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\<object>.startSync

Note:
If sync is performed in an upload cache enabled scenario, cached requests that are timed out in the previous upload session are uploaded before the latest changes.
The client does not handle partial records and expects the server to send the entire record. Full record with all the columns are expected in both upload and download responses. If the backend does not return the full record, use post processor to copy the missing columns from the request as demonstrated here.

Volt MX Iris (JavaScript)

Signature

<VMXObj>.startSync(syncOptions, successCallback, failureCallback, progressCallback)

Parameters

ParameterTypeDescriptionRequired
syncOptionsJSONThe user can provide options to customize sync behavior. For example, Filters, download batch size etc, Refer Sync Options for supported options. Refer Offline Objects Getting Started guide for more details.Yes
successCallbackFunctionThe function is invoked on a successful sync.Yes
failureCallbackFunctionThe function is invoked on an error with the cause of failure as an argument upon Sync failure.Yes
progressCallbackFunctionThe function is invoked on different sync phases along with phase specific data such as the number of records downloaded etc. Refer Offline Objects Getting Started guide for more details about sync progress events. Note: Not applicable for Mobile Web and Desktop Web channels. If the app developer passes this parameter in the options, it will be ignored.No

Sync Options

OptionsTypeDescriptionsRequired
filterStringThe filter is a valid OData filter string, allows downloading specific records based on the supplied criteria. When the sync is performed at the object-level, filters should be supplied as valid OData filter string as shown in the sample code. All records are downloaded for the object with no or invalid OData filter.No
downloadBatchSizeNumber/StringThe downloadBatchSize option defines record based batching in downloads. Care should be taken to provide appropriate batch size (number of records) based on backend’s ability to support the same. downloadBatchSize is 500 (records) by default.No
uploadBatchSizeNumber/StringuploadBatchSize option defines record based batching in uploads. uploadBatchSize is 50 (records) by default. Default BatchSize is assumed if the supplied value is <=0.No
getSyncStatsStringThe getSyncStats option is used to get sync stats information through sync success callback. This option takes two values true or false. Sync stats information is not returned to the user if the getSyncStats option is not supplied or set to false or an invalid value.No
syncTypeStringdownloadOnly will download the changes from the server. Change on the client side will not be pushed to the sever.uploadOnly will upload the changes from the client device to the server. Changes on the server will not be downloaded.fullSync will perform both upload and download from the client device to the server and vice-versa. Note: Sync will move to the error state, if any other value is provided other than the above mentioned values.If sync type is not selected, full sync is performed by default.No
uploadRequestQueryParamsJSONThe uploadRequestQueryParams option is used to pass the query parameters in upload network requests.No
downloadRequestQueryParamsJSONThe downloadRequestQueryParams is used to pass the query parameters in download network requests.No
downloadReconciliationRequiredBooleanThis parameter specifies if download reconciliation is required or not. Download reconciliation is used to compare primary keys present in backend with application database primary keys for an object. In scenarios where there are no pending edits, it is advisable to perform startSync by setting downloadReconciliationRequired to false (as in the case of initial sync). downloadReconciliationRequired is set to true, by default.No
preserveBatchContextBooleanpreserveBatchContext specifies whether to preserve the batchContext of last successful download batch. If batchContext is preserved, the successive download call resumes from the last successful batch, else it starts from the first batch again. Set the option to True, to resume the download from last successful batch. Set the option to False, to start downloading from the first batch. preserveBatchContext is set to false, by default. Note: This parameter is not supported for Mobile Web, Windows, and Desktop Web channels. 

Return Type

void

Example

function successCallback(object) {
    //Handle sync success response.
}

function failureCallback(error) {
    //Handle sync failure response.
}

function progressCallback(object) {
    //Handle sync progress response.
}

try {
    var syncObject = new voltmx.sdk.VMXObj("Employee");
    var syncOptions = {};

    //Set filters to be applied during download on object.
    syncOptions.filter = "EmployeeID eq 2";

    //Set uploadRequestQueryParams to be sent during sync in Sync Options.
    syncOptions.uploadRequestQueryParams = {
        "LocationID": "32001",
        "SiteID": "2"
    };

    //Set upload BatchSize.
    syncOptions.uploadBatchSize = "200";

    //Set getSyncStats to receive sync stats on sync success.
    syncOptions.getSyncStats = "true";

    //Set syncType to perform a sync session
    syncOptions.syncType = "uploadOnly";

    //Supplying call back to receive sync progress events too
    syncObject.startSync(syncOptions, successCallback,
        failureCallback, progressCallback);
} catch (err) {
    //Handles Exception.
}

Android (Java)

Signature

void <VMXObj>.startSync(final HashMap<String, Object> syncOptions, final VMXCallback syncCallback, final VMXProgressCallback progressCallback) throws Exception

