sch_test/mxclient/js/io/mxObjectCodec.js

1098 lines
30 KiB
JavaScript

/**
* Copyright (c) 2006-2015, JGraph Ltd
* Copyright (c) 2006-2015, Gaudenz Alder
*/
/**
* Class: mxObjectCodec
*
* Generic codec for JavaScript objects that implements a mapping between
* JavaScript objects and XML nodes that maps each field or element to an
* attribute or child node, and vice versa.
*
* Atomic Values:
*
* Consider the following example.
*
* (code)
* var obj = new Object();
* obj.foo = "Foo";
* obj.bar = "Bar";
* (end)
*
* This object is encoded into an XML node using the following.
*
* (code)
* var enc = new mxCodec();
* var node = enc.encode(obj);
* (end)
*
* The output of the encoding may be viewed using <mxLog> as follows.
*
* (code)
* mxLog.show();
* mxLog.debug(mxUtils.getPrettyXml(node));
* (end)
*
* Finally, the result of the encoding looks as follows.
*
* (code)
* <Object foo="Foo" bar="Bar"/>
* (end)
*
* In the above output, the foo and bar fields have been mapped to attributes
* with the same names, and the name of the constructor was used for the
* nodename.
*
* Booleans:
*
* Since booleans are numbers in JavaScript, all boolean values are encoded
* into 1 for true and 0 for false. The decoder also accepts the string true
* and false for boolean values.
*
* Objects:
*
* The above scheme is applied to all atomic fields, that is, to all non-object
* fields of an object. For object fields, a child node is created with a
* special attribute that contains the fieldname. This special attribute is
* called "as" and hence, as is a reserved word that should not be used for a
* fieldname.
*
* Consider the following example where foo is an object and bar is an atomic
* property of foo.
*
* (code)
* var obj = {foo: {bar: "Bar"}};
* (end)
*
* This will be mapped to the following XML structure by mxObjectCodec.
*
* (code)
* <Object>
* <Object bar="Bar" as="foo"/>
* </Object>
* (end)
*
* In the above output, the inner Object node contains the as-attribute that
* specifies the fieldname in the enclosing object. That is, the field foo was
* mapped to a child node with an as-attribute that has the value foo.
*
* Arrays:
*
* Arrays are special objects that are either associative, in which case each
* key, value pair is treated like a field where the key is the fieldname, or
* they are a sequence of atomic values and objects, which is mapped to a
* sequence of child nodes. For object elements, the above scheme is applied
* without the use of the special as-attribute for creating each child. For
* atomic elements, a special add-node is created with the value stored in the
* value-attribute.
*
* For example, the following array contains one atomic value and one object
* with a field called bar. Furthermore it contains two associative entries
* called bar with an atomic value, and foo with an object value.
*
* (code)
* var obj = ["Bar", {bar: "Bar"}];
* obj["bar"] = "Bar";
* obj["foo"] = {bar: "Bar"};
* (end)
*
* This array is represented by the following XML nodes.
*
* (code)
* <Array bar="Bar">
* <add value="Bar"/>
* <Object bar="Bar"/>
* <Object bar="Bar" as="foo"/>
* </Array>
* (end)
*
* The Array node name is the name of the constructor. The additional
* as-attribute in the last child contains the key of the associative entry,
* whereas the second last child is part of the array sequence and does not
* have an as-attribute.
*
* References:
*
* Objects may be represented as child nodes or attributes with ID values,
* which are used to lookup the object in a table within <mxCodec>. The
* <isReference> function is in charge of deciding if a specific field should
* be encoded as a reference or not. Its default implementation returns true if
* the fieldname is in <idrefs>, an array of strings that is used to configure
* the <mxObjectCodec>.
*
* Using this approach, the mapping does not guarantee that the referenced
* object itself exists in the document. The fields that are encoded as
* references must be carefully chosen to make sure all referenced objects
* exist in the document, or may be resolved by some other means if necessary.
*
* For example, in the case of the graph model all cells are stored in a tree
* whose root is referenced by the model's root field. A tree is a structure
* that is well suited for an XML representation, however, the additional edges
* in the graph model have a reference to a source and target cell, which are
* also contained in the tree. To handle this case, the source and target cell
* of an edge are treated as references, whereas the children are treated as
* objects. Since all cells are contained in the tree and no edge references a
* source or target outside the tree, this setup makes sure all referenced
* objects are contained in the document.
