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Rasqal RDF Query Library Manual | ![]() |
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int rasqal_query_results_formats_enumerate (unsigned int counter, const char **name, const char **label, unsigned char **uri_string); typedef rasqal_query_results_formatter; rasqal_query_results_formatter* rasqal_new_query_results_formatter (const char *name, raptor_uri *uri); void rasqal_free_query_results_formatter (rasqal_query_results_formatter *formatter); int rasqal_query_results_formatter_write (raptor_iostream *iostr, rasqal_query_results_formatter *formatter, rasqal_query_results *results, raptor_uri *base_uri);
Variable bindings and boolean query results can be formatted into different syntaxes such as SPARQL Query Results Format or JSON. The rasqal_query_results_formatter class allows choosing a formatter for a particular syntax and writing the syntax to a raptor_iostream which allows turning the syntax into a string, writing to a file handle or other custom destination.
int rasqal_query_results_formats_enumerate (unsigned int counter, const char **name, const char **label, unsigned char **uri_string);
Get information on query result syntaxes.
The current list of format names/URI is given below however the results of this function will always return the latest.
SPARQL XML Results 2006-01-25 (default format when counter
is 0)
name 'xml
' with
URIs http://www.w3.org/TR/2006/WD-rdf-sparql-XMLres-20060125/ or
http://www.w3.org/2005/sparql-results#
JSON name 'json
' and
URI http://www.w3.org/2001/sw/DataAccess/json-sparql/
Older formats:
Name 'xml-v2
' with
URIs http://www.w3.org/TR/2005/WD-rdf-sparql-XMLres-20050527/ or
http://www.w3.org/2001/sw/DataAccess/rf1/result2
Name 'xml-v1
' with
URIs http://www.w3.org/TR/2004/WD-rdf-sparql-XMLres-20041221/ or
http://www.w3.org/2001/sw/DataAccess/rf1/result
If the writing succeeds, the query results will be exhausted.
counter : |
index into the list of query result syntaxes |
name : |
pointer to store the name of the query result syntax (or NULL) |
label : |
pointer to store query result syntax readable label (or NULL) |
uri_string : |
pointer to store query result syntax URI string (or NULL) |
Returns : | non 0 on failure of if counter is out of range |
rasqal_graph_query_results_formatter* query_results_formatter;
Rasqal query results formatter class.
rasqal_query_results_formatter* rasqal_new_query_results_formatter (const char *name, raptor_uri *uri);
Constructor - create a new rasqal_query_results_formatter object.
A query results format can be named or identified by a URI, both
of which are optional. The default query results format will be used
if both are NULL. rasqal_query_results_formats_enumerate()
returns
information on the known query results names, labels and URIs.
name : |
the query results format name (or NULL) |
uri : |
raptor_uri query results format uri (or NULL) |
Returns : | a new rasqal_query_results_formatter object or NULL on failure |
void rasqal_free_query_results_formatter (rasqal_query_results_formatter *formatter);
Destructor - destroy a rasqal_query_results_formatter object.
formatter : |
rasqal_query_results_formatter object |
int rasqal_query_results_formatter_write (raptor_iostream *iostr, rasqal_query_results_formatter *formatter, rasqal_query_results *results, raptor_uri *base_uri);
Write the query results using the given formatter to an iostream
See rasqal_query_results_formats_enumerate()
to get the
list of syntax URIs and their description.
iostr : |
raptor_iostream to write the query to |
formatter : |
rasqal_query_results_formatter object |
results : |
rasqal_query_results query results format |
base_uri : |
raptor_uri base URI of the output format |
Returns : | non-0 on failure |