Unable to get custom property via Android Drive API

Question

Create a file and query file with custom property work fine, but it cannot retrieve custom property in queryChildren() ResultCallback.

Here is the CustomProperty definition:

/**
 * CustomPropertyKey: Uploaded file's hash code
 */
public static final CustomPropertyKey CustomPropertyKeyFileHash =
        new CustomPropertyKey("fileHash", CustomPropertyKey.PUBLIC);

query conditions:

            Query query = new Query.Builder()
                .addFilter(
                        Filters.and(
                                Filters.eq(SearchableField.MIME_TYPE, sMimeType),
                                Filters.eq(BaseDemoActivity.CustomPropertyKeyFileHash, mDriveFile.getMD5()),
                                Filters.eq(SearchableField.TRASHED, false)
                        )
                ).build();

            mDriveFile.getDriveFolder().queryChildren(mGoogleApiClient, query)
                .setResultCallback(mResultCallback);

query result callback:

            public void onResult(DriveApi.MetadataBufferResult result) {
                if (!result.getStatus().isSuccess()) {
                    showMessage("Problem while retrieving results");
                    return;
                }

                MetadataBuffer mdb = result.getMetadataBuffer();
                if (mdb.getCount() > 0) {
                    try {
                        if (mdb != null) {
                            for (Metadata md : mdb) {
                                if (md == null) continue;

                                Log.d(TAG, "[FileMetadataCallback][onResult] md.getTitle(): " + md.getTitle() + ", md.getDriveId(): " + md.getDriveId());
                                Log.d(TAG, "[FileMetadataCallback][onResult] md.getTitle(): " + md.getTitle() + ", md.getResourceId(): " + md.getDriveId().getResourceId());

                                Map<CustomPropertyKey, String> map = md.getCustomProperties();
                                if (map != null) {
                                    Log.d(TAG, "[FileMetadataCallback][onResult] file custom properties size: " + map.size());
                                    if (map.size() > 0) {
                                        Log.d(TAG, "[FileMetadataCallback][onResult] file hash: " + map.get(CustomPropertyKeyFileHash));
                                    }
                                }
                            }
                        }
                    } finally {
                        if (mdb != null) mdb.close();
                    }
                }
            }

I always get log "[FileMetadataCallback][onResult] file custom properties size: 0". However, I should able to retrieve "mDriveFile.getMD5()" since it is one of query conditions, right?

Any suggestion is appreciated.

Answer 1

Just found that it needs to wait a moment (some minutes) to get custom property properly after onCompletion callback. So this should be none issue if you don't need to get custom property immediately after onCompletion callback.