ont-app.rdf.core — ont-app/rdf 0.2.8

clj

This is a backstop for shared logic between various RDF-based implementations of IGraph. It includes:

• support for LangStr using the #voc/lstr custom reader
• support for ^^transit:json datatype tags
• templating utilities for the standard IGraph member access methods.
• i/o methods load-rdf read-rdf and write-rdf.

add-catalog-entry! clj/s

(add-catalog-entry! download-url namespace-uri prefix media-type)

Adds an entry in @resource-catalog for download-url namespace-uri prefix media-type

• Where
  • download-url is a URL (or string) naming a place on the web containing an RDF file
  • namespace-uri is the primary URI, associated with prefix
  • prefix is the preferred prefix for namespace-uri
  • media-type is the MIME type, of download-url eg 'text/turtle'

ask-s-p-o clj/s

(ask-s-p-o ask-fn rdf-store s p o)

(ask-s-p-o graph-uri ask-fn rdf-store s p o)

Returns true if s p o is a triple at endpoint of rdf-store Where:

• s p o are subject, predicate and object
• rdf-store is an RDF store
• graph-uri is a URI or KWI naming the graph, or a set of them (or nil if DEFAULT graph)
• ask-fn := fn [repo] -> bindings

ask-s-p-o-template clj/s

A 'stache template for a query ref'd in ask-s-p-o, informed by query-template-map

bnode-kwi? clj/s

(bnode-kwi? kwi)

True when kwi matches the canonical bnode representation.

cache-url-as-local-file clj/s

(cache-url-as-local-file context url)

RETURNS cached-file, with contents of url loaded SIDE-EFFECT: creates file named cached-file if it does not already exist.

• Where
  • context is a native-normal graph informed by vocabulary below.
  • url := a URL or string naming URL
  • cached-file-path names a local file to contain contents from url
• VOCABULARY (for context)
  • [:rdf-app/UrlCache :rdf-app/pathFn cached-file-path-fn]
    • optional. Default will try to derive parse-map from url first by looking it up in the @resource-catalog and then by parsing the url itself
  • [:rdf-app/UrlCache :rdf-app/directory cache-directory]
  • cached-file-path-fn := fn (uri) -> parse-map
  • parse-map := m s.t (keys m) :~ #{:url :path :stem :ext} for url informed by context

cached-file-path clj/s

(cached-file-path & {:keys [dir url stem ext]})

Returns a canonical path for cached contents read from a URL.

catalog-lookup clj/s

(catalog-lookup url)

Returns catalog-entry for url

• Where
  • catalog-entry := m s.t. (keys m) :~ #{?media-type :?prefix :?suffix :?media-url}
  • url is a URL that may be in the resource catalog
  • :?prefix is the preferred prefix associated with url (which informs the stem)
  • :?suffix is the suffix associated with the :?media-url (informs the extension)

check-ns-metadata clj/s

(check-ns-metadata kwi)

Logs a warning when kwi is in a namespace with no metadata.

check-qname clj/s

(check-qname uri-spec)

Traps the keyword assertion error in voc and throws a more meaningful error about blank nodes not being supported as first-class identifiers.

cljc-create-temp-file clj/s

(cljc-create-temp-file stem ext)

Returns a temporary file named per stem and ext. Not supported under cljs.

• where
  • stem is a general name for the file
  • ext is a file extension typically starting with '.'

cljc-file-exists? clj/s

(cljc-file-exists? path)

True when path exists in the local file system

cljc-file-length clj/s

(cljc-file-length f)

Returns length of file f. Not supported under cljs.

cljc-http-get clj/s

(cljc-http-get url req)

Makes a GET call to url with req. Not yet supported in cljs.

• Where
  • url is a URL or a URL string
  • req is an http request map

cljc-is-local-file? clj/s

(cljc-is-local-file? f)

True when f is a file in the local file system

cljc-make-file clj/s

(cljc-make-file path)

Returns new file object for path. Not supported under cljs.

cljc-make-parents clj/s

(cljc-make-parents f)

Ensures directory path for file f. Not supported under cljs.

cljc-resource clj/s

(cljc-resource r)

Returns the resource named by r. Not supported under cljs.

coerce-graph-element clj/s

(coerce-graph-element x)

(coerce-graph-element policy x)

