mxObjectCodec

XML codec for PHP object graphs.

Implementation note

The passing of the argument by reference in decode, decodeNode, decodeAttributes, decodeAttribute, decodeChildren, decodeChild, beforeDecode and afterDecode is required since the object may be an array instance, which needs an explicit reference operator even in PHP 5 to be changed in-place.

Summary
mxObjectCodecXML codec for PHP object graphs.
Variables
templateHolds the template object associated with this codec.
excludeArray containing the variable names that should be ignored by the codec.
idrefsArray containing the variable names that should be turned into or converted from references.
mappingMaps from from fieldnames to XML attribute names.
reverseMaps from from XML attribute names to fieldnames.
Functions
mxObjectCodecConstructs a new codec for the specified template object.
getNameCreates a new instance of the template for this codec.
cloneTemplateCreates a new instance of the template for this codec.
getFieldNameReturns the fieldname for the given attributename.
getAttributeNameReturns the attributename for the given fieldname.
isExcludedReturns true if the given attribute is to be ignored by the codec.
isReferenceReturns true if the given fieldname is to be treated as a textual reference (ID).
encodeEncodes the specified object and returns a node representing then given object.
encodeObjectEncodes the value of each member in then given obj into the given node using encodeValue.
encodeValueConverts the given value according to the mappings and id-refs in this codec and uses writeAttribute to write the attribute into the given node.
writeAttributeWrites the given value into node using writePrimitiveAttribute or writeComplexAttribute depending on the type of the value.
writePrimitiveAttributeWrites the given value as an attribute of the given node.
writeComplexAttributeWrites the given value as a child node of the given node.
convertValueToXmlReturns the given value without applying a conversion.
convertValueFromXmlReturns the given value.
beforeEncodeHook for subclassers to pre-process the object before encoding.
afterEncodeHook for subclassers to post-process the node for the given object after encoding and return the post-processed node.
decodeParses the given node into the object or returns a new object representing the given node.
decodeNodeCalls decodeAttributes and decodeChildren for the given node.
decodeAttributesDecodes all attributes of the given node using decodeAttribute.
decodeAttributeReads the given attribute into the specified object.
decodeChildrenDecodec all children of the given node using decodeChild.
decodeChildReads the specified child into the given object.
getFieldTemplateReturns the template instance for the given field.
addObjectValueSets the decoded child node as a value of the given object.
processIncludeReturns true if the given node is an include directive and executes the include by decoding the XML document.
beforeDecodeHook for subclassers to pre-process the node for the specified object and return the node to be used for further processing by decode.
afterDecodeHook for subclassers to post-process the object after decoding.

Variables

template

var $template

Holds the template object associated with this codec.

exclude

var $exclude

Array containing the variable names that should be ignored by the codec.

idrefs

var $idrefs

Array containing the variable names that should be turned into or converted from references.  See mxCodec.getId and mxCodec.getObject.

mapping

var $mapping

Maps from from fieldnames to XML attribute names.

reverse

var $reverse

Maps from from XML attribute names to fieldnames.

Functions

mxObjectCodec

function mxObjectCodec($template,  
$exclude =  array(),
$idrefs =  array(),
$mapping =  array())

Constructs a new codec for the specified template object.  The variables in the optional exclude array are ignored by the codec.  Variables in the optional idrefs array are turned into references in the XML.  The optional mapping may be used to map from variable names to XML attributes.

Parameters

templatePrototypical instance of the object to be encoded/decoded.
excludeOptional array of fieldnames to be ignored.
idrefsOptional array of fieldnames to be converted to/from references.
mappingOptional mapping from field- to attributenames.

getName

function getName()

Creates a new instance of the template for this codec.

cloneTemplate

function cloneTemplate()

Creates a new instance of the template for this codec.

getFieldName

function getFieldName($attributename)

Returns the fieldname for the given attributename.  Looks up the value in the reverse mapping or returns the input if there is no reverse mapping for the given name.

getAttributeName

function getAttributeName($fieldname)

Returns the attributename for the given fieldname.  Looks up the value in the mapping or returns the input if there is no mapping for the given name.

isExcluded

function isExcluded($obj,
$attr,
$value,
$write)

Returns true if the given attribute is to be ignored by the codec.  This implementation returns true if the given fieldname is in exclude or if the fieldname equals <mxObjectIdentity.FIELD_NAME>.

