Use PHP & XML to compile a mini search engine (2)

3. a simple example of XML display with PHP. The program below will parse the XML and output it to the browser according to the tree structure, and display the total number of elements at each layer. __________________________________________________________? $ Filedemo. xml; // XML file // Function for parsing XML files functionxml 3. a simple example of displaying XML with PHP



The following program parses the XML file and outputs it to the browser according to the tree structure, and displays the total number of elements at each layer.

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$ File = "demo. xml"; // XML file







// Functions used to parse XML files

Function xml_parse_from_file ($ parser, $ file)

{

If (! File_exists ($ file ))

{

Die ("Can't find file" $ file ".");

}



If (! ($ Fp = @ fopen ($ file, "r ")))

{

Die ("Can't open file" $ file ".");

}



While ($ data = fread ($ fp, 4096 ))

{

If (! Xml_parse ($ parser, $ data, feof ($ fp )))

{

Return (false );

}

}



Fclose ($ fp );



Return (true );

}







Function start_element ($ parser, $ name, $ attrs)

// If you encounter an on-element mark, execute this section,

// $ Name = a, $ attrs is an attribute array

{

Global $ level, $ levelcount, $ maxlevel;



$ Level + = 1;

If ($ level> $ maxlevel) $ maxlevel = $ level;

$ Levelcount [$ level] + = 1;

Echo"

";

For ($ I = 1; $ I <= ($ level-1); $ I ++) echo "| ";

If ($ level> 0) echo "+ ----";



Echo "". trim ($ name )."";



While (list ($ key, $ val) = each ($ attrs) {// display attributes

Echo "$ key => $ val ;";

}



}



Function stop_element ($ parser, $ name)

// An on-element mark is encountered, as shown in figureExecute this section,

{

Global $ level;



$ Level-= 1;

}



Function data ($ parser, $ data)

{

Global $ level;

If (trim ($ data )! = ""){

Echo trim ($ data );

}

}



Function showcount () // display the total number of elements in each layer

{

Global $ maxlevel, $ levelcount;

Echo"

";

For ($ I = 0; $ I <= $ maxlevel; $ I ++ ){

Echo $ levelcount [$ I]. "";

}

}



Global $ level, $ levelcount, $ maxlevel;

$ Level =-1;



// The instance that generates the parser

$ Parser = xml_parser_create ();



// Set the processing function

Xml_set_element_handler ($ parser, "start_element", "stop_element ");

Xml_set_character_data_handler ($ parser, "data ");

Xml_parser_set_option ($ parser, XML_OPTION_CASE_FOLDING, 0 );



// Parse the file

$ Ret = xml_parse_from_file ($ parser, $ file );

If (! $ Ret)

{

Die (sprintf ("XML error: % s at line % d ",

Xml_error_string (xml_get_error_code ($ parser )),

Xml_get_current_line_number ($ parser )));

}



// Release the parser

Xml_parser_free ($ parser );





Showcount ();



?>