xml_set_element_handler

    (PHP 4, PHP 5, PHP 7, PHP 8)

    xml_set_element_handler — Configura manipuladores de elementos de início e fim

    Descrição

    xml_set_element_handler(XMLParser $parser, callable|string|null $start_handler, callable|string|null $end_handler): true

    Define as funções do manipulador de elementos para o parser XML.

    start_handler é chamado quando um novo elemento XML é aberto. end_handler é chamado quando um elemento XML é fechado.

    Parâmetros

    parser

    O analisador XML.

    start_handler

    Se null for passado, o manipulador é redefinido para seu estado padrão.

    Aviso

    Uma string vazia também redefine o manipulador, entretanto isto foi descontinuado a partir do PHP 8.4.0.

    Se handler for um callable, o callable será definido como o manipulador.

    Se handler for uma string, ela pode ser o nome de um método de um objeto definido com xml_set_object().

    Aviso

    Isto foi descontinuado a partir do PHP 8.4.0.

    Aviso

    A partir do PHP 8.4.0, a função de retorno é verificada quanto à validade ao configurar o manipulador, e não quando é chamada. Isto significa que xml_set_object() precisa ser chamada antes de configurar uma string de método como a função de retorno. Entretando, como este comportamento também foi descontinuado a partir do PHP 8.4.0, usar um callable adequado para o método é recomendado.

    A assinatura do manipulador deve ser:

    start_element_handler(XMLParser $parser, string $name, array $attributes): void
    parser
    O analisador XML que chama o manipulador.
    name
    Contém o nome do elemento para o qual este manipulador é chamado. Se case-folding estiver em vigor para este analisador, o nome do elemento estará em letras maiúsculas.
    attributes
    Um array associativo com os atributos do elemento. O array estará vazio se o elemento não tiver atributos. As chaves deste array são os nomes dos atributos, os valores são os valores dos atributos. Os nomes dos atributos são convertidos para minúsculo nos mesmos critérios que os nomes dos elementos. Os valores dos atributos não são convertidos para minúsculo. A ordem em que attributes é percorrida é idêntica à ordem em que os atributos foram declarados.

    end_handler

    Se null for passado, o manipulador é redefinido para seu estado padrão.

    Aviso

    Uma string vazia também redefine o manipulador, entretanto isto foi descontinuado a partir do PHP 8.4.0.

    Se handler for um callable, o callable será definido como o manipulador.

    Se handler for uma string, ela pode ser o nome de um método de um objeto definido com xml_set_object().

    Aviso

    Isto foi descontinuado a partir do PHP 8.4.0.

    Aviso

    A partir do PHP 8.4.0, a função de retorno é verificada quanto à validade ao configurar o manipulador, e não quando é chamada. Isto significa que xml_set_object() precisa ser chamada antes de configurar uma string de método como a função de retorno. Entretando, como este comportamento também foi descontinuado a partir do PHP 8.4.0, usar um callable adequado para o método é recomendado.

    A assinatura do manipulador deve ser:

    end_element_handler(XMLParser $parser, string $name): void
    parser
    O analisador XML que chama o manipulador.
    name
    Contém o nome do elemento para o qual este manipulador é chamado. Se case-folding estiver em vigor para este analisador, o nome do elemento estará em letras maiúsculas.

    Valor Retornado

    Sempre retorna true.

    Registro de Alterações

    Versão Descrição
    8.4.0 Passar uma string não-callable no parâmetro handler foi descontinuado, use um chamável apropriado para métodos, ou null para redefinir o manipulador.
    8.4.0 A validade do manipulador handler como um tipo callable agora é verificada ao configurar o manipulador ao invés de verificar na chamada.
    8.0.0 O parâmetro parser agora espera uma instância de XMLParser; anteriormente, um resource xml válido era esperado.

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    Notas Enviadas por Usuários (em inglês) 15 notes

    up
    2
    darien at etelos dot com
    17 years ago
    This documentation is somewhat awry. I know it's been said many times before, but it bears repeating...

    If using PHP4, you may be required to use xml_set_object() instead of calling any of the xml_set_*_handler() functions with a two-item array. It will work fine on PHP5, but move the same code to PHP4 and it will create one copie of $this (even if you use &$this) for each handler you set!