Parameters

objObject instance that contains the field.
attrFieldname of the field.
valueValue of the field.
writeBoolean indicating if the field is being encoded or decoded.  Write is true if the field is being encoded, else it is being decoded.

isReference

function isReference($obj,
$attr,
$value,
$write)

Returns true if the given fieldname is to be treated as a textual reference (ID).  This implementation returns true if the given fieldname is in idrefs.

Parameters

objObject instance that contains the field.
attrFieldname of the field.
valueValue of the field.
writeBoolean indicating if the field is being encoded or decoded.  Write is true if the field is being encoded, else it is being decoded.

encode

function encode($enc,
$obj)

Encodes the specified object and returns a node representing then given object.  Calls beforeEncode after creating the node and afterEncode with the resulting node after processing.

Enc is a reference to the calling encoder.  It is used to encode complex objects and create references.

This implementation encodes all variables of an object according to the following rules:

  • If the variable name is in exclude then it is ignored.
  • If the variable name is in idrefs then mxCodec.getId is used to replace the object with its ID.
  • The variable name is mapped using mapping.
  • If obj is an array and the variable name is numeric (ie. an index) then it is not encoded.
  • If the value is an object, then the codec is used to create a child node with the variable name encoded into the “as” attribute.
  • Else, if <encodeDefaults> is true or the value differs from the template value, then ...
  • ... if obj is not an array, then the value is mapped to an attribute.
  • ... else if obj is an array, the value is mapped to an add child with a value attribute or a text child node, if the value is a function.

If no ID exists for a variable in idrefs or if an object cannot be encoded, a warning is issued using mxLog.warn.

Returns the resulting XML node that represents the given object.

Parameters

encmxCodec that controls the encoding process.
objObject to be encoded.

encodeObject

function encodeObject($enc,
$obj,
$node)

Encodes the value of each member in then given obj into the given node using encodeValue.

Parameters

encmxCodec that controls the encoding process.
objObject to be encoded.
nodeXML node that contains the encoded object.

encodeValue

function encodeValue($enc,
$obj,
$name,
$value,
$node)

Converts the given value according to the mappings and id-refs in this codec and uses writeAttribute to write the attribute into the given node.

Parameters

encmxCodec that controls the encoding process.
objObject whose property is going to be encoded.
nameXML node that contains the encoded object.
valueValue of the property to be encoded.
nodeXML node that contains the encoded object.

writeAttribute

function writeAttribute($enc,
$obj,
$attr,
$value,
$node)

Writes the given value into node using writePrimitiveAttribute or writeComplexAttribute depending on the type of the value.

writePrimitiveAttribute

function writePrimitiveAttribute($enc,
$obj,
$attr,
$value,
$node)

Writes the given value as an attribute of the given node.

writeComplexAttribute

function writeComplexAttribute($enc,
$obj,
$attr,
$value,
$node)

Writes the given value as a child node of the given node.

convertValueToXml

function convertValueToXml($value)

Returns the given value without applying a conversion.

convertValueFromXml

function convertValueFromXml($value)

Returns the given value.  In PHP there is no need to convert the boolean strings “0” and “1” to their numeric / boolean values.

beforeEncode

function beforeEncode($enc,
$obj,
$node)

Hook for subclassers to pre-process the object before encoding.  This returns the input object.  The return value of this function is used in encode to perform the default encoding into the given node.

