as is standard for the Windows OS (0x0D, 0x0A).
            </para>
        </sect2>

        <sect2 id="doc-standard.file-formatting.empty-tags">
            <title>Empty tags</title>

            <para>
                Empty tags are not allowed; all tags must contain text or child tags.
            </para>

            <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
<para>
    Some text. <link></link>
</para>

<para>
</para>
]]></programlisting>
        </sect2>

        <sect2 id="doc-standard.file-formatting.whitespace">
            <title>Usage of whitespace within documents</title>

            <sect3 id="doc-standard.file-formatting.whitespace.trailing">
                <title>Whitespace within tags</title>

                <para>
                    Opening block tags should have no whitespace immediately following them other
                    than line breaks (and indentation on the following line).
                </para>

                <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
<sect1>WHITESPACE
</sect1>
]]></programlisting>

                <para>
                    Opening inline tags should have no whitespace immediately following them.
                </para>

                <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
This is the class <classname> Zend_Class</classname>.

<!-- OK -->
This is the class <classname>Zend_Class</classname>.
]]></programlisting>

                <para>
                    Closing block tags may be preceded by whitespace equivalent to the current
                    indentation level, but no more than that amount.
                </para>

                <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
    <sect1>
     </sect1>

<!-- OK -->
    <sect1>
    </sect1>
]]></programlisting>

                <para>
                    Closing inline tags must not be preceded by any whitespace.
                </para>

                <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
This is the class <classname>Zend_Class </classname>

<!-- OK -->
This is the class <classname>Zend_Class</classname>
]]></programlisting>
            </sect3>

            <sect3 id="doc-standard.file-formatting.whitespace.multiple-line-breaks">
                <title>Multiple line breaks</title>

                <para>
                    Multiple line breaks within or between tags are not allowed.
                </para>

                <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
<para>
    Some text...

    ... and more text
</para>


<para>
    Another paragraph.
</para>

<!-- OK -->
<para>
    Some text...
    ... and more text
</para>

<para>
    Another paragraph.
</para>
]]></programlisting>
            </sect3>

            <sect3 id="doc-standard.file-formatting.whitespace.tag-separation">
                <title>Separation between tags</title>

                <para>
                    Tags at the same level must be separated by an empty line to improve
                    readability.
                </para>

                <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
<para>
    Some text...
</para>
<para>
    More text...
</para>

<!-- OK -->
<para>
    Some text...
</para>

<para>
    More text...
</para>
]]></programlisting>

                <para>
                    The first child tag should open directly below its parent, with no empty line
                    between them; the last child tag should close directly before the closing tag of
                    its parent.
                </para>

                <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
<sect1>

    <sect2>
    </sect2>

    <sect2>
    </sect2>

    <sect2>
    </sect2>

</sect1>

<!-- OK -->
<sect1>
    <sect2>
    </sect2>

    <sect2>
    </sect2>

    <sect2>
    </sect2>
</sect1>
]]></programlisting>
            </sect3>
        </sect2>

        <sect2 id="doc-standard.file-formatting.program-listing">
            <title>Program Listings</title>

            <para>
                The opening <emphasis>&lt;programlisting&gt;</emphasis> tag must indicate the
                appropriate "language" attribute and be indented at the same level as its sibling
                blocks.
            </para>

            <programlisting language="xml"><![CDATA[
<para>Sibling paragraph.</para>

<programlisting language="php">]]>&lt;<![CDATA[![CDATA[
]]></programlisting>

            <para>
                <acronym>CDATA</acronym> should be used around all program listings.
            </para>

            <para>
                <emphasis>&lt;programlisting&gt;</emphasis> sections must not add linebreaks or
                whitespace at the beginning or end of the section, as these are then represented in
                the final output.
            </para>

            <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
<programlisting language="php">]]>&lt;<![CDATA[![CDATA[

$render = "xxx";

]]]]>&gt;<![CDATA[</programlisting>

<!-- OK -->
<programlisting language="php">]]>&lt;<![CDATA[![CDATA[
$render = "xxx";
]]]]>&gt;<![CDATA[</programlisting>
]]></programlisting>

            <para>
                Ending <acronym>CDATA</acronym> and <emphasis>&lt;programlisting&gt;</emphasis>
                tags should be on the same line, without any indentation.
            </para>

            <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
    <programlisting language="php">]]>&lt;<![CDATA[![CDATA[
$render = "xxx";
]]]]>&gt;<![CDATA[
    </programlisting>

<!-- NOT ALLOWED -->
    <programlisting language="php">]]>&lt;<![CDATA[![CDATA[
$render = "xxx";
    ]]]]>&gt;<![CDATA[</programlisting>

