public static bool Evaluate(string questionCode, string displayLogic, string response)
{
var isInverse = displayLogic.Contains("!=");
displayLogic = displayLogic.Replace(questionCode, "a");
if (isInverse)
{
displayLogic = displayLogic.Replace("!=", "==");
}
var expression = new DynamicExpression(displayLogic, ExpressionLanguage.Csharp);
var context = new ExpressionContext();
context.Variables.Add("a", response);
var result = (bool)expression.Invoke(context);
return isInverse ? !result : result;
}
public object Invoke(IExecutionContext executionContext)
{
if (executionContext == null)
executionContext = new ExpressionContext();
var parameters = new object[_parameterMap.Length];
bool ignoreCase = !DynamicExpression.IsLanguageCaseSensitive(_dynamicExpression.Language);
var identifiers = _dynamicExpression.ParseResult.Identifiers;
for (int i = 0; i < parameters.Length; i++)
{
int index = _parameterMap[i];
if (index == -1)
{
parameters[i] = executionContext.Owner;
}
else
{
parameters[i] = executionContext.GetVariableValue(
identifiers[index].Name, ignoreCase
);
}
}
return _compiledMethod(parameters);
}
/// <summary>
/// Invokes the expression with the specified expression context and
/// binding options.
/// </summary>
/// <param name="expressionContext">The expression context used to
/// bind and execute the expression.</param>
/// <param name="options">The options used to bind the expression.</param>
/// <returns>The result of the expression.</returns>
public object Invoke(IExpressionContext expressionContext, BoundExpressionOptions options)
{
if (expressionContext == null)
expressionContext = new ExpressionContext();
return Bind(expressionContext, options).Invoke(expressionContext);
}
/// <summary>
/// Binds the compiled expression with the specified binding context and options.
/// </summary>
/// <param name="binder">The binding context used to bind the expression.</param>
/// <param name="options">The options used to bind the expression.</param>
/// <returns>The bound expression.</returns>
public IBoundExpression Bind(IBindingContext binder, BoundExpressionOptions options)
{
if (binder == null)
binder = new ExpressionContext();
if (options == null)
options = new BoundExpressionOptions();
options.Freeze();
return Cached.GetOrCreateBoundExpression(binder, options);
}
public object Invoke(IExecutionContext executionContext)
{
bool hadExecutionContext = executionContext != null;
if (executionContext == null)
executionContext = new ExpressionContext();
var parameters = new object[_parameterMap.Length];
bool ignoreCase = !DynamicExpression.IsLanguageCaseSensitive(_dynamicExpression.Language);
var identifiers = _dynamicExpression.ParseResult.Identifiers;
for (int i = 0; i < parameters.Length; i++)
{
int index = _parameterMap[i];
if (index == -1)
{
if (!hadExecutionContext)
{
throw new ExpressionsException(
"An owner was expected but no execution context has been provided",
ExpressionsExceptionType.InvalidOperation
);
}
parameters[i] = executionContext.Owner;
}
else
{
parameters[i] = executionContext.GetVariableValue(
identifiers[index].Name, ignoreCase
);
}
}
return _compiledMethod(parameters);
}
