Code snippet: StorageFolder.copyFolder method

Question

until now :) Needed one, so I came up with this:

copyFolderAsync = function(sourceFolder, destFolder) {
  return destFolder.createFolderAsync(sourceFolder.name, CreationCollisionOption.openIfExists).then(function(destSubFolder) {
    return sourceFolder.getFilesAsync().then(function(files) {
      return WinJS.Promise.join(files.map(function(file) {
        return file.copyAsync(destSubFolder, file.name, NameCollisionOption.replaceExisting);
      }));
    }).then(function() {
      return sourceFolder.getFoldersAsync();
    }).then(function(folders) {
      return WinJS.Promise.join(folders.map(function(folder) {
        return copyFolderAsync(folder, destSubFolder);
      }));
    });
  });
};

Copies recursively and copies files over. Could be extended to skip existing files (by size and date and/or content).

I especially like the non-recursion because of the usage of Promises.

Enjoy!

Answer 1

Hi pkursawe,

Your suggestion for the API is a good idea, I will submit to senior engineers and I think you could also report at here:http://wpdev.uservoice.com/forums/110705-dev-platform.

However I would use GetItemsAsync() | getItemsAsync() method for getting all the items and do some filters while copy.

--James

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Answer 2

However I would use GetItemsAsync() | getItemsAsync() method for getting all the items and do some filters while copy.

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right, that is a good idea. I'd assume its also faster. And then use duck typing or "instance of" to decide what to do with the item.

Answer 3

What you think, should I copy the file items sequentially, or use the WinJS.Promise.join (meaning firing all copy actions at once).

On non-SSDs sequential copying might be faster.

copyFolderAsync = function(destFolder, sourceFolder) {
  return destFolder.createFolderAsync(sourceFolder.name, CreationCollisionOption.openIfExists).then(function(destSubFolder) {
    return sourceFolder.getItemsAsync().then(function(items) {
      return WinJS.Promise.join(items.map(function(item) {
        if (item instanceof Windows.Storage.StorageFile) {
          return item.copyAsync(destSubFolder, item.name, NameCollisionOption.replaceExisting);
        } else {
          return copyFolderAsync(destSubFolder, item);
        }
      }));
    });
  });
};

Answer 4

Posted there with back-reference to this place here:

http://wpdev.uservoice.com/forums/110705-dev-platform/suggestions/6071259-add-storagefolder-copyfolderasync

Vote if you care :)