/// <summary>
/// Get an element from a table by its ID.
/// </summary>
/// <param name="id">The ID of the element.</param>
/// <param name="parameters">A dictionary of user-defined parameters and values to include in the request URI query string.</param>
/// <returns>The desired element as JSON object.</returns>
private Task <JsonObject> GetSingleValueAsync(object id, IDictionary <string, string> parameters)
{
// Create a query for just this item
string query = string.Format(
CultureInfo.InvariantCulture,
"$filter={0} eq {1}",
MobileServiceTableUrlBuilder.IdPropertyName,
TypeExtensions.ToODataConstant(id));
return(ReadAsync(query, parameters).ContinueWith(t =>
{
// Get the first element in the response
JsonObject obj = t.Result.AsObject();
if (obj == null)
{
JsonArray array = t.Result.AsArray();
if (array != null && array.Count > 0)
{
obj = array.FirstOrDefault().AsObject();
}
}
if (obj == null)
{
throw new InvalidOperationException(
string.Format(
CultureInfo.InvariantCulture,
Resources.MobileServiceTables_GetSingleValueAsync_NotSingleObject,
(t.Result ?? JsonExtensions.Null()).Stringify()));
}
return obj;
}));
}
/// <summary>
/// Get an element from a table by its ID.
/// </summary>
/// <param name="id">The ID of the element.</param>
/// <returns>The desired element as JSON object.</returns>
private async Task <JObject> GetSingleValueAsync(object id)
{
// Create a query for just this item
string query = string.Format(
CultureInfo.InvariantCulture,
"$filter={0} eq {1}",
IdPropertyName,
TypeExtensions.ToODataConstant(id));
// Send the query
JToken response = await this.ReadAsync(query);
// Get the first element in the response
JObject obj = response.AsObject();
if (obj == null)
{
JArray array = response.AsArray();
if (array != null && array.Count > 0)
{
obj = array.FirstOrDefault().AsObject();
}
}
if (obj == null)
{
throw new InvalidOperationException(
string.Format(
CultureInfo.InvariantCulture,
Resources.MobileServiceTables_GetSingleValueAsync_NotSingleObject,
(response ?? JsonExtensions.Null()).ToString()));
}
return(obj);
}
/// <summary>
/// Process constant values.
/// </summary>
/// <param name="expression">The expression to visit.</param>
/// <returns>The visited expression.</returns>
protected override Expression VisitConstant(ConstantExpression expression)
{
if (expression != null)
{
string value = TypeExtensions.ToODataConstant(expression.Value);
this.filter.Append(value);
this.MarkVisited();
}
return(expression);
}