<li><a href="#Start_and_end_callbacks">Start and end callbacks</a></li>
<li><a href="#Default_callbacks">Default callbacks</a></li>
- </ul><li><a href="#Other_API_functions">Other API functions</a></li>
+ </ul><li><a href="#Support_for_writing_GEDCOM_files">Support for writing GEDCOM files</a></li>
+ <ul>
+ <li><a href="#Opening_and_closing_files">Opening and closing files</a></li>
+ <li><a href="#Controlling_some_settings">Controlling some settings</a></li>
+ <li><a href="#Writing_data">Writing data</a><br>
+ </li>
+ </ul>
+<li><a href="#Other_API_functions">Other API functions</a></li>
<ul>
<li><a href="#Debugging">Debugging</a></li>
</ul>
<li><a href="#Converting_character_sets">Converting character sets</a></li>
- <li><a href="#Support_for_configure.in">Support for configure.in</a><br>
+ <li><a href="#Support_for_configure.in">Development support</a><br>
<br>
</li>
<li><a href="interface.html">Interface details of the callback parser</a></li><li><a href="gom.html">C object model</a><br>
</li>
-</ul>
-
- Next to these, there is also a data directory in <code>$PREFIX/share/gedcom-parse</code>
+</ul>There is a separate script to help with library and compilation flags, see the <a href="#Support_for_configure.in">development support</a>.<br>
+<br>
+Next to these, there is also a data directory in <code>$PREFIX/share/gedcom-parse</code>
that contains some additional stuff, but which is not immediately
important at first. I'll leave the description of the data directory
for later.<br>
on the linking of the program as the last option, so that its initialization
code is run first. In the case of using the C object model, the linking
options should be: <code>-lgedcom_gom -lgedcom</code><br>
- <br>
- The next sections will refine this piece of code to be able to have
+ <br>The function <code>gedcom_init()</code> also initializes locale handling by calling <code>setlocale(LC_ALL, "")</code>, in case the application would not do this (it doesn't hurt for the application to do the same).<br>
+ <br>
+The next sections will refine this piece of code to be able to have
meaningful errors and the actual data that is in the file.<br>
<hr width="100%" size="2">
is called for that tag, and when all its subordinate lines with their
tags have been processed, the "end element" callback is called for the
original tag. Since GEDCOM is hierarchical, this results in properly
-nested calls to appropriate "start element" and "end element" callbacks.<br>
+nested calls to appropriate "start element" and "end element" callbacks (note: see <a href="#Compatibility_mode">compatibility handling</a>).<br>
<br>
However, it would be typical for a genealogy program to support only
a subset of the GEDCOM standard, certainly a program that is still under
<ul>
<li>The <code>Gedcom_val</code> argument of the end callback
- is currently not used. It is there for future enhancements.</li>
+ is used to pass 'complete' values, e.g. the full text of a note. See
+ the <a href="file:///home/verthezp/src/external/gedcom-parse/doc/interface.html#Record_identifiers">interface details</a>
+ for the exact type of this argument.</li>
<li>There are also two <code>Gedcom_val</code> arguments
in the start callback for records. The first one (<code>xref</code>
) contains the <code>xref_value</code> corresponding to the cross-reference
of the "upper" tags has been subscribed upon.<br>
+<hr width="100%" size="2"><br>
+<h2><a name="Support_for_writing_GEDCOM_files"></a>Support for writing GEDCOM files</h2>
+The Gedcom parser library also contains functions to writing GEDCOM files.
+ Similar as for the parsing itself, there are two interfaces: an interface
+which is very basic, and requires you to call a function for each line in
+the GEDCOM file, and an interface which just dumps the Gedcom object model
+to a file in one shot (if you use the Gedcom object model).<br>
+<br>
+Again, this section focuses on the basic interface, the Gedcom object model interface is described <a href="gom.html#Writing_the_object_model_to_file">here</a>.<br>
+<br>
+<h3><a name="Opening_and_closing_files"></a>Opening and closing files</h3>
+The basic functions for opening and closing Gedcom files for writing are the following:<br>
+<code></code>
+<blockquote><code>Gedcom_write_hndl <b>gedcom_write_open</b> (const char* filename);<br>
+int <b>gedcom_write_close</b> (Gedcom_write_hndl hndl, int* total_conv_fails);<br></code></blockquote>
+The function <code>gedcom_write_open</code> takes a parameter the name of
+the file to write, and returns a write handle, which needs to be used in
+subsequent functions. It returns <code>NULL</code> in case of errors.<br>
+<br>
+The function <code>gedcom_write_close</code> takes, next to the write handle,
+an integer pointer as parameter. If you pass an actual pointer for
+this, the function will write in it the total number of conversion failures;
+you can pass <code>NULL</code> if you're not interested. The function returns 0 in case of success, non-zero in case of failure.<br>
+<br>
+<h3><a name="Controlling_some_settings"></a>Controlling some settings<br>
+</h3>
+Note that by default the file is written in the same encoding as the read file was in. You can change
+this by calling the following function <i>before</i> calling <code>gedcom_write_open</code>, i.e. it affects all files that are opened after it is being called:<code></code><code><br>
+</code>
+<blockquote><code>int <b>gedcom_write_set_encoding</b> (Enc_from from, const char* charset, Encoding width, Enc_bom bom);<br></code></blockquote>The <code>from</code> parameter indicates how you want the encoding to be set:<br>
+<ul>
+ <li><b><code>ENC_FROM_FILE</code></b>: The same as the read file was in (this is the default).</li>
+ <li><b><code>ENC_FROM_SYS</code></b>: Not a valid value here, see below for <code>gedcom_write_set_terminator</code><br>
+ </li>
+ <li><b><code>ENC_MANUAL</code></b>: From the values given in the following parameters.</li>
+</ul>
+When <code>ENC_FROM_FILE</code><b> </b>is selected, the other parameters in the function are ignored (they can be passed as 0). When <code>ENC_MANUAL</code> is chosen, the meaning of the other parameters is as follows:<br>
+<br>
+The valid <code>charset</code> values are given in the first column in the file <code>gedcom.enc</code> in the data directory of gedcom-parse (<code>$PREFIX/share/gedcom-parse</code>).
+ The character sets UNICODE, ASCII and ANSEL are always supported (these
+are standard for GEDCOM), as well as ANSI (not standard), but there may be
+others.<br>
+<br>
+The <code>width</code> parameter takes one of the following values:<br>
+<ul>
+</ul>
+<ul>
+ <li><code><b>ONE_BYTE</b></code>: This should be used for all character sets except UNICODE.</li>
+ <li><code><b>TWO_BYTE_HILO</b></code>: High-low encoding for UNICODE (i.e. big-endian)</li>
+ <li><code><b>TWO_BYTE_LOHI</b></code>: Low-high encoding for UNICODE (i.e. little-endian)</li>
+</ul>
+The <code>bom</code> parameter determines whether a byte-order-mark should
+be written in the file in case of UNICODE encoding (usually preferred because
+it then clearly indicates the byte ordering). It takes one of the following
+values:<br>
+<ul>
+ <li><code><b>WITHOUT_BOM</b></code></li>
+ <li><code><b>WITH_BOM</b></code></li>
+</ul> For both these parameters you can pass 0 for non-UNICODE encodings,
+since that corresponds to the correct values (and is ignored anyway). The
+function returns 0 in case of success, non-zero in case of error. Note
+that you still need to pass the correct charset value for the HEAD.CHAR tag,
+otherwise you will get a warning, and the value will be forced to the correct
+value.<br>
+<br>
+Further, it is possible to control the kind of line terminator that is used, via the following function (also to be used before <code>gedcom_write_open</code>):<br>
+<blockquote><code>int <b>gedcom_write_set_line_terminator</b> (Enc_from from, Enc_line_end end);<br></code></blockquote>The values for the <code>from</code> parameter are given above. The value <b><code>ENC_FROM_SYS</code></b>
+is valid here, and means that the normal terminator for the current system
+is used (the second parameter of the function is then ignored). This
+is the default for this setting.<br>
+<br>
+The <code>end</code> parameter takes one of the following values:<br>
+<ul>
+ <li><b><code>END_CR</code></b>: only carriage return ("/r") (system value for Macintosh)</li>
+ <li><b><code>END_LF</code></b>: only line feed ("/n") (system value for Unix, Mac OS X)</li>
+ <li><b><code>END_CR_LF</code></b>: first carriage return, then line feed ("/r/n") (system value for DOS, Windows)</li>
+ <li><b><code>END_LF_CR</code></b>: first line feed, then carriage return ("/n/r")</li>
+</ul>
+By default, this is set to the appropriate line terminator on the current
+platform, so it only needs to be changed if there is some special reason
+for it.<br>
+<h3><a name="Writing_data"></a>Writing data<br>
+</h3>
+For actually writing the data, the principle is that every line in the GEDCOM
+file to write corresponds to a call to one of the following functions, except
+that CONT/CONC lines can be automatically taken care of. Note that
+the resulting GEDCOM file should conform to the GEDCOM standard. Several
+checks are built in already, and more will follow, to force this. There
+is no compatibility mode for writing GEDCOM files (and probably never will be).<br>
+<br>
+In general, each of the following functions expect their input in UTF-8 encoding (see also <a href="#Converting_character_sets">here</a>). If this is not the case, errors will be returned.<br>
+<br>
+Note that for examples of using these functions you can look at the sources for the Gedcom object model (e.g. the function <code>write_header</code> in <code>gom/header.c</code>).<br>
+<h4>Records</h4>
+For writing lines corresponding to records (i.e. on level 0), the following function is available:
+<blockquote><code>int <b>gedcom_write_record_str</b> (Gedcom_write_hndl hndl, Gedcom_rec rec, const char* xrefstr, const char* value);<br></code></blockquote>
+The <code>hndl</code> parameter is the write handle that was returned by <code>gedcom_write_open</code>. The <code>rec</code> parameter is one of the identifiers given in the first column in <a href="interface.html#Record_identifiers">this table</a> (except <code>REC_USER</code>: see below). The <code>xrefstr</code> and <code>val</code> parameters are respectively the cross-reference key of the record (something like '<code>@FAM01@</code>'), and the value of the record line, which should be <code>NULL</code> for some record types, according to the same table.<br>
+<h4>Elements</h4>
+For writing lines corresponding to elements (inside records, i.e. on a level
+bigger than 0), the following functions are available, depending on the data
+type:
+<blockquote><code>int <b>gedcom_write_element_str</b> (Gedcom_write_hndl hndl, Gedcom_elt elt, int parsed_tag, <br>
+
+ int parent_rec_or_elt, const char* value);<br>
+i</code><code>nt <b>gedcom_write_element_xref</b> (Gedcom_write_hndl hndl, Gedcom_elt elt, int parsed_tag, <br>
+
+ int parent_rec_or_elt, const struct xref_value*
+value);</code><br>
+ <code>int <b>gedcom_write_element_date</b> (Gedcom_write_hndl hndl, Gedcom_elt elt, int parsed_tag, <br>
+
+ int parent_rec_or_elt, const struct date_value*
+value);</code><br>
+ <code>i</code><code>nt <b>gedcom_write_element_age </b> (Gedcom_write_hndl hndl, Gedcom_elt elt, int parsed_tag, <br>
+
+ int parent_rec_or_elt, const struct age_value*
+value);</code><br>
+</blockquote>
+<blockquote><code></code></blockquote>
+These functions only differ in the type of the last argument, which is the value of the element.<br>
+<br>
+The <code>hndl</code> parameter is again the write handle returned by <code>gedcom_write_open</code>. The <code>elt</code> parameter is one of the identifiers given in the first column in <a href="interface.html#Element_identifiers">this table</a> (except <code>ELT_USER</code>: see below). The <code>parent_rec_or_elt</code> is the corresponding <code>rec</code> or <code>elt</code>
+identifier of the logically enclosing statement: this will determine the
+level number written on the line, as the level number of the parent + 1.<br>
+<br>
+Some of the identifiers can actually stand for different tags. For this reason, the <code>parsed_tag</code> has to be passed for some of them. This parsed tag is the same as was returned by the callback functions defined <a href="#Start_and_end_callbacks">above</a>, and is an identifier of the form <code>TAG_<i>name</i></code>. This parameter is needed whenever the second column in <a href="interface.html#Element_identifiers">this table</a> shows several possible tags (this is e.g. the case for <code>ELT_SUB_FAM_EVT</code>).<br>
+<br>
+Note that for writing a date value, the given value should be valid, i.e.
+all its struct fields filled in properly and consistent. This can be
+done by calling <code>gedcom_normalize_date</code> (see <a href="interface.html#date">here</a>).<br>
+<h4>User-defined tags</h4>
+For user-defined tags (tags starting with an underscore), there are separate functions, again depending on the data type:<code></code>
+<blockquote><code>int <b>gedcom_write_user_str</b> (Gedcom_write_hndl hndl, int level, const char* tag, const char* xrefstr,<br>
+ const char* value);<br>
+i</code><code>nt <b>gedcom_write_user_xref</b> (Gedcom_write_hndl hndl, </code><code>int level, const char* tag, const char* xrefstr,</code><br>
+ <code>
+
+ const struct xref_value* value);</code><br>
+ <code></code></blockquote>
+In the case of user-defined tags, the level and tag string are passed verbatim
+(not controlled by the library). This allows to write any extra data
+that doesn't use a standard tag, but is only allowed for tags starting with
+an underscore.<br>
<hr width="100%" size="2">
<h2><a name="Other_API_functions"></a>Other API functions<br>
</ul>
- Currently, there is a beginning for compatibility for ftree and Lifelines (3.0.2).<br>
+ Currently, there is (some) compatibility for:<br>
+<ul>
+ <li>ftree</li>
+ <li>Lifelines (3.0.2)</li>
+ <li>Personal Ancestral File (PAF), version 2, 4 and 5</li>
+ <li>Family Origins</li>
+ <li>EasyTree</li>
+</ul>
+The following function allows to set some options for the compatibility handling:<br>
+<blockquote><code>void <b>gedcom_set_compat_options</b> (Gedcom_compat options)</code><br>
+ </blockquote>
+The parameter can be an OR'ed combination of the following options:<br>
+<ul>
+ <li><code>COMPAT_ALLOW_OUT_OF_CONTEXT</code></li>
+</ul>
+<blockquote>
+ <blockquote>In some compatibility cases, tags are coming out-of-order,
+i.e. their start element callback would have to come after the end element
+callback of the parent tag. E.g. instead of the standard GEDCOM<br>
+ <blockquote><code>1 DATE ...<br>
+2 TIME ...</code><br>
+ </blockquote>
+the genealogy program has generated something like:<br>
+ <blockquote><code>1 DATE ...<br>
+1 TIME ...</code><br>
+ </blockquote>
+This can give a problem if your end element callbacks free some resources. <br>
+ <br>
+If your program can handle elements out of context, you can enable this option.
+ By default it is disabled, and so the values of these out-of-context
+tags are lost (the parser generates a warning if this is the case). The Gedcom object model in C has this option enabled.<br>
+ </blockquote>
+</blockquote>
+<br>
+
<hr width="100%" size="2">
<h2><a name="Converting_character_sets"></a>Converting character sets</h2>
the <code>locale</code> mechanism (i.e. via the <code>LANG</code>, <code>
LC_ALL</code> or <code>LC_CTYPE</code> environment variables), which also
controls the <code>gettext</code> mechanism in the application. <br>
- <br>
- <br>
-
- The source distribution of <code>
-gedcom-parse</code> contains an example implementation (<code>utf8-locale.c</code>
- and <code> utf8-locale.h</code> in the "t" subdirectory of 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). <br>
- <br>
- Its interface is:<br>
-
-<blockquote>
- <pre><code>char *<b>convert_utf8_to_locale</b> (char *input, int *conv_failures);<br>char *<b>convert_locale_to_utf8</b> (char *input);<br></code></pre>
- </blockquote>
- 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 the <code>setlocale</code> 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.
- <br>
- <br>
- If you pass a pointer to an integer to the first function, it will be
-set to the number of conversion failures, i.e. characters that couldn't
-be converted; you can also just pass <code>NULL</code> if you are not interested
-(note that usually, the interesting information is just whether there <i>
-were</i> 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.<br>
- <br>
- You can change the "?" that is output for characters that can't be converted
- to any string you want, using the following function before the conversion
- calls:<br>
-
-<blockquote>
- <pre><code>void <b>convert_set_unknown</b> (const char *unknown);</code></pre>
- </blockquote>
- <br>
- If you want to have your own functions for it instead of this example
-implementation, the following steps need to be taken by the application
-(more detailed info can be found in the info file of the GNU libc library
-in the "Generic Charset Conversion" section under "Character Set Handling"
-or online <a href="http://www.gnu.org/manual/glibc-2.2.3/html_chapter/libc_6.html#SEC99">
- here</a>):<br>
-
-<ul>
- <li>inclusion of some headers:</li>
-
-</ul>
-
-<blockquote>
- <blockquote>
- <pre><code>#include <locale.h> /* for setlocale */<br>#include <langinfo.h> /* for nl_langinfo */<br>#include <iconv.h> /* for iconv_* functions */<br></code></pre>
- </blockquote>
- </blockquote>
-
-<ul>
- <li>set the program's current locale to what
-the user configured in the environment:</li>
-
-</ul>
-
-<blockquote>
- <blockquote>
- <pre><code>setlocale(LC_ALL, "");</code><br></pre>
- </blockquote>
- </blockquote>
-
-<ul>
- <li>open a conversion handle for conversion
- from UTF-8 to the character set of the current locale (once for the entire
- program):</li>
-
-</ul>
-
-<blockquote>
- <blockquote>
- <pre><code>iconv_t iconv_handle;<br>...<br>iconv_handle = iconv_open(nl_langinfo(CODESET), "UTF-8");</code><br>if (iconv_handle == (iconv_t) -1)<br> /* signal an error */<br></pre>
- </blockquote>
- </blockquote>
-
-<ul>
- <li>then, every string can be converted
- using the following:</li>
-
-</ul>
-
-<blockquote>
- <blockquote>
- <pre><code>/* char* in_buf is the input buffer, size_t in_len is its length */<br>/* char* out_buf is the output buffer, size_t out_len is its length */<br><br>size_t nconv;<br>char *in_ptr = in_buf;<br>char *out_ptr = out_buf;<br>nconv = iconv(iconv_handle, &in_ptr, &in_len, &out_ptr, &out_len);</code></pre>
- </blockquote>
- </blockquote>
-
-<blockquote>If the output buffer is not big enough, <code>iconv</code> will
- return -1 and set <code>errno</code> to <code>E2BIG</code>. Also,
-the <code>in_ptr</code> and <code>out_ptr</code> will point just after
-the last successfully converted character in the respective buffers, and
-the <code> in_len</code> and <code>out_len</code> will be updated to show
-the remaining lengths. There can be two strategies here:<br>
-
- <ul>
- <li>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.<br>
- <br>
- </li>
- <li>Do the conversion in several
- steps, growing the output buffer each time to make more space, and calling
- <code>iconv</code> consecutively until the conversion is complete.
