DeleteFolder

Definition:

DeleteFolder(path)

 

Description:

Delete a local folder and any subfolders and files below it from the mobile device.

 

Platforms:

All

 

Parameters:

path - required

Specify the fully qualified path of the folder to delete.

 

Specify one of the following values:

""

Specify an empty string to allow the user to browse for and select the folder to be deleted at runtime.

 

Documents\<subfolderpath>

Specify the path of a folder located in the device's Documents library, or one of its subfolders, using this special format, e.g. Documents\MyApp\DataFiles. To use this option requires permission to directly access the device's Documents library - see Notes below.

 

 

Returns:

nothing

 

Notes:

From Android 11 onwards, changes to the Android Operating System affect the ability of your apps to access certain files and folders when calling DeleteFolder. This will only affect files and folders in shared storage outside the normal folders accessible to an individual app.

If you want your app to be able to access such files and folders, you will need to build a pre-configured Client or Standalone App which includes a request for permission to do so. This requires you to select the Allow All Files option under the Permissions tab within the pre-configured Client or Standalone App build request dialog box. Then, the first time a user runs the Client or Standalone App on a device, they will be asked to grant permission for the Client or app to access these files and folders. If the user grants permission, your Client or app will be able to access files and folders in shared storage outside its own folders. If the user refuses permission, your app will not be able to access these files and folders and calls to DeleteFolder involving such files or folders will fail silently. The user can always change their decision later within the device's Settings.

  • If you upgrade a device from an earlier version of Android to Android 11 or above, this change may cause a previously working app to fail. If, after upgrading, calls to DeleteFolder fail, try rebuilding (or building) your pre-configured Client or Standalone App with the Allow All Files option selected and upgrade your Client or Standalone App.
  • The Access All Files option will generally give your app access to files and folders which are held in shared storage on the device, but doesn't give unlimited access to all files and folders, e.g. it won't allow you to access files and folders held within another app's private storage.

 

On the Universal Windows Platform, note the following:

  • If you are creating a Standalone App and you want to directly access folders in the device's Document library using this Method, you will need to turn on this capability within the build request to the Digitise Apps Build System. You do this by selecting the Access Documents Library option under the Permissions tab when configuring the Standalone App build request in App Studio. If you select Access Documents Library, you then need to create a list of file extensions determining which files in the Documents library the Scripting Methods are allowed to operate on.

    Note that when creating a store version of a Standalone App, selecting Access Documents Library affects the process by which you submit the app to the Store and requires you to justify your use of this option to Microsoft.

    For a pre-configured version of the Universal Windows Client, Access Documents Library is always selected and you only need to specify a list of file extensions, determining which files in the Documents library the Scripting Methods are allowed to operate on, under the File Extensions tab in the build request.

    You can only specify a file using the Documents\<subfolderpath> format as a parameter to this Method if Access Documents Library is selected.

    If the specified folder, or any of its subfolders, contain files, these files will only be deleted if they have file extensions included in your file extensions list specified in the build request. If it contains files with unlisted file extensions the Method will fail silently. On a Windows tablet, if you have not specified any file extensions, the folder will only be deleted if it is empty. On a Windows desktop, you must always specify at least one file extension (see below).

    The standard NDL-signed Digitise Apps Client supplied in the Digitise Apps Product Download, has Access Documents Library disabled and cannot directly access folders in the Documents library.

  • If you specify an empty string as the parameter to this Method, on a Windows tablet, generally the user can delete any folder which the operating system will allow them to select. However, in some situations, the user may be able to select a folder which cannot be deleted, e.g. because it has open files within it. In this situation, the Method will fail silently.

  • If you will be running your app in a Windows desktop environment, you can only use the DeleteFolder Method if you have Access Documents Library selected, as described above and you must also have at least one file extension listed in the File Extension table. This is true, whether you want to specify an empty string or a folder in the Documents library as the parameter to this Method. When specifying an empty string as the parameter or if you will only be deleting empty folders within the Documents library, it doesn't matter what file extensions are listed in the file extensions table, as long as there is at least one. In addition, in all cases, you can only delete folders within the Documents library.

  • When you delete a folder, any files within the folder and any subfolders will be deleted as well.

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