protected override TQuery GetQuery(Expression expression)
{
Trace(expression, "Expression");
// here we inject a special expression parser that fixes a few issues slated to be resolved in later releases of SC7
IndexQuery rawQuery = new ExpressionParserWithSpatial(typeof(TElement), ItemType, FieldNameTranslator).Parse(expression);
Trace(rawQuery, "Raw query:");
IndexQuery optimizedQuery = QueryOptimizer.Optimize(rawQuery);
Trace(optimizedQuery, "Optimized query:");
TQuery mappedQuery = QueryMapper.MapQuery(optimizedQuery);
return(mappedQuery);
}
public static async Task <ChangesFeedResponse <TSource> > QueryWithFilterAsync <TSource>(this IFlurlRequest request, CouchOptions options, ChangesFeedFilter filter,
CancellationToken cancellationToken)
where TSource : CouchDocument
{
if (filter is DocumentIdsChangesFeedFilter documentIdsFilter)
{
return(await request
.SetQueryParam("filter", "_doc_ids")
.PostJsonAsync(new ChangesFeedFilterDocuments(documentIdsFilter.Value), cancellationToken)
.ReceiveJson <ChangesFeedResponse <TSource> >()
.ConfigureAwait(false));
}
if (filter is SelectorChangesFeedFilter <TSource> selectorFilter)
{
MethodCallExpression whereExpression = Expression.Call(typeof(Queryable), nameof(Queryable.Where),
new[] { typeof(TSource) }, Expression.Constant(Array.Empty <TSource>().AsQueryable()), selectorFilter.Value);
var optimizer = new QueryOptimizer();
Expression optimizedQuery = optimizer.Optimize(whereExpression);
var jsonSelector = new QueryTranslator(options).Translate(optimizedQuery);
return(await request
.WithHeader("Content-Type", "application/json")
.SetQueryParam("filter", "_selector")
.PostStringAsync(jsonSelector, cancellationToken)
.ReceiveJson <ChangesFeedResponse <TSource> >()
.ConfigureAwait(false));
}
if (filter is DesignChangesFeedFilter)
{
return(await request
.SetQueryParam("filter", "_design")
.GetJsonAsync <ChangesFeedResponse <TSource> >(cancellationToken)
.ConfigureAwait(false));
}
if (filter is ViewChangesFeedFilter viewFilter)
{
return(await request
.SetQueryParam("filter", "_view")
.SetQueryParam("view", viewFilter.Value)
.GetJsonAsync <ChangesFeedResponse <TSource> >(cancellationToken)
.ConfigureAwait(false));
}
throw new InvalidOperationException($"Filter of type {filter.GetType().Name} not supported.");
}