Capture Patterns

Capture patterns are used to map elements in the analyzed document.

This page discusses:

See Also
About Patterns

Analysis Type

Maps a pattern and allocates fields to a traceability element:

  • Creates entity, attribute, or link when found during exploration and pattern matches
  • Specifies constant properties
  • Follows an implicit traceability hierarchy based on parent/children pattern

Content Properties
  • Literal value
  • Regular expression
  • Choice
  • Sequence
  • Reference definition
  • Analysis type
  • Rule
  • Capture fields: entity, link, attribute
  • Variable

Analysis Type: Display

The optional display setting replaces the entity title in the traceability graphical view. When the display setting is not specified, the identifier, label or both (if both exist) are displayed.

Display Syntax
The display expression is decomposed in different tokens:
  • $i: identifier
  • $l: label
  • $t: type
  • ${attribute}: attribute value
  • $$: $ (for dollar symbol display)
  • Any other character preceded by $ is ignored
  • Other text is printed as is

Leading and trailing texts are always printed.

Separator texts are printed only when the next field is not empty.

Display Example
Considering the following display expression: XX $i - $l #${Version} YY

The result is:

ID Label Version Result
REQ001 XX REQ001 YY
REQ001 Title XX REQ001 - Title YY
REQ001 Title A XX REQ001 - Title #A YY
Chapter 1 A XX Chapter 1 #A YY

Rule

Defines properties on a traceability element. Allocates fields or variables with conditionality.

Important: Contrary to an analysis type, a rule does not create entities. Rules can be useful when requirement or links are determined by another pattern.

Content Properties
  • Literal value
  • Regular expression
  • Choice
  • Sequence
  • Reference definition
  • Analysis type
  • Rule
  • Capture fields: entity, link, attribute
  • Variable
Optional: Setters
  • Set flag
    • Entity flag
    • Attribute flag
    • Link flag
  • Set string
  • Set string format
For more information, see Setters for Analysis Types and Rules.

Entity, Attribute, Link Fields

Applicable to the nearest parent analysis type.

Content Properties

None

  • Entity field: Identifier, label, text, or type
  • Attribute field: Name or value
  • Link field: Source, target, or type

Variable

Applicable to the whole pattern schema when executing the pattern on a document.

Content Properties

None

Variable: Name
Note: Variables can be used as content in many pattern types. For more information, see Pattern Elements Overview.

Usually, they are used in a string format, with other variables. For more information, see String Format below.

Setters for Analysis Types and Rules

Allocates a field (depending on its position) to a traceability element.

Content Properties
  • Entity field
  • Attribute field
  • Link field
  • Variable
A value

Setter Creation

To create a setter:

  1. Select an analysis type or rule.
  2. From the context bar, click Create Setter .
  3. Select the allocation type, the field to be allocated and a value:
    Allocation Type Allocated Field Value
    Set Flag Flag True ou False
    Set String Field or variable Field or variable
    Set String Format Field or variable Formatted string

Multiple Flags on Attribute

If the Multiple flag is false or not specified, the pattern is not able to capture multiple values for the same attribute. Only the last encountered value is assigned to the parent node.

If the Multiple flag is true, the pattern accumulates all the values that are encountered for the same attribute name under the same node.

Here are few examples:

Use Case Result (Allocation) Comment
  • Attribute: Allocation
    • Multiple=true
      • Occurrence 1
        • Captures: A
      • Occurrence 2
        • Captures: B
A, B The multiple values are cumulated under a single occurrence of the same attribute with multiple enabled (multiple=true).
  • Occurrence 1
    • Attribute: Allocation
      • Multiple=true
      • Captures: A
  • Occurrence 2
    • Attribute: Allocation
      • Multiple=true
      • Captures: B
A, B The multiple values are cumulated for consecutive attributes with same name and multiple enabled (multiple=true).
  • Occurrence 1
    • Attribute: Allocation
      • Multiple=true
      • Captures: A
  • Occurrence 2
    • Attribute: Allocation
      • Multiple=false
      • Captures: B
  • Occurrence 3
    • Attribute: Allocation
      • Multiple=true
      • Captures: C
B, C The previous values are discarded as soon as a value is captured and multiple is disabled (multiple=false).

However, it does not prevent from capturing other values afterward.

String Format

String Format Usage
The string format can be applied on:
  • An analysis type to produce a formatted string with captured variables.
  • A rule to assign this string to any field (indent, label, text, source, target) or to a variable.

Variables can be added at the same location as the fields with the Create Pattern command. Once a variable is assigned, the corresponding value can be used anywhere during the pattern analysis. For more information, see Variable.

String Format Syntax

The string format is decomposed in different tokens:

  • ${variable}: the variable value
  • $$: $ (for dollar symbol display)
  • Any other character preceded by $ is ignored
  • Other text considered as a separator is printed as is

Leading and trailing texts are always printed.

Separator texts are printed only when the next field is not empty.

String Format Example

Considering the following format expression: XX $(A) - $(B) #${C} YY

The result is:

A B C Result
REQ001 XX REQ001 YY
REQ001 Title XX REQ001 - Title YY
REQ001 Title A XX REQ001 - Title #A YY
Chapter 1 A XX Chapter 1 #A YY