mirror of https://github.com/davisking/dlib.git
147 lines
3.8 KiB
C++
Executable File
147 lines
3.8 KiB
C++
Executable File
/*
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This is an example illustrating the use of the xml_parser component in
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the dlib C++ Library.
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This example simply reads in an xml file and prints the parsing events
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to the screen.
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*/
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#include "dlib/xml_parser.h"
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#include <iostream>
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#include <fstream>
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using namespace std;
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using namespace dlib;
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// ----------------------------------------------------------------------------------------
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class doc_handler : public document_handler
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{
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/*
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As the parser runs it generates events when it encounters tags and
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data in an XML file. To be able to receive these events all you have to
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do is make a class that inherits from dlib::document_handler and
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implements its virtual methods. Then you simply associate an
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instance of your class with the xml_parser.
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So this class is a simple example document handler that just prints
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all the events to the screen.
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*/
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public:
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virtual void start_document (
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)
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{
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cout << "parsing begins" << endl;
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}
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virtual void end_document (
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)
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{
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cout << "Parsing done" << endl;
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}
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virtual void start_element (
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const unsigned long line_number,
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const std::string& name,
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const dlib::attribute_list& atts
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)
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{
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cout << "on line " << line_number << " we hit the <" << name << "> tag" << endl;
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// print all the tag's attributes
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atts.reset();
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while (atts.move_next())
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{
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cout << "\tattribute: " << atts.element().key() << " = " << atts.element().value() << endl;
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}
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}
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virtual void end_element (
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const unsigned long line_number,
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const std::string& name
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)
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{
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cout << "on line " << line_number << " we hit the closing tag </" << name << ">" << endl;
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}
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virtual void characters (
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const std::string& data
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)
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{
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cout << "Got some data between tags and it is:\n" << data << endl;
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}
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virtual void processing_instruction (
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const unsigned long line_number,
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const std::string& target,
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const std::string& data
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)
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{
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cout << "on line " << line_number << " we hit a processing instruction with a target of '"
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<< target << "' and data '" << data << "'" << endl;
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}
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};
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// ----------------------------------------------------------------------------------------
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class xml_error_handler : public error_handler
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{
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/*
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This class handles error events that occur during parsing.
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Just like the document_handler class above it just prints the events to the screen.
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*/
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public:
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virtual void error (
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const unsigned long line_number
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)
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{
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cout << "There is a non-fatal error on line " << line_number << " in the file we are parsing." << endl;
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}
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virtual void fatal_error (
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const unsigned long line_number
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)
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{
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cout << "There is a fatal error on line " << line_number << " so parsing will now halt" << endl;
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}
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};
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// ----------------------------------------------------------------------------------------
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int main(int argc, char** argv)
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{
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// Check if the user entered an argument to this application.
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if (argc != 2)
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{
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cout << "Please enter an xml file to parse on the command line" << endl;
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return 1;
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}
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// Try to open the file given on the command line
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ifstream fin(argv[1]);
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if (!fin)
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{
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cout << "unable to open file: " << argv[1] << endl;
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return 1;
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}
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// now make the xml parser and our document and error handlers
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xml_parser::kernel_1a_c parser;
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doc_handler dh;
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xml_error_handler eh;
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// now associate the handlers with the parser and tell it to parse
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parser.add_document_handler(dh);
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parser.add_error_handler(eh);
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parser.parse(fin);
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}
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