Returns x, possibly coerced to either a kwi or a java.net.URI per policy

• where
  • policy := m s.t. (keys m) :- #{::kwi-if ::uri-if}
  • x is any candidate as an element in an IGraph
  • kwi-if := fn [x] -> truthy if x should be translated to a keyword id
  • uri-if := fn [x] -> truthy if x should be translated to a java.net.URI
• NOTE: Some implementations of IGraph may be a lot more tolarant of datatypes in s/p/o position than the URI/URI/URI-or-literal that RDF expects.

collect-ns-catalog-metadata clj/s

(collect-ns-catalog-metadata gacc _prefix ns)

Reducing function outputs gacc' given voc metadata assigned to namespace

• NOTE: typically used to initialize the resource catalog.

default-context clj/s

An atom containing a native-normal graph with default i/o context configurations.

• NOTE: This would typically be the starting point for the i/o context of individual implementations.
• VOCABULARY
  • [:rdf-app/UrlCache :rdf-app/directory URL cache directory]

from-clause-for clj/s

(from-clause-for graph-uri)

Returns FROM graph-uri' Note: typically informs query-template-map

get-cached-file-path-spec clj/s

(get-cached-file-path-spec context url)

Returns m s.t (keys m) :~ #{:url :path :stem :ext} for url informed by context

• Where
  • url (as arg) is x s.t. (str x) -> a URL string
  • context is an native-normal graph describing the I/O context
  • url (as key) is a URL string
  • path is the path component of url
  • stem is the 'stem portion of /path/to/<stem>.<ext>
  • ext is the 'ext' portion of /path/to/<stem>.<ext>
  • dir is the directory containing cache files
• NOTE: this should be sufficient to create a unique temp file path for caching contents of url.
• VOCABULARY
  • [:rdf-app/UrlCache :rdf-app/pathFn cached-file-path-fn]
    • optional. Default will try to infer m from url automatically Either through lookup-file-specs-in-catalog or by parsing url itself.
  • [:rdf-app/UrlCache :rdf-app/directory dir]
  • cached-file-path-fn := fn (uri) -> m

http-get-from-catalog clj/s

(http-get-from-catalog url)

returns an http response to a GET request for url

• Where
  • url is a URL with an entry in the @resource-catalog

load-rdf clj/s multimethod

Returns a new IGraph with contents for to-load,

• args: [context to-load]

• dispatched on: [graph-dispatch to-load-rdf-dispatch]

• Where

  • context is a native-normal graph with descriptions per the vocabulary below. It may also provide platform-specific details that inform specific methods.
  • to-load is typically a path or URL, but could be anything you write a method for
    • if this is a file name that exists in the local file system this will be dispatched as :rdf-app/LocalFile. We may need to derive file-extension.
  • graph-dispatch is the dispatch value identifying the IGraph implementation
  • to-load-rdf-dispatch is the dispatch value derived for to-load-rdf
  • file-extension may be implicit from a file name or derived per vocabulary below It may be necesary to inform your RDF store about the expected format.

• VOCABULARY (in context)

  • [#'load-rdf :rdf-app/hasGraphDispatch graph-dispatch]
  • [#'load-rdf :rdf-app/toImportDispatchFn (fn [to-load] -> to-load-dispatch)] ... optional. Defaults to output of standard-data-transfer-dispatch
  • [#'load-rdf :rdf-app/extensionFn (fn [to-load] -> file-extension)] ... optional. By default it parses the presumed path name described by to-load
  • [rdf-app/UrlCache rdf-app/directory cache-directory]
  • [rdf-app/UrlCache rdf-app/cacheMaintenance :rdf-app/DeleteOnRead] ... optional. specifies that a cached file should be deleted after a read.
    • by default it will not be deleted.

load-rdf-dispatch clj/s

(load-rdf-dispatch context to-load)

Returns [graph-dispatch to-load-dispatch]. See docstring for rdf/load-rdf

lookup-file-specs-in-catalog clj/s

(lookup-file-specs-in-catalog url)

Returns file-specs for url

• Where
  • file-specs := m s.t. (keys m) :~ #{:url :path :stem :ext}
  • url (as arg) is a URL we may want to get from an http call
  • url (as key) is the string version of url
  • path is the file path of url
  • stem is the preferred prefix for url in the catalog
  • ext is the file suffix associated with the media type of url in the catalog

normal-form-query-template clj/s

A 'stache template for a query ref'd in query-for-normal-form, informed by query-template-map

on-js-reload cljs

(on-js-reload)

ontology clj/s

The supporting vocabulary for the RDF module

parse-url clj/s

(parse-url url)