Parameters

encmxCodec that controls the encoding process.
objObject to be encoded.
nodeXML node to encode the object into.

afterEncode

function afterEncode($enc,
$obj,
$node)

Hook for subclassers to post-process the node for the given object after encoding and return the post-processed node.  This implementation returns the input node.  The return value of this method is returned to the encoder from encode.

Parameters

encmxCodec that controls the encoding process.
objObject to be encoded.
nodeXML node that represents the default encoding.

decode

function decode($dec,  
$node,  
&$into =  null)

Parses the given node into the object or returns a new object representing the given node.

Dec is a reference to the calling decoder.  It is used to decode complex objects and resolve references.

If a node has an id attribute then the object cache is checked for the object.  If the object is not yet in the cache then it is constructed using the constructor of template and cached in mxCodec.objects.

This implementation decodes all attributes and childs of a node according to the following rules:

  • If the variable name is in exclude or if the attribute name is “id” or “as” then it is ignored.
  • If the variable name is in idrefs then mxCodec.getObject is used to replace the reference with an object.
  • The variable name is mapped using a reverse mapping.
  • If the value has a child node, then the codec is used to create a child object with the variable name taken from the “as” attribute.
  • If the object is an array and the variable name is empty then the value or child object is appended to the array.
  • If an add child has no value or the object is not an array then the child text content is evaluated using <mxUtils.eval>.

For add nodes where the object is not an array and the variable name is defined, the default mechanism is used, allowing to override/add methods as follows:

<Object>
  <add as="hello"><![CDATA[
    function(arg1) {
      alert('Hello '+arg1);
    }
  ]]></add>
</Object>

If no object exists for an ID in idrefs a warning is issued using mxLog.warn.

Returns the resulting object that represents the given XML node or the object given to the method as the into parameter.

Parameters

decmxCodec that controls the decoding process.
nodeXML node to be decoded.
intoOptional objec to encode the node into.

decodeNode

function decodeNode($dec,
$node,
&$obj)

Calls decodeAttributes and decodeChildren for the given node.

decodeAttributes

function decodeAttributes($dec,
$node,
&$obj)

Decodes all attributes of the given node using decodeAttribute.

decodeAttribute

function decodeAttribute($dec,
$attr,
&$obj)

Reads the given attribute into the specified object.

decodeChildren

function decodeChildren($dec,
$node,
&$obj)

Decodec all children of the given node using decodeChild.

decodeChild

function decodeChild($dec,
$child,
&$obj)

Reads the specified child into the given object.

getFieldTemplate

function getFieldTemplate(&$obj,
$fieldname,
$child)

Returns the template instance for the given field.  This returns the value of the field, null if the value is an array or an empty collection if the value is a collection.  The value is then used to populate the field for a new instance.  For strongly typed languages it may be required to override this to return the correct collection instance based on the encoded child.

addObjectValue

function addObjectValue(&$obj,
$fieldname,
$value,
$template)

Sets the decoded child node as a value of the given object.  If the object is a map, then the value is added with the given fieldname as a key.  If the fieldname is not empty, then setFieldValue is called or else, if the object is a collection, the value is added to the collection.  For strongly typed languages it may be required to override this with the correct code to add an entry to an object.

processInclude

function processInclude($dec,
$node,
$into)

Returns true if the given node is an include directive and executes the include by decoding the XML document.  Returns false if the given node is not an include directive.

Parameters

decmxCodec that controls the encoding/decoding process.
nodeXML node to be checked.
intoOptional object to pass-thru to the codec.

beforeDecode

function beforeDecode($dec,
$node,
&$obj)

Hook for subclassers to pre-process the node for the specified object and return the node to be used for further processing by decode.  The object is created based on the template in the calling method and is never null.  This implementation returns the input node.  The return value of this function is used in decode to perform the default decoding into the given object.

