/// <summary>
/// Called when the dialog is started and pushed onto the dialog stack.
/// </summary>
/// <param name="dc">The <see cref="DialogContext"/> for the current turn of conversation.</param>
/// <param name="options">Optional, initial information to pass to the dialog.</param>
/// <param name="cancellationToken">A cancellation token that can be used by other objects
/// or threads to receive notice of cancellation.</param>
/// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
public override async Task <DialogTurnResult> BeginDialogAsync(DialogContext dc, object options = null, CancellationToken cancellationToken = default(CancellationToken))
{
if (options is CancellationToken)
{
throw new ArgumentException($"{nameof(options)} cannot be a cancellation token");
}
if (this.Disabled != null && this.Disabled.GetValue(dc.State) == true)
{
return(await dc.EndDialogAsync(cancellationToken : cancellationToken).ConfigureAwait(false));
}
lock (this.Condition)
{
if (this.caseExpressions == null)
{
this.caseExpressions = new Dictionary <string, Expression>();
foreach (var @case in this.Cases)
{
if (long.TryParse(@case.Value, out long intVal))
{
// you don't have to put quotes around numbers, "23" => 23 OR "23"
this.caseExpressions[@case.Value] = Expression.OrExpression(
Expression.EqualsExpression(this.Condition, Expression.ConstantExpression(intVal)),
Expression.EqualsExpression(this.Condition, Expression.ConstantExpression(@case.Value)));
}
else if (float.TryParse(@case.Value, out float floatVal))
{
// you don't have to put quotes around numbers, "23" => 23 OR "23"
this.caseExpressions[@case.Value] = Expression.OrExpression(
Expression.EqualsExpression(this.Condition, Expression.ConstantExpression(floatVal)),
Expression.EqualsExpression(this.Condition, Expression.ConstantExpression(@case.Value)));
}
else if (bool.TryParse(@case.Value, out bool boolVal))
{
// you don't have to put quotes around bools, "true" => true OR "true"
this.caseExpressions[@case.Value] = Expression.OrExpression(
Expression.EqualsExpression(this.Condition, Expression.ConstantExpression(boolVal)),
Expression.EqualsExpression(this.Condition, Expression.ConstantExpression(@case.Value)));
}
else
{
// if someone does "=23" that will be numeric comparison or "='23'" that will be string comparison, or it can be a
// real expression bound to memory.
var(value, _) = new ValueExpression(@case.Value).TryGetValue(dc.State);
this.caseExpressions[@case.Value] = Expression.EqualsExpression(this.Condition, Expression.ConstantExpression(value));
}
}
}
}
ActionScope actionScope = this.DefaultScope;
foreach (var caseScope in this.Cases)
{
var(value, error) = this.caseExpressions[caseScope.Value].TryEvaluate(dc.State);
// Compare both expression results. The current switch case triggers if the comparison is true.
if (value != null && ((bool)value) == true)
{
actionScope = caseScope;
break;
}
}
return(await dc.ReplaceDialogAsync(actionScope.Id, null, cancellationToken : cancellationToken).ConfigureAwait(false));
}
public override async Task <DialogTurnResult> BeginDialogAsync(DialogContext dc, object options = null, CancellationToken cancellationToken = default(CancellationToken))
{
if (options is CancellationToken)
{
throw new ArgumentException($"{nameof(options)} cannot be a cancellation token");
}
var dcState = dc.GetState();
if (this.Disabled != null && this.Disabled.GetValue(dcState) == true)
{
return(await dc.EndDialogAsync(cancellationToken : cancellationToken).ConfigureAwait(false));
}
lock (this.Condition)
{
if (this.caseExpressions == null)
{
this.caseExpressions = new Dictionary <string, Expression>();
foreach (var cse in this.Cases)
{
Expression caseExpression = null;
// Values for cases are always coerced to constant
if (long.TryParse(cse.Value, out long i))
{
caseExpression = Expression.ConstantExpression(i);
}
else if (float.TryParse(cse.Value, out float f))
{
caseExpression = Expression.ConstantExpression(f);
}
else if (bool.TryParse(cse.Value, out bool b))
{
caseExpression = Expression.ConstantExpression(b);
}
else
{
caseExpression = Expression.ConstantExpression(cse.Value);
}
var caseCondition = Expression.EqualsExpression(this.Condition, caseExpression);
// Map of expression to actions
this.caseExpressions[cse.Value] = caseCondition;
}
}
}
ActionScope actionScope = this.DefaultScope;
foreach (var caseScope in this.Cases)
{
var(value, error) = this.caseExpressions[caseScope.Value].TryEvaluate(dcState);
if (error != null)
{
throw new Exception($"Expression evaluation resulted in an error. Expression: {caseExpressions[caseScope.Value].ToString()}. Error: {error}");
}
// Compare both expression results. The current switch case triggers if the comparison is true.
if (((bool)value) == true)
{
actionScope = caseScope;
break;
}
}
return(await dc.ReplaceDialogAsync(actionScope.Id, null, cancellationToken : cancellationToken).ConfigureAwait(false));
}