Returns a file specification parsed directly from a URL (not in the catalog), or nil

• where
  • url is a URL, probably a file resource

parse-url-re clj/s

A regex to parse a file URL string with a file name and an extension.

prefixed clj/s

Returns query, with prefix declarations prepended Where

• query is presumed to be a SPARQL query

query-for-normal-form clj/s

(query-for-normal-form query-fn rdf-store)

(query-for-normal-form graph-uri query-fn rdf-store)

Returns IGraph normal form for graph named by graph-uri in rdf-store Where

• graph is a named graph in rdf-store
• graph-uri is a URI or KWI naming the graph, or a set of them (default nil -> DEFAULT graph)
• rdf-store is an RDF store
• query-fn := fn [rdf-store sparql-query] -> #{bmap, ...}
• bmap := {:?s :?p :?o}
• sparql-query :- normal-form-query-template

query-for-o clj/s

(query-for-o query-fn rdf-store s p)

(query-for-o graph-uri query-fn rdf-store s p)

Returns #{o...} for s and p at endpoint of rdf-store Where:

• o is an object rendered per binding translator of rdf-store
• s is a subject URI rendered per binding translator of rdf-store
• p is a predicate URI rendered per binding translator of rdf-store
• rdf-store is an RDF store
• query-fn := fn [repo] -> bindings
• graph-uri is a URI or KWI naming the graph, or a set of them (or nil if DEFAULT graph)

query-for-o-template clj/s

A 'stache template for a query ref'd in query-for-o, informed by query-template-map

query-for-p-o clj/s

(query-for-p-o query-fn rdf-store s)

(query-for-p-o graph-uri query-fn rdf-store s)

Returns {p #{o...}...} for s from query to rdf-store Where

• p is a predicate URI rendered per binding translator of rdf-store
• o is an object value, rendered per the binding translator of rdf-store
• s is a subject uri keyword. ~ voc/voc-re
• rdf-store is and RDF store.
• query-fn := fn [repo] -> bindings
• graph-uri is a URI or KWI naming the graph, or a set of them (or nil if DEFAULT graph)

query-for-p-o-template clj/s

A 'stache template for a query ref'd in query-for-p-o, informed by query-template-map

query-for-subjects clj/s

(query-for-subjects query-fn rdf-store)

(query-for-subjects graph-uri query-fn rdf-store)

Returns [subject ...] at endpoint of rdf-store for graph-uri Where

• subject is the uri of a subject from rdf-store, rendered per the binding translator of rdf-store
• rdf-store conforms to ::sparql-client spec
• query-fn := fn [repo] -> bindings
• graph-uri is a URI or KWI naming the graph, or a set of them (or nil if DEFAULT graph)

query-template-defaults clj/s

Default key/value pairs appicable to query templates for your platform. Where

• :from-clauses one FROM clause for each graph informing the query
• :rebind-_s asserts new binding for ?_s in ?_s ?_p ?_o
• :rebind-_p asserts a new binding the value retrieved for ?_p in ?_s ?_p ?_o
• :rebind-_o aserts a new binding the value retrieved for ?_o in ?_s ?_p ?_o
• NOTE: For example we may assert :rebind-_s as IRI(?_S) in jena to set up bnode round-tripping for ?_s.

quote-str clj/s

(quote-str s)

Returns s, in escaped quotation marks. Where

• s is a string, typically to be rendered in a query or RDF source.

read-rdf clj/s multimethod

Side-effect: updates g with added contents from to-read, Returns: modified g

• args: [context g to-read]

• dispatched on: [graph-dispatch to-read-dispatch]

• Where

  • context is a native-normal graph with descriptions per the vocabulary below. It may also provide platform-specific details that inform specific methods.

  • to-read is typically a path or URL, but could be anything you write a method for

    • if this is a file name that exists in the local file system this will be dispatched as :rdf-app/LocalFile. We may need to derive file-extension.

  • graph-dispatch is the dispatch value identifying the IGraph implementation

  • to-read-dispatch is the dispatch value derived for to-read

  • file-extension may be implicit from a file name or derived per vocabulary below It may be necesary to inform your RDF store about the expected format.

