public static string ToODataString(QueryNode filter)
{
if (filter == null)
{
return(String.Empty);
}
var visitor = new ODataExpressionVisitor();
filter.Accept(visitor);
return(visitor.Expression.ToString());
}
/// <summary>
/// Convert the query structure into the standard OData URI protocol
/// for queries.
/// </summary>
/// <returns>
/// URI fragment representing the query.
/// </returns>
public string ToODataString()
{
char? separator = null;
StringBuilder text = new StringBuilder();
// Add the filter
if (this.Filter != null)
{
string filterStr = ODataExpressionVisitor.ToODataString(this.Filter);
text.AppendFormat(CultureInfo.InvariantCulture, "{0}{1}={2}", separator, ODataOptions.Filter, filterStr);
separator = '&';
}
// Add the ordering
if (this.Ordering.Count > 0)
{
IEnumerable <string> orderings = this.Ordering
.Select(o =>
{
string result = ODataExpressionVisitor.ToODataString(o.Expression);
if (o.Direction == OrderByDirection.Descending)
{
result += " desc";
}
return(result);
});
text.AppendFormat(CultureInfo.InvariantCulture, "{0}{1}={2}", separator, ODataOptions.OrderBy, string.Join(",", orderings));
separator = '&';
}
// Skip any elements
if (this.Skip.HasValue && this.Skip >= 0)
{
text.AppendFormat(CultureInfo.InvariantCulture, "{0}{1}={2}", separator, ODataOptions.Skip, this.Skip);
separator = '&';
}
// Take the desired number of elements
if (this.Top.HasValue && this.Top >= 0)
{
text.AppendFormat(CultureInfo.InvariantCulture, "{0}{1}={2}", separator, ODataOptions.Top, this.Top);
separator = '&';
}
// Add the selection
if (this.Selection.Count > 0)
{
text.AppendFormat(CultureInfo.InvariantCulture, "{0}{1}={2}", separator, ODataOptions.Select, string.Join(",", this.Selection.Select(Uri.EscapeDataString)));
separator = '&';
}
// Add the total count
if (this.IncludeTotalCount)
{
text.AppendFormat(CultureInfo.InvariantCulture, "{0}{1}=allpages", separator, ODataOptions.InlineCount);
separator = '&';
}
return(text.ToString());
}
