Printing strings with new lines

[sumiya-kuroda]

Hi,

I have a List<string> that I want to print each element, separated by new lines. However, at the moment it prints with just a space, not a new line. This is a screenshot of my visualizer:

And this is a screenshot of my workflow:

And this is what is going on inside my custom C# script ListToMultilineString:

using Bonsai;
using System;
using System.ComponentModel;
using System.Collections.Generic;
using System.Reactive.Linq;

[Combinator]
[Description("Converts a List<string> into a single string with each element separated by a new line.")]
[WorkflowElementCategory(ElementCategory.Transform)]
public class ListToMultilineString
{
    public IObservable<string> Process(IObservable<List<string>> source)
    {
        return source.Select(list =>
            list == null ? string.Empty : string.Join(Environment.NewLine, list));
    }
}

Does anyone know what still needs to be done?

[sumiya-kuroda]

This is my workflow,
Visualizer.zip

[bruno-f-cruz]

What you are observing is indeed the behavior of the text visualizer. At rendering time, any \n are stripped from the incoming string and shown on the console. This behavior ensures that new lines are reserved for new notifications.

[sumiya-kuroda]

I see. Thank you very much! @bruno-f-cruz What is then a Bonsai-friendly way to achieve what I want in this case? Should I use Loop to go through each element?

[bruno-f-cruz]

The easiest way is to add a "Merge" after a List. This will "flatten" the list and emit each value inside as a separate element.

[sumiya-kuroda]

Neat! Unfortunately, this separated them too much to chars not strings.

[bruno-f-cruz]

<?xml version="1.0" encoding="utf-8"?>
<WorkflowBuilder Version="2.9.0"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xmlns:rx="clr-namespace:Bonsai.Reactive;assembly=Bonsai.Core"
                 xmlns="https://bonsai-rx.org/2018/workflow">
  <Workflow>
    <Nodes>
      <Expression xsi:type="Combinator">
        <Combinator xsi:type="rx:Range">
          <rx:Start>20</rx:Start>
          <rx:Count>20</rx:Count>
        </Combinator>
      </Expression>
      <Expression xsi:type="Format" />
      <Expression xsi:type="Combinator">
        <Combinator xsi:type="rx:Take">
          <rx:Count>10</rx:Count>
        </Combinator>
      </Expression>
      <Expression xsi:type="Combinator">
        <Combinator xsi:type="rx:ToList" />
      </Expression>
      <Expression xsi:type="Combinator">
        <Combinator xsi:type="rx:Merge" />
      </Expression>
    </Nodes>
    <Edges>
      <Edge From="0" To="1" Label="Source1" />
      <Edge From="1" To="2" Label="Source1" />
      <Edge From="2" To="3" Label="Source1" />
      <Edge From="3" To="4" Label="Source1" />
    </Edges>
  </Workflow>
</WorkflowBuilder>

Are you sure you have a List<string> and not string? Both are enumerables, so Merge will flatten them regardless (List<T> -> T and string -> char, respectively)

[sumiya-kuroda]

Oh that is true! My bad. Yes Merge beautifully separated the List to each element. Thank you very much!!

[sumiya-kuroda]