*
* In the case of a tree structure we must further avoid infinite recursion by
* ignoring the parent reference of each child. This is done by returning true
* in <isExcluded>, whose default implementation uses the array of excluded
* fieldnames passed to the mxObjectCodec constructor.
*
* References are only used for cells in mxGraph. For defining other
* referencable object types, the codec must be able to work out the ID of an
* object. This is done by implementing <mxCodec.reference>. For decoding a
* reference, the XML node with the respective id-attribute is fetched from the
* document, decoded, and stored in a lookup table for later reference. For
* looking up external objects, <mxCodec.lookup> may be implemented.
*
* Expressions:
*
* For decoding JavaScript expressions, the add-node may be used with a text
* content that contains the JavaScript expression. For example, the following
* creates a field called foo in the enclosing object and assigns it the value
* of <mxConstants.ALIGN_LEFT>.
*
* (code)
* <Object>
* <add as="foo">mxConstants.ALIGN_LEFT</add>
* </Object>
* (end)
*
* The resulting object has a field called foo with the value "left". Its XML
* representation looks as follows.
*
* (code)
* <Object foo="left"/>
* (end)
*
* This means the expression is evaluated at decoding time and the result of
* the evaluation is stored in the respective field. Valid expressions are all
* JavaScript expressions, including function definitions, which are mapped to
* functions on the resulting object.
*
* Expressions are only evaluated if <allowEval> is true.
*
* Constructor: mxObjectCodec
*
* 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:
*
* (code)
* var mapping = new Object();
* mapping['variableName'] = 'attribute-name';
* (end)
*
* 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.
*/
function mxObjectCodec(template, exclude, idrefs, mapping)
{
this.template = template;
this.exclude = (exclude != null) ? exclude : [];
this.idrefs = (idrefs != null) ? idrefs : [];
this.mapping = (mapping != null) ? mapping : [];
this.reverse = new Object();
for (var i in this.mapping)
{
this.reverse[this.mapping[i]] = i;
}
};
/**
* Variable: allowEval
*
* Static global switch that specifies if expressions in arrays are allowed.
* Default is false. NOTE: Enabling this carries a possible security risk.
*/
mxObjectCodec.allowEval = false;
/**
* Variable: template
*
* Holds the template object associated with this codec.
*/
mxObjectCodec.prototype.template = null;
/**
* Variable: exclude
*
* Array containing the variable names that should be
* ignored by the codec.
*/
mxObjectCodec.prototype.exclude = null;
/**
* Variable: idrefs
*
* Array containing the variable names that should be
* turned into or converted from references. See
* <mxCodec.getId> and <mxCodec.getObject>.
*/
mxObjectCodec.prototype.idrefs = null;
/**
* Variable: mapping
*
* Maps from from fieldnames to XML attribute names.
*/
mxObjectCodec.prototype.mapping = null;
/**
* Variable: reverse
*
* Maps from from XML attribute names to fieldnames.
*/
mxObjectCodec.prototype.reverse = null;
/**
* Function: 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.
*/
mxObjectCodec.prototype.getName = function()
{
return mxUtils.getFunctionName(this.template.constructor);
};
/**
* Function: cloneTemplate
*
* Returns a new instance of the template for this codec.
*/
mxObjectCodec.prototype.cloneTemplate = function()
{
return new this.template.constructor();
};
/**
* Function: getFieldName
*
* 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.
*/
mxObjectCodec.prototype.getFieldName = function(attributename)
{
if (attributename != null)
{
var mapped = this.reverse[attributename];
if (mapped != null)
{
attributename = mapped;
}
}
return attributename;
};
/**
* Function: getAttributeName
*
* 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.
*/
mxObjectCodec.prototype.getAttributeName = function(fieldname)
{
if (fieldname != null)
{
var mapped = this.mapping[fieldname];
if (mapped != null)
{
fieldname = mapped;
}
}
return fieldname;
};
/**
* Function: isExcluded
*
* 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:
*
* 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.
*/
mxObjectCodec.prototype.isExcluded = function(obj, attr, value, write)
{
return attr == mxObjectIdentity.FIELD_NAME ||
mxUtils.indexOf(this.exclude, attr) >= 0;
};
/**
* Function: isReference
*
* 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.
* 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.
*/
mxObjectCodec.prototype.isReference = function(obj, attr, value, write)
{
return mxUtils.indexOf(this.idrefs, attr) >= 0;
};
/**
* Function: encode
*
* 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:
*
* enc - <mxCodec> that controls the encoding process.
* obj - Object to be encoded.
