borland Packages Class Hierarchy dx.dataset Package
ProviderHelp class
java.lang.Object
+----com.borland.dx.dataset.ProviderHelp
About the ProviderHelp class
Properties Methods
This class collects utility functions that operate on the StorageDataSet and DataSet classes
that are helpful for provider/resolver implementations. These methods are implemented inside
StorageDataSet, but are not functions typical for DataSet usage.
ProviderHelp properties
*Read-only properties **Write-only properties
Properties implemented in java.lang.Object
ProviderHelp methods
Methods implemented in this class
- endResolution(com.borland.dx.dataset.StorageDataSet)
- failIfOpen(com.borland.dx.dataset.StorageDataSet)
- getResolverDataSet(com.borland.dx.dataset.DataSet)
- getStructureAge(com.borland.dx.dataset.StorageDataSet)
- initData(com.borland.dx.dataset.StorageDataSet, com.borland.dx.dataset.Column[], boolean, boolean)
- initData(com.borland.dx.dataset.StorageDataSet, com.borland.dx.dataset.Column[], boolean, boolean, boolean)
- isCopyProviderStreams(com.borland.dx.dataset.StorageDataSet)
- isProviderPropertyChanged(com.borland.dx.dataset.StorageDataSet)
- markPendingStatus(com.borland.dx.dataset.DataSet, boolean)
- setMetaDataMissing(com.borland.dx.dataset.StorageDataSet, boolean)
- setProviderPropertyChanged(com.borland.dx.dataset.StorageDataSet, boolean)
- startResolution(com.borland.dx.dataset.StorageDataSet, boolean)
Methods implemented in java.lang.Object
- clone()
- equals(java.lang.Object)
- finalize()
- hashCode()
- notify()
- notifyAll()
- toString()
- wait()
- wait(long)
- wait(long, int)
ProviderHelp methods
endResolution(com.borland.dx.dataset.StorageDataSet)
public static final void endResolution(StorageDataSet dataSet)
Used by the ResolutionManager to signal that StorageDataSet is no longer in a
"resolving" mode. Once the startResolution() method is called, any other providing or resolving
operation is prohibited until this method is called.
failIfOpen(com.borland.dx.dataset.StorageDataSet)
public static final void failIfOpen(StorageDataSet dataSet)
Causes a DataSetException to be thrown if the DataSet is open.
getResolverDataSet(com.borland.dx.dataset.DataSet)
public static final StorageDataSet getResolverDataSet(DataSet dataSet)
Returns a StorageDataSet that contains the metadata for a given StorageDataSet or
DataSetView.
getStructureAge(com.borland.dx.dataset.StorageDataSet)
public static final int getStructureAge(StorageDataSet dataSet)
Returns an int, which can be saved and used by a provider as a flag that a column restructure has occurred. This
number is incremented each time a column structure changes. Therefore, if a resolver initially calls this method and
stores the return value, any change in its return value on a subsequent call indicates that the resolver must discard any cached information about the DataSet.
initData(com.borland.dx.dataset.StorageDataSet, com.borland.dx.dataset.Column[], boolean, boolean)
public static final int[] initData(StorageDataSet dataSet, Column[] columns, boolean updateColumns, boolean keepExistingColumns)
Used by providers, initData() initializes the data storage of a DataSet for a new set of columns and returns an ordinal map of the passed in columns to the corresponding columns in the DataSet. This method differs from the StorageDataSet.setColumns() method in that it preserves persistent columns. Note that several column properties in the columns array will be merged in with existing columns in the StorageDataSet columns that have the same name.
Parameters:
- dataSet
- The StorageDataSet whose data storage is to be initialized.
- columns
- The array of columns that represents the added columns.
- updateColumns
-
Boolean that determines whether columns will be merged into existing persistent columns.
If true, the columns will not be added. Instead the returned column map is computed with the current columns.
If both updateColumns and keepExistingColumns parameters are true,
non-persistent columns will also be retained.
- keepExistingColumns
- If true, new columns will be merged into existing columns. If false all non-persistent columns are removed before merging in the persistent columns.
initData(com.borland.dx.dataset.StorageDataSet, com.borland.dx.dataset.Column[], boolean, boolean, boolean)
public static final int[] initData(StorageDataSet dataSet, Column[] columns, boolean updateColumns, boolean keepExistingColumns, boolean emptyRows)
This method has been deprecated. Use
initData(com.borland.dx.dataset.StorageDataSet, com.borland.dx.dataset.Column[], boolean, boolean) instead.
isCopyProviderStreams(com.borland.dx.dataset.StorageDataSet)
public static final boolean isCopyProviderStreams(StorageDataSet dataSet)
A provider can call this method to determine if it should make copies of data from columns of type Variant.INPUT_STREAM. The method will return false if the storage is going to copy the stream, thus there is no need for the provider to copy the data. The method returns true if the storage is just storing a reference to the InputStream. In this case, the provider might need to make a memory copy of the data, if the stream has a limited lifetime or is not resetable.
isProviderPropertyChanged(com.borland.dx.dataset.StorageDataSet)
public static final boolean isProviderPropertyChanged(StorageDataSet dataSet)
Reflects whether this StorageDataSet has received some property change which could affect the
column structure or set of row data, for example, a change in QueryDescriptor or TextDataFile.
Used by Provider classes. The JdbcProvider uses this to decide if it needs to discard cached information about the JDBC data source.
See also:
setProviderPropertyChanged(StorageDataSet,boolean)
markPendingStatus(com.borland.dx.dataset.DataSet, boolean)
public static final void markPendingStatus(DataSet dataSet, boolean on)
Marks a row as pending resolution. Used by the ResolutionManager when saving
changes from a DataSet to a remote data provider that supports transactions, for example, JDBC connections.
setMetaDataMissing(com.borland.dx.dataset.StorageDataSet, boolean)
public static final void setMetaDataMissing(StorageDataSet dataSet, boolean hasRowIds)
Normally set by Providers to indicate that there is insufficient
metadata to post any changes back to its original source.
setProviderPropertyChanged(com.borland.dx.dataset.StorageDataSet, boolean)
public static final void setProviderPropertyChanged(StorageDataSet dataSet, boolean propertiesChanged)
Used by Provider classes. This property reflects whether this StorageDataSet
has received some property change which could affect the column structure or set of row data, for example, a change in QueryDescriptor or TextDataFile.
See also:
isProviderPropertyChanged(com.borland.dx.dataset.StorageDataSet)
startResolution(com.borland.dx.dataset.StorageDataSet, boolean)
public static final void startResolution(StorageDataSet dataSet, boolean postEdits)
Used by the ResolutionManager to place a StorageDataSet into a "resolving" mode.
This mode prohibits any other resolution or providing to occur. After the resolution phase is complete,
the endResolution() method should be called.
If the postEdits parameter is true, the StorageDataSet will post
an unposted row for itself and any DataSetViews that may be associated with the
StorageDataSet.