Parameters

decmxCodec that controls the decoding process.
nodeXML node to be decoded.
objObject to encode the node into.

afterDecode

function afterDecode($dec,
$node,
&$obj)

Hook for subclassers to post-process the object after decoding.  This implementation returns the given object without any changes.  The return value of this method is returned to the decoder from decode.

Parameters

encmxCodec that controls the encoding process.
nodeXML node to be decoded.
objObject that represents the default decoding.
var $template
Holds the template object associated with this codec.
var $exclude
Array containing the variable names that should be ignored by the codec.
var $idrefs
Array containing the variable names that should be turned into or converted from references.
var $mapping
Maps from from fieldnames to XML attribute names.
var $reverse
Maps from from XML attribute names to fieldnames.
function mxObjectCodec($template,  
$exclude =  array(),
$idrefs =  array(),
$mapping =  array())
Constructs a new codec for the specified template object.
function getName()
Creates a new instance of the template for this codec.
function cloneTemplate()
Creates a new instance of the template for this codec.
function getFieldName($attributename)
Returns the fieldname for the given attributename.
function getAttributeName($fieldname)
Returns the attributename for the given fieldname.
function isExcluded($obj,
$attr,
$value,
$write)
Returns true if the given attribute is to be ignored by the codec.
function isReference($obj,
$attr,
$value,
$write)
Returns true if the given fieldname is to be treated as a textual reference (ID).
function encode($enc,
$obj)
Encodes the specified object and returns a node representing then given object.
function encodeObject($enc,
$obj,
$node)
Encodes the value of each member in then given obj into the given node using encodeValue.
function encodeValue($enc,
$obj,
$name,
$value,
$node)
Converts the given value according to the mappings and id-refs in this codec and uses writeAttribute to write the attribute into the given node.
function writeAttribute($enc,
$obj,
$attr,
$value,
$node)
Writes the given value into node using writePrimitiveAttribute or writeComplexAttribute depending on the type of the value.
function writePrimitiveAttribute($enc,
$obj,
$attr,
$value,
$node)
Writes the given value as an attribute of the given node.
function writeComplexAttribute($enc,
$obj,
$attr,
$value,
$node)
Writes the given value as a child node of the given node.
function convertValueToXml($value)
Returns the given value without applying a conversion.
function convertValueFromXml($value)
Returns the given value.
function beforeEncode($enc,
$obj,
$node)
Hook for subclassers to pre-process the object before encoding.
function afterEncode($enc,
$obj,
$node)
Hook for subclassers to post-process the node for the given object after encoding and return the post-processed node.
function decode($dec,  
$node,  
&$into =  null)
Parses the given node into the object or returns a new object representing the given node.
function decodeNode($dec,
$node,
&$obj)
Calls decodeAttributes and decodeChildren for the given node.
function decodeAttributes($dec,
$node,
&$obj)
Decodes all attributes of the given node using decodeAttribute.
function decodeChildren($dec,
$node,
&$obj)
Decodec all children of the given node using decodeChild.
function decodeAttribute($dec,
$attr,
&$obj)
Reads the given attribute into the specified object.
function decodeChild($dec,
$child,
&$obj)
Reads the specified child into the given object.
function getFieldTemplate(&$obj,
$fieldname,
$child)
Returns the template instance for the given field.
function addObjectValue(&$obj,
$fieldname,
$value,
$template)
Sets the decoded child node as a value of the given object.
function processInclude($dec,
$node,
$into)
Returns true if the given node is an include directive and executes the include by decoding the XML document.
function beforeDecode($dec,
$node,
&$obj)
Hook for subclassers to pre-process the node for the specified object and return the node to be used for further processing by decode.
function afterDecode($dec,
$node,
&$obj)
Hook for subclassers to post-process the object after decoding.
function getId($obj)
Returns the ID of the specified object.
function getObject($id)
Returns the decoded object for the element with the specified ID in document.
static function warn($text)
Logs a warn trace.
XML codec for PHP object graphs.
var $objects
Maps from IDs to objects.
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