CustomACHFormula.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using PX.Data;
using PX.DataSync;
using PX.DataSync.ACH;
using PX.Api;

namespace PX.DataSync
{
    public class MyACHProvider : ACHProvider, IPXSYProvider
    {
        public override string ProviderName
        {
          get
          {
            return PX.Data.PXMessages.Localize("My ACH Provider");
          }
        }

        protected override void InitialiseProxy(byte[] data)
        {
            InitialiseMySchemaFile();
        }
        protected override void InitialiseSchema()
        {
            InitialiseMySchemaFile();
        }

        protected void InitialiseMySchemaFile()
        {
            this.schemaFile = GetFile(GetParameter(SCHEMA_PARAMETER));
            if (schemaFile == null) throw new PXException(Messages.FileNotFound, GetParameter(SCHEMA_PARAMETER));

            MySchemaBuilder builder = new MySchemaBuilder(new MemoryStream(schemaFile.BinData, false), GetEncoding());
            schema = builder.ParceSchema();
        }
    }

    public class MySchemaBuilder : SchemaBuilder
    {
        public MySchemaBuilder(Stream stream, Encoding encoding)
            : base(stream, encoding)
        {
            fieldBuilder = new MyFieldBuilder();
        }
    }

    public class MyFieldBuilder : PX.DataSync.ACH.FieldBuilder
    {
        #region Constants
        public const String TOTAL_COUNT_TWO_BASED_FLAG = "TotalCountPlusTwo";
        #endregion

        protected override FieldInfo CreateField(String fieldName, String[] settings)
        {
            if (fieldName.StartsWith(FORMULA_SEPARATOR.ToString()))
            {
                String s = fieldName.TrimStart(FORMULA_SEPARATOR);
                if (s == TOTAL_COUNT_TWO_BASED_FLAG) return CreateTotalCountTwoBasedRegistrator(fieldName);
            }

            return base.CreateField(fieldName, settings);
        }

        protected virtual TotalCountTwoBasedField CreateTotalCountTwoBasedRegistrator(String name)
        {
            TotalCountTwoBasedField field = new TotalCountTwoBasedField(name);
            return field;
        }
    }

    #region FieldInfo
    public class TotalCountTwoBasedField : SurogateField, IResetableField
    {
        private Int32 _count;

        public TotalCountTwoBasedField(String name)
            : base(name)
        {
            FillOnEnd = true;
        }

        public virtual void Reset()
        {
            _count = default(Int32);
        }

        public override string GetValue(FillContext context, InstanceInfo instance, IEnumerable<String> values)
        {
            _count++;
            return (_count + 2).ToString(System.Globalization.CultureInfo.InvariantCulture);
        }
    }
    #endregion

}