Document Properties

Document properties describe or identify a document through metadata, such as its title, its subject or the name of its author. In rich text formats such as RTF, DOC and DOCX, TXTextControl sets and reads them with the LoadSaveAttribute property, and a Visual Basic sample shows how a form edits them, saves them with a document and reads them back.

The code shown here is in the Samples\VB6\DocProperties sample source directory.

How LoadSaveAttribute Works

LoadSaveAttribute sets and gets various attributes when a document is loaded or saved. You pass the attribute as a constant: set the value before you call Save to store it in the document, and read it after you call Load to get the value the document contains.

The sample uses these document properties:

The constants of LoadSaveAttribute list all attributes.

Save the Document Properties

When the program starts, it sets a default value for each attribute, including the creation and modification dates, and shows the values in text boxes. The user can edit every value except the two dates, which are set automatically.

When the user clicks the Save button, the document properties are taken from the text boxes and assigned to the attributes:

Private Sub SaveButton_Click()

   ' Retrieve each attribute from the corresponding text box
   With TXTextControl1
      .LoadSaveAttribute(txDocTitle) = Text_Title.Text
      .LoadSaveAttribute(txDocSubject) = Text_Subject.Text
      .LoadSaveAttribute(txAuthor) = Text_Author.Text
      .LoadSaveAttribute(txLastModificationDate) = DateTime.Now
      .LoadSaveAttribute(txDocKeywords) = SetKeyWords(Text_Keywords.Text)
      ' Check if a creation date had already been through a load operation.
      ' If a creation date has not been set, use the current date and time.
      If (Text_CreationDate.Text = "") Then .LoadSaveAttribute(txCreationDate) = DateTime.Now
      .Save App.Path + "\Document_Properties.rtf", 0, 5, False
   End With

   ' Show message box to the user to make sure the Load button is clicked next.
   MsgBox "Document properties have been saved!" + vbCr + "Please click on the Load button.", vbOKOnly, "Document properties saved"

   ' Clear the text boxes once the document has been saved.
   Text_Title.Text = ""
   Text_Subject.Text = ""
   Text_Author.Text = ""
   Text_Keywords.Text = ""
   Text_ModDate.Text = ""
   Text_CreationDate.Text = ""
   ' Reset and clear the TXTextControl
   TXTextControl1.ResetContents

End Sub

The code works as follows:

• Each text box value is assigned to its LoadSaveAttribute constant.
• txLastModificationDate is set to the current system date and time on every save.
• txCreationDate is set to the current date and time only if no creation date was retrieved before, by a load operation. This way it isn't overwritten each time the document is saved.
• Save writes the document as RTF to Document_Properties.rtf in the application directory.
• A message box tells the user to click the Load button next. Then the text boxes are cleared, and ResetContents clears TXTextControl.

Load the Document Properties

When the user loads the document, its attributes are read from LoadSaveAttribute and assigned to the text boxes:

Private Sub LoadButton_Click()

   ' Retrieve each attribute from the loaded document
   With TXTextControl1
      .Load App.Path + "\Document_Properties.rtf", 0, 5, False
      Text_Title.Text = .LoadSaveAttribute(txDocTitle)
      Text_Subject.Text = .LoadSaveAttribute(txDocSubject)
      Text_Author.Text = .LoadSaveAttribute(txAuthor)
      Text_Keywords.Text = GetKeyWords(.LoadSaveAttribute(txDocKeywords))
      Text_ModDate.Text = .LoadSaveAttribute(txLastModificationDate)
      Text_CreationDate.Text = .LoadSaveAttribute(txCreationDate)
   End With

End Sub

Convert the Keywords

Two helper functions of the sample convert between TAB-separated and comma-separated strings. Both take a string and return the converted string:

• GetKeyWords replaces all TAB characters of a string with commas. The sample uses it after loading, to show the keywords in a text box.
• SetKeyWords replaces all commas with TAB characters. The sample uses it before saving, to assign the keywords to txDocKeywords.

Related Pages

• Working with Files: the file formats Load and Save read and write.
• PDF Export: exporting documents to PDF.
• Loading, Saving and Database Support: the members that load and save documents.