mxObjectCodec (mxGraph 3.3.0.0 API Specification)

java.lang.Object
- com.mxgraph.io.mxObjectCodec

Direct Known Subclasses:

mxCellCodec, mxChildChangeCodec, mxGenericChangeCodec, mxModelCodec, mxRootChangeCodec, mxStylesheetCodec, mxTerminalChangeCodec
```
public class mxObjectCodec
extends Object
```
Generic codec for Java objects. See below for a detailed description of the encoding/decoding scheme. Note: Since booleans are numbers in JavaScript, all boolean values are encoded into 1 for true and 0 for false.

Field Summary

Fields
Modifier and Type	Field and Description
`protected Map<String,Method>`	`accessors` Caches accessors for the given method names.
`protected Set<String>`	`exclude` Array containing the variable names that should be ignored by the codec.
`protected Map<Class,Map<String,Field>>`	`fields` Caches fields for faster access.
`protected Set<String>`	`idrefs` Array containing the variable names that should be turned into or converted from references.
`protected Map<String,String>`	`mapping` Maps from from fieldnames to XML attribute names.
`protected Map<String,String>`	`reverse` Maps from from XML attribute names to fieldnames.
`protected Object`	`template` Holds the template object associated with this codec.

Constructor Summary

Constructors
Constructor and Description
`mxObjectCodec(Object template)` Constructs a new codec for the specified template object.
`mxObjectCodec(Object template, String[] exclude, String[] idrefs, Map<String,String> mapping)` Constructs a new codec for the specified template object.

