We want to initialize the XML parser in PHP, define some handlers for different XML events, and then parse the XML file.
Example
< ?php
//Initialize the XML parser
$parser=xml_parser_create();
//Function to use at the start of an element
function start($parser,$element_name,$element_attrs)
{
switch($element_name)
{
case "NOTE":
echo "-- Note --<>";
break;
case "TO":
echo "To: ";
break;
case "FROM":
echo "From: ";
break;
case "HEADING":
echo "Heading: ";
break;
case "BODY":
echo "Message: ";
}
}
//Function to use at the end of an element
function stop($parser,$element_name)
{
echo " <>";
}
//Function to use when finding character data
function char($parser,$data)
{
echo $data;
}
//Specify element handler
xml_set_element_handler($parser,"start","stop");
//Specify data handler
xml_set_character_data_handler($parser,"char");
//Open XML file
$fp=fopen("test.xml","r");
//Read data
while ($data=fread($fp,4096))
{
xml_parse($parser,$data,feof($fp)) or
die (sprintf("XML Error: %s at line %d",
xml_error_string(xml_get_error_code($parser)),
xml_get_current_line_number($parser)));
}
//Free the XML parser
xml_parser_free($parser);
? > |
The output of the code above will be:
-- Note --
To: Tove
From: Jani
Heading: Reminder
Message: Don't forget me this weekend! |
How it works:
1. Initialize the XML parser with the xml_parser_create() function
2. Create functions to use with the different event handlers
3. Add the xml_set_element_handler() function to specify which function will be executed when the parser encounters the opening and closing tags
4. Add the xml_set_character_data_handler() function to specify which function will execute when the parser encounters character data
5. Parse the file "test.xml" with the xml_parse() function
6. In case of an error, add xml_error_string() function to convert an XML error to a textual description
7. Call the xml_parser_free() function to release the memory allocated with the xml_parser_create() function
