MicroStation Wiki Searching and Evaluating Data in a drawing with VBA: Part 6 - Evaluating Simple Complex Elements

Searching and Evaluating Data in a drawing with VBA: Part 6 - Evaluating Simple Complex Elements


	Applies To

	Product(s):	MicroStation
	Version(s):	08.11.09.578
	Environment:	N\A
	Area:	Programming
	Subarea:	VBA
	Original Author:	Tristan Anderson, Bentley Technical Support Group

In the previous sections, we looked at retrieving data from elements such as lines, circles, and text. For more complex structures, we need more functions to get detailed information.

We will start again with text nodes. Text nodes are interesting elements because you can access targeted text without knowing the exact position by using the text node number. Text nodes, although usually comprised of text, can also be empty, or have one or more lines of text.

An essential function in accessing text of a node is the .GetSubElements method.
This will give us a range of elements, similar to those we have already gotten when using the ElementEnumerator. In the evaluation of elements, we will encounter complex elements that we can break down into simpler individual elements. This will help us extract data from groups or cells much more easily. In text nodes, however, there is no further nesting, because a text node only contains text with a size of 0 to n.

Using the previous examples as a basis for the evaluation of text nodes, we can create a simple routine for evaluating text nodes that might look something like this:

Sub elementinfo()
Dim ele As Element
Dim ee As ElementEnumerator
Dim eeSub As ElementEnumerator
Dim startpoint, endpoint As Point3d
Dim header, Line As String
 Dim file As String
If ActiveWorkspace.IsConfigurationVariableDefined("MeineAusgabeFile") Then
 file = ActiveWorkspace.ConfigurationVariableValue("MeineAusgabeFile")
Else
 MsgBox "The variable MyOutputFile is not defined. Stopped processing", vbCritical
 Exit Sub
End If
Open file For Append As #1
Set ee = ActiveModelReference.GraphicalElementCache.Scan()
Do While ee.MoveNext
If ee.Current.IsTextNodeElement Then
 Set eeSub = ee.Current.AsTextNodeElement.GetSubElements
 Do While eeSub.MoveNext
 Set ele = eeSub.Current
Lin e = "TextNode#: " & ee.Current.AsTextNodeElement.NodeNumber & ";"
 If ele.Type = msdElementTypeText Then
 Line = Line & ele.Type & ";Origin (xy) = " & ele.AsTextElement.Origin.X & "," & ele.AsTextElement.Origin.Y & ";"
 Line = Line & "Height: " & ele.AsTextElement.TextStyle.Height & ";"
 Line = Line & "Text: " & ele.AsTextElement.Text
 Print #1, Line
 End If
 Loop
End If
Loop
Close #1
End Sub

The text output will be the same as before, with the exception of the node number of the text node at the beginning.

I have put a two line text node 3 different times using the place text command. The issue here is that the text nodes are automatically numbered, so that when a new text node is placed, it gets the next available node number.

The evaluation of many drawings have always presented problems from the fact that both texts and text nodes can be present. Text nodes may occur when hitting the return key while creating a text element so that there are 2 lines of text, but the second one is blank. Visually, they will look the same, but the element types will have changed.

The method that we have learned (.GetSubElements) is important to know when extracting data from nested structures if you know that text nodes are in any nested structures such as groups, cells, or pseudo-cells.

Before we continue to go deeper into this, let's first take a look at other complex data structures that have direct access possibilities.
In addition, I have drawn the following shapes: a red line, a blue line string, and a green shape:

Whatever differentes or similarities these elements have, I read out the geometric data using the key points of the elements with the previously stated method.

The line is only a special case of a line string except with only 2 vertices.

To read vertices, I define an array of points:

Dim l() As Point3d

With the query:

If ee.Current.IsLineElement Then ...

I can identify both the line and the line string. Because I can identify the shape, I add another option:

If ee.Current.IsLineElement Or ee.Current.IsShapeElement Then ...

The following analysis should be able to write the vertices of the elements in a file. However, because the number of vertices per element is previously unclear, I will output one line per vertex.

The module could look something like this:

Sub elementinfo()
Dim ele As Element
Dim ee As ElementEnumerator
Dim startpoint, endpoint As Point3d
Dim header, Line As String
Dim l() As Point3d
 Dim file As String
If ActiveWorkspace.IsConfigurationVariableDefined("MyOutputFile") Then
 file = ActiveWorkspace.ConfigurationVariableValue("MyOutputFile")
Else
 MsgBox "The variable MyOutputFile is not defined. Stopped processing", vbCritical
 Exit Sub
End If
Open file For Append As #1
Set ee = ActiveModelReference.GraphicalElementCache.Scan()
Do While ee.MoveNext
 If ee.Current.IsLineElement Or ee.Current.IsShapeElement Then
 l = ee.Current.AsVertexList.GetVertices
 Line = "Typ: " & ee.Current.Type & " with " & UBound(l) - LBound(l) + 1 & " Vertices"
 Print #1, Line
 For i = LBound(l) To UBound(l)
 Line = "Vertex # " & i + 1 & "(xyz);"
 Line = Line & l(i).X & ";" & l(i).Y & ";" & l(i).Z
 Print #1, Line
 Next
 End If
Loop
Close #1

The example with 3 different elements has the following output: