Exporting recorded output of a Live display can give empty results.

[bmic86]

Hello everyone 👋. I was exploring this awesome library and started to improve my personal CLI tools with it, but unfortunately I have found an issue, which I wanted to share.

Information

• OS: Windows
• Version: 0.49.1
• Terminal: Windows Terminal

Describe the bug
I have observed that live display of a table is not always properly recorded. For relatively small tables, when I call AnsiConsole.ExportText() after recording, it returns an empty string. However for large tables, it returns string with the full table output (as expected).

To Reproduce
Example C# program to simulate issue:

using Spectre.Console;

AnsiConsole.Record();

var table = new Table().Centered();

AnsiConsole
    .Live(table)
    .AutoClear(false)
    .Start(ctx =>
    {
        table.AddColumn("Foo");
        table.AddColumn("Bar");

        for (int i = 0; i < 5; i++)
        {
            table.AddRow($"Foo {i}", $"Bar {i}");
        }
    });


var text = AnsiConsole.ExportText();
Console.WriteLine(text);

Expected behavior
In the example the value of a text is empty, but should contain an exported table output (the expected result of the whole example program is to print the same table twice). When I increase number of rows to for ex. 50 or 100, it produces the expected result.

Additional context
I want to be able to save my program live outputs into a file. Piping live outputs from shell is not possible/supported, and it throws System.IO.IOException (as described in this issue comment: #1393 (comment)), so the only reasonable way to do it seems to be: record, export and save into a file.

Possible fix/workaround
I have looked into the source code and found that method LiveDisplayRenderer.Completed(bool autoclear) forces to redraw when overflow occurs, which causes, the output to be correctly recorded and exported for larger tables.
As a workaround solution I have created small fix that turn this redraw behavior on, every time when recorder has been registered. You can see it on my fork: main...bmic86:spectre.console:fix/recording_on_live

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Please upvote 👍 this issue if you are interested in it.

[FrankRay78]

Hello @bmic86, see this closely related issue: #1733

[patriksvensson]

@FrankRay78 No, this is not related.

[FrankRay78]

I want to be able to save my program live outputs into a file. Piping live outputs from shell is not possible/supported, and it throws System.IO.IOException

@patriksvensson I thought they were related because if I could get the TestConsole injected into the Live call somehow (which I have just done with your guidance, see: #1733), then @bmic86 could avoid the IOException and be able to inspect the TestConsole output instead.

Perhaps not directly related, but more like an alternative approach / workaround to using AnsiConsole Recording. Although I'm happy to be corrected.

[bmic86]

Hi. Thank you for your reply.

I came back to this topic after a while and tried the TestConsole for live outputs, so I might use it as a workaround. However, it still will be useful to have a working recording in cases when the exported content has to be also live displayed on a terminal (I don't think TestConsole can do that).

I have created PR with the fix, so you can decide if you want it to be merged.

Thank you.

[patriksvensson]

There can't be any guarantees about live recording (animations) and text output I'm afraid.