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Work with Tables and Files

In AutoPlay Media Studio, tables are frequently used when working with files. Specifically, we will look at how the results of a Dialog.FileBrowse action are stored in a table, and how it is possible to work with a text file loaded into a table.

Tables, in their basic form, are simply variables with many rows. The Dialog.FileBrowse action stores one file path per row in a table. When reading a text file into a table, every line in the text file is a separate row in the table.

Example 1

Using the Dialog.FileBrowse action, we will allow the user to browse a folder, and select multiple files. We will open each file with its default application:

-- Present the user with a file browse dialog (with multiple select set to true)
tFiles = Dialog.FileBrowse(true, "Multiple Select", "", "All Files(*.*)|*.*|", "", "", true, true);
-- Ensure that tFiles contains something
if tFiles then
   -- Check if the user pressed "Cancel"
   if tFiles[1] == "CANCEL" then
      -- The user pressed cancel, do nothing
   else
      -- The user did not press cancel, traverse the table of files.
      for nIndex, sFile in pairs(tFiles) do
         -- Open file with the default program.
         File.Open(sFile, "", SW_SHOWNORMAL);
      end
   end
end

In the example above, the Dialog.FileBrowse action returns a table containing all the files that were selected. If the cancel button is pressed, the first row in the table (referenced by tFiles[1]) is set to 'CANCEL'. Otherwise, each row in the table contains the path to one file.

Example 2

Using the TextFile actions, we will load the contents of a text file into a table, and insert the text "Line two is the best line ever!!" into the second line of the text file:

-- Present the user with a file browse dialog (with multiple select set to false)
tFiles = Dialog.FileBrowse(true, "Single Select", "", "All Files(*.*)|*.*|", "", "", false, true);

-- Ensure that tFiles contains something
if tFiles then
   -- Check if the user pressed "Cancel"
   if tFiles[1] ~= "CANCEL" then
      -- The user did not press Cancel, continue

      -- Read the selected text file to a table
      tTextFileContents = TextFile.ReadToTable(tFiles[1]);

      -- Insert the text into line (row) two
      Table.Insert(tTextFileContents, 2, "Line two is the best line ever!!");

      -- Write the altered table back to the text file selected (DON'T append)
      TextFile.WriteFromTable(tFiles[1], tTextFileContents, false);
   end
end