CSV to JSON with dynamic objects name fields

Question

I have a number of CSV files which I desire to translate to JSON files using Cinchoo. I'll need to rename the fields (and convert them into the desired data type). I'm having trouble renaming the fields.

Dummy input file:

VE NUMMER;VE NAAM;EFFECTDATUM;EINDDATUM
123;abc;20221001;
124;def;20221001;
125;ter;20221001;
126;ddf;20221001;

Expected Output:

[
{
    "Id": 123,
    "Name": "abc",
    "Date": "20221001"
},
{
    "Id": 124,
    "Name": "def",
    "Date": "20221001"
}, ...
]

I've tried

Using the BeforeRecordWrite event, but this is throwing errors when renaming the property
Using a custom ContractResolver but this seems to be ignored
Using a custom JsonConverter but this seems to be ignored

using ChoETL;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using System.Reflection;

internal class Program
{
    private static void Main(string[] args)
    {
        QuickConversion();

    }

    private static void QuickConversion()
    {
        using var r = new ChoCSVReader("./Data./DummyFile.CSV")
               .WithFirstLineHeader()
               .WithDelimiter(";")
               .WithEOLDelimiter("\r\n")
               .MayHaveQuotedFields();

        using var w = new ChoJSONWriter(Console.Out)
           //.JsonSerializationSettings(settings =>
           //{
           //    settings.NullValueHandling = NullValueHandling.Ignore;
           //    settings.Formatting = Formatting.Indented;
           //    settings.MaxDepth = 2;
           //    settings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
           //    settings.ContractResolver = new CustomContractResolver("VE NUMMER", "ID");
           //})
           .WithJSONConverter(new CustomConverter())
        .UseJsonSerialization();

        w.Write(r);
    }
}

public class CustomConverter : JsonConverter
{
    public override bool CanConvert(Type objectType) => true;
    public override object? ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer) => throw new NotImplementedException();
    public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
    {
        serializer.ContractResolver = new CustomContractResolver("VE NUMMER", "ID");
    }
}
public class CustomContractResolver : DefaultContractResolver
{
    public string SourcePropertyName { get; set; }
    public string TargetPropertyName { get; set; }
    public CustomContractResolver(string sourcePropertyName, string targetPropertyName)
    {
        SourcePropertyName = sourcePropertyName;
        TargetPropertyName = targetPropertyName;
    }

    protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
    {
        var property = base.CreateProperty(member, memberSerialization);
        Console.WriteLine(property.PropertyName);

        if (property.PropertyName == SourcePropertyName)
        {
            property.PropertyName = TargetPropertyName;
        }
        return property;
    }
}

score 2 · Accepted Answer · answered Feb 13 '23 at 11:21

2

Maybe it is possible to specify the fields already during import:

using var r = new ChoCSVReader("./Data./DummyFile.CSV")
        .WithFields("Id", "Name", "Date")
        .WithFirstLineHeader(true)
        .WithDelimiter(";")
        .WithEOLDelimiter("\r\n")
        .MayHaveQuotedFields();

Then you do not need a CustomConverter

answered Feb 13 '23 at 11:21

PinBack

2,499
12
16

I unfortunately can't change the name of the input fields. They are provided by a 3rd party with their respective field names. Using with Fields (or withField) requires to match with the source from my understanding of it. – Reinard Feb 13 '23 at 13:10
You can use this method if you know the order of the columns. `.WithFirstLineHeader(true)` ignore the header and `.WithFields("Id", "Name", "Date")` means, that the first column will read as "Id" and so on. You do not need to change the file – PinBack Feb 13 '23 at 13:22
works like a charm with ```.WithFirstLineHeader(true).WithFields(new string[] { "Id", "Name" })``` – Reinard Feb 13 '23 at 14:02

CSV to JSON with dynamic objects name fields

1 Answers1