*/
mxObjectCodec.prototype.encode = function(enc, obj)
{
var node = enc.document.createElement(this.getName());
obj = this.beforeEncode(enc, obj, node);
this.encodeObject(enc, obj, node);
return this.afterEncode(enc, obj, node);
};
/**
* Function: encodeObject
*
* Encodes the value of each member in then given obj into the given node using
* <encodeValue>.
*
* Parameters:
*
* enc - <mxCodec> that controls the encoding process.
* obj - Object to be encoded.
* node - XML node that contains the encoded object.
*/
mxObjectCodec.prototype.encodeObject = function(enc, obj, node)
{
enc.setAttribute(node, 'id', enc.getId(obj));
for (var i in obj)
{
var name = i;
var value = obj[name];
if (value != null && !this.isExcluded(obj, name, value, true))
{
if (mxUtils.isInteger(name))
{
name = null;
}
this.encodeValue(enc, obj, name, value, node);
}
}
};
/**
* Function: encodeValue
*
* 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:
*
* enc - <mxCodec> that controls the encoding process.
* obj - Object whose property is going to be encoded.
* name - XML node that contains the encoded object.
* value - Value of the property to be encoded.
* node - XML node that contains the encoded object.
*/
mxObjectCodec.prototype.encodeValue = function(enc, obj, name, value, node)
{
if (value != null)
{
if (this.isReference(obj, name, value, true))
{
var tmp = enc.getId(value);
if (tmp == null)
{
mxLog.warn('mxObjectCodec.encode: No ID for ' +
this.getName() + '.' + name + '=' + value);
return; // exit
}
value = tmp;
}
var defaultValue = this.template[name];
// Checks if the value is a default value and
// the name is correct
if (name == null || enc.encodeDefaults || defaultValue != value)
{
name = this.getAttributeName(name);
this.writeAttribute(enc, obj, name, value, node);
}
}
};
/**
* Function: writeAttribute
*
* Writes the given value into node using <writePrimitiveAttribute>
* or <writeComplexAttribute> depending on the type of the value.
*/
mxObjectCodec.prototype.writeAttribute = function(enc, obj, name, value, node)
{
if (typeof(value) != 'object' /* primitive type */)
{
this.writePrimitiveAttribute(enc, obj, name, value, node);
}
else /* complex type */
{
this.writeComplexAttribute(enc, obj, name, value, node);
}
};
/**
* Function: writePrimitiveAttribute
*
* Writes the given value as an attribute of the given node.
*/
mxObjectCodec.prototype.writePrimitiveAttribute = function(enc, obj, name, value, node)
{
value = this.convertAttributeToXml(enc, obj, name, value, node);
if (name == null)
{
var child = enc.document.createElement('add');
if (typeof(value) == 'function')
{
child.appendChild(enc.document.createTextNode(value));
}
else
{
enc.setAttribute(child, 'value', value);
}
node.appendChild(child);
}
else if (typeof(value) != 'function')
{
enc.setAttribute(node, name, value);
}
};
/**
* Function: writeComplexAttribute
*
* Writes the given value as a child node of the given node.
*/
mxObjectCodec.prototype.writeComplexAttribute = function(enc, obj, name, value, node)
{
var child = enc.encode(value);
if (child != null)
{
if (name != null)
{
child.setAttribute('as', name);
}
node.appendChild(child);
}
else
{
mxLog.warn('mxObjectCodec.encode: No node for ' + this.getName() + '.' + name + ': ' + value);
}
};
/**
* Function: convertAttributeToXml
*
* Converts true to "1" and false to "0" is <isBooleanAttribute> returns true.
* All other values are not converted.
*
* Parameters:
*
* enc - <mxCodec> that controls the encoding process.
* obj - Objec to convert the attribute for.
* name - Name of the attribute to be converted.
* value - Value to be converted.
*/
mxObjectCodec.prototype.convertAttributeToXml = function(enc, obj, name, value)
{
// Makes sure to encode boolean values as numeric values
if (this.isBooleanAttribute(enc, obj, name, value))
{
// Checks if the value is true (do not use the value as is, because
// this would check if the value is not null, so 0 would be true)
value = (value == true) ? '1' : '0';
}
return value;
};
/**
* Function: isBooleanAttribute
*
* Returns true if the given object attribute is a boolean value.
*
* Parameters:
*
* enc - <mxCodec> that controls the encoding process.
* obj - Objec to convert the attribute for.
* name - Name of the attribute to be converted.
* value - Value of the attribute to be converted.
