CXLIX. SimpleXML functions
Wstęp
The SimpleXML extension provides a very simple and easily usable toolset to convert XML to an object that can be processed with normal property selectors and array iterators.
Wymagania
The SimpleXML extension requires PHP 5.
Instalacja
The SimpleXML extension is enabled by default. To disable it, use the
--disable-simplexml
configure option.
Przykłady
Many examples in this reference require an XML string. Instead of repeating this string in every example, we put it into a file which we include in each example. This included file is shown in the following example section. Alternatively, you could create an XML document and read it with simplexml_load_file().
The simplicity of SimpleXML appears most clearly when one extracts a string or number from a basic XML document.
Przykład 3. Accessing non-unique elements in SimpleXML When multiple instances of an element exist as children of a single parent element, normal iteration techniques apply.
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Przykład 4. Using attributes So far, we have only covered the work of reading element names and their values. SimpleXML can also access element attributes. Access attributes of an element just as you would elements of an array.
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Przykład 5. Comparing Elements and Attributes with Text To compare an element or attribute with a string or pass it into a function that requires a string, you must cast it to a string using (string). Otherwise, PHP treats the element as an object.
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Przykład 6. Using XPath SimpleXML includes built-in XPath support. To find all <character> elements:
'//' serves as a wildcard. To specify absolute paths, omit one of the slashes. |
Przykład 7. Setting values Data in SimpleXML doesn't have to be constant. The object allows for manipulation of all of its elements.
The above code will output a new XML document, just like the original, except that the new XML will change Ms. Coder to Miss Coder. |
Przykład 8. Adding elements and attributes Since PHP 5.1.3, SimpleXML has had the ability to easily add children and attributes.
The above code will output an XML document based on the original but having a new character and rating. |
Przykład 9. DOM Interoperability PHP has a mechanism to convert XML nodes between SimpleXML and DOM formats. This example shows how one might change a DOM element to SimpleXML.
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- Spis treści
- SimpleXMLElement->addAttribute() -- Adds an attribute to the SimpleXML element
- SimpleXMLElement->addChild() -- Adds a child element to the XML node
- SimpleXMLElement->asXML() -- Return a well-formed XML string based on SimpleXML element
- SimpleXMLElement->attributes() -- Identifies an element's attributes
- SimpleXMLElement->children() -- Finds children of given node
- SimpleXMLElement->__construct() -- Creates a new SimpleXMLElement object
- SimpleXMLElement->getDocNamespaces() -- Returns namespaces declared in document
- SimpleXMLElement->getName() -- Gets the name of the XML element
- SimpleXMLElement->getNamespaces() -- Returns namespaces used in document
- SimpleXMLElement->registerXPathNamespace() -- Creates a prefix/ns context for the next XPath query
- SimpleXMLElement->xpath() -- Runs XPath query on XML data
- simplexml_import_dom -- Get a SimpleXMLElement object from a DOM node.
- simplexml_load_file -- Interprets an XML file into an object
- simplexml_load_string -- Interprets a string of XML into an object