protected virtual void EvaluateColumns(DataTable table, ArrayExpression columnsExpression, IDeserializerHandler deserializer)
{
foreach (Expression colExpr in columnsExpression.Items)
{
table.Columns.Add(EvaluateColumn(colExpr, deserializer));
}
}
public void Visit(ArrayExpression list)
{
VisitComplex(list);
foreach (Expression item in list.Items)
Visit(item);
}
public virtual void Visit(ArrayExpression expression)
{
OnArrayStart(expression);
Visit((ComplexExpressionBase)expression);
foreach (Expression item in expression.Items)
item.Accept(this);
OnArrayEnd(expression);
}
/// <summary>
/// Resolve a reference to an item within the collection
/// </summary>
/// <param name="refID">the reference to resolve</param>
/// <returns>the referenced expression</returns>
public void VisitListExpression(ArrayExpression expression)
{
Visit(typeof(ComplexExpressionBase), expression);
if (_expr != null)
return; // found it
int index = _refID.TopAsInt;
if (index < 0 || index >= expression.Items.Count)
{
throw new ArgumentOutOfRangeException("Reference to collection item out of range: " + _refID);
}
Expression expr = expression.Items[index];
Visit(expr);
}
protected virtual void EvaluateRows(DataTable table, ArrayExpression rowsExpression, IDeserializerHandler deserializer)
{
for (int i = 0; i < rowsExpression.Items.Count; i++)
{
ArrayExpression rowExpr = (ArrayExpression) rowsExpression.Items[i];
for (int j = 0; j < rowExpr.Items.Count; j++)
{
rowExpr.Items[j] = new CastExpression(table.Columns[j].DataType, rowExpr.Items[j]);
}
rowExpr.ResultType = typeof(object[]);
DataRow dr = table.NewRow();
dr.ItemArray = (object[]) deserializer.Evaluate(rowExpr);
table.Rows.Add(dr);
}
}
/// <summary>
/// Called on an array expression before the items are visited
/// </summary>
/// <param name="expression"></param>
public virtual void OnArrayStart(ArrayExpression expression)
{
}
/// <summary>
/// Called on an array expression after the items are visited
/// </summary>
/// <param name="expression"></param>
public virtual void OnArrayEnd(ArrayExpression expression)
{
}
protected virtual Expression GetColumnsExpression(DataTable table, JsonPath currentPath, IExpressionBuilder serializer)
{
ArrayExpression columns = new ArrayExpression();
int colCount = 0;
foreach (DataColumn dc in table.Columns)
{
columns.Add(GetColumnExpression(dc, currentPath.Append(colCount), serializer));
colCount++;
}
return columns;
}
protected virtual Expression GetRowsExpression(DataTable table, JsonPath currentPath, IExpressionBuilder serializer)
{
ArrayExpression rowsExpr = new ArrayExpression();
for (int i = 0; i < table.Rows.Count; i++)
{
DataRow row = table.Rows[i];
object[] values = row.ItemArray;
JsonPath rowPath = currentPath.Append(i);
ArrayExpression rowExpr = new ArrayExpression();
for (int j = 0; j < values.Length; j++)
{
rowExpr.Add(serializer.Serialize(values[j], rowPath.Append(j)));
}
rowsExpr.Add(rowExpr);
}
return rowsExpr;
}
/// <summary>
/// Serializes the data into a json array expression.
/// </summary>
/// <param name="data">the data to serialize</param>
/// <param name="currentPath">the current path to the data</param>
/// <param name="serializer">serializer instance to use to serialize list items</param>
/// <returns>a json array expression representation</returns>
public override Expression GetExpression(object data, JsonPath currentPath, IExpressionBuilder serializer)
{
TypeData handler = Config.GetTypeHandler(data.GetType());
CollectionHandler collectionHandler = handler.CollectionHandler;
Type elemType = collectionHandler.GetItemType(handler.ForType);
int index = 0;
ArrayExpression expression = new ArrayExpression();
foreach (object value in collectionHandler.GetEnumerable(data))
{
Expression itemExpr = serializer.Serialize(value, currentPath.Append(index));
if (value != null && !ReflectionUtils.AreEquivalentTypes(value.GetType(), elemType))
{
itemExpr = new CastExpression(value.GetType(), itemExpr);
}
expression.Add(itemExpr);
index++;
}
return expression;
}
/// <summary>
/// Evaluates the items in the expression and assigns them to the collection using the builder
/// </summary>
/// <param name="expression">the expression to evaluate</param>
/// <param name="builder">builder used to build the collection</param>
/// <param name="itemType">the type of the collection's elements</param>
/// <param name="deserializer">deserializer instance to deserialize items</param>
/// <returns>evaluated collection object</returns>
protected virtual object EvaluateItems(ArrayExpression expression, ICollectionBuilder builder, Type itemType, IDeserializerHandler deserializer)
{
object result = null;
bool constructedEventSent = false;
try
{
result = builder.GetReference();
expression.OnObjectConstructed(result);
constructedEventSent = true;
}
catch
{
// this might fail if the builder's not ready
}
foreach (Expression item in expression.Items)
{
item.ResultType = itemType;
object itemResult = deserializer.Evaluate(item);
builder.Add(itemResult);
}
result = builder.GetResult();
if (!constructedEventSent)
expression.OnObjectConstructed(result);
return result;
}
/// <summary>
/// Constructs a builder used to build the deserialized collection
/// </summary>
/// <param name="collection">an existing collection object or null for a new collection</param>
/// <param name="list">the list expression</param>
/// <param name="itemType">the type of the items</param>
/// <returns>collection builder</returns>
protected virtual ICollectionBuilder ConstructBuilder(object collection, ArrayExpression list, out Type itemType)
{
Type listType = collection != null ? collection.GetType() : list.ResultType;
TypeData typeHandler = Config.GetTypeHandler(listType);
CollectionHandler collHandler = typeHandler.CollectionHandler;
itemType = collHandler.GetItemType(listType);
if (itemType == null)
throw new Exception("Null item type returned from " + collHandler.GetType() + " for Collection type: " + listType);
if (collection != null)
return collHandler.ConstructBuilder(collection);
else
return collHandler.ConstructBuilder(listType, list.Items.Count);
}
/// <summary>
/// Parses a javascript array
/// </summary>
/// <returns></returns>
private ArrayExpression ParseCollection()
{
Token tok = ReadToken();
Debug.Assert(tok == LSquareToken);
ArrayExpression value = new ArrayExpression() { LineNumber = tok.linenumber, CharacterPosition = tok.position };
Expression item;
bool first = true;
while (ReadAhead(CommaToken, RSquareToken, new ExpressionMethod(ParseExpression), out item, ref first))
{
value.Add(item);
}
return value;
}