- This is the preferred way (a function could be written to encapsulate
- all this).</li>
-
- </ul>
- Another error case is when the conversion was unsuccessful (if one of
-the characters can't be represented in the target character set). The
- <code> iconv</code> function will then also return -1 and set <code>errno</code>
- to <code>EILSEQ</code>; the <code>in_ptr</code> will point to the character
- that couldn't be converted. In that case, again two strategies are
-possible:<br>
-
- <ul>
- <li>Just fail the conversion,
-and show an error. This is not very user friendly, of course.<br>
- <br>
- </li>
- <li>Skip over the character that
- can't be converted and append a "?" to the output buffer, then call <code>
- iconv</code> again. Skipping over a UTF-8 character is fairly simple,
- as follows from the <a href="http://www.cl.cam.ac.uk/%7Emgk25/unicode.html#utf-8">encoding rules</a>
- :</li>
-
- </ul>
-
- <ol>
-
- <ol>
- <li>if the first byte is in
-binary 0xxxxxxx, then the character is only one byte long, just skip over
-that byte<br>
- <br>
- </li>
- <li>if the first byte is in
-binary 11xxxxxx, then skip over that byte and all bytes 10xxxxxx that follow.<br>
- </li>
-
- </ol>
-
- </ol>
- </blockquote>
-
-<ul>
- <li>eventually, the conversion
-handle needs to be closed (when the program exits):<br>
- </li>
-
-</ul>
-
-<blockquote>
- <blockquote>
- <pre><code>iconv_close(iconv_handle);<br></code></pre>
- </blockquote>
- </blockquote>
- The example implementation
- mentioned above grows the output buffer dynamically and outputs "?" for characters
- that can't be converted.<br>
+ <br>With<code>
+gedcom-parse</code> comes a library implementing help functions for UTF-8 encoding (<code></code>see
+the <a href="utf8tools.html">documentation</a> for this library).<br>
<hr width="100%" size="2">
-<h2><a name="Support_for_configure.in"></a>Support for configure.in</h2>There
+<h2><a name="Support_for_configure.in"></a>Development support</h2>
+<h3>Macro for configure.in<br>
+</h3>
+There
is a macro available for use in configure.in for applications that are using
autoconf to configure their sources. The following macro checks whether
the Gedcom parser library is available and whether its version is high enough:<br>
-<blockquote><code>AM_LIB_GEDCOM_PARSER([<i>major</i>,[<i>minor</i>,[<i>patch</i>]]])</code><br>
+<blockquote><code>AM_PATH_GEDCOM_PARSER([<i>min_version</i>,[<i>action_if_found</i>,[<i>action_if_not_found,</i>[<i>modules</i>]]]])</code><br>
</blockquote>
All the arguments are optional and default to 0. E.g. to check for
-version 1.34, you would put in configure.in the following statement:<br>
-<blockquote><code>AM_LIB_GEDCOM_PARSER(1,34)</code><br>
+version 1.34.2, you would put in configure.in the following statement:<br>
+<blockquote><code>AM_PATH_GEDCOM_PARSER(1.34.2)</code><br>
+</blockquote>Note that version numbers now contains three parts (since version
+0.20.0: this is also the first version in which this macro is available).<br>
+<br>
+The macro also sets the variables <code>GEDCOM_CFLAGS</code> and <code>GEDCOM_LIBS</code> for use in Makefiles. Typically, this would be done as follows in a Makefile.am:<br>
+<blockquote><code>bin_programs = myprg</code><br>
+ <code>myprg_SOURCES = myprg.c foo.c bar.c<br>
+INCLUDES = @GEDCOM_CFLAGS@<br>
+LDADD = @GEDCOM_LIBS@</code></blockquote>
+If your program uses some extra modules, they can be passed as fourth argument
+in the macro, so that the CFLAGS and LIBS are correctly filled in. Currently,
+the only available module is <code>gom</code> (the Gedcom object model). For example:<br>
+<blockquote><code>AM_PATH_GEDCOM_PARSER(0.21.2, , ,gom)</code><br>
</blockquote>
To be able to use this macro in the sources of your application, you have three options:<br>
<ul>
</li>
</ul>
- The last one is equal to <code>(GEDCOM_PARSE_VERSION_MAJOR * 1000) + GEDCOM_PARSE_VERSION_MINOR.</code><br>
+ The last one is equal to <code>(GEDCOM_PARSE_VERSION_MAJOR * 1000) + GEDCOM_PARSE_VERSION_MINOR.</code> As you see, this only checked the major and minor version, not the patch number, so this is obsolete.<br>
+<br>
+<h3>Compilation and linking flags</h3>
+Similar to other libraries, the GEDCOM parse library installs a script <code>gedcom-config</code> to help with compilation and linking flags for programs that don't use autoconf/automake.<br>
+<br>
+To get compilation flags for your program, use (depending on whether you
+only use the callback parser, or also the GEDCOM object model):
+<blockquote><code>gedcom-config --cflags<br>
+gedcom-config --cflags gom</code><br>
+</blockquote>
+Similarly, to get linking flags, use one of the following:
+<blockquote><code>gedcom-config --libs<br>
+gedcom-config --libs gom</code><br>
+</blockquote>
+
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<pre> </pre>
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projects / gedcom-parse.git / blobdiff