openpanel statement/function

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OpenPanel		statement / function

Statement syntax
openpanel tag, msg, fileTypes, prompt, dirURL, sheetFlag

Function syntax
url | array = openpanel tag, msg, fileTypes, prompt, dirURL

Description
Use this statement/function to:

Create a new openpanel dialog;

Run an existing openpanel;

Alter an existing openpanel's characteristics.

Parameters

Parameter	Description
tag	A number (1 through 1000000) that you assign when you create the openpanel and that you refer to when altering the panel. A negative value builds the panel invisibly and doesn't run it until the statement is executed with a positive value. Note: Once the panel has been dismissed, its tag value is no longer valid.
msg	The message text displayed in the open panel.
fileTypes	A semicolon-delimited string or an array of strings specifying the allowed file types for the panel. The value of this property specifies the file types the user can open. A file type can be a common file extension, or a UTI. The default value of this property is nil, which indicates that any file type can be opened. Note: old four character OSTypes are not supported.
prompt	The prompt of the default button.
dirURL	The URL of the initial directory shown when the panel is displayed.
sheetFlag	A boolean value to indicate if the panel will be a sheet attached to the current output window. Note A sheet panel does *not* return a value from the openpanel statement, but instead posts an _openPanelDidEnd event to the user on dialog function.

Return value (non-sheet dialog only)
A file URL (or an array of URLs when the panel's multiple selection flag is set to true). Returns NULL if the dialog was cancelled.

Ancillary functions
The following optional functions enhance the openpanel and should be called while the openpanel is invisible (before running the panel).

OpenPanelSetCanChooseFiles
OpenPanelSetCanChooseDirectories
OpenPanelSetResolvesAliases
OpenPanelSetAllowsMultipleSelection
OpenPanelSetCanDownloadUbiquitousContents
OpenPanelSetCanResolveUbiquitousConflicts
OpenPanelSetAccessoryViewDisclosed
OpenPanelSetAccessoryView
OpenPanelSetTitle
OpenPanelSetCanCreateDirectories
OpenPanelSetShowsHiddenFiles
OpenPanelSetAllowsOtherFileTypes
OpenPanelSetTreatsFilePackagesAsDirectories

Notes

Using openpanel to select a file does not actually open the selected file. Use the open statement if you need to open the file.
A returned CFURLRef should not be saved to refer to a file/directory at a later date (i.e. across machine restarts). If you need to keep track of a file's location over time, create and save an alias or bookmark for the file.
When an openpanel has been given the multiple selection option (OpenPanelSetAllowsMultipleSelection), the returned value will be an array of selected file/directory URLs.
Returned CFURLRef and/or CFArrayRef objects will need to be retained if not used immediately.

Dialog event
_openPanelDidEnd

Is called for both sheet and non-sheet panels. The sheetFlag parameter above explains creating a sheet/non-sheet panel.
Is only available within the user on dialog function, so make sure a on dialog fn xxxxxxx function is specified prior to calling openpanel

See also
savepanel

Apple documentation
NSOpenPanel