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How to use php __construct function

藏色散人

May 27, 2019 pm 01:24 PM

php __construct function is used to create a new SimpleXMLElement object. The syntax is __construct(data, options, data_is_url, ns, is_prefix). The parameter data is required.

How to use php __construct function

#php How to use the __construct function?

Definition and Usage

__construct() function creates a new SimpleXMLElement object.

Syntax

__construct(data,options,data_is_url,ns,is_prefix);

Parameters

data Required. A well-formed XML string or the path or URL of an XML document (if data_is_url is TRUE).

options Optional. Specifies additional Libxml parameters. Set by specifying the option to 1 or 0 (TRUE or FALSE, such as LIBXML_NOBLANKS(1)).

Possible values:

● LIBXML_COMPACT - Activates an optimized configuration of the node (can speed up the application)

● LIBXML_DTDATTR - Sets the default DTD attribute

● LIBXML_DTDLOAD - Load additional subset

● LIBXML_DTDVALID - Verify DTD validity

● LIBXML_NOBLANKS - Remove empty nodes

● LIBXML_NOCDATA - Set CDATA to text node

● LIBXML_NOEMPTYTAG - expands empty tags (e.g.
to
), only valid in DOMDocument->save() and DOMDocument->saveXML() functions

● LIBXML_NOENT - Alternative entity

● LIBXML_NOERROR - Do not display error reports

● LIBXML_NONET - Stop access to the network while loading the document

● LIBXML_NOWARNING - Do not display Warning Report

● LIBXML_NOXMLDECL - Discard XML declarations when storing a document

● LIBXML_NSCLEAN - Remove redundant namespace declarations

● LIBXML_PARSEHUGE - Set the XML_PARSE_HUGE flag for relaxation Any restrictions imposed by the parser. This will affect things like the maximum document depth and text node size limits.

● LIBXML_XINCLUDE - Use XInclude instead

● LIBXML_ERR_ERROR - Get correctable errors

● LIBXML_ERR_FATAL - Get fatal errors

● LIBXML_ERR_NONE - Get no errors

● LIBXML_ERR_WARNING - Get a simple warning

● LIBXML_VERSION - Get the libxml version (e.g. 20605 or 20617)

● LIBXML_DOTTED_VERSION - Get the dotted libxml version (e.g. 2.6.5 or 2.6.17)

data_is_url Optional. If TRUE indicates that data is the path or URL of the XML document rather than string data. Default is FALSE.

ns Optional. Specifies a namespace prefix or URI.

is_prefix Optional. Specifies a boolean value. TRUE if ns is a prefix, FALSE if ns is a URI. Default is FALSE.

Return value:

Returns the SimpleXMLElement object representing data.

PHP Version: 5.0.1

PHP Change Log:

PHP 5.1.2: Added options and data_is_url parameters.

PHP 5.2: Added ns and is_prefix parameters.

Example

Suppose we have the following XML file, "note.xml":

<?xml version="1.0" encoding="ISO-8859-1"?>
<note>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don&#39;t forget me this weekend!</body>
</note>

Example 1

Create a SimpleXMLElement object from the URL:

<?php
$xml=new SimpleXMLElement("note.xml",NULL,TRUE);
echo $xml->asXML();
?>

Instance 2

The function creates a new SimpleXMLElement object and then outputs the content of the body node :

<?php
$note=<<<XML
<note>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don&#39;t forget me this weekend!</body>
</note>
XML;
$xml=new SimpleXMLElement($note);
echo $xml->body;
?>

Output:

Don&#39;t forget me this weekend!

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