Querying the CTAN Database with XML – Topic

The information about a single topic can be obtained under the URL like

https://www.ctan.org/xml/2.0/topic/cv

The last element in the URl is the key of the topic as used by CTAN. Those keys are also listed in the list of topics.

The result is an XML file as in the following listing:

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE topic SYSTEM 'https://www.ctan.org/xml/2.0/catalogue.dtd'>
<topic name="cv" details="curriculum vitae/Resumé" />  

The entry has the outer tag <topic>. This tag has several attributes:

name

This attribute contains the key of the topic. This attribute is mandatory.

details

This attribute contains a short description of the topic.

References

You can request that more information about the topics is provided. This information is the list of packages in which the topic is mentioned. This is accomplished with the parameter ref. It can be set to true as in the following example:

https://www.ctan.org/xml/2.0/topic/cv?ref=true

This results in an XML file like in the following listing;

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE authors SYSTEM 'https://www.ctan.org/xml/2.0/catalogue.dtd'>
<topic name="cv" details="curriculum vitae/Resumé">
  <package key="currvita" />
  <package key="cvsty" />
  <package key="cv" />
  <package key="curve" />
  …
</topic  

In this case the <topic> tag contains a list of inner tags for the packages. Each package is contained in the tag <package> which has the following attributes:

key

This attribute contains the key of the package. This attribute is mandatory.

Omitting Or Enforcing the Doctype Declaration

The list of licenses may include a doctype declaration. This declaration can be suppressed with the URL parameter no-dtd which should be set to true as in

https://www.ctan.org/xml/2.0/licenses?no-dtd=true

A doctype declaration can be enforced with the URL parameter no-dtd which should be set to false in this case.

The default is no-dtd=false.

Omitting the XML Declaration

The list of licenses starts with an XML declaration. This declaration can be suppressed with the URL parameter no-xml which should be set to true as in

https://www.ctan.org/xml/2.0/licenses?no-xml=true