private Expression <Func <TodoListItem, object> > GetSortByExpression(TodoQuery query)
{
var operandString = GetOperandString(query.OrderBy.Value);
if (query.OrderBy.Value == QueryOperand.Important || query.OrderBy.Value == QueryOperand.Done)
{
return((Expression <Func <TodoListItem, object> >)DynamicExpressionParser.ParseLambda(
new[] { _itemParameter },
typeof(object),
$"{operandString}"));
}
else if (query.OrderBy.Value == QueryOperand.DueDate)
{
// bounds tells sorting what to do with null dates
var direction = query.OrderByDirection ?? QueryDirection.Ascending;
var bounds = direction == QueryDirection.Ascending ? DateTime.MaxValue : DateTime.MinValue;
return((Expression <Func <TodoListItem, object> >)DynamicExpressionParser.ParseLambda(
new[] { _itemParameter },
typeof(object),
$"{operandString} ?? @0", bounds));
}
else
{
throw new InvalidOperationException("Invalid operand.");
}
}
private Expression <Func <TodoListItem, bool> > GetWhereExpression(TodoQuery query)
{
var expression = new StringBuilder();
List <object> values = new List <object>(10);
foreach (var predicate in query.Predicates)
{
if (predicate.Group.HasValue && predicate.Group.Value == QueryPredicateGroup.Begin)
{
expression.Append("(");
}
object value = GetPredicateValue(predicate);
expression.Append($"{GetOperandComparisonString(predicate.Operand, value)}");
expression.Append($" {GetOperatorString(predicate.Operator)}");
expression.Append($" @{values.Count}");
values.Add(value);
if (predicate.Group.HasValue && predicate.Group.Value == QueryPredicateGroup.End)
{
expression.Append(")");
}
if (predicate.Keyword.HasValue)
{
expression.Append($" {GetKeywordString(predicate.Keyword.Value)} ");
}
}
return((Expression <Func <TodoListItem, bool> >)DynamicExpressionParser.ParseLambda(
new[] { _itemParameter },
typeof(bool),
expression.ToString(),
values.ToArray()));
}
public UnCompleteTodo() : base("/todos")
{
Put("/{TodoId:Guid}/uncomplete", args =>
{
TodoDataModel todo = TodoQuery.GetTodo(args.TodoId);
todo.Complete = false;
return(HttpStatusCode.OK);
});
}
public RemoveTodo() : base("/todos")
{
Delete("/{TodoId:Guid}", args =>
{
TodoDataModel todo = TodoQuery.GetTodo(args.TodoId);
TodoQuery.RemoveTodo(todo);
return(HttpStatusCode.OK);
});
}
private async Task DeleteQuery(TodoQuery query)
{
// delete last results
var results = await _context.TodoReferences.GetAsync(r => r.TodoQueryId == query.Id);
results.ForEach(r => _context.TodoReferences.Delete(r));
// and query
_context.TodoQueries.Delete(query);
}
public async Task <ActionResult <TodoQuery> > CreateQueryAsync([FromBody] TodoQuery query)
{
// adjust predicate positions to match their positions in collection
PositionAdjuster.AdjustChildren(query.Predicates.ToList <ISortable>());
await _context.TodoQueries.AddAsync(query);
await _context.SaveChangesAsync();
return(CreatedAtRoute("GetQuery", new { id = query.Id }, query));
}
public AddTodo() : base("/todos")
{
Post("/create", args =>
{
var post = this.Bind <CreateModel>();
var nextOrder = TodoQuery.GetNextOrder();
var todo = new TodoDataModel(post.Title, nextOrder);
TodoQuery.AddTodo(todo);
return(HttpStatusCode.OK);
});
}
public async Task <List <TodoItemReference> > ExecuteQueryAsync(TodoQuery query)
{
// get last set of results
var lastResults = await _context.TodoReferences.GetAsync(r => r.TodoQueryId == query.Id, r => r.Item);
// re-execute query (get new list items)
var matchedItems = await InternalExecuteQueryAsync(query);
// re-arrange new results based on existing result positions
var mergedResults = await MergeResultsAsync(query.Id, lastResults, matchedItems);
await _context.SaveChangesAsync();
return(mergedResults);
}
public async Task <ActionResult <TodoQuery> > UpdateQueryAsync(int id, [FromBody] TodoQuery query)
{
var current = await FetchQueryAsync(id);
if (current == null)
{
return(NotFound());
}
// adjust predicate positions to match their positions in collection
PositionAdjuster.AdjustChildren(query.Predicates.ToList <ISortable>());
current.UpdateFrom(query);
_context.TodoQueries.Update(current);
await _context.SaveChangesAsync();
return(current);
}
private RetrievalOptions <TodoListItem> ToRetrievalOptions(TodoQuery query)
{
var options = new RetrievalOptions <TodoListItem>();
if (query.OrderBy.HasValue)
{
options.OrderBy.Predicate = GetSortByExpression(query);
if (!query.OrderByDirection.HasValue)
{
options.OrderBy.Ascending = true;
}
else
{
options.OrderBy.Ascending = query.OrderByDirection.Value == QueryDirection.Ascending;
}
}
options.Where = GetWhereExpression(query);
return(options);
}
public async Task <Result <TodoItem> > GetTodos(TodoQuery query, User user)
{
var result = new Result <TodoItem>();
var q = context.TodoItems.Where(i => i.User == user);
if (query.Limit <= 0)
{
query.Limit = 10;
}
if (query.Offset <= 0)
{
query.Offset = 0;
}
q = q.Skip(query.Offset).Take(query.Limit);
result.data = await q.ToListAsync();
result.TotalItems = await q.CountAsync();
return(result);
}
public GetTodo() : base("/todos")
{
Get("/{TodoId:int}", args => TodoQuery.GetTodo(args.TodoId));
}
public async Task <TodoItem> GetByIdAndUserID(Guid id, string userId) => await _todoDbContext.TodoItems .AsNoTracking() .Where(TodoQuery.GetByIdAndUserId(id, userId)) .FirstOrDefaultAsync();
public GetTodos() : base("/todos")
{
Get("/", args => TodoQuery.GetTodos());
}
public TodoSchema()
{
Query = new TodoQuery();
Mutation = new TodoMutation();
}
private async Task <IList <TodoListItem> > InternalExecuteQueryAsync(TodoQuery query)
{
return(await _context.TodoItems.GetAsync(ToRetrievalOptions(query)));
}
public async Task <ICollection <TodoItem> > GetAll(string userId) => await _todoDbContext.TodoItems.AsNoTracking() .Where(TodoQuery.GetAll(userId)) .OrderBy(x => x.CreateDate) .ToListAsync();
