Opening and saving files: an example
This example consists of several scripts that handle opening
and saving files. Users can open existing files and save changes.
They can also save the contents to another file. If users save the
file they opened, saving proceeds without interrupting the user.
If users save to a file name that exists, but is not the file they
opened, they are asked whether to overwrite the file:
The example includes instance variable declarations, scripts,
functions, and events.
Instance variable declarations
ib_saveas
A flag for the FileExists event. When FALSE,
the user is saving to the file that was opened, so overwriting is
expected:
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boolean ib_saveas=FALSE |
is_filename
The current file name for the contents, initially set to “Untitled”:
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string is_filename |
Open Document script
This script opens a file chosen by the user. Since opening
a file triggers the Modified event and sets the Modified property,
the script resets Modified to FALSE. The Checked
property of the Modified check box is set to FALSE too:
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integer li_answer, li_result<br>string ls_name, ls_path<br> <br>li_answer = GetFileOpenName("Open File", ls_path, &<br>   ls_name, "rtf", &<br>   "Rich Text(*.RTF),*.RTF, Text files(*.TXT),*.TXT")<br> <br>IF li_answer = 1 THEN<br>   // User did not cancel<br>   li_result = rte_1.InsertDocument(ls_path, TRUE)<br> <br>   IF li_result = 1 THEN  // Document open successful<br>      // Save and display file name<br>      is_filename = ls_path<br>      st_filename.Text = is_filename<br> <br>      // Save and display modified status   <br>      rte_1.Modified = FALSE<br> <br>      cbx_modified.Checked = rte_1.Modified   <br>   ELSE |
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      MessageBox("Error", "File not opened.")   <br>   END IF<br> <br>   END IF<br>RETURN 0 |
Scripts that save the document
The user might choose to save the document to the same name
or to a new name. These scripts could be assigned to menu items
as well as buttons. The Save button script checks whether the instance
variable is_filename holds a valid
name. If so, it passes that file name to the of_save function.
If not, it triggers the SaveAs button’s script instead:
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integer li_result<br>string ls_name<br> <br>// If not associated with file, get file name<br>IF is_filename = "Untitled" THEN<br>   cb_saveas.EVENT Clicked()<br> <br>ELSE<br>   li_result = Parent.of_save(is_filename)<br>END IF<br>RETURN 0 |
The SaveAs script sets the instance variable ib_saveas so
that the FileExists event, if triggered, knows to ask about overwriting
the file. It calls of_getfilename to
prompt for a file name before passing that file name to the of_save function.
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integer li_result<br>string ls_name<br> <br>ib_saveas = TRUE<br> <br>ls_name = Parent.of_getfilename()<br>// If the user canceled or an error occurred, abort<br>IF ls_name = "" THEN RETURN -1<br> <br>li_result = Parent.of_save(ls_name)<br> <br>ib_saveas = FALSE<br>RETURN 0 |
Functions for saving and getting a file name
of_save function
This function accepts a file name argument and saves the document.
It updates the file name instance variable with the new name and sets
the check box to correspond with the Modified property, which is automatically
set to FALSE after you call SaveDocument successfully:
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integer li_result<br> <br>MessageBox("File name", as_name)<br> <br>// Don't need a file type because the extension<br>// will trigger the correct type of save<br>li_result = rte_1.SaveDocument(as_name)<br> <br>IF li_result = -1 THEN<br>   MessageBox("Warning", "File not saved.")<br>   RETURN -1<br>ELSE<br>   // File saved successfully<br>   is_filename = as_name<br>   st_filename.Text = is_filename<br>   cbx_modified.Checked = rte_1.Modified<br>   RETURN 1<br>END IF |
of_getfilename function
The function prompts the user for a name and returns the file
name the user selects. It is called when a file name has not yet been
specified or when the user chooses Save As. It returns a file name:
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integer li_answer<br>string ls_name, ls_path<br> <br>li_answer = GetFileSaveName("Document Name", ls_path, &<br>   ls_name, "rtf", &<br>   "Rich Text(*.RTF),*.RTF,Text files(*.TXT),*.TXT")<br> <br>IF li_answer = 1 THEN<br>   // Return specified file name<br>   RETURN ls_path<br>ELSE<br>   RETURN ""<br>END IF |
Events for saving and closing
FileExists event
When the user has selected a file name and the file already exists,
this script warns the user and allows the save to be canceled. The
event occurs when SaveDocument tries to save
a file and it already exists. The script checks whether ib_saveas is TRUE and,
if so, asks if the user wants to proceed with overwriting the existing
file:
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integer li_answer<br> <br>// If user asked to Save to same file,<br>// don't prompt for overwriting<br>IF ib_saveas = FALSE THEN RETURN 0<br> <br>li_answer = MessageBox("FileExists", &<br>   filename + " already exists. Overwrite?", &<br>   Exclamation!, YesNo!)<br> <br>// Returning a non-zero value cancels save<br>IF li_answer = 2 THEN RETURN 1 |
Modified event
This script sets a check box so the user can see that changes have
not been saved. The Modified property is set automatically when
the event occurs. The event is triggered when the first change is
made to the contents of the control:
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cbx_modified.Checked = TRUE |
CloseQuery event
This script for the window’s CloseQuery event checks whether
the control has unsaved changes and asks whether to save the document
before the window closes:
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integer li_answer<br> <br>// Are there unsaved changes? No, then return.<br>IF rte_1.Modified = FALSE THEN RETURN 0<br> <br>// Ask user whether to save<br>li_answer = MessageBox("Document not saved", &<br>   "Do you want to save " + is_filename + "?", &<br>   Exclamation!, YesNo! )<br> <br>IF li_answer = 1 THEN<br>   // User says save. Trigger Save button script.<br>   cb_save.EVENT Clicked()<br>END IF<br>RETURN 0 |