Parameters

ParameterTypeDescriptionRequired
syncOptionsHashMap<String, Object>The user can provide event callbacks, batchsize to the sync engine. Refer Sync Options for supported options. Refer Offline Objects Getting Started Guide for more details.Yes
callbackVMXCallbackApplication implements onSuccess and onFailure methods of VMXCallback interface.Yes
progressCallbackVMXProgressCallbackApplication implements onProgress method of VMXProgressCallback interface if progress callback is supplied.No

Sync Options

OptionsTypeDescriptionsRequired
filterStringThe filter is a valid OData filter string, allows downloading specific records based on the supplied criteria. When the sync is performed at the object-level, filters should be supplied as valid OData filter string as shown in the sample code. All records are downloaded for object with no or invalid OData filter.No
downloadBatchSizeNumber/StringThe downloadBatchSize option defines record based batching in downloads. Care should be taken to provide appropriate batch size (number of records) based on backend’s ability to support the same. downloadBatchSize is 500 (records) by default.No
uploadBatchSizeNumber/StringuploadBatchSize option defines record based batching in uploads. uploadBatchSize is 50(records) by default. BatchSize is assumed if the supplied value is <=0.No
getSyncStatsStringThe getSyncStats option is used to get sync stats information through sync success callback. This option takes two values true or false. Sync stats information is not returned to the user if the getSyncStats option is not supplied or set to false or an invalid value.No
syncTypeStringdownloadOnly will download the changes from the server. Change on the client side will not be pushed to the sever.uploadOnly will upload the changes from the client device to the server. Changes on the server will not be downloaded.fullSync will perform both upload and download from the client device to the server and vice-versa. Note: Sync will move to the error state, if any other value is provided other than the above mentioned values.If sync type is not selected, full sync is performed by default.No
uploadRequestQueryParamsHashMap<String, String>The uploadRequestQueryParams option is used to pass the query parameters in upload network requests. Note: The keys and values in the Hashmap must be of the string data type.No
downloadRequestQueryParamsHashMap<String, String>The downloadRequestQueryParams is used to pass the query parameters in download network requests. Note: The keys and values in the Hashmap must be of the string data type.No
downloadReconciliationRequiredBooleanThis parameter specifies if download reconciliation is required or not. Download reconciliation is used to compare primary keys present in backend with application database primary keys for an object. In scenarios where there are no pending edits, it is advisable to perform startSync by setting downloadReconciliationRequired to false (as in the case of initial sync). downloadReconciliationRequired is set to true, by default.No
preserveBatchContextBooleanpreserveBatchContext specifies whether to preserve the batchContext of last successful download batch. If batchContext is preserved, the successive download call resumes from the last successful batch, else it starts from the first batch again. Set the option to True, to resume the download from last successful batch. Set the option to False, to start downloading from the first batch. preserveBatchContext is set to false, by default.No

Return Type

void

Example

try {
    //Create VMXObj object for object which needs to be synced.
    VMXObj syncObject = new VMXObj("Employee");

    HashMap < String, Object > syncOptions = new HashMap < String,
    Object > ();

    //Set downloadRequestQueryParams to be applied while downloading object
    HashMap < String, String > downloadRequestQueryParams = new HashMap < String, String > ();
    downloadRequestQueryParams("Location ID", "32001");
    downloadRequestQueryParams("SiteID", "2");
    syncOptions.put("downloadRequestQueryParams", downloadRequestQueryParams);

    //Set filters to be applied during download on object.
    syncOptions.put("filter", "EmployeeID eq 2");

    //Set download BatchSize.
    syncOptions.put("downloadBatchSize", "100");


    //Set getSyncStats to receive sync stats on sync success.   
    syncOptions.put("getSyncStats", "true");

    //Set syncType to perform a sync session
    syncOptions.put("syncType", "downloadOnly");

    //Supplying call back to receive sync progress events too
    syncObject.startSync(syncOptions, new VMXCallback() {
            @Override
            public void onSuccess(Object object) {

                Log.d("ObjectSync", "Object sync successful");
            }

            @Override
            public void onFailure(Object error) {
                OfflineObjectsException e = (OfflineObjectsException) error;
                Log.e("ObjectSync", "Object sync failed with error: " + e.getMessage());
            }
        },
        new VMXProgressCallback() {
            @Override
            Public void onProgress(Object object) {
                Log.d("ObjectSync", "Object sync Progress");
            }
        });
} catch (Exception e) {
    Log.e("ObjectSync", "Object sync failed with error:" + e.getMessage());
}

iOS (Objective C)

Signature

void <VMXObj> startSync:(NSDictionary <NSString *, id> *)syncOptions
       onSuccess:(VMXSuccessCompletionHandler)onSuccess
       onFailure:(VMXFailureCompletionHandler)onFailure
      onProgress:(VMXProgressCompletionHandler)onProgress;

Parameters

ParameterTypeDescriptionRequired
syncOptionsNSDictionary<NSString*, id>A User can provide options to customize sync behavior. For example, Filters, download