# NAME

s1kd-icncatalog - Manage the catalog used to resolve ICNs

# SYNOPSIS

    s1kd-icncatalog [options] [<object>...]

# DESCRIPTION

The *s1kd-icncatalog* tool is used to manage a catalog of ICNs for a
project, and to resolve ICNs using this catalog. Resolving an ICN means
placing the actual filename of the ICN in to the SYSTEM ID of the ENTITY
declaration within CSDB objects.

# OPTIONS

  - \-a, --add \<ICN\>  
    Add an ICN to the catalog. Follow with the -u and -n options to
    specify the URI and notation to use for this ICN. The -m option
    specifies a media group to add the ICN to.

  - \-C, --create  
    Create a new empty catalog.

  - \-c, --catalog \<catalog\>  
    Specify the catalog file to manage or resolve against. By default,
    the file `.icncatalog` in the current directory is used. If the
    current directory does not contain this file, the parent directories
    will be searched.

  - \-d, --del \<ICN\>  
    Delete an ICN from the catalog. The -m option specifies a media
    group to delete the ICN from.

  - \-f, --overwrite  
    Overwrite the input CSDB objects when resolving ICNs, or overwrite
    the catalog file when modifying it. Otherwise, output is written to
    stdout.

  - \-h, -?, --help  
    Show help/usage message.

  - \-l, --list  
    Treat input (stdin or arguments) as lists of filenames of CSDB
    objects, rather than CSDB objects themselves.

  - \-m, --media \<media\>  
    Resolve ICNs for this intended output media. The catalog may contain
    alternative formats for the same ICN to be used for different output
    media.

  - \-n, --ndata \<notation\>  
    Specify the notation to reference when adding an ICN with the -a
    option.

  - \-q, --quiet  
    Quiet mode. Errors are not printed.

  - \-t, --type \<type\>  
    Specify the type of catalog entry when adding an ICN with the -a
    option.

  - \-u, --uri \<URI\>  
    Specify the URI when adding an ICN with the -a option.

  - \-v, --verbose  
    Verbose output.

  - \--version  
    Show version information.

In addition, the following options allow configuration of the XML
parser:

  - \--dtdload  
    Load the external DTD.

  - \--huge  
    Remove any internal arbitrary parser limits.

  - \--net  
    Allow network access to load external DTD and entities.

  - \--noent  
    Resolve entities.

  - \--parser-errors  
    Emit errors from parser.

  - \--parser-warnings  
    Emit warnings from parser.

  - \--xinclude  
    Do XInclude processing.

  - \--xml-catalog \<file\>  
    Use an XML catalog when resolving entities. Multiple catalogs may be
    loaded by specifying this option multiple times.

# EXAMPLES

## Resolving ICNs to filenames

A CSDB object may reference an ICN as follows:

    <!NOTATION png SYSTEM "png">
    <!ENTITY ICN-12345-00001-001-01 SYSTEM "ICN-12345-00001-001-01.PNG"
    NDATA png>

The SYSTEM ID of this ENTITY indicates that the ICN file will be in the
same directory relative to the CSDB object. However, the ICN files in
this example are located in a separate folder called 'graphics'. Rather
than manually updating every ENTITY declaration in every CSDB object, a
catalog file can be used to map ICNs to actual filenames:

    <icnCatalog>
    <icn infoEntityIdent="ICN-12345-00001-001-01"
    uri="graphics/ICN-12345-00001-001-01.PNG"/>
    </icnCatalog>

Then, using this tool, the ICN can be resolved against the catalog:

    $ s1kd-icncatalog -c <catalog> <object>

Producing the following output:

    <!NOTATION png SYSTEM "png">
    <!ENTITY ICN-12345-00001-001-01 SYSTEM
    "graphics/ICN-12345-00001-001-01.PNG" NDATA png>

## Alternative ICN formats

A catalog can also be used to provide alternative file formats for an
ICN depending on the intended output media. For example:

    <icnCatalog>
    <notation name="jpg" systemId="jpg"/>
    <notation name="svg" systemId="svg"/>
    <media name="pdf">
    <icn infoEntityIdent="ICN-12345-00001-001-01"
    uri="ICN-12345-00001-001-01.JPG" notation="jpg"/>
    </media>
    <media name="web">
    <icn infoEntityIdent="ICN-12345-00001-001-01"
    uri="ICN-12345-00001-001-01.SVG" notation="svg"/>
    </media>
    </icnCatalog>

The -m option allows for specifying which type of media to resolve for:

    <!NOTATION png SYSTEM "png">
    <!ENTITY ICN-12345-00001-001-01 SYSTEM "ICN-12345-00001-001-01.PNG"
    NDATA png>

    $ s1kd-icncatalog -c <catalog> -m pdf <object>

    <!NOTATION png SYSTEM "png">
    <!NOTATION jpg SYSTEM "jpg">
    <!ENTITY ICN-12345-00001-001-01 SYSTEM "ICN-12345-00001-001-01.JPG"
    NDATA jpg>

