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Subsections

     
11. TCM File format

11.1 Introduction

Each TCM document is stored in a separate Unix file as plain text. This chapter contains a specification of the TCM file format of documents that are generated by the TCM version that is described in this manual ( file format version 1.31). The TCM editors read also older file formats, down to file format version 1.0, but they only generate the latest file format of that TCM tool. Older file format versions are not described here. Each file can be converted to the latest format by reading it in with an editor of the latest version and then saving it back to file.

You can see and even modify a document file within TCM. With Document Source from the Document menu, the contents of the file, from which the TCM document was loaded, is read into a text edit dialog. You can then view and edit these file contents and save it back to the file (or to another file). You can see the updates when you append or load that file again.

11.2 Elements of a TCM document

A document is stored as a number of sections  consisting of a number of fields. The order of fields  within a section is significant. The order of the sections in a diagram file is not significant except that the file should start with first the Storage section and then the Document and Page sections. The order of the row and column sections of a table is significant as is explained in section C.5.

A section starts with a keyword indicating the kind of section and, when there is possibly more than one section of a certain keyword in the same file, it has an identifier which makes the section unique within the file. The rest of the section is enclosed by curly braces. Sections are separated by white space. white space is a sequence of one or more spaces, tabs, carriage-return or newline characters.

A field is an attribute-value pair enclosed by curly  braces. The order of the fields in a section is significant. Attribute values are of one of the types listed in figure C.1. Fields within a section are separated by white space. The attribute name and the value within a field are also separated by white space. Section names and attribute names are case sensitive.

It is possible to include comment text in a TCM file. Comments in a file start with a hash (#). The text in the same line after the hash is comment text and is ignored.


  
Figure C.1: The value types of attributes stored in a file.
\includegraphics{p/valuetypes.eps}

When a file is read, TCM checks the syntax and checks the semantics, i.e. that all required fields are present, that the attribute values have the correct type and it checks references (such as that an edge section has subject fields referring to existing subject sections). TCM reports errors that are found together with a line number in the file where the error is encountered. The errors are displayed in the error log pop-up-window.

11.3 Storage, Document and Page Information

Each TCM document in a file starts with the Storage section with information about the file such as the file format number. This is followed by the Document section in which you can find general information about the document, like the name and the author. Then you have the Page section with some information about the page layout and then the Scale section that contains (only) the scale of the diagram.

  
11.3.0.1 Storage section

Storage 
{
   { Format <rational> }   # File format, e.g. 1.26.
   { GeneratedFrom <word> }# Tool name and version e.g. TGD-version-1.84.
   { WrittenBy <word> }    # Unix login name that has generated this file.
   { WrittenOn <string> }  # Writing date/time (in Unix ctime format).
}

  
11.3.0.2 Document section

Document
{
    { Type <string> }      # Document type: e.g. "Generic Diagram".
    { Name <word> }        # Document name, e.g. mydocument.gd.
    { Author <word> }      # Unix login name of document creator.
    { CreatedOn <string> } # Creation time 
                           # e.g. "Wed Sep 24 15:42:47 MET DST 1997".
    { Annotation <string> }# Free annotation text about this document.
    { Hierarchy <bool> }   # For diagram types that allow hierarchic
                           # documents only: Is this document hierarchic?
}

  
11.3.0.3 Page section

Page
{
    { PageOrientation <word> } # Portrait or Landscape
    { PageSize <word> }        # PageSize: A4, A3, Letter, Legal,...
    { ShowHeaders <bool> }     # Show a header on every page?
    { ShowFooters <bool> }     # Show a footer on every page?
    { ShowNumbers <bool> }     # Show a page number on every page?
}

  
11.3.0.4 Scale section

Scale
{
    { ScaleValue <rational> }  # The scale of the diagram. Normally 1.00.
}

11.4 Diagram Editor File Format


  
Figure C.2: Node types and the tools in which they occur.
\includegraphics{p/nodetype.eps}


