label.pl -- Support for showing labels

This module provides HTML components to display labels for resources.

See also

- library(semweb/rdf_label) returns textual labels.

 turtle_label(+RDFTerm)// is det

HTML rule to emit an RDF term (resource or object) in turtle-like notation with CSS classes.

To be done

- Implement possibility for a summary.

 bnode_label(+Resource, +Options)// is semidet[private]

Display an HTML label for an RDF blank node. This DCG rules first calls the hook cliopatria:bnode_label//1. On failure performs its default task:

• If the bnode has an rdf:value, display the label thereof with [<label>...]
• If the bnode is an RDF collection, display its first 5 members as (<member-1>, <member-2, ...)

 rdf_link(+URI)// is det

 rdf_link(+URI, +Options)// is det

Make a hyper-link to an arbitrary RDF resource or object using the label. Options processed:

resource_format(+Format)

Determines peference for displaying resources. Values are:

plain

Display full resource a plain text

label

Try to display a resource using its label

nslabel

Try to display a resource as <prefix>:<Label>

turtle

Try to display as Turtle <prefix>:<local>

max_length(+Len)

Truncate long texts to Len characters, using ellipses to indicate that the text is truncated.

target(+Target)

Passed to the HTML <a> element as target attribute.

role(+Role)

Passed to display_link/2 hook as option. Can be used to differentiate display of URI depending on role as subject, predicate, object, bnode, domain, or range.

This predicate creates two types of links. Resources are linked to the handler implementing list_resource using r=<resource> and literals that appear multiple times are linked to list_triples_with_object using a Prolog representation of the literal.

This predicate can be hooked using display_link//2.

To be done

- Make it easier to determine the format of the label

- Allow linking to different handlers.

 resource_link(+URI, -URL) is det

Generate a link to display more information about a resource. The default is to link to the HTTP handler implementing list_resource using the parameter r. See cpa_browse:list_resource/1. This predicate calls the hook resource_link/2, which allows for overruling the default.

Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 rdf_link(Arg1, Arg2, Arg3, Arg4)