X-Git-Url: https://git.dlugolecki.net.pl/?a=blobdiff_plain;f=doc%2Fusage.html;h=409ebbf308878bf17f0b2726ade6faf57a8eedb3;hb=a9ef3e45e68f855ec594bd5f1fa5e25618a706fd;hp=3d13ab0d8f93eedabbd68c4f3fdb7deb04af6e8c;hpb=a6f453d612fe285d2585b689e3e4d675de455510;p=gedcom-parse.git diff --git a/doc/usage.html b/doc/usage.html index 3d13ab0..409ebbf 100644 --- a/doc/usage.html +++ b/doc/usage.html @@ -1,399 +1,615 @@ - - -
-libgedcom.so
), to be linked in the application
- programgedcom.h
), to be used in the sources
-of the application programlibgedcom.so
), to be linked in the application
+ programgedcom.h
), to be used in the sources
+ of the application programgedcom-tags.h
) that is also installed,
+ but that is automatically included via gedcom.h
$PREFIX/share/gedcom-parse
- that contains some additional stuff, but which is not immediately important
- at first. I'll leave the description of the data directory for later.$PREFIX/share/gedcom-parse
+ that contains some additional stuff, but which is not immediately
+important at first. I'll leave the description of the data directory
+for later.int result;
- ...
- result = gedcom_parse_file("myfamily.ged");
-
- Although this will not provide much information, one thing it does is parse
-the entire file and return the result. The function returns 0 on success
-and 1 on failure. No other information is available using this function
-only.- In the above piece of code,void my_message_handler (Gedcom_msg_type type, -char *msg)
- {
- ...
- }
- ...
- gedcom_set_message_handler(my_message_handler);
- ...
- result = gedcom_parse_file("myfamily.ged");
-
my_message_handler
is the callback
-that will be called for errors (type=ERROR
), warnings (
-type=WARNING
) and messages (type=MESSAGE
). The callback
-must have the signature as in the example. For errors, the
-msg
passed to the callback will have the format:my_message_handler
is the callback
+ that will be called for errors (type=ERROR
), warnings (type=WARNING
) and messages (type=MESSAGE
). The
+ callback must have the signature as in the example. For errors, the
+ msg
passed to the callback will have the format:- Note that the entire string will be properly internationalized, and encoded -in UTF-8 (see "Why UTF-8?" LINK TBD). Also, no newline -is appended, so that the application program can use it in any way it wants. - Warnings are similar, but use "Warning" instead of "Error". Messages -are plain text, without any prefix.Error on line
<lineno>: <actual_message>
-
printf
- is used in the message handler.
+printf
is used in the message handler.- Using theGedcom_ctxt my_header_start_cb (int level, -Gedcom_val xref, char *tag)
- {
- printf("The header starts\n");
- return (Gedcom_ctxt)1;
- }
-
- void my_header_end_cb (Gedcom_ctxt self)
- {
- printf("The header ends, context is %d\n", self); /* context -will print as "1" */
- }
-
- ...
- gedcom_subscribe_to_record(REC_HEAD, my_header_start_cb, -my_header_end_cb);
- ...
- result = gedcom_parse_file("myfamily.ged");
-
gedcom_subscribe_to_record
function, the application
-requests to use the specified callbacks as start and end callback. The end
-callback is optional: you can pass NULL
if you are not interested
-in the end callback. The identifiers to use as first argument to the
-function (here REC_HEAD
) are described in the
-interface details.Gedcom_ctxt
type that is used as a result of the start
-callback and as an argument to the end callback is vital for passing context
-necessary for the application. This type is meant to be opaque; in
-fact, it's a void pointer, so you can pass anything via it. The important
-thing to know is that the context that the application returns in the start
-callback will be passed in the end callback as an argument, and as we will
-see shortly, also to all the directly subordinate elements of the record.struct
that will contain the information for the
-header. In the end callback, the application could then e.g. do some
-finalizing operations on the struct
to put it in its database.Gedcom_val
type for the xref
argument
-was not discussed, see further for this)- The subscription mechanism for elements is similar, only the signatures -of the callbacks differ. The signature for the start callback shows -that the context of the parent line (e.g. theGedcom_ctxt my_header_source_start_cb(Gedcom_ctxt -parent,
- - int - level,
- - char* - tag,
+
- char* - raw_value,
+ Gedcom_val xref,
- Gedcom_val parsed_value)
- {
- char *source = GEDCOM_STRING(parsed_value);
- printf("This file was written by %s\n", source);
- return parent;
- }
-
- void my_header_source_end_cb(Gedcom_ctxt parent,
+ char *tag,
- Gedcom_ctxt self,
+ char *raw_value,
- Gedcom_val parsed_value)
- {
- printf("End of the source description\n");
- }
-
- ...