  
Figure C.3: Edge types and the tools in which they occur.
\includegraphics{p/edgetype.eps}


  
Figure C.4: Node shape types and the tools in which they occur.
\includegraphics{p/nodeshapetype.eps}


  
Figure C.5: Line types and the tools in which they occur.
\includegraphics{p/linetype.eps}


  
Figure C.6: Diagram file format in the form of a class-diagram.
\includegraphics{p/fileformat.eps}

A stored diagram contains a section for each node, edge, view and shape (in no particular order) which follow after the three obligatory storage, document and page sections. Each node type, edge type and shape type section starts with a keyword. A view has the keyword View. In figures C.2 to C.5 you can see which keywords (and accessory sections) are generated and read by which tool. After the node, edge, view or shape keyword there is an identifier which is unique within the file. These identifiers are used for referring from one section to another section. Figure C.6 gives an overview of the global structure of the diagram file format in which file format section types are represented as object classes. The CRD does not show the significant order of the fields in a section. On the other hand, the CRD shows specializations and other relationships between classes and also some cardinality constraints which can not be made explicit in the file format sections. Specific node sections would be subclasses of class Node, specific edge sections would be subclasses of class Edge and specific Shape sections would be subclasses of classes NodeShape or Line.

  
11.4.0.1 Node sections

You can see what node types exist in figure C.2. Each node has a name, annotation and parent field. Some node types have additional fields which are mentioned below.
<NodeType> <id>                     # e.g. EntityType 123456.
{
    { Name <string> }               # name label of the node.
    { Annotation <string> }         # annotation text of the node.
    { Parent <id> }                 # parent node (always 0 in this TCM version).
    { Index <string> }              # index label of the node.
    # possibly other node attributes
}

The parent field is not used in the current TCM version but it will be used for hierarchical diagrams. In hierarchical diagrams the parent identifier refers to an existing node section. That would mean that a node in a diagram is further specified as a sub-diagram. The newly created nodes and edges in that sub-diagram have that node as parent. Nodes and edges in the top-level diagram have parent 0 (which means they have no parent). Furthermore, in sub-diagrams, shapes representing higher level nodes may also occur. In the generic editor, TGD, these structures will be almost unconstrained. In data flow diagram editors (TDFD and TEFD) and data view editors (TERD and TCRD) these structures are more constrained, for instance only data processes respectively subject areas can be parent nodes and flows respectively relationships have to be balanced. The parent relationship can also used in the tree editors (TFRT, TGTT) but here the entire hierarchy is presented in one view.

When the parent relationship is not used in some editor then the entire diagram is treated as a top-level diagram and the parents of the subjects are always set to 0. In the current version of TCM there are only top-level diagrams so the parent fields are always 0.

Other attributes of node types are:

  
11.4.0.2 Edge sections

For which edge types are generated by which tools see figure C.3.

<EdgeType> <id>                # e.g. BinaryRelationship 654321
{
    { Name <string> }          # name of edge.
    { Annotation <string> }    # annotation of edge.
    { Parent <id> }            # parent node.
    { Subject1 <id> }          # 'departure' subject
    { Subject2 <id> }          # 'arrival' subject
    # possibly other edge attributes #
}
Edge types also have a parent field which is intended to be used for hierarchical editors that are still to be build. For the moment the Parent identifier is always 0. The Subject1 and Subject2 identifiers should refer to existing subject sections in this file. It is in principle possible that and edge (line) connects another edge (line). At this moment this feature of edge-edge connections is only available in TGD and in a limited form in TSSD (for association link edges and connection of notes).

The other attributes of edge types:

When components > 0 then it has for each component a distinct field. This component field should refer to an existing event flow edge. In the current version of TEFD it is not possible to specify the components of an event flow. Therefore the components fields is always 0.