    <?php
    // This code will fail mysteriously on PHP4.
    $this->parser = xml_parser_create();
    xml_set_element_handler(
    $this->parser,
    array(&    $this,"start_tag"),
    array(&    $this,"end_tag")
    );
    xml_set_character_data_handler(
    $this->parser,
    array(&    $this,"tag_data")
    );
    ?>

    <?php
    // This code will work on PHP4.
    $this->parser = xml_parser_create();
    xml_set_object($this->parser,&$this);
    xml_set_element_handler(
    $this->parser,
    "start_tag",
    "end_tag"
    );
    xml_set_character_data_handler(
    $this->parser,
    "tag_data"
    );
    ?>
    up
    3
    aw at avatartechnology dot com
    20 years ago
    In response to landb at mail dot net...

    As the notes mention, you can pass an array that contains the reference to an object and a method name when you need... so you can call methods in your own class as handlers like this:

    xml_set_element_handler($parser, array($this,"_startElement"), array($this,"_endElement"));

    Hope it helps...
    up
    2
    youniforever at naver dot com
    19 years ago
    <html>
    <head>
    <title>SAX Demonstration</title>
    <META HTTP-EQUIV='Content-type' CONTENT='text/html; charset=euc-kr'>
    </head>
    <body>
    <h1>RSS ¸®´õ±â</h1>

    <?php

    $file     = "data.xml";

    $currentTag = "";
    $currentAttribs = "";

    function     startElement($parser, $name, $attribs)
    {
    global     $currentTag, $currentAttribs;
    $currentTag = $name;

    $currentAttribs = $attribs;
    switch (    $name) {

    default:
    echo(    "<b>&lt$name&gt</b><br>");
    break;
    }
    }

    function     endElement($parser, $name)
    {
    global     $currentTag;
    switch (    $name) {
    default:
    echo(    "<br><b>&lt/$name&gt</b><br><br>");
    break;
    }
    $currentTag = "";
    $currentAttribs = "";
    }

    function     characterData($parser, $data)
    {
    global     $currentTag;
    switch (    $currentTag) {
    case     "link":
    echo(    "<a href=\"$data\">$data</a>\n");
    break;
    case     "title":
    echo(    "title : $data");
    break;
    default:
    echo(    $data);
    break;
    }
    }

    $xmlParser = xml_parser_create();

    $caseFold = xml_parser_get_option($xmlParser,
    XML_OPTION_CASE_FOLDING);

    $targetEncoding = xml_parser_get_option($xmlParser,
    XML_OPTION_TARGET_ENCODING);

    if (    $caseFold == 1) {
    xml_parser_set_option($xmlParser, XML_OPTION_CASE_FOLDING, false);
    }

    xml_set_element_handler($xmlParser, "startElement", "endElement");
    xml_set_character_data_handler($xmlParser, "characterData");

    if (!(    $fp = fopen($file, "r"))) {
    die(    "Cannot open XML data file: $file");
    }

    while (    $data = fread($fp, 4096)) {
    if (!    xml_parse($xmlParser, $data, feof($fp))) {
    die(    sprintf("XML error: %s at line %d",
    xml_error_string(xml_get_error_code($xmlParser)),
    xml_get_current_line_number($xmlParser)));
    xml_parser_free($xmlParser);
    }
    }
    xml_parser_free($xmlParser);
    ?>
    </table>
    </body>
    </html>
    up
    1
    rubentrancoso at gmail dot com
    18 years ago
    My 25 cents. This example show how to parse a XML in a associative array tree.

    <?php

    $file     = "flow/flow.xml";
    $depth = 0;
    $tree = array();
    $tree['name'] = "root";
    $stack[count($stack)] = &$tree;

    function     startElement($parser, $name, $attrs) {
    global     $depth;
    global     $stack;
    global     $tree;

    $element = array();
    $element['name'] = $name;
    foreach (    $attrs as $key => $value) {
    //echo $key."=".$value;
    $element[$key]=$value;
    }

    $last = &$stack[count($stack)-1];
    $last[count($last)-1] = &$element;
    $stack[count($stack)] = &$element;

    $depth++;
    }

    function     endElement($parser, $name) {
    global     $depth;
    global     $stack;

    array_pop($stack);
    $depth--;
    }

    $xml_parser = xml_parser_create();
    xml_set_element_handler($xml_parser, "startElement", "endElement");
    if (!(    $fp = fopen($file, "r"))) {
    die(    "could not open XML input");
    }

    while (    $data = fread($fp, 4096)) {
    if (!    xml_parse($xml_parser, $data, feof($fp))) {
    die(    sprintf("XML error: %s at line %d",
    xml_error_string(xml_get_error_code($xml_parser)),
    xml_get_current_line_number($xml_parser)));
    }
    }
    xml_parser_free($xml_parser);
    $tree = $stack[0][0];
    echo     "<pre>";
    print_r($tree);
    echo     "</pre>";
    up
    1
    lloeki at gmail dot com
    18 years ago
    I modified the previous script, so that it is associative. I find it more useful that way. BTW I prefer strtolower() things, but that's not mandatory at all.