- gedcom_subscribe_to_element(ELT_HEAD_SOUR,
+ int parsed_tag,
- my_header_source_start_cb,
- - my_header_source_end_cb);
- ...
- result = gedcom_parse_file("myfamily.ged");
-
struct
that describes
-the header) is passed to this start callback. The callback itself returns
-here the same context, but this can be its own context object of course. The
-end callback is called with both the context of the parent and the context
-of itself, which will be the same in the example. Again, the list of
-identifiers to use as a first argument for the subscription function are
-detailed in the interface details
-.Gedcom_val
type is meant to be an opaque type. The
-only thing that needs to be known about it is that it can contain specific
-data types, which have to be retrieved from it using pre-defined macros. These
-data types are described in the
-interface details. gedcom_subscribe_to_record
function, the application
+ requests to use the specified callbacks as start and end callback. The end
+ callback is optional: you can pass NULL
if you are not interested
+ in the end callback. The identifiers to use as first argument to
+the function (here REC_HEAD
) are described in the
+ interface details.Gedcom_ctxt
type that is used as a result of the start
+ callback and as an argument to the end callback is vital for passing context
+ necessary for the application. This type is meant to be opaque; in
+ fact, it's a void pointer, so you can pass anything via it. The important
+ thing to know is that the context that the application returns in the start
+ callback will be passed in the end callback as an argument, and as we will
+ see shortly, also to all the directly subordinate elements of the record.tag
is the GEDCOM tag in string format, the parsed_tag
+ is an integer, for which symbolic values are defined as TAG_HEAD,
+ TAG_SOUR,
TAG_DATA,
... and USERTAG
+ for the application-specific tags. These values are defined in the
+ header gedcom-tags.h
that is installed, and included via
+ gedcom.h
(so no need to include gedcom-tags.h
yourself).struct
(or an object in a C++ application) that will contain the information for the
+ header. In the end callback, the application could then e.g. do some
+ finalizing operations on the struct
to put it in its database.Gedcom_val
type for the xref
+ and parsed_value
arguments was not discussed, see further
+for this)+ The subscription mechanism for elements is similar, only the signatures + of the callbacks differ. The signature for the start callback shows + that the context of the parent line (here e.g. theGedcom_ctxt my_header_source_start_cb(Gedcom_ctxt + parent,
+ + int + level,
+ + char* + tag,
+ + char* + raw_value,
+ + int + parsed_tag,
+ + Gedcom_val + parsed_value)
+ {
+ char *source = GEDCOM_STRING(parsed_value);
+ printf("This file was written by %s\n", source);
+ return parent;
+ }
+
+ void my_header_source_end_cb(Gedcom_ctxt parent,
+ + Gedcom_ctxt self,
+ + Gedcom_val parsed_value)
+ {
+ printf("End of the source description\n");
+ }
+
+ ...
+ gedcom_subscribe_to_element(ELT_HEAD_SOUR,
+ + my_header_source_start_cb,
+ + my_header_source_end_cb);
+ ...
+ result = gedcom_parse_file("myfamily.ged");
+
struct
that
+describes the header) is passed to this start callback. The callback
+itself returns here in this example the same context, but this can be its own context object
+of course. The end callback is called with both the context of the
+parent and the context of itself, which in this example will be the same.
+ Again, the list of identifiers to use as a first argument for the
+subscription function are detailed in the
+ interface details .Gedcom_val
type is meant to be an opaque type. The
+ only thing that needs to be known about it is that it can contain specific
+ data types, which have to be retrieved from it using pre-defined macros.
