This specification defines version 0.5 of the Connexions Markup Language (CNXML), an XML application for marking up educational texts. It is designed for use in the Connexions Project, but we are making it generally available in the hopes that others may find it useful. CNXML marks up the structure and semantic content of a document and encourages the separation of content from presentation. It contains few (if any) elements that deal with style or presentation. Decisions about how to display CNXML documents should be made elsewhere (in a Style Sheet, for example.)
Each CNXML element may have several attributes, some of which are required and some are optional. In the following sections, each element is listed with its accompanying attributes. The attributes can be one of several types (see the XML specification for details on what these mean) :
CNXML 0.5 introduces the notion of tag groupings. In order to simplify the rules for nesting tags, we have created three groups of tags. Each CNXML element belongs to one of the three groups. This group will determine the children that can be nested in the tag. The actual nesting rules will be explained further below. The groupings are:
Structural tags are called so because they are containers for almost all other tags. The following tags are considered structural tags: Structural Tags: • content; • section; • example; • meaning; • proof; • statement; • problem; • solution. Structural tags can contain tags the following children:
Any tag that is listed, or is in one of the groups listed above can be nested as a child of a structural tag.
Section is a structural tag, which
therefore allows it to have either para, special, or other
structural children as it's children. Therefore, you could
have a section with a figure as a child, since figure is a special tag and structural
tags are allowed to have special tags as children.
The section tag is used to divide a document into sections, as its name suggests.
The section tag may have an optional name tag as its first child followed by a combination of Structural Tags.
<section id="res">
<name>Resistor</name>
<para id="para2">
.
.
.
</para>
</section>
<section id="cap">
<name>Capacitor</name>
<para id="para3">
.
.
.
</para>
</section>
<section id="ind">
<name>Inductor</name>
<para id="para4">
.
.
.
<para>
</section>
The example tag is used to contain an example of something. This is especially useful in connection with the definition tag where it can be used to give an example of the meaning of a term.
See structural tags.
<example id="example">
<para id="paraex1">
The Lincoln Memorial is an example of a monument.
</para>
</example>
The Lincoln Memorial is an example of a monument.
The exercise tag is used to create exercises, such as would be used in a text book of a college course. An exercise consists of two parts: a problem and a solution.
An exercise may contain a problem followed by zero or more optional solutions.
The problem tag is used to specify the problem portion of an exercise tag.
None
See structural tags.
<problem>
<para id="prob_1">
What is the capital of Texas?
</para>
</problem>
The solution tag is used to specify the solution portion of an exercise tag.
None
See structural tags.
<solution>
<para id="sol_1">
Austin is the capital of Texas.
</para>
</solution>
What is the capital of Texas?
Austin is the capital of Texas.
The proof tag contains the proof or explanation of a rule tag.
See structural tags.
See the example for rule.
The statement tag is used inside the rule tag. It is used to write a definition or description of the rule in which it is placed.
See structural tags.
See the example for rule.
Inline tags are used inside of paragraphs and anywhere else that it is necessary to add content to text. The following tags are included in the inline tag group: Inline Tags: • emphasis; • code; • term; • cite; • cnxn; • link; • foreign; • quote. Unicode text can also be included inline.
The emphasis tag is used to emphasize text in a CNXML document where emphasis would be needed or desired. It is important to note that this refers to semantic emphasis and not a typeface, although many stylesheets may choose to render it as a change in typeface.
None
See inline tags.
<para id="emphexample">
In addition to bananas and ice cream, a proper banana split
requires whipped cream, nuts, <emphasis>and</emphasis>
cherries. Remember that the quality of the dessert depends
on the ice cream, so do <emphasis>not</emphasis> use a
generic brand.
</para>
In addition to bananas and ice cream, a proper banana split requires whipped cream, nuts, and cherries. Remember that the quality of the dessert depends on the ice cream, so do not use a generic brand.
The quote is used to create block quotes.
Quote may take a combination of inline tags.