    <?php

    $file     = "data.xml";
    $depth = 0;
    $tree = array();
    $tree['name'] = "root";
    $stack[] = &$tree;

    function     startElement($parser, $name, $attrs) {
    global     $depth;
    global     $stack;
    global     $tree;

    $element = array();
    foreach (    $attrs as $key => $value) {
    $element[strtolower($key)]=$value;
    }

    end($stack);
    $stack[key($stack)][strtolower($name)] = &$element;
    $stack[strtolower($name)] = &$element;

    $depth++;
    }

    function     endElement($parser, $name) {
    global     $depth;
    global     $stack;

    array_pop($stack);
    $depth--;
    }

    $xml_parser = xml_parser_create();
    xml_set_element_handler($xml_parser, "startElement", "endElement");
    if (!(    $fp = fopen($file, "r"))) {
    die(    "could not open XML input");
    }

    while (    $data = fread($fp, 4096)) {
    if (!    xml_parse($xml_parser, $data, feof($fp))) {
    die(    sprintf("XML error: %s at line %d",
    xml_error_string(xml_get_error_code($xml_parser)),
    xml_get_current_line_number($xml_parser)));
    }
    }
    xml_parser_free($xml_parser);
    $tree = end(end($stack));
    echo     "<pre>";
    print_r($tree);
    echo     "</pre>";

    ?>
    up
    1
    hendra_g at hotmail dot com
    19 years ago
    I ran into the same problem with 'ibjoel at hotmail dot com' in regards to self-closing tags, and found that the script that he/she wrote did not work as I expected.
    I played around with some of php's functions and examples and compiled something, which may not be the neatest solution, but it works for the data that 'ibjoel at hotmail dot com' provided.
    The data needs to be read from a file though, so the fp can be utilised. It still uses the xml_get_current_byte_index(resource parser) trick, but this time, I check for the last 2 character before the index and test if it's "/>".

    <?php
    /* myxmltest.xml:
    <normal_tag>
    <self_close_tag />
    data
    <normal_tag>data
    <self_close_tag attr="value" />
    </normal_tag>
    data
    <normal_tag></normal_tag>
    </normal_tag>
    */

    //## Global Variables ##//
    $file = "myxmltest.xml";
    $character_data_on = false;
    $tag_complete = true;

    function     startElement($parser, $name, $attrs)
    {
    global     $character_data_on;
    global     $tag_complete;

    echo     "&lt;<font color=\"#0000cc\">$name</font>";
    //## Print the attributes ##//
    if (sizeof($attrs)) {
    while (list(    $k, $v) = each($attrs)) {
    echo     " <font color=\"#009900\">$k</font>=\"<font
    color=\"#990000\">    $v</font>\"";
    }
    }
    //## Tag is still still incomplete,
    //## will be completed at either endElement or characterData ##//
    $tag_complete = false;
    $character_data_on = false;
    }

    function     endElement($parser, $name)
    {
    global     $fp;
    global     $character_data_on;
    global     $tag_complete;

    //#### Test for self-closing tag ####//
    //## xml_get_current_byte_index(resource parser) when run in this
    //## function, gives the index at (indicated by *):
    //## for self closing tag: <br />*
    //## for individual closing tag: <div>character data*</div>
    //## So to test for self-closing tag, we can just test for the last 2
    //## characters from the index
    //###################################//

    if (!$character_data_on) {
    //## Record current fp position ##//
    $temp_fp = ftell($fp);

    //## Point fp to 2 bytes before the end element byte index ##//
    $end_element_byte_index = xml_get_current_byte_index($parser);
    fseek($fp,$end_element_byte_index-2);

    //## Gets the last 2 characters before the end element byte index ##//
    $validator = fgets($fp, 3);

    //## Restore fp position ##//
    fseek($fp,$temp_fp);