*/
mxObjectCodec.prototype.isBooleanAttribute = function(enc, obj, name, value)
{
return (typeof(value.length) == 'undefined' && (value == true || value == false));
};
/**
* Function: convertAttributeFromXml
*
* Converts booleans and numeric values to the respective types. Values are
* numeric if <isNumericAttribute> returns true.
*
* Parameters:
*
* dec - <mxCodec> that controls the decoding process.
* attr - XML attribute to be converted.
* obj - Objec to convert the attribute for.
*/
mxObjectCodec.prototype.convertAttributeFromXml = function(dec, attr, obj)
{
var value = attr.value;
if (this.isNumericAttribute(dec, attr, obj))
{
value = parseFloat(value);
if (isNaN(value) || !isFinite(value))
{
value = 0;
}
}
return value;
};
/**
* Function: isNumericAttribute
*
* Returns true if the given XML attribute is or should be a numeric value.
*
* Parameters:
*
* dec - <mxCodec> that controls the decoding process.
* attr - XML attribute to be converted.
* obj - Objec to convert the attribute for.
*/
mxObjectCodec.prototype.isNumericAttribute = function(dec, attr, obj)
{
// Handles known numeric attributes for generic objects
var result = (obj.constructor == mxGeometry &&
(attr.name == 'x' || attr.name == 'y' ||
attr.name == 'width' || attr.name == 'height')) ||
(obj.constructor == mxPoint &&
(attr.name == 'x' || attr.name == 'y')) ||
mxUtils.isNumeric(attr.value);
return result;
};
/**
* Function: beforeEncode
*
* 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 - <mxCodec> that controls the encoding process.
* obj - Object to be encoded.
* node - XML node to encode the object into.
*/
mxObjectCodec.prototype.beforeEncode = function(enc, obj, node)
{
return obj;
};
/**
* Function: afterEncode
*
* 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:
*
* enc - <mxCodec> that controls the encoding process.
* obj - Object to be encoded.
* node - XML node that represents the default encoding.
*/
mxObjectCodec.prototype.afterEncode = function(enc, obj, node)
{
return node;
};
/**
* Function: decode
*
* 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:
*
* (code)
* <Object>
* <add as="hello"><![CDATA[
* function(arg1) {
* mxUtils.alert('Hello '+arg1);
* }
* ]]></add>
* </Object>
* (end)
*
* 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:
*
* dec - <mxCodec> that controls the decoding process.
* node - XML node to be decoded.
* into - Optional objec to encode the node into.
*/
mxObjectCodec.prototype.decode = function(dec, node, into)
{
var id = node.getAttribute('id');
var obj = dec.objects[id];
if (obj == null)
{
obj = into || this.cloneTemplate();
if (id != null)
{
dec.putObject(id, obj);
}
}
node = this.beforeDecode(dec, node, obj);
this.decodeNode(dec, node, obj);
return this.afterDecode(dec, node, obj);
};
/**
* Function: decodeNode
*
* Calls <decodeAttributes> and <decodeChildren> for the given node.
*
* Parameters:
*
* dec - <mxCodec> that controls the decoding process.
* node - XML node to be decoded.
* obj - Objec to encode the node into.
*/
mxObjectCodec.prototype.decodeNode = function(dec, node, obj)
{
if (node != null)
{
this.decodeAttributes(dec, node, obj);
this.decodeChildren(dec, node, obj);
}
};
/**
* Function: decodeAttributes
*
* Decodes all attributes of the given node using <decodeAttribute>.
*
* Parameters:
*
* dec - <mxCodec> that controls the decoding process.
* node - XML node to be decoded.
* obj - Objec to encode the node into.
*/
mxObjectCodec.prototype.decodeAttributes = function(dec, node, obj)
{
var attrs = node.attributes;
if (attrs != null)
{
for (var i = 0; i < attrs.length; i++)
{
this.decodeAttribute(dec, attrs[i], obj);
}
}
};
/**
* Function: isIgnoredAttribute
*
* Returns true if the given attribute should be ignored. This implementation
* returns true if the attribute name is "as" or "id".
*
* Parameters:
*
* dec - <mxCodec> that controls the decoding process.
* attr - XML attribute to be decoded.
* obj - Objec to encode the attribute into.
*/
mxObjectCodec.prototype.isIgnoredAttribute = function(dec, attr, obj)
{
return attr.nodeName == 'as' || attr.nodeName == 'id';
};
/**
* Function: decodeAttribute
*
* Reads the given attribute into the specified object.
*
* Parameters:
*
* dec - <mxCodec> that controls the decoding process.
* attr - XML attribute to be decoded.