+ These data types are described in the
+ interface details. Gedcom_val
argument of the end callback
-is currently not used. It is there for future enhancements.Gedcom_val
argument in the
-start callback for records. This argument is currently a string value
-giving the pointer in string form.Gedcom_val
argument of the end callback
+ is currently not used. It is there for future enhancements.Gedcom_val
arguments in
+the start callback for records. The first one (xref
) contains the xref_value
corresponding to the cross-reference (or NULL
if there isn't one), the second one (parsed_value
) contains the value that is parsed from the raw_value
. See the interface details.- This callback has a similar signature as the previous ones, but -it doesn't contain a parsed value. However, it does contain the parent -context, that was returned by the application for the most specific containing -tag that the application supported.void my_default_cb (Gedcom_ctxt parent, -int level, char* tag, char* raw_value)
-{
- ...
-}
-
-...
- gedcom_set_default_callback(my_default_cb);
-...
-result = gedcom_parse_file("myfamily.ged");
-
+ Note that the default callback will be called for any tag that isn't +specifically subscribed upon by the application, and can thus be called +in various contexts. For simplicity, the example above doesn't take +this into account (thestruct header {
- char* source;
- ...
- char* extra_text;
-};
-
-Gedcom_ctxt my_header_start_cb(int level, Gedcom_val xref, char* tag)
-{
- struct header head = my_make_header_struct();
- return (Gedcom_ctxt)head;
-}
-
-void my_default_cb(Gedcom_ctxt parent, int level, char* tag, char* raw_value)
-{
- struct header head = (struct header)parent;
- my_header_add_to_extra_text(head, level, tag, raw_value);
-}
+ char* source;
+ ...
+ char* extra_text;
+ };
+
+ Gedcom_ctxt my_header_start_cb(int level, Gedcom_val xref, char* tag, +char *raw_value,
+ + int parsed_tag, Gedcom_val parsed_value)
+ {
+ struct header head = my_make_header_struct();
+ return (Gedcom_ctxt)head;
+ }
+
+ void my_default_cb(Gedcom_ctxt parent, int level, char* tag, char* raw_value, + int parsed_tag)
+ {
+ struct header head = (struct header)parent;
+ my_header_add_to_extra_text(head, level, tag, raw_value);
+ }
+
+ gedcom_set_default_callback(my_default_cb);
+ gedcom_subscribe_to_record(REC_HEAD, my_header_start, NULL);
+ ...
+ result = gedcom_parse_file(filename);
+
parent
could be of different
+types, depending on the context).parent
could be of different types, depending
-on the context).NULL
. This is e.g. the case if none of the "upper" tags has been subscribed upon.-Thevoid gedcom_set_debug_level (int level, -FILE* trace_output)
-
level
can be one of the following values:level
can be one of the following values:trace_output
is NULL
, debugging information
-will be written to stderr
, otherwise the given file handle is
-used (which must be open).trace_output
is NULL
, debugging information
+ will be written to stderr
, otherwise the given file handle
+is used (which must be open).-Thevoid gedcom_set_error_handling (Gedcom_err_mech -mechanism)
-
mechanism
can be one of:mechanism
can be one of:IMMED_FAIL
: immediately fail the parsing
-on an error (this is the default)DEFER_FAIL
: continue parsing after an
-error, but return a failure code eventuallyIGNORE_ERRORS
: continue parsing after
-an error, return success alwaysIMMED_FAIL
: immediately fail the
+parsing on an error (this is the default)DEFER_FAIL
: continue parsing after
+ an error, but return a failure code eventuallyIGNORE_ERRORS
: continue parsing
+after an error, return success always-The argument can be:void gedcom_set_compat_handling - (int enable_compat)
-
locale
mechanism (i.e. via the LANG
, LC_ALL
or LC_CTYPE
environment variables), which also controls the gettext
+ mechanism in the application. gedcom-parse
contains an example implementation (utf8-locale.c
and utf8-locale.h
+ in the top directory). Feel free to use it in
+your source code (it is not part of the library, and it isn't installed anywhere,
+so you need to take over the source and header file in your application).
