A record object is a retrieval record on the client side - created from result sets.
void ZOOM_resultset_records(ZOOM_resultset r,
ZOOM_record *recs,
size_t start, size_t count);
ZOOM_record ZOOM_resultset_record(ZOOM_resultset s, size_t pos);
const char *ZOOM_record_get(ZOOM_record rec, const char *type,
size_t *len);
int ZOOM_record_error(ZOOM_record rec, const char **msg,
const char **addinfo, const char **diagset);
ZOOM_record ZOOM_record_clone(ZOOM_record rec);
void ZOOM_record_destroy(ZOOM_record rec);
References to temporary records are returned by functions
ZOOM_resultset_records or
ZOOM_resultset_record.
If a persistent reference to a record is desired
ZOOM_record_clone should be used.
It returns a record reference that should be destroyed
by a call to ZOOM_record_destroy.
A single record is returned by function
ZOOM_resultset_record that takes a
position as argument. First record has position zero.
If no record could be obtained NULL is returned.
Error information for a record can be checked with
ZOOM_record_error which returns non-zero
(error code) if record is in error, called Surrogate
Diagnostics in Z39.50.
Function ZOOM_resultset_records retrieves
a number of records from a result set. Parameter start
and count specifies the range of records to
be returned. Upon completion, the array
recs[0], ..recs[count-1]
holds record objects for the records. The array of records
recs should be allocated prior the call
ZOOM_resultset_records. Note that for those
records that couldn't be retrieved from the target,
recs[ ..] is set to NULL.
In order to extract information about a single record,
ZOOM_record_get is provided. The
function returns a pointer to certain record information. The
nature (type) of the pointer depends on the parameter,
type.
The type is a string of the format:
format[;charset=from[/opacfrom][,to]][;format=v][;base64=xpath]
If charset is given, then from
specifies the character set of the record in its original form
(as returned by the server), to specifies
the output (returned) character set encoding.
If to is omitted, then UTF-8 is assumed.
If charset is not given, then no character set conversion takes place.
OPAC records may be returned in a different
set from the bibliographic MARC record. If this is this the case,
opacfrom should be set to the character set
of the OPAC record part.
The format is generic but can only be used to
specify XML indentation when the value v
is 1 (format=1).
The base64 allows a full record to be extracted
from base64-encoded string in an XML document.
Specifying the OPAC record character set requires YAZ 4.1.5 or later.
Specifying the base64 parameter requires YAZ 4.2.35 or later.
The format argument controls whether record data should be XML
pretty-printed (post process operation).
It is enabled only if format value v is
1 and the record content is XML well-formed.
In addition, for certain types, the length
len passed will be set to the size in bytes of
the returned information.
The following are the supported values for form.
databaseThe Database of the record is returned
as a C null-terminated string. Return type
const char *.
syntaxThe transfer syntax of the record is returned
as a C null-terminated string containing the symbolic name of
the record syntax, e.g. Usmarc. Return type
is
const char *.
schemaThe schema of the record is returned
as a C null-terminated string. Return type is
const char *.
renderThe record is returned in a display friendly
format. Upon completion, buffer is returned
(type const char *) and length is stored in
*len.
rawThe record is returned in the internal
YAZ specific format. For GRS-1, Explain, and others, the
raw data is returned as type
Z_External * which is just the type for
the member retrievalRecord in
type NamePlusRecord.
For SUTRS and octet aligned record (including all MARCs) the
octet buffer is returned and the length of the buffer.
xmlThe record is returned in XML if possible.
SRU, Solr and Z39.50 records with transfer syntax XML are
returned verbatim. MARC records are returned in
MARCXML
(converted from ISO2709 to MARCXML by YAZ).
OPAC records are also converted to XML and the
bibliographic record is converted to MARCXML (when possible).
GRS-1 records are not supported for this form.
Upon completion, the XML buffer is returned
(type const char *) and length is stored in
*len.
opacOPAC information for record is returned in XML if an OPAC record is present at the position given. If no OPAC record is present, a NULL pointer is returned.
txmlThe record is returned in TurboMARC if possible.
SRU and Z39.50 records with transfer syntax XML are
returned verbatim. MARC records are returned in
TurboMARC
(converted from ISO2709 to TurboMARC by YAZ).
Upon completion, the XML buffer is returned
(type const char *) and length is stored in
*len.
jsonLike xml, but MARC records are converted to MARC-in-JSON.
Most MARC21 records uses the MARC-8 character set encoding. An application that wishes to display in Latin-1 would use
render; charset=marc8,iso-8859-1
The functions ZOOM_resultset_record and
ZOOM_resultset_records inspects the client-side
record cache. Records not found in cache are fetched using
Present.
The functions may block (and perform network I/O) - even though option
async is 1, because they return records objects.
(And there's no way to return records objects without retrieving them!)
There is a trick, however, in the usage of function
ZOOM_resultset_records that allows for
delayed retrieval (and makes it non-blocking). By using
a null pointer for recs you're indicating
you're not interested in getting records objects
now.