CODEWITHSUNDEEP
.net-corerule-engine
Mar Chal
Mar Chal

Reputation: 303

Validate the expression in Microsoft RulesEngine

I have been using the Microsoft RulesEngine nuget package in my .NET Core-based project. I wonder if there is a way to validate the format of the expression before running RulesEngine.Execute. According to the README file, the expression is a lambda expression. Also, there is a schema definition that can be used to validate the schema of the root object (WorkflowRules) but that wouldn't validate the expressions used under the Rules. enter image description here

Upvotes: 3

Views: 1642

Answers (1)

Mar Chal
Mar Chal

Reputation: 303

I found a way to make sure the expression is valid. In the below code, if an exception occurs, it means the expression has an invalid format:

    using System.Linq.Dynamic.Core;
    using System.Linq.Expressions;
    ...
    private bool Evaluate<TParameterType>(TParameterType fact, string rule)
    {
        var parameter = Expression.Parameter(typeof(TParameterType));
        try
        {
            var lambdaExpression = DynamicExpressionParser.ParseLambda(new[] { parameter }, null, rule);
            return (bool) lambdaExpression.Compile().DynamicInvoke(fact);
        }
        catch
        {
            return false;
        }
    }

Upvotes: 3

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