+ + +Both functions return a pointer to a static buffer that is overwritten on +each call. To function properly, the application must first set the +locale using thechar *convert_utf8_to_locale (char *input, int *conv_failures);
char *convert_locale_to_utf8 (char *input);
setlocale
function (the second step detailed below).
+ All other steps given below, including setting up and closing down the conversion
+handles, are transparantly handled by the two functions. NULL
if you are not interested (note that usually, the interesting information is just whether there were
+ conversion failures or not, which is then given by the integer being bigger
+than zero or not). The second function doesn't need this, because any
+locale can be converted to UTF-8.+void convert_set_unknown (const char *unknown);
+++++#include <locale.h> /* for setlocale */
#include <langinfo.h> /* for nl_langinfo */
#include <iconv.h> /* for iconv_* functions */
+++++setlocale(LC_ALL, "");
+++++iconv_t iconv_handle;
...
iconv_handle = iconv_open(nl_langinfo(CODESET), "UTF-8");
if (iconv_handle == (iconv_t) -1)
/* signal an error */
+++++/* char* in_buf is the input buffer, size_t in_len is its length */
/* char* out_buf is the output buffer, size_t out_len is its length */
size_t nconv;
char *in_ptr = in_buf;
char *out_ptr = out_buf;
nconv = iconv(iconv_handle, &in_ptr, &in_len, &out_ptr, &out_len);
If the output buffer is not big enough,+iconv
will return -1 and seterrno
toE2BIG
. Also, thein_ptr
andout_ptr
will point just after the last successfully converted character in the respective buffers, and thein_len
andout_len
will be updated to show the remaining lengths. There can be two strategies here:
++
+Another error case is when the conversion was unsuccessful (if one of the +characters can't be represented in the target character set). The- Make sure from the beginning +that the output buffer is big enough. However, it's difficult to find +an absolute maximum length in advance, even given the length of the input +string.
+
+
+- Do the conversion in several steps, growing the output buffer each time to make more space, and calling
+iconv
+ consecutively until the conversion is complete. This is the preferred +way (a function could be written to encapsulate all this).iconv
function will then also return -1 and seterrno
toEILSEQ
; thein_ptr
will point to the character that couldn't be converted. In that case, again two strategies are possible:
++
+- Just fail the conversion, and show an error. This is not very user friendly, of course.
+
+
+- Skip over the character that can't be converted and append a "?" to the output buffer, then call
+iconv
again. Skipping over a UTF-8 character is fairly simple, as follows from the encoding rules:+
++
+- if the first byte is in binary 0xxxxxxx, then the character is only one byte long, just skip over that byte
+
+
+- if the first byte is in binary 11xxxxxx, then skip over that byte and all bytes 10xxxxxx that follow.
+
+
++ The example implementation +mentioned above grows the output buffer dynamically and outputs "?" for characters +that can't be converted.+++iconv_close(iconv_handle);
+ +There are three preprocessor symbols defined for version checks in the header:AC_CHECK_LIB(gedcom, gedcom_parse_file,,
+ AC_MSG_ERROR(Cannot find libgedcom: Please install gedcom-parse))
+AC_MSG_CHECKING(for libgedcom version)
+AC_TRY_RUN([
+#include <stdio.h>
+#include <stdlib.h>
+#include <gedcom.h>
+int
+main()
+{
+if (GEDCOM_PARSE_VERSION >= 1034) exit(0);
+exit(1);
+}],
+ac_gedcom_version_ok='yes',
+ac_gedcom_version_ok='no',
+ac_gedcom_version_ok='no')
+if test "$ac_gedcom_version_ok" = 'yes' ; then
+ AC_MSG_RESULT(ok)
+else
+ AC_MSG_RESULT(not ok)
+ AC_MSG_ERROR(You need at least version 1.34 of gedcom-parse)
+fi
+
GEDCOM_PARSE_VERSION_MAJOR
GEDCOM_PARSE_VERSION_MINOR
GEDCOM_PARSE_VERSION
(GEDCOM_PARSE_VERSION_MAJOR * 1000) + GEDCOM_PARSE_VERSION_MINOR.
$Id$+ +
$Name$
+ + + \ No newline at end of file