<para id="quoteexample">
<quote src='http://www.artofeurope.com/shakespeare/sha8.htm'>
To be, or not to be: that is the question: Whether 'tis nobler
in the mind to suffer The slings and arrows of outrageous
fortune, Or to take arms against a sea of troubles, And by
opposing end them?</quote>
</para>
To be, or not to be: that is the question: Whether 'tis nobler in the mind to suffer The slings and arrows of outrageous fortune, Or to take arms against a sea of troubles, And by opposing end them? [source]
The foreign tag is used to denote that a tag is a foreign word or phrase.
See inline tags.
<para id="foreignexample">In spanish speaking countries
you may often hear people say <foreign>Hola
Amigo</foreign>, which means 'hello friend'.
</para>
In spanish speaking countries you may often hear people say Hola Amigo, which means 'hello friend'.
The code tag is used to insert a line or block of computer code (for example a command) into a document. When displayed, it will often be typeset in a fixed-width font.
Code can contain a combination of inline tags.
Enter the command <code>ls /etc</code> to
get a listing of configuration files.
Enter the command ls /etc
to get a listing of configuration files.
The cnxn tag links to a Connexions system document or a tag inside a Connexions system document, possibly different from the current document.
The cnxn tag may contain one or more inline tags.
<cnxn document="m7473" target="figure12">Resistance Figure</cnxn>
<cnxn target="para32">As mentioned earlier</cnxn>
<cnxn document="m3423">A previous document</cnxn>
The link tag is used to insert links to external resources.
Link may contain one or more inline tags.
<para id="linkexample">
<link src="http://www.laurynhill.com">Lauryn Hill</link> is
one of the most influential R&B artists to date. Having
performed with <link src="http://www.fugees.net">The
Fugees</link> and now solo, she is a defining force in worlds
of Rap, Hip-Hop and R&B. Her voice is powerful and her
<link src="http://www.lyricsondemand.com/l/laurynhilllyrics/">lyrics</link>
are moving. It is no wonder that she set records, taking away
5 awards at the 1999 Grammies.
</para>
Lauryn Hill is one of the most influential R&B artists to date. Having performed with The Fugees and now solo, she is a defining force in worlds of Rap, Hip-Hop and R&B. Her voice is powerful and her lyrics are moving. It is no wonder that she set records, taking away 5 awards at the 1999 Grammies.
The cite tag is used to refer to non-electronic materials (ones without a hypertext link). It typically will contain the title of the work.
<cite
src="#white1998">White, 1998</cite>
Cite may contain one or more inline tags.
<para id="citeexample">
<cite>A Tale of Two Cities</cite> is a classic novel by Mark Twain.
</para>
A Tale of Two Cities is a classic novel by Mark Twain.
The term tag marks the word or phrase being defined. It can be used in either a definition tag or in a sentence in a para.
<term
src="#square">square</term>
Term may contain one or more inline tags.
<para id='parterm2'>
A <term>square</term> is a rectangle with equal sides.
</para>
This might be displayed as in the next paragraph.
A square is a rectangle with equal sides.
See also definition examples.
The following tags are considered to be 'special' because the content model for each of them is very specific: Special Tags: • para; • definition; • rule; • figure; • subfigure; • caption; • media; • table; • name; • list; • item; • exercise; • equation; • note; • glossary; • seealso. Special tags are tags which adhere to one or more of the following:
The document tag is the root document element of CNXML documents, commonly called "modules."
none
<document id="spec">
<name>CNXML 0.5 Language Specification</name>
<metadata>
.
.
.
</metadata>
<content>
.
.
.
</content>
<glossary>
.
.
.
</glossary>
<bib:file>
.
.
.
</bib:file>
</document>
The metadata tag is where all the
metadata tags and information is placed. In cnxml 0.5 the
metadata namespace must be included in the document tag as an
attribute, and all metadata tags must begin with the prefix
md:. For more information on how to include the
namespace in the document tag see the Basic Cnxml. Information on the tags listed as
children for the metadata tag can be found in the Editing
Metadata section of the CNXML tutorial.
