Common Node Attributes

Some attributes are common to all nodes, except for Grammar Nodes. These are:

Attribute name	Description	Possible Values	Mandatory	Default
optional	Whether the structure or value represented by the node will always be present in the file.	T for true or F for false	No	F
template	Whether this node and all its children represent a template. Templates must be defined before any nodes that use them.	T for true or F for false	No	F
definedBy	Indicates that this node uses a pre-defined template. If set, all of the attributes of the template node will be used as defaults for the attributes of this node, unless specific attribute values are set on this node to override the template values. Copies of the children of the template node will be added as children of this node. Any additional child nodes specified on this node will be added after the child nodes copied from the template. The template node specified must be of the same type as this node.	The name of the node defining the template. The referenced node must have the template attribute set to T.	No	None
name	The name that will be reported in error messages, and that must be used when referring to this node from another node (e.g. to a template node). Although the name attribute is not mandatory on most nodes, it is best to always specify a name because this will improve error reporting if there is a problem processing a file.	Any alphanumberic string. However, must not start with a number or contain any spaces.	Yes for data nodes (Attribute, Tag, Length, Value, Bytes and Record). Otherwise no.	None
scriptVariables	The names of Attribute Nodes that will be used as variables in Expressions elsewhere in the hierarchy of nodes inside this node. These variable names must match the names of Attributes Nodes contained somewhere in the hierarchy inside this node. When referring to these variables in expressions you need to specify the scope and the variable name in the format $scope_variableName. The node that the variables are declared on - i.e. this node - is the scope of the variable. Only nodes that are part of the hierarchy inside this node may refer to these variables. Variable names may not be duplicated in the same scope - i.e. within the hierarchy under the node that they are declared on - but may be duplicated across different scopes. An example is shown in Repeat Node attributes.	A comma separated list of Attribute Node names, e.g. attr1,attr2.	No	None
variables	The names of Attributes Nodes that will be used as variables in the bits, bytes, length or times attributes of other nodes. These variable names must match the names of Attributes Nodes contained somewhere in the hierarchy inside this node. When referring to these variables in attributes of other nodes you can just specify the variable name. You do not need to specify the scope. The node that the variables are declared on - i.e. this node - is the scope of the variable. Only nodes that are part of the hierarchy inside this node may refer to these variables. Variable names may not be duplicated in the same scope - i.e. within the hierarchy under the node that they are declared on - but may be duplicated across different scopes. An example is shown in Repeat Node attributes.	A comma separated list of Attribute Node names, e.g. attr1,attr2.	No	None