  
11.4.0.3 View sections

A view is a set of shapes that represents a sub-diagram. Sub-diagrams are hierarchical and are defined by a parent relationship between nodes. Which shapes exactly may occur in the view is determined by the diagram technique. For instance, a view in a DFD shows the refinement of a data process and a view in an ERD shows the refinement of a subject area. The current version of TCM has no hierarchical sub-diagrams implemented. So there is one single view that contains all the shapes of the diagram.

View <id>
{
    { Index <word> }           # index of hierarchical view.
    { Parent <id> }            # the parent node of the view.
}
The index of a view is the same kind of unique index that is used for data and control processes. The top-level view has index 0. The children of the top-level view are numbered 1 to n, the children of non-top-level view x have index x.1 to x.n. Each view, except the top-level view, has a parent node. The parent field should refer to an existing node section. The top-level view has as parent 0. The diagrams of the current version of TCM have only a top-level view. The indexes of the individual nodes are stored separately in the node section. The reason is that not all nodes need to have an index, and in some editors a different naming scheme could be used (for instance, in TGD, nodes can have an arbitrary index label and in TDFD, data stores do not have an index label).

The shapes that are contained in the view are not listed in the view section itself. But all shape sections have a reference to the view section in which they are contained.

  
11.4.0.4 Node shape sections

See figure C.4 for which node shape types are made by which tool.
<NodeShapeType> <id>               # e.g. Box 214365
{
    { View <id> }                  # view in which the shape occurs.
    { Subject <id> }               # the node that the shape represents.
    { Position <number> <number> } # center (x,y) position of shape.
    { Size <number> <number> }     # width and height of shape.
    { Color <color> }              # the line color of the shape.
    { LineWidth <number> }         # the line width of the shape.
    { LineStyle <linestyle> }      # the line style of the shape.
    { FillStyle <fillstyle> }      # the way the shape is filled.
    { FillColor <color> }          # the fill color when the shape not unfilled.
    { FixedName <bool> }           # string of name-textshape is fixed?
    { Font <xlfd> }                # text font of text strings.
    { TextAlignment <alignment> }  # multi-line text alignment.
    { TextColor <color> }          # the color of the text in the shape.
    { NameUnderlined <bool> }      # name-textshape is underlined?
}
Each node shape is contained in an existing view and represents an existing node. The name label of the node shape is not given in the node shape section but it is equal to the name of the node subject, but some other attributes of the labels, i.e. the font and text alignment are specified in this section.

Node shapes have a (line) color, a text color, and a fill color (only visible with a fill style that is not unfilled). By default the line color and text color are black, the shape is unfilled and the line width is 1.

The node shapes SSDSingleClassBox, SSDDoubleClassBox and SSDTripleClassBox in TSSD and TESD have additionally the following two attributes to indicate whether the stereotype and properties labels of the subject should be shown:

    { ShowStereotype <bool> }
    { ShowProperties <bool> }

  
11.4.0.5 Line sections

See figure C.5 for which line type is made by which tool.
<LineType> <id>                       # e.g. Arrow 563412
{
    { View <id> }                     # diagram in which the shape occurs.
    { Subject <id> }                  # edge that the line represents.
    { FromShape <id> }                # 'departure' shape.
    { ToShape <id> }                  # 'arrival' shape.
    { Curved <bool> }                 # straight (False) or curved (True)
    { End1 <line-end> }               # type of line end at departure side.
    { End2 <line-end> }               # type of line end at arrival side.
    { Points <number> }               # number of line points
    { Point <number> <number> }       # line point (>=2 points).
    { NamePosition <number> <number> }# position of name label.
    { Color <color> }                 # the color of the line (default=black).
    { LineWidth <number> }            # the width of the line (default=1).
    { LineStyle <linestyle> }         # the style (solid, dashed etc.).
    { FixedName <bool> }              # string of name-textshape is fixed?
    { Font <xlfd> }                   # text font of text labels.
    { TextAlignment <alignment> }     # multi-line text alignment.
    { TextColor <color> }             # the color of the text (default=black).
    { NameUnderlined <bool> }         # name-textshape is underlined?
    # possibly other line attributes 
}
Each line is contained in an existing view and represents an existing edge and connects two existing (not necessarily different) shapes, called FromShape and ToShape. Both at the beginning point as at the end point of the line there is some line end  which can be some kind of arrow head or a little circle, diamond or triangle or the line end is just Empty. The Points field in the line section specifies how many point fields will follow. A line has at least two points. Each point has a distinct Point field. The name position field gives the coordinates of the name label. The text of this label can be found in the edge section of the subject, in its Name field. Because the labels of a line can be positioned at free will, whereas node shape labels can not, only line sections have a distinct name position field. For the rest, line sections have a number of fields that also occur in node shape section, like for the colors, text alignment and line width. Extra attributes for some specific line types are:

