PDM-UG: Product Definition or Document Representation
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The AIM entity product_definition or document_file is used with the identification of document properties and apply to the associated files.
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The Instance Model: EXPRESS entities and attributes
The general schema for the assignment of properties to document representation (i.e., product_definition) or document files (i.e., document_file) is to instantiate a property definition tree with property_definition, property_definition_representation, representation and eventually multiple instantiations of descriptive_representation_item (or measure_representation_item) that provide the representation of a specific aspect of the represented property.
Diagram 40: General pattern for the association of document properties
Property definition
A property_definition is, in the given context, a property that characterizes a document representation or document file. It applies either to a product_definition (for the document representation) or a document_file.
Attributes
- The name attribute indicates via 'document property' that the property is related to a document representation or a document file.
- The description attribute provides additional description of the property.
- The definition attribute references the document object, which is characterized by the property_definition.
| ENTITY property_definition | Attribute Population | Remarks |
| name | Type: identifier = string | should be instantiated as 'document property' in the given context |
| description | Type: text = string | optional, shall not be instantiated |
| definition | Type: entity = product_definition or product_definition_with_associated_documents or document_file | References associated document |
===Preprocessor Recommendations=== It is recommended to instantiate not more than one property_definition with the value of the name attribute equal to 'document property' for each document representation definition (product_definition or product_definition_with_associated_documents) or document_file. One property_definition per document object shall be used to collect all document object properties via associated property_definition_representations.
===Postprocessor Recommendations=== None specified.
===Related Entities=== None specified.
Property definition representation
A property_definition_representation is, in the given context, an association between a document property and its representation.
Attributes
- The definition attribute references the property_definition that is defined by the associated representation.
- The used_representation attribute points to a representation that collects the representations items that together describe the property.
| ENTITY property_definition_representation | Attribute Population | Remarks |
| definition | Type: entity = property_definition | References associated property_definition |
| used_representation | Type: entity = representation | References associated representation |
===Preprocessor Recommendations=== None specified.
===Postprocessor Recommendations=== None specified.
===Related Entities=== None specified.
Representation
A representation is, in the context of document properties, a collection of one or more descriptive_representations_items that are related in a representation_context with type 'document parameters'. Herein a representation represents a document property.
Attributes
- The name attribute characterizes the type of the document related property via a string.
- The items attribute collect items that represent the values for a given property instantiation.
- The context_of_items attribute points to a representation_context. The representation_context has the type 'document parameters'.
| ENTITY representation | Attribute Population | Remarks |
| name | Type: label = STRING | the name attribute characterizes the document related property |
| items | Type: entity = descriptive_representation_item or measure_representation_item | the items that constitute the representation of the document property |
| context_of_items | Type: entity = representation_context | is required to point to a representation_context with representation_context.type set to 'document parameters' |
| id | Derived | should not be instantiated |
| description | Derived | should not be instantiated |
===Preprocessor Recommendations=== The name characterizes the document related property. The representation is required to have a context with representation_context.type = 'document parameters'
===Postprocessor Recommendations=== A postprocessor shall, in the given context, support the following values for representation.name 'document content', 'document creation', 'document format', 'document size'.
===Related Entities=== None specified.
Representation context
A representation_context is identifies the context (of type 'document parameters') of interpretation for the value of items in a representation.
Attributes
- The context_identifier attribute identifies the context.
- The context_type attribute specifies the type of the context.
| ENTITY representation_context | Attribute Population | Remarks |
| context_identifier | Type: label = STRING | |
| context_type | Type: text = STRING | should be instantiated with value ‘document parameters’. |
===Preprocessor Recommendations=== In order to distinguish the use of a representation for document properties, the context_type attribute of the representation_context entity has the value 'document parameters'.
===Postprocessor Recommendations=== None specified.
===Related Entities=== None specified.
Descriptive representation item
A descriptive_representation_item is, in the document property context, a textual element that participates in one or more representations to define the respective properties.
Attributes
- The name attribute characterizes the information modeled with the descriptive_representation_item via a string.
- The description attribute defines a textual value as an instantiation of the modeled property.
| ENTITY descriptive_representation_item | Attribute Population | Remarks |
| name | Type: label = STRING | the name attribute indicates the name of the represented property |
| description | Type: text = STRING | the description is the value associated with the representation item in textual form |
===Preprocessor Recommendations=== None specified.
===Postprocessor Recommendations=== In the given context the following instantiations of descriptive_representation_item.name shall be expected: 'detail level', 'geometry', 'language', 'real world scale', 'creating interface', 'creating system', 'operating system', 'data format', 'character code', 'size format', 'size format standard'.
===Related Entities=== The descriptive_representation_items for a given document property are collected in a representation. The representation characterizes the property via the attribute representation.name.