Method Summary

Methods
Modifier and Type	Method and Description
`protected void`	`addObjectValue(Object obj, String fieldname, Object value, Object template)` Sets the decoded child node as a value of the given object.
`Object`	`afterDecode(mxCodec dec, Node node, Object obj)` Hook for subclassers to post-process the object after decoding.
`Node`	`afterEncode(mxCodec enc, Object obj, Node node)` Hook for subclassers to post-process the node for the given object after encoding and return the post-processed node.
`Node`	`beforeDecode(mxCodec dec, Node node, Object 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(mxCodec, Node)`.
`Object`	`beforeEncode(mxCodec enc, Object obj, Node node)` Hook for subclassers to pre-process the object before encoding.
`protected Object`	`cloneTemplate(Node node)` Returns a new instance of the template object for representing the given node.
`protected Object`	`convertValueFromXml(Class<?> type, Object value)` Converts XML attribute values to object of the given type.
`protected Object`	`convertValueToXml(Object value)` Converts true to "1" and false to "0".
`Object`	`decode(mxCodec dec, Node node)` Parses the given node into the object or returns a new object representing the given node.
`Object`	`decode(mxCodec dec, Node node, Object into)` Parses the given node into the object or returns a new object representing the given node.
`protected void`	`decodeAttribute(mxCodec dec, Node attr, Object obj)` Reads the given attribute into the specified object.
`protected void`	`decodeAttributes(mxCodec dec, Node node, Object obj)` Decodes all attributes of the given node using decodeAttribute.
`protected void`	`decodeChild(mxCodec dec, Node child, Object obj)` Reads the specified child into the given object.
`protected void`	`decodeChildren(mxCodec dec, Node node, Object obj)` Decodec all children of the given node using decodeChild.
`protected void`	`decodeNode(mxCodec dec, Node node, Object obj)` Calls decodeAttributes and decodeChildren for the given node.
`Node`	`encode(mxCodec enc, Object obj)` Encodes the specified object and returns a node representing then given object.
`protected void`	`encodeElements(mxCodec enc, Object obj, Node node)` Encodes the child objects of arrays, maps and collections.
`protected void`	`encodeFields(mxCodec enc, Object obj, Node node)` Encodes the declared fields of the given object into the given node.
`protected void`	`encodeObject(mxCodec enc, Object obj, Node node)` Encodes the value of each member in then given obj into the given node using `encodeFields(mxCodec, Object, Node)` and `encodeElements(mxCodec, Object, Node)`.
`protected void`	`encodeValue(mxCodec enc, Object obj, String fieldname, Object value, Node node)` Converts the given value according to the mappings and id-refs in this codec and uses `writeAttribute(mxCodec, Object, String, Object, Node)` to write the attribute into the given node.
`protected Method`	`getAccessor(Object obj, Field field, boolean isGetter)` Returns the accessor (getter, setter) for the specified field.
`protected String`	`getAttributeName(String fieldname)` Returns the XML node attribute name for the given Java field name.
`protected Field`	`getField(Object obj, String fieldname)` Returns the field with the specified name.
`protected String`	`getFieldName(String attributename)` Returns the Java field name for the given XML attribute name.
`protected Object`	`getFieldTemplate(Object obj, String fieldname, Node child)` Returns the template instance for the given field.
`protected Object`	`getFieldValue(Object obj, String fieldname)` Returns the value of the field with the specified name in the specified object instance.
`protected Object`	`getFieldValueWithAccessor(Object obj, Field field)` Returns the value of the field using the accessor for the field if one exists.
`protected Method`	`getMethod(Object obj, String methodname, Class[] params)` Returns the method with the specified signature.
`String`	`getName()` Returns the name used for the nodenames and lookup of the codec when classes are encoded and nodes are decoded.
`Object`	`getTemplate()` Returns the template object associated with this codec.
`boolean`	`isExcluded(Object obj, String attr, Object value, boolean write)` Returns true if the given attribute is to be ignored by the codec.
`protected boolean`	`isPrimitiveValue(Object value)` Returns true if the given object is a primitive value.
`boolean`	`isReference(Object obj, String attr, Object value, boolean isWrite)` Returns true if the given fieldname is to be treated as a textual reference (ID).
`boolean`	`processInclude(mxCodec dec, Node node, Object into)` Returns true if the given node is an include directive and executes the include by decoding the XML document.
`protected void`	`setFieldValue(Object obj, String fieldname, Object value)` Sets the value of the field with the specified name in the specified object instance.
`protected void`	`setFieldValueWithAccessor(Object obj, Field field, Object value)` Sets the value of the given field using the accessor if one exists.
`protected void`	`writeAttribute(mxCodec enc, Object obj, String attr, Object value, Node node)` Writes the given value into node using writePrimitiveAttribute or writeComplexAttribute depending on the type of the value.
`protected void`	`writeComplexAttribute(mxCodec enc, Object obj, String attr, Object value, Node node)` Writes the given value as a child node of the given node.
`protected void`	`writePrimitiveAttribute(mxCodec enc, Object obj, String attr, Object value, Node node)` Writes the given value as an attribute of the given node.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - template
```
protected Object template
```
    Holds the template object associated with this codec.
  - exclude
```
protected Set<String> exclude
```
    Array containing the variable names that should be ignored by the codec.
  - idrefs
```
protected Set<String> idrefs
```
    Array containing the variable names that should be turned into or converted from references. See and .
  - mapping
```
protected Map<String,String> mapping
```
    Maps from from fieldnames to XML attribute names.
  - reverse
```
protected Map<String,String> reverse
```
    Maps from from XML attribute names to fieldnames.
  - accessors
```
protected Map<String,Method> accessors
```
    Caches accessors for the given method names.
  - fields
```
protected Map<Class,Map<String,Field>> fields
```
    Caches fields for faster access.
- Constructor Detail
  - mxObjectCodec
```
public mxObjectCodec(Object template)
```
    Constructs a new codec for the specified template object.
  - mxObjectCodec
```
public mxObjectCodec(Object template,
             String[] exclude,
             String[] idrefs,
             Map<String,String> mapping)
```
    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. The argument is created as follows:
    
    Parameters:
    template - Prototypical instance of the object to be encoded/decoded.
    exclude - Optional array of fieldnames to be ignored.
    idrefs - Optional array of fieldnames to be converted to/from references.
    mapping - Optional mapping from field- to attributenames.
- Method Detail
  - getName
```
public String getName()
```
    Returns the name used for the nodenames and lookup of the codec when classes are encoded and nodes are decoded. For classes to work with this the codec registry automatically adds an alias for the classname if that is different than what this returns. The default implementation returns the classname of the template class. Here is an example on how to use this for renaming mxCell nodes: mxCodecRegistry.register(new mxCellCodec() { public String getName() { return "anotherName"; } });
  - getTemplate
```
public Object getTemplate()
```
    Returns the template object associated with this codec.
    
