PullStream.Json

PullStream.Json

PullStream.Json allows to create lazy System.IO.Stream that contains json array of sequence of elements. PullStream.Json uses PullStream, and therefore inherits all aspects of it.

Installation

Install NuGet package using Package Manager

Install-Package PullStream.Json

PullStream.Json uses the Json.Net package and supports a broad range of its versions. So, if it is desired to use a new version of Json.Net package, direct reference to Json.Net should be added.

Install-Package PullStream.Json
Install-Package Json.Net -Version 13.0.1

Usage

using System.Collections.Generic;
using PullStream.Json;

class Person
{
    public string Name { get; }
    public int Age { get; }
}

IEnumerable<Person> persons = ...;
var stream = JsonStream.ArrayOf(persons).Build();

The resulting stream will contain json array of persons with no indentation. If you need an indented output, use factory and configuration:

var stream = JsonStream
    .Using(
        new JsonTextWriterFactory(
            configuration: new Indented(),
            bufferSize: 1024
        )
    )
    .ArrayOf(sequence)
    .Build();

There are different configurations and you can combine them with Configuration.Composite class like this

using System.Globalization;

new JsonTextWriterFactory(
    configuration: new Configuration.Composite(
        new Culture(CultureInfo.GetCultureInfo("en-us")),
        new Indented()
    ),
    bufferSize: 1024
)

A way to create csv stream from IAsyncEnumerable is also presented and is similar.

Caveats

PullStream.Json allows you to control Newtonsoft.Json.JsonWriter creation as well as pass custom Newtonsoft.Json.JsonSerializer instance during stream configuration. This can cause wrong or unexpected output.

Let's see some examples:

var numbers = new[] {1, 2, 3};
var rightStream = JsonStream
    .Using(
        new JsonTextWriterFactory(
            configuration: new Indented(),
            bufferSize: 1024
        )
    )
    .ArrayOf(numbers)
    .Build();
/*
 * Produces nice indented output
 * [
 *   1,
 *   2,
 *   3
 * ]
 */

on the other hand

using Newtonsoft.Json;

var numbers = new[] {1, 2, 3};
var wrongStream = JsonStream
    .Using(
        new JsonTextWriterFactory()
    )
    .ArrayOf(
        numbers,
        JsonSerializer.Create(
            new JsonSerializerSettings
            {
                Formatting = Formatting.Indented
            }
        )
    )
    .Build();
/*
 * Produces partially indented result
 * [
 *   1,
 *   2,
 *   3]
 */

This inconsistency exists because open and close brackets of main array are written directly on JsonWriter, but items of main array are written using JsonSerializer.

The general rule here is to configure JsonSerializer only if particular aspect could not be configured on JsonWriter.