    //## If the last 2 character is "/>" ##//
    if ($validator=="/>") {
    //// Complete the self-closing tag ////
    echo " /&gt";
    //// Otherwise it is an individual closing tag ////
    } else echo "&gt&lt/<font color=\"#0000cc\">$name</font>&gt";
    $tag_complete = true;
    } else echo     "&lt/<font color=\"#0000cc\">$name</font>&gt";

    $character_data_on = false;
    }

    function     characterData($parser, $data)
    {
    global     $character_data_on;
    global     $tag_complete;

    if ((!    $character_data_on)&&(!$tag_complete)) {
    echo     "&gt";
    $tag_complete = true;
    }
    echo     "<b>$data</b>";
    $character_data_on = true;
    }

    $xml_parser = xml_parser_create();
    xml_parser_set_option($xml_parser, XML_OPTION_CASE_FOLDING, false);
    xml_set_element_handler($xml_parser, "startElement", "endElement");
    xml_set_character_data_handler($xml_parser, "characterData");
    if (!(    $fp = fopen($file, "r"))) {
    die(    "could not open XML input");
    }

    echo     "<pre>";
    while (    $file_content = fread($fp, 4096)) {
    if (!    xml_parse($xml_parser, $file_content, feof($fp))) {
    die(    sprintf("XML error: %s at line %d",
    xml_error_string(xml_get_error_code($xml_parser)),
    xml_get_current_line_number($xml_parser)));
    }
    }
    echo     "</pre>";
    xml_parser_free($xml_parser);
    ?>
    up
    1
    jg at jmkg dot net
    23 years ago
    If you are using a class for xml parsing, and want to check the return value of xml_set_element_handler in case it fails, you must do this outside of the class's constructor. Inside the constructor, PHP-4.0.5 will die.

    Basically, put all your xml initialisation code in another function of the class, and keep it out of the constructor.
    up
    0
    turan dot yuksel at tcmb dot gov dot tr
    19 years ago
    The method that 'ibjoel at hotmail dot com' have described requires libxml2 as the xml parser, it does not work with expat. For a brief explanation, see xml_get_current_byte_index.
    up
    0
    ibjoel at hotmail dot com
    19 years ago
    I noticed that in the example below, and all the examples I've seen on this site for viewing xml in html, the look of self closing tags such as <br /> are not preserved. The parser cannot distinguish between <tag /> and <tag></tag>, and if your start and end element functions are like these examples, both instances will be output with both an indvidual start and end tag. I needed to preserve self-closing tags and it took me a while to figure out this work around. Hope this helps someone...

    The start tag is left open, and then completed by it's first child, the next start tag or its end tag. The end tag will complete with " />", or </tag> depending on the number of bytes between the start and end tags in the parsed data.
    <?php
    //$data=filepath or string
    $data=<<<DATA
    <normal_tag>
    <self_close_tag />
    data
    <normal_tag>data
    <self_close_tag attr="value" />
    </normal_tag>
    data
    <normal_tag></normal_tag>
    </normal_tag>
    DATA;

    function     startElement($parser, $name, $attrs)
    {
    xml_set_character_data_handler($parser, "characterData");
    global     $first_child, $start_byte;
    if(    $first_child) //close start tag if neccessary
    echo "><br />";
    $first_child=true;
    $start_byte=xml_get_current_byte_index ($parser);
    if(    count($attrs)>=1){
    foreach(    $attrs as $x=>$y){
    $attr_string .= " $x=\"$y\"";
    }
    }
    echo     htmlentities("<{$name}{$attr_string}"); //unclosed starttag
    }

    function     endElement($parser, $name)
    {
    global     $first_child, $start_byte;
    $byte=xml_get_current_byte_index ($parser);
    if(    $byte-$start_byte>2){ //if end tag is more than 2 bytes from start tag
    if($first_child) //close start tag if neccessary
    echo "><br />";
    echo     htmlentities("</{$name}>")."<br />"; //individual end tag
    }else
    echo     " /><br />"; // self closing tag
    $first_child=false;