• VOCABULARY (in context)

• [#'read-rdf :rdf-app/hasGraphDispatch graph-dispatch]

• [#'read-rdf :rdf-app/toImportDispatchFn (fn [to-read] -> to-read-dispatch)] ... optional. Defaults to output of standard-data-transfer-dispatch

• [#'read-rdf :rdf-app/extensionFn (fn [to-read] -> file-extension)] ... optional. By default it parses the presumed path name described by to-read

read-rdf-dispatch clj/s

(read-rdf-dispatch context g to-read)

Returns [graph-dispatch to-read-dispatch]. See docstring for rdf/read-rdf

read-transit-json clj/s

(read-transit-json s)

Returns a value parsed from transit string s Where

• s is a "-escaped string encoded as transit Note: custom datatypes will be informed by @transit-read-handlers

render-literal clj/s multimethod

Returns an RDF (Turtle) rendering of literal for methods with signature (fn [literal] -> rdf)

render-literal-as-transit-json clj/s

(render-literal-as-transit-json x)

Returns 'x^^transit:json' NOTE: this will be encoded on write and decoded on read by the cognitect/transit library.

render-literal-dispatch clj/s

(render-literal-dispatch literal)

Returns a key for the render-literal method to dispatch on given literal Where

• literal is any non-keyword
• NOTE: LangStr and non-nil special-dispatch are special cases; otherwise (type literal)

render-transit-json clj/s

(render-transit-json value)

Returns a string of transit for value Where

• value is any value that be handled by cognitict/transit
• Note: custom datatypes will be informed by @transit-write-handlers

resource-catalog clj/s

A native normal graph using this vocabulary:

• [namespace-uri :dcat/downloadURL download-url]
• [namespace-uri :vann/preferredNamespacePrefix prefix]
• [download-url :dcat/mediaType media-type]
• where
  • download-url is a URL string
  • media-type := :rdf/type :dct/MediaTypeOrExtent

special-literal-dispatch clj/s

A function [x] -> dispatch-value Where

• x is any value, probabaly an RDF literal
• dispatch-value is a value to be matched to a render-literal-dispatch method. Default is to return nil, signalling no special dispatch.

standard-data-transfer-dispatch clj/s

(standard-data-transfer-dispatch to-transfer)

Returns a standard dispatch-key for to-transfer, defaulting to (type to-transfer)

• Where
  • to-transfer is typically an argument to the load-rdf, read-rdf or write-rdf methods.
  • dispatch-key :~ #{:rdf-app/LocalFile, :rdf-app/FileResource :rdf/WebResource} or the type of to-transfer.
  • :rdf-app/LocalFile indicates that to-transfer is a local path string
  • :rdf-app/FileResource indicates that to-transfer is a file resource (maybe from a jar)
  • :rdf-app/WebResource indicates something accessible through a curl call.

subjects-query-template clj/s

A 'stache template for a query ref'd in query-for-subjects, informed by query-template-map

transit-re clj/s

Matches data tagged as transit:json

transit-read-handlers clj/s

Atom of the form {className read-handler, ...} Where

• className is a fully qualified string naming a class to be encoded
• read-handler := fn [from-rep] -> instance
• from-rep := an Object s.t. (field from-rep), encoded in corresponding write-handler in @transit-write-handlers.

transit-write-handlers clj/s

Atom of the form {Class write-handler, ...} Where

• Class, a symbol, is a direct reference to the class instance to be encoded
• write-handler := fn [s] -> {field value, ...}

write-rdf clj/s multimethod

Side-effect: writes contents of g to to-write in fmt, Returns: modified g

• args: [context g to-write fmt]

• dispatched on: [graph-dispatch to-write-dispatch fmt]

• Where

  • context is a native-normal graph with descriptions per the vocabulary below. It may also provide platform-specific details that inform specific methods.
  • to-write is typically a path or URL, but could be anything you write a method for
    • if this is a file name that exists in the local file system this will be dispatched as :rdf-app/LocalFile.
  • graph-dispatch is the dispatch value identifying the IGraph implementation
  • to-write-dispatch is the dispatch value derived for to-write
  • fmt is typically a KWI derived from :dct/MediaTypeOrExtent

• VOCABULARY (in context)

• [#'write-rdf :rdf-app/hasGraphDispatch graph-dispatch]

• [#'write-rdf :rdf-app/toExportDispatchFn (fn [to-write] -> to-write-dispatch)] ... optional. Defaults to (type to-write)

write-rdf-dispatch clj/s

(write-rdf-dispatch context g to-write fmt)

Returns [graph-dispatch to-write-dispatch fmt]. See docstring for rdf/write-rdf