    $ s1kd-icncatalog -c <catalog> -m web <object>

    <!NOTATION png SYSTEM "png">
    <!NOTATION svg SYSTEM "svg">
    <!ENTITY ICN-12345-00001-001-01 SYSTEM "ICN-12345-00001-001-01.SVG"
    NDATA svg>

## Reconstructing ICN entity declarations

Some processing, such as XSL transformations, may remove the DTD and
external entity declarations as part of parsing an XML CSDB object. A
catalog can be used to restore the necessary external entity
declarations afterwards. For example:

    $ xsltproc ex.xsl <object>

The resulting XML will not include a DTD or the external entity
declarations for the ICNs referenced in the object, so it will not be
valid according to the S1000D schema:

    $ xsltproc ex.xsl <object> | s1kd-validate
    -:49:element graphic: Schemas validity error: Element 'graphic',
    attribute 'infoEntityIdent': 'ICN-12345-00001-001-01' is not a valid
    value of the atomic type 'xs:ENTITY'.

Passing the result to this tool, with a catalog containing all the ICNs
used by the project:

    $ xsltproc ex.xsl <object> | s1kd-icncatalog -c <catalog>

will reconstruct the required external entity declarations in the DTD.

<div class="note">

The s1kd-tools will copy the DTD and external entity declarations
automatically when performing transformations, so this is only necessary
when using more generic XML tools.

</div>

## ICN pattern rules

By default, each catalog entry matches a single ICN, but multiple ICNs
can be resolved with a single entry by using a pattern rule. An entry
with attribute `type="pattern"` specifies a regular expression to use to
match ICNs and a template used to construct the resolved URI:

    <icn
    type="pattern"
    infoEntityIdent="ICN-(.{5})-(.*)"
    uri="graphics/\1/ICN-\1-\2.PNG"
    notation="PNG"/>

The above entry would match a series of CAGE-based ICNs, resolving them
to a subfolder of 'graphics' based on their CAGE code. Using this entry,
the following input:

    <!DOCTYPE dmodule [
    <!NOTATION PNG SYSTEM PNG>
    <!ENTITY ICN-12345-00001-001-01
    SYSTEM "ICN-12345-00001-001-01"
    NDATA PNG>
    <!ENTITY ICN-54321-00001-001-01
    SYSTEM "ICN-54321-00001-001-01"
    NDATA PNG>
    ]>

would be resolved as follows:

    <!DOCTYPE dmodule [
    <!NOTATION PNG SYSTEM PNG>
    <!ENTITY ICN-12345-00001-001-01
    SYSTEM "graphics/12345/ICN-12345-00001-001-01.PNG"
    NDATA PNG>
    <!ENTITY ICN-54321-00001-001-01
    SYSTEM "graphics/54321/ICN-54321-00001-001-01.PNG"
    NDATA PNG>
    ]>

The regular expressions must conform to the extended POSIX regular
expression syntax. Backreferences \\1 through \\9 can be used in the URI
template to substitute captured groups.

# CATALOG SCHEMA

The following describes the schema of an ICN catalog file.

## Catalog

*Markup element:* `<icnCatalog>`

*Attributes:*

  - None

*Child elements:*

  - `<notation>`

  - `<media>`

  - `<icn>`

## Notation

The element `<notation>` represents a NOTATION declaration.

*Markup element:* `<notation>`

*Attributes:*

  - `name`, the NDATA name.

  - `publicId`, the optional PUBLIC ID of the notation.

  - `systemId`, the optional SYSTEM ID of the notation.

*Child elements:*

  - None

## Media

The element `<media>` groups a set of alternative ICN formats for a
particular output media type.

*Markup element:* `<media>`

*Attributes:*

  - `name`, the identifier of the output media.

*Child elements:*

  - `<icn>`

## ICN

The element `<icn>` maps an ICN to a filename and optionally a notation.
When this element occurs as a child of a `<media>` element, it will be
used when that output media is specified with the -m option. When it
occurs as a child of `<icnCatalog>`, it will be used if no media is
specified.

*Markup element:* `<icn>`

*Attributes:*

  - `type`, the type of ICN entry, with one of the following values:
    
      - `"single"` (D) - Specifies a single ICN to resolve.
    
      - `"pattern"` - Specifies a pattern to resolve one or more ICNs.

  - `infoEntityIdent`, the ICN, or pattern used to match ICNs.

  - `uri`, the filename the ICN will resolve to.

  - `notation`, a reference to a previously declared `<notation>`
    element.

*Child elements:*

  - None

## Example ICN catalog

    <icnCatalog>
    <notation name="jpg" systemId="jpg"/>
    <notation name="png" systemId="png"/>
    <notation name="svg" systemId="svg"/>
    <media name="pdf">
    <icn infoEntityIdent="ICN-12345-00001-001-01"
    uri="ICN-12345-00001-001-01.JPG" notation="jpg"/>
    </media>
    <media name="web">
    <icn infoEntityIdent="ICN-12345-00001-001-01"
    uri="ICN-12345-00001-001-01.SVG" notation="svg"/>
    </media>
    <icn infoEntityIdent="ICN-12345-00001-001-01"
    uri="ICN-12345-00001-001-01.PNG" notation="png"/>
    </icnCatalog>