None
version tag.
created tag.
revised tag.
authorlist tag.
maintainerlist tag.
keywordlist tag may appear next, if it
appears at all.
abstract tag must appear next.
objectives tag may appear after that, if
it appears at all.
<metadata>
<md:version>2.1</md:version>
<md:created>01-12-06</md:created>
<md:revised>01-12-07</md:revised>
<md:authorlist>
<md:author id="selc">
<md:firstname>Sarah</md:firstname>
<md:surname>Coppin</md:surname>
</md:author>
<md:author id="bmh">
<md:firstname>Brent</md:firstname>
<md:surname>Hendricks</md:surname>
</md:author>
<md:author id="drewlin">
<md:firstname>Andrew</md:firstname>
<md:surname>Lin</md:surname>
</md:author>
<md:author id="rars">
<md:firstname>Ricky</md:firstname>
<md:surname>Radaelli-Sanchez</md:surname>
</md:author>
</md:authorlist>
<md:maintainerlist>
<md:maintainer id="selc">
<md:firstname>Sarah</md:firstname>
<md:surname>Coppin</md:surname>
</md:maintainer>
<md:maintainer id="bmh">
<md:firstname>Brent</md:firstname>
<md:surname>Hendricks</md:surname>
</md:maintainer>
<md:maintainer id="rars">
<md:firstname>Ricky</md:firstname>
<md:surname>Radaelli-Sanchez</md:surname>
</md:maintainer>
</md:maintainerlist>
<md:keywordlist>
<md:keyword>CNXML</md:keyword>
<md:keyword>MathML</md:keyword>
<md:keyword>XML</md:keyword>
<md:keyword>specification</md:keyword>
</md:keywordlist>
<md:abstract>
CNXML 0.3 Language Specification
</md:abstract>
<md:objectives>
Explain in detail how the CNXML language should be used.
</md:objectives>
</metadata>
The content tag is where the content information of a document is stored.
None
See Structural Tags.
<content>
<section id="version">
<name>Document History</name>
<list id="p1">
<item>
Release 0.1 -- Pre release.
</item>
</list>
</section>
.
.
.
</content>
The para tag contains a paragraph of possibly marked-up text.
Two paragraphs from War and Peace.
<para id="para1">
Prince Andrei was on duty that day and in constant attendance
on the Commander in Chief.
</para>
<para id="para2">
At six o'clock in the evening Kutuzov went to the Emperor's
headquarters, and after remaining but a short time with him,
went to the Grand Marshal of the Court, Count Tolstoy.
</para>
The name tag provides a searchable name for a particular object such as a document, section or a figure.
None
Unicode text representing an object's name
<section id="intro">
<name>An Introduction to CNXML</name>
.
.
.
</section>
The definition tag is used to define a word or a term.
<definition id='quardef'>
<term>quarter</term>
<meaning>One fourth of something.</meaning>
<example id='defex1'>
<para id='parex1'>
"He cut the pie into quarters and gave all four people a
piece."
</para>
</example>
<meaning>25 cents, a quarter of a dollar.</meaning>
<example id='defex2'>
<para id='parex2'>
"The drink cost a quarter."
</para>
</example>
<example id='defex3'>
<para id='parex3'>
"She picked up a roll of quarters so that she could do
laundry."
</para>
</example>
<seealso><term>dollar</term><term>penny</term></seealso>
</definition>
"He cut the pie into quarters and gave all four people a piece."
"The drink cost a quarter."
"She picked up a roll of quarters so that she could do laundry."
The meaning tag gives one definition of the word or phrase being defined in a definition. Each definition tag can have multiple meanings and therefore multiple meaning tags.
None
Meaning can contain a combination of inline tags, and special tags.
See the definition examples.
The glossary tag is where definitions that can be placed if the author does not wish to place them in the flow of text. For more information see CNXML Reference Extensions.
One or more definition tags.
<glossary id='glossary1'>
<definition id='quardef'>
<term>quarter</term>
<meaning>
<name>Meaning Name</name>
One fourth of something.
</meaning>
<example id='def'>
<para id='par'>
"He cut the pie into quarters and gave all four people a
piece."