    }

    function     characterData($parser, $data)
    {
    global     $first_child;
    if(    $first_child) //if $data is first child, close start tag
    echo "><br />";
    if(    $data=trim($data))
    echo     "<font color='blue'>$data</font><br />";
    $first_child=false;
    }

    function     ParseData($data)
    {
    $xml_parser = xml_parser_create();
    xml_set_element_handler($xml_parser, "startElement", "endElement");
    xml_parser_set_option($xml_parser,XML_OPTION_CASE_FOLDING,0);
    if(    is_file($data))
    {
    if (!(    $fp = fopen($file, "r"))) {
    die(    "could not open XML input");
    }

    while (    $data = fread($fp, 4096)) {
    if (!    xml_parse($xml_parser, $data, feof($fp))) {
    $error=xml_error_string(xml_get_error_code($xml_parser));
    $line=xml_get_current_line_number($xml_parser);
    die(    sprintf("XML error: %s at line %d",$error,$line));
    }
    }
    }else{
    if (!    xml_parse($xml_parser, $data, 1)) {
    $error=xml_error_string(xml_get_error_code($xml_parser));
    $line=xml_get_current_line_number($xml_parser);
    die(    sprintf("XML error: %s at line %d",$error,$line));
    }
    }

    xml_parser_free($xml_parser);
    }

    ParseData($data);
    ?>
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    0
    tj at tobyjoe dot com
    21 years ago
    It seems that the tag handlers don't block on one another (the end handler is called whether or not the begin handler has finished). this can put you in a tight spot if you don't realize it while planning your app.
    up
    -1
    vladimir-leontiev at uiowa dot edu
    19 years ago
    It seems that characterData() gets characters in chuncks of 1024; therefore if you have string of characters between you tags that is longer than 1024 then characterData() will be called more that once for single pair of tags. I don't know if this feature(bug?) is documented anywhere, I just wanted to warn everyone about this; it had tripped me. I use php 4.3.10 on Linux.
    up
    -1
    kok at nachon dot nl
    16 years ago
    Here is another example of detecting empty elements. I works with libxml2. Note that it handles buffer boundaries.

    <?php

    $depth     = 0; //current depth, used for pretty printing
    $empty = false; //whether the tag is empty
    $offset = 0; //the index of the start of the current buffer within the stream

    function tagStart($parser, $name, array $attribs) {
    global     $depth, $empty, $data, $offset, $lastchar;
    $idx = xml_get_current_byte_index($parser);
    /* xml_get_current_byte_index returns index within the streams and not
    within the buffer.*/

    /* Check if the index is within the buffer. */
    if (isset($data[$idx - $offset])) {
    $c = $data[$idx - $offset];
    } else {
    /* If it isn't simple use the last character of the buffer. */
    $c = $lastchar;
    }
    $empty = $c == '/';
    echo     str_repeat("\t", $depth), "<$name", ($empty ? '/>' : '>'), "\n";
    if (!    $empty) ++$depth;
    }

    function     tagEnd($parser, $name) {
    global     $depth, $empty;
    if (!    $empty) {
    --    $depth;
    echo     str_repeat("\t", $depth), "</$name>\n";
    } else {
    $empty = false;
    }
    }

    $parser = xml_parser_create();
    xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, false);
    xml_set_element_handler($parser, 'tagStart', 'tagEnd');

    $data1 = '
    <test>
    <empty att="3" />
    <nocontent></nocontent>
    <content>
    <empty/>
    <empty/>
    </content>
    <empty/'    ;

    $data2 = '>
    <empty att="5" />
    </test>
    '    ;

    $data = &$data1;
    $length = strlen($data1);
    $lastchar = $data[$length-1];
    xml_parse($parser, $data1);
    $offset .= $length;
    $data = &$data2;
    xml_parse($parser, $data2);
    up
    -1
    redb
    18 years ago
    Example below (BadParser) works fine with some changes.

    xml_set_element_handler ( $parser, array ( &$this, 'tagStart' ), array ( &$this, 'tagEnd' ) );
    xml_set_character_data_handler ( $parser, array ( &$this, 'tagContent' ) );
    up
    -2
    Anonymous
    19 years ago
    In response to aw at avatartechnology dot com...
    In response to landb at mail dot net...

    When your functions are in an object:
    Careful ! Don't forget to add: & (reference) to your parameters.

    xml_set_element_handler($parser, array(&$this,"_startElement"), array(&$this,"_endElement"));
    --> xmlparse will work on your object (good).

    instead of:
    xml_set_element_handler($parser, array($this,"_startElement"), array($this,"_endElement"));
    ---> xmlparse will work on a COPY of your object (often bad)

    Vin-s
    (sorry for my english)
    up
    -2
    Anonymous
    23 years ago
    You CAN use classes to parse XML. Just take a look at the following function:

    xml_set_object
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