// <summary>
// Construct a new placeholder with the shape of the given placeholder. Key values are
// injected into the resulting place holder and default values are substituted with
// either propagator constants or progagator nulls depending on the mode established
// by the <paramref name="mode" /> flag.
// </summary>
// <remarks>
// The key is essentially an array of values. The key map indicates that for a particular
// placeholder an expression (keyMap.Keys) corresponds to some ordinal in the key array.
// </remarks>
// <param name="placeholder"> Placeholder to clone </param>
// <param name="key"> Key to substitute </param>
// <param name="placeholderKey"> Key elements in the placeholder (ordinally aligned with 'key') </param>
// <param name="mode"> Mode of operation. </param>
// <returns> Cloned placeholder with key values </returns>
internal static PropagatorResult Populate(
PropagatorResult placeholder, CompositeKey key,
CompositeKey placeholderKey, PopulateMode mode)
{
DebugCheck.NotNull(placeholder);
DebugCheck.NotNull(key);
DebugCheck.NotNull(placeholderKey);
// Figure out which flags to apply to generated elements.
var isNull = mode == PopulateMode.NullModified || mode == PopulateMode.NullPreserve;
var preserve = mode == PopulateMode.NullPreserve || mode == PopulateMode.Unknown;
var flags = PropagatorFlags.NoFlags;
if (!isNull)
{
flags |= PropagatorFlags.Unknown;
} // only null values are known
if (preserve)
{
flags |= PropagatorFlags.Preserve;
}
var result = placeholder.Replace(
node =>
{
// See if this is a key element
var keyIndex = -1;
for (var i = 0; i < placeholderKey.KeyComponents.Length; i++)
{
if (placeholderKey.KeyComponents[i] == node)
{
keyIndex = i;
break;
}
}
if (keyIndex != -1)
{
// Key value.
return(key.KeyComponents[keyIndex]);
}
else
{
// for simple entries, just return using the markup context for this
// populator
var value = isNull ? null : node.GetSimpleValue();
return(PropagatorResult.CreateSimpleValue(flags, value));
}
});
return(result);
}
// <summary>
// Construct a new placeholder with the shape of the given placeholder. Key values are
// injected into the resulting place holder and default values are substituted with
// either propagator constants or progagator nulls depending on the mode established
// by the <paramref name="mode" /> flag.
// </summary>
// <remarks>
// The key is essentially an array of values. The key map indicates that for a particular
// placeholder an expression (keyMap.Keys) corresponds to some ordinal in the key array.
// </remarks>
// <param name="placeholder"> Placeholder to clone </param>
// <param name="key"> Key to substitute </param>
// <param name="placeholderKey"> Key elements in the placeholder (ordinally aligned with 'key') </param>
// <param name="mode"> Mode of operation. </param>
// <returns> Cloned placeholder with key values </returns>
internal static PropagatorResult Populate(
PropagatorResult placeholder, CompositeKey key,
CompositeKey placeholderKey, PopulateMode mode)
{
DebugCheck.NotNull(placeholder);
DebugCheck.NotNull(key);
DebugCheck.NotNull(placeholderKey);
// Figure out which flags to apply to generated elements.
var isNull = mode == PopulateMode.NullModified || mode == PopulateMode.NullPreserve;
var preserve = mode == PopulateMode.NullPreserve || mode == PopulateMode.Unknown;
var flags = PropagatorFlags.NoFlags;
if (!isNull)
{
flags |= PropagatorFlags.Unknown;
} // only null values are known
if (preserve)
{
flags |= PropagatorFlags.Preserve;
}
var result = placeholder.Replace(
node =>
{
// See if this is a key element
var keyIndex = -1;
for (var i = 0; i < placeholderKey.KeyComponents.Length; i++)
{
if (placeholderKey.KeyComponents[i] == node)
{
keyIndex = i;
break;
}
}
if (keyIndex != -1)
{
// Key value.
return key.KeyComponents[keyIndex];
}
else
{
// for simple entries, just return using the markup context for this
// populator
var value = isNull ? null : node.GetSimpleValue();
return PropagatorResult.CreateSimpleValue(flags, value);
}
});
return result;
}
