/// <summary>
/// Try get value from a given path.
/// </summary>
/// <param name="path">Given path.</param>
/// <param name="value">Resolved value.</param>
/// <returns>True if the memory contains an element with the specified key; otherwise, false.</returns>
public bool TryGetValue(string path, out object value)
{
value = null;
if (memory == null || path.Length == 0)
{
return(false);
}
var parts = path.Split(".[]".ToCharArray(), StringSplitOptions.RemoveEmptyEntries)
.Select(x => x.Trim('\'', '"'))
.ToArray();
var curScope = memory;
foreach (var part in parts)
{
string error = null;
if (int.TryParse(part, out var idx) && ExpressionFunctions.TryParseList(curScope, out var li))
{
(value, error) = ExpressionFunctions.AccessIndex(li, idx);
if (error != null)
{
return(false);
}
}
else
{
if (!ExpressionFunctions.TryAccessProperty(curScope, part, out value))
{
return(false);
}
}
curScope = value;
}
if (value is IExpressionProperty ep)
{
value = ep.GetObject(memory);
}
return(true);
}
// In this simple object scope, we don't allow you to set a path in which some parts in middle don't exist
// for example
// if you set dialog.a.b = x, but dialog.a don't exist, this will result in an error
// because we can't and shouldn't smart create structure in the middle
// you can implement a customized Scope that support such behavior
/// <summary>
/// Set value to a given path.
/// </summary>
/// <param name="path">Memory path.</param>
/// <param name="value">Value to set.</param>
public void SetValue(string path, object value)
{
if (memory == null)
{
return;
}
var parts = path.Split(".[]".ToCharArray(), StringSplitOptions.RemoveEmptyEntries)
.Select(x => x.Trim('\'', '"'))
.ToArray();
var curScope = memory;
var curPath = string.Empty; // valid path so far
string error = null;
// find the 2nd last value, the container
for (var i = 0; i < parts.Length - 1; i++)
{
if (int.TryParse(parts[i], out var index) && ExpressionFunctions.TryParseList(curScope, out var li))
{
curPath += $"[{parts[i]}]";
(curScope, error) = ExpressionFunctions.AccessIndex(li, index);
}
else
{
curPath += $".{parts[i]}";
if (ExpressionFunctions.TryAccessProperty(curScope, parts[i], out var newScope))
{
curScope = newScope;
}
else
{
return;
}
}
if (error != null || curScope == null)
{
return;
}
}
// set the last value
if (int.TryParse(parts.Last(), out var idx))
{
if (ExpressionFunctions.TryParseList(curScope, out var li))
{
if (li is JArray)
{
value = JToken.FromObject(value);
}
if (idx > li.Count)
{
error = $"{idx} index out of range";
}
else if (idx == li.Count)
{
// expand for one
li.Add(value);
}
else
{
li[idx] = value;
}
}
else
{
error = $"set value for an index to a non-list object";
}
if (error != null)
{
return;
}
}
else
{
(_, error) = ExpressionFunctions.SetProperty(curScope, parts.Last(), value);
if (error != null)
{
return;
}
}
// Update the version once memory has been updated
version++;
}