<!-- OK -->
    <programlisting language="php">]]>&lt;<![CDATA[![CDATA[
$render = "xxx";
]]]]>&gt;<![CDATA[</programlisting>
]]></programlisting>

            <para>
                The <emphasis>&lt;programlisting&gt;</emphasis> tag should contain the "language"
                attribute with a value appropriate to the contents of the program listing. Typical
                values include "css", "html", "ini", "javascript", "php", "text", and "xml".
            </para>

            <programlisting language="xml"><![CDATA[
<!-- PHP -->
<programlisting language="php">]]>&lt;<![CDATA[![CDATA[

<!-- Javascript -->
<programlisting language="javascript">]]>&lt;<![CDATA[![CDATA[

<!-- XML -->
<programlisting language="xml">]]>&lt;<![CDATA[![CDATA[
]]></programlisting>

            <para>
                For program listings containing only <acronym>PHP</acronym> code,
                <acronym>PHP</acronym> tags (e.g., "&lt;?php", "?&gt;") are not required, and
                should not be used. They simply clutter the narrative, and are implied by the use
                of the <emphasis>&lt;programlisting&gt;</emphasis> tag.
            </para>

            <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
<programlisting language="php"]]>&lt;<![CDATA[![CDATA[<?php
    // ...
?>]]]]>&gt;<![CDATA[</programlisting>

<programlisting language="php"]]>&lt;<![CDATA[![CDATA[
<?php
    // ...
?>
]]]]>&gt;<![CDATA[</programlisting>
]]></programlisting>

            <para>
                Line lengths within program listings should follow the <link
                    linkend="coding-standard.php-file-formatting.max-line-length">coding standards
                recommendations</link>.
            </para>

            <para>
                Refrain from using <methodname>require_once()</methodname>,
                <methodname>require()</methodname>, <methodname>include_once()</methodname>, and
                <methodname>include()</methodname> calls within <acronym>PHP</acronym> listings.
                They simply clutter the narrative, and are largely obviated when using an
                autoloader. Use them only when they are essential to the example.
            </para>

            <note>
                <title>Never use short tags</title>

                <para>
                    Short tags (e.g., "&lt;?", "&lt;?=") should never be used within
                    <emphasis>programlisting</emphasis> or the narrative of a document.
                </para>
            </note>
        </sect2>

        <sect2 id="doc-standard.file-formatting.inline-tags">
            <title>Notes on specific inline tags</title>

            <sect3 id="doc-standard.file-formatting.inline-tags.classname">
                <title>classname</title>

                <para>
                    The tag <emphasis>&lt;classname&gt;</emphasis> must be used each time a class
                    name is represented by itself; it should not be used when combined with a
                    method name, variable name, or constant, and no other content is allowed within
                    the tag.
                </para>

                <programlisting language="xml"><![CDATA[
<para>
    The class <classname>Zend_Class</classname>.
</para>
]]></programlisting>
            </sect3>

            <sect3 id="doc-standard.file-formatting.inline-tags.varname">
                <title>varname</title>

                <para>
                    Variables must be wrapped in the <emphasis>&lt;varname&gt;</emphasis> tag.
                    Variables must be written using the "$" sigil. No other content is allowed
                    within this tag, unless a class name is used, which indicates a class variable.
                </para>

                <programlisting language="xml"><![CDATA[
<para>
    The variable <varname>$var</varname> and the class variable
    <varname>Zend_Class::$var</varname>.
</para>
]]></programlisting>
            </sect3>

            <sect3 id="doc-standard.file-formatting.inline-tags.methodname">
                <title>methodname</title>

                <para>
                    Methods must be wrapped in the <emphasis>&lt;methodname&gt;</emphasis> tag.
                    Methods must either include the full method signature or at the least a pair of
                    closing parentheses (e.g., "()"). No other content is allowed within this tag,
                    unless a class name is used, which indicates a class method.
                </para>

                <programlisting language="xml"><![CDATA[
<para>
    The method <methodname>foo()</methodname> and the class method
    <methodname>Zend_Class::foo()</methodname>. A method with a full signature:
    <methodname>foo($bar, $baz)</methodname>
</para>
]]></programlisting>
            </sect3>

            <sect3 id="doc-standard.file-formatting.inline-tags.constant">
                <title>constant</title>

                <para>
                    Use the <emphasis>&lt;constant&gt;</emphasis> tag when denoting constants.
                    Constants must be written in <acronym>UPPERCASE</acronym>. No other content is
                    allowed within this tag, unless a class name is used, which indicates a class
                    constant.
                </para>

                <programlisting language="xml"><![CDATA[
<para>
    The constant <constant>FOO</constant> and the class constant
    <constant>Zend_Class::FOO</constant>.
</para>
]]></programlisting>
            </sect3>