* obj - Objec to encode the attribute into.
*/
mxObjectCodec.prototype.decodeAttribute = function(dec, attr, obj)
{
if (!this.isIgnoredAttribute(dec, attr, obj))
{
var name = attr.nodeName;
// Converts the string true and false to their boolean values.
// This may require an additional check on the obj to see if
// the existing field is a boolean value or uninitialized, in
// which case we may want to convert true and false to a string.
var value = this.convertAttributeFromXml(dec, attr, obj);
var fieldname = this.getFieldName(name);
if (this.isReference(obj, fieldname, value, false))
{
var tmp = dec.getObject(value);
if (tmp == null)
{
mxLog.warn('mxObjectCodec.decode: No object for ' +
this.getName() + '.' + name + '=' + value);
return; // exit
}
value = tmp;
}
if (!this.isExcluded(obj, name, value, false))
{
//mxLog.debug(mxUtils.getFunctionName(obj.constructor)+'.'+name+'='+value);
obj[name] = value;
}
}
};
/**
* Function: decodeChildren
*
* Decodes all children of the given node using <decodeChild>.
*
* Parameters:
*
* dec - <mxCodec> that controls the decoding process.
* node - XML node to be decoded.
* obj - Objec to encode the node into.
*/
mxObjectCodec.prototype.decodeChildren = function(dec, node, obj)
{
var child = node.firstChild;
while (child != null)
{
var tmp = child.nextSibling;
if (child.nodeType == mxConstants.NODETYPE_ELEMENT &&
!this.processInclude(dec, child, obj))
{
this.decodeChild(dec, child, obj);
}
child = tmp;
}
};
/**
* Function: decodeChild
*
* Reads the specified child into the given object.
*
* Parameters:
*
* dec - <mxCodec> that controls the decoding process.
* child - XML child element to be decoded.
* obj - Objec to encode the node into.
*/
mxObjectCodec.prototype.decodeChild = function(dec, child, obj)
{
var fieldname = this.getFieldName(child.getAttribute('as'));
if (fieldname == null || !this.isExcluded(obj, fieldname, child, false))
{
var template = this.getFieldTemplate(obj, fieldname, child);
var value = null;
if (child.nodeName == 'add')
{
value = child.getAttribute('value');
if (value == null && mxObjectCodec.allowEval)
{
value = mxUtils.eval(mxUtils.getTextContent(child));
}
}
else
{
value = dec.decode(child, template);
}
try
{
this.addObjectValue(obj, fieldname, value, template);
}
catch (e)
{
throw new Error(e.message + ' for ' + child.nodeName);
}
}
};
/**
* Function: getFieldTemplate
*
* 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.
*/
mxObjectCodec.prototype.getFieldTemplate = function(obj, fieldname, child)
{
var template = obj[fieldname];
// Non-empty arrays are replaced completely
if (template instanceof Array && template.length > 0)
{
template = null;
}
return template;
};
/**
* Function: addObjectValue
*
* 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.
*/
mxObjectCodec.prototype.addObjectValue = function(obj, fieldname, value, template)
{
if (value != null && value != template)
{
if (fieldname != null && fieldname.length > 0)
{
obj[fieldname] = value;
}
else
{
obj.push(value);
}
//mxLog.debug('Decoded '+mxUtils.getFunctionName(obj.constructor)+'.'+fieldname+': '+value);
}
};
/**
* Function: processInclude
*
* 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:
*
* dec - <mxCodec> that controls the encoding/decoding process.
* node - XML node to be checked.
* into - Optional object to pass-thru to the codec.
*/
mxObjectCodec.prototype.processInclude = function(dec, node, into)
{
if (node.nodeName == 'include')
{
var name = node.getAttribute('name');
if (name != null)
{
try
{
var xml = mxUtils.load(name).getDocumentElement();
if (xml != null)
{
dec.decode(xml, into);
}
}
catch (e)
{
// ignore
}
}
return true;
}
return false;
};
/**
* Function: beforeDecode
*
* 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:
*
* dec - <mxCodec> that controls the decoding process.
* node - XML node to be decoded.
* obj - Object to encode the node into.
*/
mxObjectCodec.prototype.beforeDecode = function(dec, node, obj)
{
return node;
};
/**
* Function: afterDecode
*
* 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:
*
* enc - <mxCodec> that controls the encoding process.
* node - XML node to be decoded.
* obj - Object that represents the default decoding.
*/
mxObjectCodec.prototype.afterDecode = function(dec, node, obj)
{
return obj;
};