protected override Expression VisitBinary(BinaryExpression node)
{
using var mc = log?.Enter(LogLevel.LinqExpression, node);
if (ExpressionTreeHelpers.SupportedComparisons.ContainsKey(node.NodeType))
{
foreach (var prop in TypeProperties)
{
if (ExpressionTreeHelpers.IsMatchingMemberValueExpression(node, typeof(T), prop.Name))
{
object testValue = TranslateValue(prop, ExpressionTreeHelpers.GetValueFromExpression(node, typeof(T), prop.Name));
AddClause($"[{TranslateFieldName(prop)}] {ExpressionTreeHelpers.SupportedComparisons[node.NodeType]} '{testValue}' ");
return(node);
}
}
if (node.Left.NodeType == ExpressionType.Call)
{
object testValue = TranslateValue(null, ExpressionTreeHelpers.GetValueFromExpression(node.Right));
futureComparisons.Push($"{ExpressionTreeHelpers.SupportedComparisons[node.NodeType]} '{testValue}'");
}
return(base.VisitBinary(node));
}
else if (node.NodeType == ExpressionType.OrElse || node.NodeType == ExpressionType.Or)
{
log?.WriteLine(LogLevel.LinqQuery, $"\t[{node.NodeType}]: {node.Left.NodeType} vs. {node.Right.NodeType}");
AddClause("(");
base.Visit(node.Left);
AddClause(" OR ");
base.Visit(node.Right);
AddClause(")");
return(node);
}
else if (node.NodeType == ExpressionType.AndAlso || node.NodeType == ExpressionType.And)
{
log?.WriteLine(LogLevel.LinqQuery, $"\t[{node.NodeType}]: {node.Left.NodeType} vs. {node.Right.NodeType}");
AddClause("(");
base.Visit(node.Left);
AddClause(" AND ");
base.Visit(node.Right);
AddClause(")");
return(node);
}
else
{
log?.WriteLine(LogLevel.LinqQuery, $"ERROR: unsupported comparison: {node.NodeType}");
return(base.VisitBinary(node));
}
}
protected override Expression VisitMethodCall(MethodCallExpression node)
{
string prefix = (futureComparisons.TryPop(out string literalCompare) && literalCompare == "= 'False'") ? "NOT " : "";
using var mc = log?.Enter(LogLevel.LinqExpression, node);
// member.Contains(...) || member.StartsWith(...)
if (node.Method.DeclaringType == typeof(string) && (node.Method.Name == nameof(string.StartsWith) ||
node.Method.Name == nameof(string.Contains)))
{
foreach (var prop in TypeProperties.Where(prop => prop.PropertyType == typeof(string)))
{
if (ExpressionTreeHelpers.IsSpecificMemberExpression(node.Object, typeof(T), prop.Name))
{
object testValue = TranslateValue(prop, ExpressionTreeHelpers.GetValueFromExpression(node.Arguments[0]));
AddClause($"{prefix}[{TranslateFieldName(prop)}] CONTAINS '{testValue}' ");
return(node);
}
}
}
// array.Contains(member) || List<string>.Contains(member)
else if (node.Method.Name == nameof(string.Contains))
{
PropertyInfo propertyInfo = null;
Expression valuesExpression = null;
if (node.Method.DeclaringType == typeof(Enumerable))
{
foreach (var prop in TypeProperties)
{
if (ExpressionTreeHelpers.IsSpecificMemberExpression(node.Arguments[0], typeof(T), prop.Name))
{
propertyInfo = prop;
valuesExpression = node.Arguments[1];
break;
}
else if (ExpressionTreeHelpers.IsSpecificMemberExpression(node.Arguments[1], typeof(T), prop.Name))
{
propertyInfo = prop;
valuesExpression = node.Arguments[0];
break;
}
}
}
else if (node.Method.DeclaringType == typeof(List <string>))
{
foreach (var prop in TypeProperties)
{
if (ExpressionTreeHelpers.IsSpecificMemberExpression(node.Arguments[0], typeof(T), prop.Name))
{
propertyInfo = prop;
valuesExpression = node.Object;
break;
}
if (ExpressionTreeHelpers.IsSpecificMemberExpression(node.Object, typeof(T), prop.Name))
{
propertyInfo = prop;
valuesExpression = node.Arguments[0];
break;
}
}
}
else
{
throw new Exception($"{node.Method.DeclaringType} must be Enumerable or List<string> to use 'Contains'");
}
if (valuesExpression == null || valuesExpression.NodeType != ExpressionType.Constant)
{
throw new Exception($"'Contains' expression must compare to a set of literals - {valuesExpression?.NodeType}");
}
ConstantExpression ce = (ConstantExpression)valuesExpression;
if (ce.Value is string text) // single value
{
AddClause($"{prefix}[{TranslateFieldName(propertyInfo)}] CONTAINS '{ce.Value}' ");
}
else
{
// Add each string in the collection to the list of locations to obtain data about.
var textValues = (IEnumerable <string>)ce.Value;
AddClause($"{prefix}[{TranslateFieldName(propertyInfo)}] IN ({string.Join(',', textValues.Select(s => "'" + s + "'"))}) ");
}
return(node);
}
return(base.VisitMethodCall(node));
}