            <sect3 id="doc-standard.file-formatting.inline-tags.filename">
                <title>filename</title>

                <para>
                    Filenames and paths must be wrapped in the
                    <emphasis>&lt;filename&gt;</emphasis> tag. No other content is allowed in this
                    tag.
                </para>

                <programlisting language="xml"><![CDATA[
<para>
    The filename <filename>application/Bootstrap.php</filename>.
</para>
]]></programlisting>
            </sect3>

            <sect3 id="doc-standard.file-formatting.inline-tags.command">
                <title>command</title>

                <para>
                    Commands, shell scripts, and program calls must be wrapped in the
                    <emphasis>&lt;command&gt;</emphasis> tag. If the command includes arguments,
                    these should also be included within the tag.
                </para>

                <programlisting language="xml"><![CDATA[
<para>
    Execute <command>zf.sh create project</command>.
</para>
]]></programlisting>
            </sect3>

            <sect3 id="doc-standard.file-formatting.inline-tags.code">
                <title>code</title>

                <para>
                    Usage of the <emphasis>&lt;code&gt;</emphasis> tag is discouraged, in favor of
                    the other inline tasks discussed previously.
                </para>
            </sect3>
        </sect2>

        <sect2 id="doc-standard.file-formatting.block-tags">
            <title>Notes on specific block tags</title>

            <sect3 id="doc-standard.file-formatting.block-tags.title">
                <title>title</title>

                <para>
                    The <emphasis>&lt;title&gt;</emphasis> tag is not allowed to hold other tags.
                </para>

                <programlisting language="xml"><![CDATA[
<!-- NOT ALLOWED -->
<title>Using <classname>Zend_Class</classname></title>

<!-- OK -->
<title>Using Zend_Class</title>
]]></programlisting>
            </sect3>
        </sect2>
    </sect1>

    <sect1 id="doc-standard.recommendations">
        <title>Recommendations</title>

        <sect2 id="doc-standard.recommendations.editors">
            <title>Use editors without autoformatting</title>

            <para>
                For editing the documentation, typically you should not use formal
                <acronym>XML</acronym> editors. Such editors normally autoformat existing documents
                to fit their own standards and/or do not strictly follow the docbook standard. As
                examples, we have seen them erase the <acronym>CDATA</acronym> tags, change 4 space
                separation to tabs or 2 spaces, etc.
            </para>

            <para>
                The style guidelines were written in large part to assist translators in recognizing
                the lines that have changed using normal <command>diff</command> tools.
                Autoformatting makes this process more difficult.
            </para>
        </sect2>

        <sect2 id="doc-standard.recommendations.images">
            <title>Use Images</title>

            <para>
                Good images and diagrams can improve readability and comprehension. Use them
                whenever they will assist in these goals. Images should be placed in the
                <filename>documentation/manual/en/figures/</filename> directory, and be named after
                the section identifier in which they occur.
            </para>
        </sect2>

        <sect2 id="doc-standard.recommendations.examples">
            <title>Use Case Examples</title>

            <para>
                Look for good use cases submitted by the community, especially those posted in
                proposal comments or on one of the mailing lists. Examples often illustrate usage
                far better than the narrative does.
            </para>

            <para>
                When writing your examples for inclusion in the manual, follow
                all coding standards and documentation standards.
            </para>
        </sect2>

        <sect2 id="doc-standard.recommendations.phpdoc">
            <title>Avoid Replicating phpdoc Contents</title>

            <para>
                The manual is intended to be a reference guide for end-user usage. Replicating
                the phpdoc documentation for internal-use components and classes is not wanted, and
                the narrative should be focussed on usage, not the internal workings. In any case,
                at this time, we would like the documentation teams to focus on translating the
                English manual, not the phpdoc comments.
            </para>
        </sect2>

        <sect2 id="doc-standard.recommendations.links">
            <title>Use Links</title>

            <para>
                Link to other sections of the manual or to external sources
                instead of recreating documentation.
            </para>

            <para>
                Linking to other sections of the manual may be done using the
                <emphasis>&lt;link&gt;</emphasis> tag (to which you must provide link text).
            </para>

            <programlisting language="xml"><![CDATA[
<para>
    "Link" links to a section, using descriptive text: <link
        linkend="doc-standard.recommendations.links">documentation on
        links</link>.
</para>
]]></programlisting>

            <para>
                To link to an external resource, use <emphasis>&lt;ulink&gt;</emphasis>:
            </para>

            <programlisting language="xml"><![CDATA[
<para>
    The <ulink url="http://framework.zend.com/">Zend Framework site</ulink>.
</para>
]]></programlisting>
        </sect2>
    </sect1>
</appendix>