</para>
</example>
<meaning>25 cents, a quarter of a dollar.</meaning>
<example id='def2'>
<para id='par2'>
"The drink cost a quarter."
</para>
</example>
<example id='def3'>
<para id='par3'>
"She picked up a roll of quarters so that she could do
laundry."
</para>
</example>
</definition>
</glossary>
The seealso tag is a list of terms that the author believes would be beneficial to the person reviewing the document. Each definition tag can contain one see also tag.
None
Seealso can contain one or more term tags.
See the definition examples.
The note tag is used to add a note about text in a CNXML document.
Note can take a combination of inline tags.
<para id="noteexample">
Chemistry lab was always a lot of fun. We played with a lot
of chemicals such as Sulfuric and Hydrochloric acid. <note
type="warning">Sulfuric and Hydrochloric Acid are very
dangerous. Please handle with caution.</note>
</para>
Chemistry lab was always a lot of fun. We played with a lot of chemicals such as Sulfuric and Hydrochloric acid.
The rule tag defines any type of "rule" such as theorems, axiom, lemmas, rule of thumb, etc. This tag is especially useful for mathematical texts.
First, rule may contain an optional name tag. Next, it must contain one or more statement tags. Finally, rule may contain zero or more proof tags and zero or more example tags in any order.
<rule type='theorem' id='ruleexcode'>
<name>Pythagorean Theorem</name>
<statement>
<para id='ruleexp1'>
On a right triangle, the sum of the squares of the
sides equals the square of the hypotenuse.
</para>
</statement>
<proof>
<para id='ruleexp2'>
Your favorite proof goes here.
</para>
</proof>
<example>
<para id='ruleexp3'>
Take a right triangle whose sides are of length 3, 4,
and 5. In this case the sum of the square of the two
shorter sides is 9+16=25. The square of the hypotenuse
is 25. So the theorem holds.
</para>
</example id='pythexamp1'>
<proof>
<para id='ruleexp4'>
Another proof could go here.
</para>
</proof>
<example id='pythexamp2'>
<para id='ruleexp5'>
Another example could go here.
</para>
</example>
</rule>
On a right triangle, the sum of the squares of the sides equals the square of the hypotenuse.
Your favorite proof goes here.
Take a right triangle whose sides are of length 3, 4, and 5. In this case the sum of the square of the two shorter sides is 9+16=25. The square of the hypotenuse is 25. So the theorem holds.
Another proof could go here.
Another example could go here.
These are the tags specific to adding lists and figures to the document.
The list tag is used to create ordered or unordered lists of items.
The list tag may contain an optional name tag followed by one or more item tags.
<list id="grocerylist" type="enumerated">
<name>Grocery List</name>
<item>Milk</item>
<item>Eggs</item>
<item>Sugar</item>
</list>
The item tag is used to specify an item of a list. It appears only as the child of list tags.
The item tag may contain an optional name tag followed by one or more inline tags.
<list id='forces'>
<name>Four fundamental forces</name>
<item>Electromagnetism</item>
<item>Gravity</item>
<item>Strong nuclear force</item>
<item>Weak nuclear force</item>
</list>
The figure tag provides the structure for creating a figure within a document. A figure could contain such things as an image, or a table, or several of these.
<figure id="fig1">
<name>A Happy Dog</name>
<media type="image/jpg" src="image1.jpg"/>
<caption>The dog displayed in this picture is enjoying a
comfortable bed.</caption>
</figure>
| A Happy Dog |
|---|
 |
The subfigure tag is used when you want to use more than one media tag or table tag, etc. inside of the same figure tag. It is only appropriate to use subfigures if the subfigures are related in some way. The usage of the subfigure tag is similar to that of figure, except that it cannot contain another subfigure tag.
Here are two subfigures appearing in a figure whose orient attribute is set to "horizontal".
