FileHelpers: mixing Delimited and Fixed Length Records

Question

Here I have to write out a file which records are Pipe Separated, using FileHelpers and C#. Great part of fields have variable length (so, my records would be [DelimitedRecord("|")] ). But some fields must have fixed length (they must have paddings, specific format and so on).

I've googled a bunch with no goal on how to accomplish that.

Example:

[DelimitedRecord("|")]
public class Customer
{
    public int CustId; //variable length

    public string Name; //variable length

    public decimal Balance; //variable length

    [FieldConverter(ConverterKind.Date, "dd-MM-yyyy")]
    public DateTime AddedDate;

    public int Code; // this one must have 10 characters with "zero-fill", like
             // 153 must look like 0000000153

}

How do I accomplish that? Do I have to use a Converter approach and write my own converter for this?

Thank you in advance.

Yeah, I would just write a simple converter. `string s = Code.ToString("D10")` should work, then `Convert.ToInt32(s)` to convert it back. — Dan Bechard, Feb 25 '14 at 14:20
@Dan Thank you for the clue! I'll write a converter which receives some parameters and post as answer here. — cezarlamann, Feb 26 '14 at 14:56

score 6 · Answer 1 · answered Sep 04 '14 at 22:48

For anyone who comes across this question in the future, here is some working code to solve this problem.

This class is a converter which the FileHelper engine will use to convert the integer to a string, padded with 0s up to the size specified in the constructor.

public class PaddedIntConverter:ConverterBase
{
    private int _size;
    public PaddedIntConverter(int size)
    {
        _size = size;
    }

    public override object StringToField(string from)
    {
        return int.Parse(from);
    }

    public override string FieldToString(object from)
    {
        return from.ToString().PadLeft(_size,'0');
    }
}

The converter can then be applied to your class like this:

[FixedLengthRecord(FixedMode.ExactLength)]
public class MyClass{
    [FieldFixedLength(7)]
    [FieldConverter(typeof(PaddedIntConverter), 7)]
    public int RecordCount;
}

score 1 · Answer 2 · answered Feb 25 '14 at 16:32

1

FileHelpers has an attribute [FieldFixedLength(xxx)], I believe this should get you what you are looking for (http://filehelpers.sourceforge.net/attributes.html).

answered Feb 25 '14 at 16:32

TYY

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14

Thank you for answering, but FileHelpers Documentation says: "FieldFixedLength: Indicates the length of the record (only valid when the class have a FixedLengthRecord)", and here I'm working with "DelimitedRecord". Thank you anyway. – cezarlamann Feb 25 '14 at 17:13
2

Alright I found a solution if you are allowed to specify a FieldConverter then you can specify one that does Converts it to the Length you want. This is the example I am referring to http://filehelpers.sourceforge.net/example_customconv.html – TYY Feb 25 '14 at 17:35
Thank you for the clue! I'll write a converter which receives some parameters and post as answer here. – cezarlamann Feb 26 '14 at 15:01

score 0 · Accepted Answer · answered Jun 07 '14 at 18:17

As mentioned by @TYY, I wrote my own "multiuse" converter, just like this:



    public StringNumberCharConverter(
        string Size, 
        string PaddingChar, 
        string PaddingType, 
        string RemoveSpecialChars)
    { 
        //implementation here 
    }

Since FileHelpers converters accept string args only, I had to parse everything on proper objects inside the Converter constructor.

For the parameters, I've converted "Size" to an "integer", PaddingChar onto a "char", PaddingType onto a custom padding type enum (i.e: Padding.LEFT or Padding.RIGHT, so if a "left" is comming from parameters, I should use String.PadLeft() and so on), and the "RemoveSpecialChars" parameter were converted onto a boolean (flag to check if the converter should remove special characters or not.)

Since I need Object-to-File conversion, all the conversion logic is inside "FieldToString" method implementation of ConverterBase abstract method.

FileHelpers: mixing Delimited and Fixed Length Records

3 Answers3