/// <summary>
/// Convert this ordering node into an OData string representation.
/// </summary>
/// <returns>The OData string</returns>
public static string ToODataString(this OrderByNode node)
{
string field = ODataExpressionVisitor.ToODataString(node.Expression);
string direction = node.Direction == OrderByDirection.Ascending ? "" : " desc";
return($"{field}{direction}");
}
/// <summary>
/// Translates an expression tree of <see cref="QueryNode"/> elements
/// to an OData expression.
/// </summary>
/// <param name="filter">The top <see cref="QueryNode"/> representing the entire expression.</param>
/// <returns>An OData string.</returns>
public static string ToODataString(QueryNode filter)
{
if (filter == null)
{
return(string.Empty);
}
var visitor = new ODataExpressionVisitor();
filter.Accept(visitor);
return(visitor.Expression.ToString());
}
/// <summary>
/// Converts the query structure into a standard OData URI protocol for queries.
/// </summary>
/// <param name="value">The <see cref="QueryDescription"/> to convert to OData.</param>
/// <param name="parameters">A list of optional parameters to include in the query string.</param>
/// <returns>A URI query string representing the query.</returns>
public static string ToODataString(this QueryDescription value, IDictionary <string, string> parameters = null)
{
List <string> queryFragments = new();
if (value.Filter != null)
{
string filterStr = ODataExpressionVisitor.ToODataString(value.Filter);
queryFragments.Add($"{ODataOptions.Filter}={filterStr}");
}
if (value.Ordering.Count > 0)
{
var orderings = value.Ordering.Select(o => o.ToODataString());
queryFragments.Add($"{ODataOptions.OrderBy}={string.Join(",", orderings)}");
}
if (value.Skip.HasValue && value.Skip >= 0)
{
queryFragments.Add($"{ODataOptions.Skip}={value.Skip}");
}
if (value.Top.HasValue && value.Top >= 0)
{
queryFragments.Add($"{ODataOptions.Top}={value.Top}");
}
if (value.Selection.Count > 0)
{
queryFragments.Add($"{ODataOptions.Select}={string.Join(",", value.Selection.Select(Uri.EscapeDataString))}");
}
if (value.IncludeTotalCount)
{
queryFragments.Add($"{ODataOptions.InlineCount}=true");
}
if (parameters?.Count > 0)
{
foreach (var kv in parameters)
{
queryFragments.Add($"{Uri.EscapeDataString(kv.Key)}={Uri.EscapeDataString(kv.Value)}");
}
}
return(string.Join("&", queryFragments));
}