<figure orient="horizontal" id="horfig">
<subfigure id="subfig1">
<media type="image/jpg" src="image1.jpg"/>
</subfigure>
<subfigure id="subfig2">
<media type="image/jpg" src="image2.jpg"/>
</subfigure>
</figure>
|
Similarly, here are two subfigures appearing in a figure whose orient attribute is set to "vertical".
<figure orient="vertical" id="vertfig">
<subfigure id="subfig3">
<media type="image/jpg" src="image1.jpg"/>
<caption>Dog sitting</caption>
</subfigure>
<subfigure id="subfig4">
<media type="image/jpg" src="image2.jpg"/>
<caption>Dog standing</caption>
</subfigure>
</figure>
|
The caption tag is only used to provide a caption for a figure or a subfigure. The caption tag is distinct from the name tag in that it provides a possibly lengthy description of the figure for the reader's use and not an overall title or name.
None
Caption may contain one or more inline tags.
In this example, notice the different roles played by the name tag and the caption tag.
<figure id="fig3">
<name>A Happy Dog</name>
<media type="image/jpg" src="image1.jpg"/>
<caption>The dog displayed in this picture is enjoying a
comfortable bed.</caption>
</figure>
| A Happy Dog |
|---|
|
The media tag inserts "media objects", such as images, applets, movies, sounds, or any valid mimetype, into CNXML documents.
The media tag may take one or more param tags, followed by one or more media tags.
<media type="application/postscript" src="image1.eps">
<param name='height' value='300'/>
<param name='width' value='200'/>
<media type='image/png' src='image2.png'/>
</media>
The example code illustrates the use of nested media tags. The outer image tag specifies the preferred (default) image. If the browser does not support that particular file type, the child media tag will be used instead.
<media type="application/x-java-applet" src="applet.class">
<param name='height' value='300'/>
<param name='width' value='200'/>
<media type='image/png' src='image2.png'/>
</media>
The param tag allows you to pass parameters to the media tag.
Special
none (EMPTY)
<media type="image/jpg" src="image1.jpg">
<param name='height' value='300'/>
<param name='width' value='200'/>
</media>
The equation tag is used to set off equations in CNXML documents by using unicode text and embedded media to display math.
The equation tag may optionally have name as the first child, to associate a name with the equation. The equation tag must contain any number of media tags, or mathml.
<equation id="eqn14">
<name>Euler's Relation</name>
<media type='image/gif' src='euler.gif' />
</equation>
<equation id='eqn15'>
<name>Simple Arithmetic</name>
11+27=38
</equation>
(1)CNXML uses the CALS Table Model for including tables into CNXML documents. Provided below is a brief description of the CALS tags, their attributes, and children (along with a helpful example; a second example). For a more complete description of the CALS Table consult the CALS Table Spec.
The table tag marks beginning of a table.
<table frame="all" id="budgettable1">
<name>Budget - Comparison by year</name>
<tgroup cols="4" align="left" colsep="1" rowsep="1">
<colspec colnum="2" colname="c2"/>
<colspec colnum="4" colname="c4"/>
<thead valign="top">
<row>
<entry morerows="1" align="center">Item</entry>
<entry namest="c2" nameend="c4" align="center">Year</entry>
</row>
<row>
<entry align="center">1998</entry>
<entry align="center">1999</entry>
<entry align="center">2000</entry>
</row>
</thead>
<tbody valign="top">
<row>
<entry>Income</entry>
<entry>12,293</entry>
<entry>12,398</entry>
<entry>14,298</entry>
</row>
<row>
<entry>Expenditure</entry>
<entry>293</entry>
<entry>398</entry>
<entry>298</entry>
</row>
<row>
<entry>Surplus</entry>
<entry>12000</entry>
<entry>12000</entry>
<entry>14000</entry>
</row>
</tbody>
</tgroup>
</table>
| Item | Year | ||
|---|---|---|---|
| 1998 | 1999 | 2000 | |
| Income | 12,293 | 12,398 | 14,298 |
| Expenditure | 293 | 398 | 298 |
| Surplus | 12000 | 12000 | 14000 |
The tgroup tag identifies a new portion of a table.
See the table example.
The colspec tag specifies a column of a table or entrytbl.