    Returns:
    Returns the template object.
  - cloneTemplate
```
protected Object cloneTemplate(Node node)
```
    Returns a new instance of the template object for representing the given node.
    
    Parameters:
    node - XML node that the object is going to represent.
    
    Returns:
    Returns a new template instance.
  - isExcluded
```
public boolean isExcluded(Object obj,
                 String attr,
                 Object value,
                 boolean 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.
    
    Parameters:
    obj - Object instance that contains the field.
    attr - Fieldname of the field.
    value - Value of the field.
    write - Boolean indicating if the field is being encoded or decoded. write is true if the field is being encoded, else it is being decoded.
    
    Returns:
    Returns true if the given attribute should be ignored.
  - isReference
```
public boolean isReference(Object obj,
                  String attr,
                  Object value,
                  boolean isWrite)
```
    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:
    obj - Object instance that contains the field.
    attr - Fieldname of the field.
    value - Value of the field.
    isWrite - Boolean indicating if the field is being encoded or decoded. isWrite is true if the field is being encoded, else it is being decoded.
    
    Returns:
    Returns true if the given attribute should be handled as a reference.
  - encode
```
public Node encode(mxCodec enc,
          Object 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(Object) 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 mxCodec.isEncodeDefaults() 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 printed to System.err.
    Parameters:
    enc - Codec that controls the encoding process.
    obj - Object to be encoded.
    
    Returns:
    Returns the resulting XML node that represents the given object.
  - encodeObject
```
protected void encodeObject(mxCodec enc,
                Object obj,
                Node node)
```
    Encodes the value of each member in then given obj into the given node using encodeFields(mxCodec, Object, Node) and encodeElements(mxCodec, Object, Node).
    
    Parameters:
    enc - Codec that controls the encoding process.
    obj - Object to be encoded.
    node - XML node that contains the encoded object.
  - encodeFields
```
protected void encodeFields(mxCodec enc,
                Object obj,
                Node node)
```
    Encodes the declared fields of the given object into the given node.
    
    Parameters:
    enc - Codec that controls the encoding process.
    obj - Object whose fields should be encoded.
    node - XML node that contains the encoded object.
  - encodeElements
```
protected void encodeElements(mxCodec enc,
                  Object obj,
                  Node node)
```
    Encodes the child objects of arrays, maps and collections.
    
    Parameters:
    enc - Codec that controls the encoding process.
    obj - Object whose child objects should be encoded.
    node - XML node that contains the encoded object.
  - encodeValue
```
protected void encodeValue(mxCodec enc,
               Object obj,
               String fieldname,
               Object value,
               Node node)
```
    Converts the given value according to the mappings and id-refs in this codec and uses writeAttribute(mxCodec, Object, String, Object, Node) to write the attribute into the given node.
    
    Parameters:
    enc - Codec that controls the encoding process.
    obj - Object whose field is going to be encoded.
    fieldname - Name if the field to be encoded.
    value - Value of the property to be encoded.
    node - XML node that contains the encoded object.
  - isPrimitiveValue
```
protected boolean isPrimitiveValue(Object value)
```
    Returns true if the given object is a primitive value.
    
    Parameters:
    value - Object that should be checked.
    
