问题
I have a problem with datasource binding in ListGrid with smartGWT. I have GWT-RPC-DataSource and i have set it as my datasource
grid.setDataSource(ds);
On one button click I have some changes in my datasource and I am generating new datasource and rebinding with smartgwt's grid. but it fails. I have tried grid.redraw() function to redraw the grid.
Below is my class for GWTRPCDATASOURCE
public abstract class GwtRpcDataSource extends DataSource {
/**
* Creates new data source which communicates with server by GWT RPC. It is
* normal server side SmartClient data source with data protocol set to
* <code>DSProtocol.CLIENTCUSTOM</code> ("clientCustom" - natively supported
* by SmartClient but should be added to smartGWT) and with data format
* <code>DSDataFormat.CUSTOM</code>.
*/
public GwtRpcDataSource() {
setDataProtocol(DSProtocol.CLIENTCUSTOM);
setDataFormat(DSDataFormat.CUSTOM);
setClientOnly(false);
}
/**
* Executes request to server.
*
* @param request
* <code>DSRequest</code> being processed.
* @return <code>Object</code> data from original request.
*/
@Override
protected Object transformRequest(DSRequest request) {
String requestId = request.getRequestId();
DSResponse response = new DSResponse();
response.setAttribute("clientContext",
request.getAttributeAsObject("clientContext"));
// Asume success
response.setStatus(0);
switch (request.getOperationType()) {
case FETCH:
executeFetch(requestId, request, response);
break;
case ADD:
executeAdd(requestId, request, response);
break;
case UPDATE:
executeUpdate(requestId, request, response);
break;
case REMOVE:
executeRemove(requestId, request, response);
break;
default:
// Operation not implemented.
break;
}
return request.getData();
}
/**
* Executed on <code>FETCH</code> operation.
* <code>processResponse (requestId, response)</code> should be called when
* operation completes (either successful or failure).
*
* @param requestId
* <code>String</code> extracted from
* <code>DSRequest.getRequestId ()</code>.
* @param request
* <code>DSRequest</code> being processed.
* @param response
* <code>DSResponse</code>. <code>setData (list)</code> should be
* called on successful execution of this method.
* <code>setStatus (<0)</code> should be called on failure.
*/
protected abstract void executeFetch(String requestId, DSRequest request,
DSResponse response);
/**
* Executed on <code>ADD</code> operation.
* <code>processResponse (requestId, response)</code> should be called when
* operation completes (either successful or failure).
*
* @param requestId
* <code>String</code> extracted from
* <code>DSRequest.getRequestId ()</code>.
* @param request
* <code>DSRequest</code> being processed.
* <code>request.getData ()</code> contains record should be
* added.
* @param response
* <code>DSResponse</code>. <code>setData (list)</code> should be
* called on successful execution of this method. Array should
* contain single element representing added row.
* <code>setStatus (<0)</code> should be called on failure.
*/
protected abstract void executeAdd(String requestId, DSRequest request,
DSResponse response);
/**
* Executed on <code>UPDATE</code> operation.
* <code>processResponse (requestId, response)</code> should be called when
* operation completes (either successful or failure).
*
* @param requestId
* <code>String</code> extracted from
* <code>DSRequest.getRequestId ()</code>.
* @param request
* <code>DSRequest</code> being processed.
* <code>request.getData ()</code> contains record should be
* updated.
* @param response
* <code>DSResponse</code>. <code>setData (list)</code> should be
* called on successful execution of this method. Array should
* contain single element representing updated row.
* <code>setStatus (<0)</code> should be called on failure.
*/
protected abstract void executeUpdate(String requestId, DSRequest request,
DSResponse response);
/**
* Executed on <code>REMOVE</code> operation.
* <code>processResponse (requestId, response)</code> should be called when
* operation completes (either successful or failure).
*
* @param requestId
* <code>String</code> extracted from
* <code>DSRequest.getRequestId ()</code>.
* @param request
* <code>DSRequest</code> being processed.
* <code>request.getData ()</code> contains record should be
* removed.
* @param response
* <code>DSResponse</code>. <code>setData (list)</code> should be
* called on successful execution of this method. Array should
* contain single element representing removed row.
* <code>setStatus (<0)</code> should be called on failure.
*/
protected abstract void executeRemove(String requestId, DSRequest request,
DSResponse response);
private ListGridRecord getEditedRecord(DSRequest request) {
// Retrieving values before edit
JavaScriptObject oldValues = request
.getAttributeAsJavaScriptObject("oldValues");
// Creating new record for combining old values with changes
ListGridRecord newRecord = new ListGridRecord();
// Copying properties from old record
JSOHelper.apply(oldValues, newRecord.getJsObj());
// Retrieving changed values
JavaScriptObject data = request.getData();
// Apply changes
JSOHelper.apply(data, newRecord.getJsObj());
return newRecord;
}
}
I have implemented this abstract class to my own datasource class named NTDatasource.
public class NTDataSource extends GwtRpcDataSource {
public static int total = 991;
Record[] records;
public NTDataSource() {
}
public void setData(List<NTListGridField> lstFields, Record[] records) {
// setTestData(records);
for (NTListGridField lstField : lstFields) {
if (lstField.getType() == ListGridFieldType.DATE) {
DataSourceDateField dateField = new DataSourceDateField(
lstField.getName());
dateField.setHidden(lstField.getAttributeAsBoolean("visible"));
if (lstField.getName().equals("id")) {
dateField.setHidden(true);
}
addField(dateField);
} else {
DataSourceTextField textField = new DataSourceTextField(
lstField.getName());
textField.setHidden(lstField.getAttributeAsBoolean("visible"));
if (lstField.getName().equals("id")) {
textField.setHidden(true);
textField.setPrimaryKey(true);
}
addField(textField);
}
}
total = records.length;
this.records = records;
}
@Override
protected void executeFetch(String requestId, DSRequest request,
DSResponse response) {
// assume we have 1000 items.
response.setTotalRows(total);
int end = request.getEndRow();
if (end > total) {
end = total;
}
Record returnRecords[] = new Record[end
- request.getStartRow()];
for (int i = request.getStartRow(); i < end; i++) {
ListGridRecord r = new ListGridRecord();
r = (ListGridRecord) records[i];
returnRecords[i - request.getStartRow()] = r;
}
GWT.log(" called from " + request.getStartRow() + " to "
+ request.getEndRow() + " result " + returnRecords.length, null);
response.setData(returnRecords);
processResponse(requestId, response);
}
@Override
protected void executeAdd(String requestId, DSRequest request,
DSResponse response) {
// TODO Auto-generated method stub
}
@Override
protected void executeUpdate(String requestId, DSRequest request,
DSResponse response) {
// TODO Auto-generated method stub
}
@Override
protected void executeRemove(String requestId, DSRequest request,
DSResponse response) {
// TODO Auto-generated method stub
}
}
回答1:
I have solve this question myself.
the answer is i need to use grid.fetchData() method and bind datasource one more time to use it.... !! I hope it might help someone else.
回答2:
Try grid.invalidateCache() .This call will clear the current data in the grid and executes the NTDataSource.executeFetch method.
来源：https://stackoverflow.com/questions/4734638/smartgwt-datasource-gwt-rpc-datasource-listgrid