EMPTY
See the table example.
The spanspec tag identifies a horizontal span of columns and associated attributes that can subsequently be referenced by its spanname for repeated use in entry or entrytbl in different rows.
EMPTY
See the table example.
The thead tag identifies the heading row of a tgroup or entrytbl.
See the table example.
The tfoot tag identifies the rows of footer information that are displayed after the tbody.
See the table example.
The tbody tag identifies the body of a tgroup or entrytbl.
See the table example.
The row tag identifies the row of information in a thead, tbody, or tfoot.
See the table example.
The entrytbl tag takes the place of an entry, but fits into a single row of tbody in a tgroup. The content model is the same as that of a tgroup except that tfoot is ommitted and entrytbl is self-excluding.
See the table example.
The entry tag identifies a entry in a row.
The entry tag contains any number of inline tags and media.
See the table example.
To aid in testing conformance with this specification, we provide implementations in various schema formats below. In some cases, however, the schema language is not expressive enough to capture the full specification. In these cases we have chosen to allow the schema implementation to be more lax. In other words, any document conforming to the specification will validate according to the schema, but not necessarily vice versa. In all cases, consider this specification to be the definitive reference for CNXML, taking precedence over any provided schema. In other words, by definition the spec is always right.
<document>
<!DOCTYPE document PUBLIC "-//CNX//DTD CNXML 0.5//EN"
"http://cnx.rice.edu/cnxml/0.5/DTD/cnxml_plain.dtd">
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://cnx.rice.edu/cnxml http://cnx.rice.edu/cnxml/0.5/schema/cnxml.xsd"
CNXML does not encompass all possible markup that someone might wish to include in a document. Rather, it is intended to serve as a general-purpose framework for marking the structure and semantics of the material. For more specific markup in a particular area, you can can combine CNXML with other XML markup languages. A common example is the use of MathML to mark up mathematical equations (see below).
Since the same tag may be used to mean different things in
different XML languages, each language defines a URI to
act as a namespace, distinguishing it from
other languages. The combination of namespace URI and tag
name is globally unique. The CNXML namespace is:
http://cnx.rice.edu/cnxml. For more
information on how to use namespaces, see the W3C's Namespaces in
XML specification.
The combination of CNXML and MathML occurs commonly since much educational material has mathematical content. To aid in this, we have included a special DTD in the DTD archive above that allows you to validate combined CNXML/MathML files. To take advantage of this, do the following three things:
<document>
<!DOCTYPE document PUBLIC "-//CNX//DTD CNXML 0.5 plus MathML//EN"
"http://cnx.rice.edu/cnxml/0.5/DTD/cnxml_mathml.dtd">
xmlns:m="http://www.w3.org/1998/Math/MathML"
on <document>
m: to every MathML tag in your documentFormal equations and relations should be wrapped in the CNXML equation tag. These may be given names and are easy to search for. Additionally, some presentations of CNXML may provide automatic numbering for equations. In addition to formal equations, you may include math in any CNXML tag that allows inline tags.
<m:math> tag.
A short CNXML/MathML is listed below.
Note the DOCTYPE declaration at the top, the
xmlns and xmlns:m attributes on
the document tag, and the use of the m:
prefix on MathML tags.
<?xml version="1.0" standalone="no"?>
<!DOCTYPE document PUBLIC "-//CNX//DTD CNXML 0.5 plus MathML//EN"
"http://cnx.rice.edu/cnxml/0.5/DTD/cnxml_mathml.dtd">
<document xmlns="http://cnx.rice.edu/cnxml"
xmlns:m="http://www.w3.org/1998/Math/MathML"
id='mathml'>
<name>Combining MathML and CNXML</name>
<content>
<para id="p1">
This is a small piece of math written using MathML:
<m:math>
<m:apply>
<m:plus/>
<m:cn>2</m:cn>
<m:cn>3</m:cn>
</m:apply>
</m:math>
</para>
</content>
</document>
For more information on combining CNXML and MathML (including many examples), see the Connexions module Content MathML.