diff options
Diffstat (limited to 'xsd/examples/cxx/tree/streaming/driver.cxx')
| -rw-r--r-- | xsd/examples/cxx/tree/streaming/driver.cxx | 167 |
1 files changed, 65 insertions, 102 deletions
diff --git a/xsd/examples/cxx/tree/streaming/driver.cxx b/xsd/examples/cxx/tree/streaming/driver.cxx index 6c6fd51..eb7026a 100644 --- a/xsd/examples/cxx/tree/streaming/driver.cxx +++ b/xsd/examples/cxx/tree/streaming/driver.cxx @@ -1,5 +1,4 @@ // file : examples/cxx/tree/streaming/driver.cxx -// author : Boris Kolpackov <boris@codesynthesis.com> // copyright : not copyrighted - public domain #include <iostream> @@ -16,9 +15,6 @@ using namespace std; using namespace xercesc; -static void -measure_position (unsigned int n, float& lat, float& lon); - int main (int argc, char* argv[]) { @@ -40,96 +36,92 @@ main (int argc, char* argv[]) using namespace op; namespace xml = xsd::cxx::xml; - // Parse. + // Parse and serialize at the same time, in the streaming mode. // ifstream ifs; ifs.exceptions (ifstream::badbit | ifstream::failbit); ifs.open (argv[1]); - parser p; - - // The first document we get is the "carcase" of the complete document. - // That is, the root element with all the attributes but without any - // content. We may need it to get to the attributes in the root element. - // - // There are two ways this can be done. The easiest approach is to - // instantiate the root element's type (object in our case). This - // will only work if all the content in the root element is optional. - // Alternatively, we can manually look up attributes that we are - // interested in and instantiate the corresponding type. The following - // fragment shows how to use the second approach. - // - xml_schema::dom::auto_ptr<DOMDocument> doc (p.start (ifs, argv[1], true)); - - // Find the id attribute. - // - DOMAttr* id_attr ( - doc->getDocumentElement ()->getAttributeNode ( - xml::string ("id").c_str ())); - - // Use the type and traits aliases from the object model. - // - object::id_type id (object::id_traits::create (*id_attr, 0, 0)); - cerr << "id: " << id << endl; - - // The next chunk we get is the header element. - // - doc = p.next (); - header hdr (*doc->getDocumentElement ()); - cerr << "name: " << hdr.name () << endl - << "type: " << hdr.type () << endl; - - // The rest is position elements. - // - for (doc = p.next (); doc.get () != 0; doc = p.next ()) - { - position p (*doc->getDocumentElement ()); - cerr << "lat: " << p.lat () << " lon: " << p.lon () << endl; - } - - // Serialize. - // - ofstream ofs; ofs.exceptions (ios_base::badbit | ios_base::failbit); ofs.open ("out.xml"); - serializer s; + xml_schema::namespace_infomap ns_map; + ns_map["op"].name = "http://www.codesynthesis.com/op"; + ns_map["op"].schema = "position.xsd"; - // With this approach we manually write the XML declaration, opening - // and closing root element tags, as well as any attributes in the - // root element. - // - ofs << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" << endl - << "<op:object xmlns:op=\"http://www.codesynthesis.com/op\"" << endl - << " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"" << endl - << " xsi:schemaLocation=\"http://www.codesynthesis.com/op " << - "position.xsd\"" << endl - << " id=\"" << 123 << "\">" << endl; + parser p; + serializer s; + p.start (ifs, argv[1], true); s.start (ofs); - // Serialize the header. + typedef xml_schema::dom::auto_ptr<DOMDocument> document_ptr; + + // Peek at the root element. This way we only get the "carcase" + // of the document, that is, the root element with its name, all + // the attributes, and namespace declarations but without any of + // the nested elements. // - header h ("Lion's Head", "rock"); - s.next ("header", h); + document_ptr docr (p.peek ()); + bool parsed (false); - // Serialize position elements, one at a time. + // Parse first-level elements. // - for (unsigned short i (0); i < 8; i++) + for (document_ptr doc1 (p.peek ()); doc1.get () != 0; doc1 = p.peek ()) { - float lat, lon; - measure_position (i, lat, lon); - position p (lat, lon); - s.next ("position", p); + // Check whether it is an element that we should stream (position) or + // just add to the root (header). + // + string n1 (xml::transcode<char> ( + doc1->getDocumentElement ()->getLocalName ())); + + // If we see the first streaming element, then parse the root carcase. + // + if (!parsed && n1 == "position") + { + object o (*docr->getDocumentElement ()); + + cerr << "id: " << o.id () << endl + << "name: " << o.header ().name () << endl + << "type: " << o.header ().type () << endl; + + // Start serializing the document by writing out the root carcase. + // Note that we leave it open so that we can serialize more elements. + // + s.next_open (ns_map["op"].name, "op:object", ns_map, o); + parsed = true; + } + + // Handle elements that need streaming. + // + if (n1 == "position") + { + // Position has no nested elements that we need to stream so we + // finish parsing it in one go. + // + doc1 = p.next (doc1); + position pos (*doc1->getDocumentElement ()); + + cerr << "lat: " << pos.lat () << " lon: " << pos.lon () << endl; + + // Serialize it (append) to the root element. + // + s.next ("position", pos); + } + else + { + // Element that doesn't require streaming (header in our case). Add + // to the root element and finish parsing. + // + docr = p.next (doc1, docr); + } } - // Close the root element. + // Close the root element in serializer. // - ofs << endl - << "</op:object>" << endl; - + s.next_close ("op:object"); } catch (const xml_schema::exception& e) { @@ -145,32 +137,3 @@ main (int argc, char* argv[]) xercesc::XMLPlatformUtils::Terminate (); return r; } - -// Position measurement instrument interface. -// -struct measurements -{ - float lat; - float lon; -}; - -measurements test_measurements [8] = -{ - {-33.8569F, 18.5083F}, - {-33.8568F, 18.5083F}, - {-33.8568F, 18.5082F}, - {-33.8570F, 18.5083F}, - {-33.8569F, 18.5084F}, - {-33.8570F, 18.5084F}, - {-33.8570F, 18.5082F}, - {-33.8569F, 18.5082F} -}; - -static void -measure_position (unsigned int n, float& lat, float& lon) -{ - // Call the instrument to measure the position. - // - lat = test_measurements[n].lat; - lon = test_measurements[n].lon; -} |