    Returns:
    Returns true if the given object is a primitive value.
  - writeAttribute
```
protected void writeAttribute(mxCodec enc,
                  Object obj,
                  String attr,
                  Object value,
                  Node node)
```
    Writes the given value into node using writePrimitiveAttribute or writeComplexAttribute depending on the type of the value.
  - writePrimitiveAttribute
```
protected void writePrimitiveAttribute(mxCodec enc,
                           Object obj,
                           String attr,
                           Object value,
                           Node node)
```
    Writes the given value as an attribute of the given node.
  - writeComplexAttribute
```
protected void writeComplexAttribute(mxCodec enc,
                         Object obj,
                         String attr,
                         Object value,
                         Node node)
```
    Writes the given value as a child node of the given node.
  - convertValueToXml
```
protected Object convertValueToXml(Object value)
```
    Converts true to "1" and false to "0". All other values are ignored.
  - convertValueFromXml
```
protected Object convertValueFromXml(Class<?> type,
                         Object value)
```
    Converts XML attribute values to object of the given type.
  - getAttributeName
```
protected String getAttributeName(String fieldname)
```
    Returns the XML node attribute name for the given Java field name. That is, it returns the mapping of the field name.
  - getFieldName
```
protected String getFieldName(String attributename)
```
    Returns the Java field name for the given XML attribute name. That is, it returns the reverse mapping of the attribute name.
    
    Parameters:
    attributename - The attribute name to be mapped.
    
    Returns:
    String that represents the mapped field name.
  - getField
```
protected Field getField(Object obj,
             String fieldname)
```
    Returns the field with the specified name.
  - getAccessor
```
protected Method getAccessor(Object obj,
                 Field field,
                 boolean isGetter)
```
    Returns the accessor (getter, setter) for the specified field.
  - getMethod
```
protected Method getMethod(Object obj,
               String methodname,
               Class[] params)
```
    Returns the method with the specified signature.
  - getFieldValue
```
protected Object getFieldValue(Object obj,
                   String fieldname)
```
    Returns the value of the field with the specified name in the specified object instance.
  - getFieldValueWithAccessor
```
protected Object getFieldValueWithAccessor(Object obj,
                               Field field)
```
    Returns the value of the field using the accessor for the field if one exists.
  - setFieldValue
```
protected void setFieldValue(Object obj,
                 String fieldname,
                 Object value)
```
    Sets the value of the field with the specified name in the specified object instance.
  - setFieldValueWithAccessor
```
protected void setFieldValueWithAccessor(Object obj,
                             Field field,
                             Object value)
```
    Sets the value of the given field using the accessor if one exists.
  - beforeEncode
```
public Object beforeEncode(mxCodec enc,
                  Object obj,
                  Node 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:
    enc - Codec that controls the encoding process.
    obj - Object to be encoded.
    node - XML node to encode the object into.
    
    Returns:
    Returns the object to be encoded by the default encoding.
  - afterEncode
```
public Node afterEncode(mxCodec enc,
               Object obj,
               Node 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 . Parameters:
    
    Parameters:
    enc - Codec that controls the encoding process.
    obj - Object to be encoded.
    node - XML node that represents the default encoding.
    
    Returns:
    Returns the resulting node of the encoding.
  - decode
```
public Object decode(mxCodec dec,
            Node node)
```
    Parses the given node into the object or returns a new object representing the given node.
    
    Parameters:
    dec - Codec that controls the encoding process.
    node - XML node to be decoded.
    
    Returns:
    Returns the resulting object that represents the given XML node.
  - decode
```
public Object decode(mxCodec dec,
            Node node,
            Object into)
```
    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

Class mxObjectCodec

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

template

exclude

idrefs

mapping

reverse

accessors

fields

Constructor Detail

mxObjectCodec

mxObjectCodec

Method Detail

getName

getTemplate

cloneTemplate

isExcluded

isReference

encode

encodeObject

encodeFields

encodeElements

encodeValue

isPrimitiveValue

writeAttribute

writePrimitiveAttribute

writeComplexAttribute

convertValueToXml

convertValueFromXml

getAttributeName

getFieldName

getField

getAccessor

getMethod

getFieldValue

getFieldValueWithAccessor

setFieldValue

setFieldValueWithAccessor

beforeEncode

afterEncode

decode

decode

decodeNode

decodeAttributes

decodeAttribute

decodeChildren

decodeChild

getFieldTemplate

addObjectValue

processInclude

beforeDecode

afterDecode