FileFlowsPlugins/BasicNodes/Functions/Function.cs

namespace FileFlows.BasicNodes.Functions
{
    using System.ComponentModel;
    using FileFlows.Plugin;
    using FileFlows.Plugin.Attributes;
    using Jint.Runtime;
    using Jint.Native.Object;
    using Jint;
    using System.Text;
    using System.ComponentModel.DataAnnotations;

    public class Function : Node
    {
        public override int Inputs => 1;
        public override FlowElementType Type => FlowElementType.Logic;
        public override string Icon => "fas fa-code";

        [DefaultValue(1)]
        [NumberInt(1)]
        public new int Outputs { get; set; }

        [Required]
        [DefaultValue("// Variables contain variables available to this node from previous nodes.\n// Logger lets you log messages to the flow output.\n\n// return 0 to complete the flow.\n// return -1 to signal an error in the flow\n// return 1+ to select which output node will be processed next\n\nif(Variables.FileSize === 0)\n\treturn -1;\n\nreturn 0;")]
        [Code(2)]
        public string Code { get; set; }

        delegate void LogDelegate(params object[] values);
        public override int Execute(NodeParameters args)
        {
            if (string.IsNullOrEmpty(Code))
                return -1; // no code, flow cannot continue doesnt know what to do

            args.Logger.DLog("Code: ", Environment.NewLine + new string('=', 40) + Environment.NewLine + Code + Environment.NewLine + new string('=', 40));


            long fileSize = 0;
            var fileInfo = new FileInfo(args.WorkingFile);
            if(fileInfo.Exists)
                fileSize = fileInfo.Length;

            var sb = new StringBuilder();
            var log = new
            {
                ILog = new LogDelegate(args.Logger.ILog),
                DLog = new LogDelegate(args.Logger.DLog),
                WLog = new LogDelegate(args.Logger.WLog),
                ELog = new LogDelegate(args.Logger.ELog),
            };
            var engine = new Engine(options =>
            {
                options.LimitMemory(4_000_000);
                options.MaxStatements(100);
            })
            .SetValue("Logger", args.Logger)
            .SetValue("Variables", args.Variables);

            try
            {
                var result = int.Parse(engine.Evaluate(Code).ToObject().ToString());
                return result;
            }
            catch (Exception ex)
            {
                args.Logger.ELog("Failed executing function: " + ex.Message);
                return -1;
            }
        }
    }
}