/// <inheritdoc />
protected override bool CanBindImpl(DataBinding binding)
{
string bindingPath = binding.Path;
if (bindingPath == null)
{
return(false);
}
string fullPath = itemPath + "/" + bindingPath;
try
{
IXPathNavigable document = documentProvider();
return(document.CreateNavigator().Select(fullPath).MoveNext());
}
catch (XPathException)
{
// Return false if the combined path is not a valid XPath expression.
return(false);
}
}
/// <summary>
/// Registers a data binding for a given data set and adds the data set
/// to the list of data sets to be enumerated during data binding.
/// Returns a <see cref="IDataAccessor" /> that may be used to
/// retrieve the values associated with the binding.
/// </summary>
/// <remarks>
/// <para>
/// A <see cref="IDataBinder" /> uses this method to register interest
/// in querying a particular <see cref="IDataSet" />. It must do so
/// before <see cref="GetItems" /> is called to ensure that the <see cref="IDataSet"/>
/// is included in the enumeration.
/// </para>
/// </remarks>
/// <param name="dataSet">The data set.</param>
/// <param name="binding">The data binding.</param>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="dataSet"/> or <paramref name="binding"/> is null.</exception>
public IDataAccessor RegisterBinding(IDataSet dataSet, DataBinding binding)
{
if (dataSet == null)
{
throw new ArgumentNullException("dataSet");
}
if (binding == null)
{
throw new ArgumentNullException("binding");
}
if (!joinedDataSet.DataSets.Contains(dataSet))
{
joinedDataSet.AddDataSet(dataSet);
}
DataBinding translatedBinding = joinedDataSet.TranslateBinding(dataSet, binding);
translatedBindings.Add(translatedBinding);
return(new BoundDataAccessor(translatedBinding));
}
/// <inheritdoc />
protected override bool CanBindImpl(DataBinding binding)
{
// TODO: compute from the document
return(true);
}
/// <inheritdoc />
protected override bool CanBindImpl(DataBinding binding)
{
return binding.Index.GetValueOrDefault(-1) == 0;
}
/// <summary> /// Determines whether a binding can be satisfied by the data set. /// </summary> /// <param name="binding">The data binding, not null.</param> /// <returns>True if the binding can be satisfied.</returns> protected abstract bool CanBindImpl(DataBinding binding);
/// <inheritdoc />
protected override object GetValueImpl(DataBinding binding)
{
return(null);
}
/// <summary> /// Implements <see cref="GetValue" />. /// </summary> /// <param name="binding">The binding, never null.</param> /// <returns>The associated value.</returns> protected abstract object GetValueImpl(DataBinding binding);
/// <summary>
/// Creates an exception with an associated data binding.
/// </summary>
/// <param name="message">The message.</param>
/// <param name="binding">The associated data binding, or null if none.</param>
/// <param name="innerException">The inner exception.</param>
public DataBindingException(string message, DataBinding binding, Exception innerException)
: base(FormatMessageWithBinding(message, binding), innerException)
{
}
private static string FormatMessageWithBinding(string message, DataBinding binding)
{
return(binding != null ? message + "\nAttempted binding: " + binding : message);
}
public ResolvedBinding(DataSetInfo dataSetInfo, DataBinding inner, int?externalIndex)
: base(externalIndex, inner.Path)
{
this.dataSetInfo = dataSetInfo;
this.inner = inner;
}
/// <summary>
/// Creates an exception with an associated data binding.
/// </summary>
/// <param name="message">The message.</param>
/// <param name="binding">The associated data binding, or null if none.</param>
public DataBindingException(string message, DataBinding binding)
: base(FormatMessageWithBinding(message, binding))
{
}
private ResolvedBinding ResolveBinding(DataBinding binding)
{
var resolvedBinding = binding as ResolvedBinding;
if (resolvedBinding != null && resolvedBinding.DataSetInfo.IsOwnedBy(this))
{
return(resolvedBinding);
}
int?externalIndex = binding.Index;
if (!externalIndex.HasValue)
{
foreach (IDataSet dataSet in DataSets)
{
if (dataSet.CanBind(binding))
{
return(new ResolvedBinding(lookupTable[dataSet], binding, null));
}
}
}
else
{
DataBinding nullIndexBinding = null;
int currentOffset = 0;
foreach (IDataSet dataSet in DataSets)
{
int currentColumnCount = dataSet.ColumnCount;
DataBinding currentBinding;
if (currentOffset == 0)
{
currentBinding = binding;
}
else
{
int internalIndex = externalIndex.Value - currentOffset;
if (internalIndex < 0 || internalIndex >= currentColumnCount)
{
if (nullIndexBinding == null)
{
nullIndexBinding = binding.ReplaceIndex(null);
}
currentBinding = nullIndexBinding;
}
else
{
currentBinding = binding.ReplaceIndex(internalIndex);
}
}
if (dataSet.CanBind(currentBinding))
{
return(new ResolvedBinding(lookupTable[dataSet], currentBinding, binding.Index));
}
currentOffset += currentColumnCount;
}
}
return(null);
}
/// <inheritdoc />
protected override bool CanBindImpl(DataBinding binding)
{
ResolvedBinding resolvedBinding = ResolveBinding(binding);
return(resolvedBinding != null && DataSets[resolvedBinding.DataSetInfo.DataSetIndex].CanBind(resolvedBinding.Inner));
}
/// <inheritdoc />
protected override bool CanBindImpl(DataBinding binding)
{
int bindingIndex = binding.Index.GetValueOrDefault(int.MaxValue);
return(bindingIndex >= 0 && bindingIndex < columnCount);
}
private DataBinding ReverseTranslateBinding(DataBinding binding)
{
string alias = FindAliasForIndex(binding.Index);
return(alias != null ? new DataBinding(binding.Index, alias) : binding);
}
/// <inheritdoc />
protected override bool CanBindImpl(DataBinding binding)
{
return(true);
}