<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><title>Using the GEDCOM parser library</title>
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-
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<h1 align="center">Using the GEDCOM parser library</h1>
<br>
result = <b>gedcom_parse_file</b>("myfamily.ged");</code><br>
</blockquote>
In the above piece of code, <code>my_message_handler</code> is the callback
- that will be called for errors (<code>type=ERROR</code>), warnings (<code>
- type=WARNING</code>) and messages (<code>type=MESSAGE</code>). The
+ that will be called for errors (<code>type=ERROR</code>), warnings (<code>type=WARNING</code>) and messages (<code>type=MESSAGE</code>). The
callback must have the signature as in the example. For errors, the
<code> msg</code> passed to the callback will have the format:<br>
<br>
void <b>my_header_end_cb</b> (Gedcom_ctxt self)<br>
{<br>
- printf("The header ends, context is %d\n", self); /* context
+ printf("The header ends, context is %d\n", (int)self); /* context
will print as "1" */<br>
}<br>
<br>
gedcom.h</code> (so no need to include <code>gedcom-tags.h</code> yourself).<br>
<br>
The example passes a simple integer as context, but an application could
- e.g. pass a <code>struct</code> that will contain the information for the
+ e.g. pass a <code>struct</code> (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 <code>struct</code> to put it in its database.<br>
<br>
</blockquote>
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. the <code>struct</code> that
+ that the context of the parent line (here e.g. the <code>struct</code> 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
+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 will be the same in the example.
+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 <a href="interface.html#Element_identifiers">
interface details</a> .<br>
raw value is just the raw string that occurs as value on the line next to
the tag (in UTF-8 encoding). The parsed value is the meaningful value
that is parsed from that raw string. The parsed tag is described in
- the section for record callbacks.<br>
+ the section for record callbacks above.<br>
<br>
The <code>Gedcom_val</code> type is meant to be an opaque type. The
only thing that needs to be known about it is that it can contain specific
<ul>
<li>The <code>Gedcom_val</code> argument of the end callback
is currently not used. It is there for future enhancements.</li>
- <li>There is also a <code>Gedcom_val</code> argument in
-the start callback for records. This argument is currently a string
-value giving the pointer in string form.</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 (or <code>NULL</code> if there isn't one), the second one (<code>parsed_value</code>) contains the value that is parsed from the <code>raw_value</code>. See the <a href="interface.html#Record_identifiers">interface details</a>.</li>
</ul>
in various contexts. For simplicity, the example above doesn't take
this into account (the <code>parent</code> could be of different
types, depending on the context).<br>
+ <br>
+Note also that the default callback is not called when the parent context is <code>NULL</code><code></code>. This is e.g. the case if none of the "upper" tags has been subscribed upon.<br>
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