All of the examples so far have concentrated on creating and @@ -483,5 +484,147 @@ function:
mxmlIndexDelete(ind); +Mini-XML supports an implementation of the Simple API for XML +(SAX) which allows you to load and process an XML document as a +stream of nodes. Aside from allowing you to process XML documents of +any size, the Mini-XML implementation also allows you to retain +portions of the document in memory for later processing.
+ +The mxmlSAXLoadFd, mxmlSAXLoadFile, and mxmlSAXLoadString functions +provide the SAX loading APIs. Each function works like the +corresponding mxmlLoad function but uses a callback to +process each node as it is read.
+ +The callback function receives the node, an event code, and +a user data pointer you supply:
+ +
+ void
+ sax_cb(mxml_node_t *node, mxml_sax_event_t event,
+ void *data)
+ {
+ ... do something ...
+ }
+
+
+The event will be one of the following:
+ +Elements are released after the close element is +processed. All other nodes are released after they are processed. +The SAX callback can retain the node using the mxmlRetain function. For example, +the following SAX callback will retain all nodes, effectively +simulating a normal in-memory load:
+ +
+ void
+ sax_cb(mxml_node_t *node, mxml_sax_event_t event,
+ void *data)
+ {
+ if (event != MXML_SAX_ELEMENT_CLOSE)
+ mxmlRetain(node);
+ }
+
+
+More typically the SAX callback will only retain a small portion +of the document that is needed for post-processing. For example, the +following SAX callback will retain the title and headings in an +XHTML file. It also retains the (parent) elements like <html>, <head>, and <body>, and processing +directives like <?xml ... ?> and <!DOCTYPE ... >:
+ + +
+ void
+ sax_cb(mxml_node_t *node,
+ mxml_sax_event_t event,
+ void *data)
+ {
+ if (event == MXML_SAX_ELEMENT_OPEN)
+ {
+ /*
+ * Retain headings and titles...
+ */
+
+ const char *name = node->value.element.name;
+
+ if (!strcmp(name, "html") ||
+ !strcmp(name, "head") ||
+ !strcmp(name, "title") ||
+ !strcmp(name, "body") ||
+ !strcmp(name, "h1") ||
+ !strcmp(name, "h2") ||
+ !strcmp(name, "h3") ||
+ !strcmp(name, "h4") ||
+ !strcmp(name, "h5") ||
+ !strcmp(name, "h6"))
+ mxmlRetain(node);
+ }
+ else if (event == MXML_SAX_DIRECTIVE)
+ mxmlRetain(node);
+ else if (event == MXML_SAX_DATA &&
+ node->parent->ref_count > 1)
+ {
+ /*
+ * If the parent was retained, then retain
+ * this data node as well.
+ */
+
+ mxmlRetain(node);
+ }
+ }
+
+
+The resulting skeleton document tree can then be searched just +like one loaded using the mxmlLoad functions. For example, +a filter that reads an XHTML document from stdin and then shows the +title and headings in the document would look like:
+ +
+ mxml_node_t *doc, *title, *body, *heading;
+
+ doc = mxmlSAXLoadFd(NULL, 0,
+ MXML_TEXT_CALLBACK,
+ sax_cb, NULL);
+
+ title = mxmlFindElement(doc, doc, "title",
+ NULL, NULL,
+ MXML_DESCEND);
+
+ if (title)
+ print_children(title);
+
+ body = mxmlFindElement(doc, doc, "body",
+ NULL, NULL,
+ MXML_DESCEND);
+
+ if (body)
+ {
+ for (heading = body->child;
+ heading;
+ heading = heading->next)
+ print_children(heading);
+ }
+
+