jehugaleahsa/FlatFiles sample codes

1.FlatFiles.FixLength.Reader-Model.cs

/*
  * FlatFiles: https://github.com/jehugaleahsa/FlatFiles
  * Sample code: https://github.com/jehugaleahsa/FlatFiles/issues/63
  */

internal class MyModel
{
   [MaxLength(5)]
   public string Prop1 {get; set;}
   
   [MaxLength(5)]
   public string Prop2 {get; set;}
}

internal class MyFooterModel
{
   [MaxLength(8)]
   public string TotalCnt {get; set;}
}

/* Sample file

XXXXXYYYYY
ZZZZZWWWWW

00000002

/*

2.FlatFiles.FixLength.Reader-Multiple Mapper.cs

/* Read file for multiple mappers */

IList<MyModel> myDatas = null;

var fixedLenOptions = new FixedLengthOptions()
{
    IsFirstRecordHeader = false,
};

#region FixedLengthTypeMapper for Records
Func<string, int> getRecordPropMaxLen = (prop) => typeof(MyModel).GetAttributeValue(prop, (MaxLengthAttribute a) => a.Length);

var recordMapper = FixedLengthTypeMapper.Define<BloTransAuth>();
recordMapper.Property(c => c.Prop1, new Window(getRecordPropMaxLen(nameof(MyModel.Prop1)))).ColumnName(nameof(MyModel.Prop1));
recordMapper.Property(c => c.Prop2, new Window(getRecordPropMaxLen(nameof(MyModel.Prop2)))).ColumnName(nameof(MyModel.Prop2));
#endregion

#region FixedLengthTypeMapper for Footer
Func<string, int> getFooterPropMaxLen = (prop) => typeof(BloTransAuthFooter).GetAttributeValue(prop, (MaxLengthAttribute a) => a.Length);

var footerMapper = FixedLengthTypeMapper.Define<MyFooterModel>();
footerMapper.Property(c => c.TotalCnt, new Window(getFooterPropMaxLen(nameof(MyFooterModel.TotalCnt)))).ColumnName(nameof(MyFooterModel.TotalCnt));
#endregion

int expectedCnt = 0;

#region Read data
using (var streamReader = new StreamReader(file.FullPath))
{
    // transAuths = recordMapper.Read(streamReader, fixedLenOptions).ToList(); // Use this way if all lines are the same length, or it will throw an exception.
    var readerTransAuth = recordMapper.GetReader(streamReader, fixedLenOptions); // fixedLenOptions is optional.
    readerTransAuth.RecordRead += (sender, e) =>
    {
        e.IsSkipped = e.Record.Length != 10;
    };
    transAuths = readerTransAuth.ReadAll().ToList();
}
#endregion

#region Read Trailer
using (var streamReader = new StreamReader(file.FullPath))
{
    var readerFooter = footerMapper.GetReader(streamReader);
    readerFooter.RecordRead += (sender, e) =>
    {
        e.IsSkipped = e.Record.Length != 8;
    };
    var footer = readerFooter.ReadAll().FirstOrDefault();
    _ = int.TryParse(footer?.TotalCnt, out expectedCnt);
}
#endregion

3.FlatFiles.FixLength.Reader-Multiple Mapper.cs

/* Another sample to read file once for multiple mappers */

var selector = new FixedLengthSchemaSelector();
selector.When(values => values.Length == 161).Use(recordMapper.GetSchema());
selector.When(values => values.Length == 9).Use(recordMapper.GetSchema());
selector.WithDefault(recordMapper.GetSchema());

using (var streamReader = new StreamReader(file.FullPath))
{
    var reader = new FixedLengthReader(streamReader, selector, fixedLenOptions);
    while (reader.Read())
    {
        object[] values = reader.GetValues();
    }
}