    
11.5 Table Editor File Format

Like diagrams, the table editor file format starts first with a Storage section and then a Document section and a Page section. Directly after the Page section follows the Table section with some attributes of the entire table.

  
11.5.0.1 Table section

Table {
    { TopLeft <number> <number> }    # top-left (x,y) of entire table.
    { NumberOfRows <number> }        # nr. of rows in table (cells per column).
    { NumberOfColumns <number> }     # nr. of columns in table (cells per row).
    { MarginWidth <number> }         # min. distance text and column line.
    { MarginHeight <number> }        # min. distance text and line.
}
In an earlier version of TCM other attributes where stored as well such as DefaultLineStyle, DefaultRowAlignment, DefaultColumnAlignment etc. but they are now treated as attributes of the table editor itself not of a table stored in a file.

  
11.5.0.2 Row sections

After the Table section follow the row sections in consecutive order (they are numbered from 0 to NumberOfRows-1). Each row section starts with the following three attributes:
Row <number> {
    { Height <number> }           # all cells in row have the same height.
    { Alignment <alignment> }     # all texts in row have the same alignment.
    { NumberOfCells <number> }    # a row having n cells has n+1 lines
    ... rest of the row attributes.
}
The NumberOfCells of a row has to be equal to the NumberOfColumns field in the table section. This field indicates how many cells the rows contain. The rest of the row attributes consist of the attributes of the cells and lines (line pieces) in a row. The line pieces to the left and to the right of the cells in a row are seen as part of the row too. For each line piece a separate line style and width field are stored. About the cell itself, the cell text string, the fonts and some annotation text is stored. So for every cell the following information is stored:

    ...
    { LineStyle <linestyle> }        # Line style of the line piece
    { LineWidth <number> }           # Line width of the line piece
    { Text <string> }                # texts in a cell.
    { Font <xlfd> }                  # XLFD font description.
    { Annotation <string> }          # annotation text of this cell.
    ...
}

The size of the cell is determined by the sizes of its row and column. Text alignment of a cell is determined by the combined row and column alignment. In a row section, the two line fields and the three cell fields alternate and, because the number of line pieces is the number of cells plus one, the row always end with two extra fields for the line style and line width of the last line piece.

  
11.5.0.3 Column sections

After the Table section follow the column sections (numbered from 0 to NumberOfColumns-1):
Column <number> {
    { Width <number> }          # all cells in column have the same width.
    { Alignment <alignment> }   # all texts in column have the same alignment.
    { NumberOfCells <number> }  # a column having n cells has n+1 lines
    ...
}

The NumberOfCells of a column has to be equal to the NumberOfRows field in the table section. Because the cell texts are already specified in the row sections, a column section only needs the line style and width fields for horizontal line pieces. There are NumberOfCells+1 line style and width fields in a column. Therefore the rest of the column section consists of NumberOfRows+1 times the following two attributes:

    ...
    { LineStyle <linestyle> }        # line style of a line piece
    { LineWidth <number> }           # line width of a line piece
    ...

 


Footnotes

... group 11.1
A process group is also called a compound process or a decomposed process.

next up previous contents index
Next: Bibliography Up: Toolkit for Conceptual Modeling Previous: 10. Frequently Asked Questions
Henk van de Zandschulp
2003-01-20