Dump

Use the powerful Dump() method to visualize almost any object in the results console.

Usage

Use the .Dump() extension method on pretty much any object or value.

"some text".Dump();
new MyClass().Dump();
new List<MyClass> { new MyClass() }.Dump();

// Dump returns the object/value being dumped
var personsOver30 = Persons.Where(p => p.Age > 30).Dump();

// Dump is chainable
var names = Persons
  .Where(p => p.Age > 30)
  .Dump()
  .Select(p => p.Name);

Parameters

The Dump() method has the following optional parameters.

title: shows a title text above the output.

Persons.Where(p => p.Age > 30).Dump("Persons above the age of 30");

css: CSS class(es) to add to the output. You can use any Bootstrap v5 classes.

Logs.Where(l => l.Level == "WRN").Dump(css: "card text-bg-warning w-25");

You can also define your own CSS classes in Settings > Styles and use them here!

clear: removes the output after the specified milliseconds.

while (true)
{
    Stocks.First(s => s.Name == "AAPL").Dump(clear: 2000);
    await Task.Delay(2010);
}

code: syntax-highlight an output string using the specified language code.

"""
<root>
  <list>
    <item>Airplane</item>
    <item>Broom</item>
    <item>Carpet</item>
  </list>
</parent>
""".Dump(code: "xml");

This is powered by the excellent highlight.js library which supports an exhaustive list of languages. You can also just use auto which will auto-detect the language.

Media Files

To dump media files, use the built-in Image, Audio and Video types from the NetPad.Media namespace.

new Image("/path/to/image/png").Dump();
Image.FromPath("/path/to/image.png").Dump();
Image.FromUri(new Uri("https://web.com/image.png")).Dump();
Image.FromBase64("data:image/png;base64,/9j/4AAQSkZJRgABAQAA...").Dump();
Image.FromBytes(File.ReadAllBytes("/path/to/image.png"), "image/png").Dump();

// Same thing for Audio and Video classes
Audio.FromPath(...).Dump();
Video.FromPath(...).Dump();
...

Note: using the FromBytes method will internally convert the source to a Base64 string and is provided as a convenience method.

Sizing

Media files will be rendered in their original size, but you can specify size using the DisplayWidth and DisplayHeight properties:

new Image("/path/to/img.png")
{
    DisplayWidth = "128px",
    DisplayHeight = "128px"
}.Dump();

Or using extension methods:

// Individually
Image.FromPath("/path/to/img.png")
  .WithDisplayWidth("100%");
  .WithDisplayHeight("400px");

// Together
Image.FromPath(imageFile).WithDisplaySize("100%", "400px");

Methods

These types inherit from the MediaFile base class which has these methods:

var image = Image.FromPath("/path/to/image.png");

// Opens the file with the default application and immediately returns.
image.Open();

// Opens the file with the default application and waits for it to exit.
image.OpenAndWait();

HTML

Support is still experimental

You can dump HTML and create your own interactive views.

TextNode.RawText("<h1>Heading 1</h1>").Dump();

You need to add the following namepsaces to your script:

O2Html
O2Html.Dom

More documentation and examples will be added soon. Advanced scenarios like JS interop and Blazor support are planned.

Examples

Dump raw HTML:

TextNode.RawText("""
<div class="card" style="width: 300px" id="myCard">
  <img src="https://raw.githubusercontent.com/dotnet/brand/main/logo/dotnet-logo.svg" class="card-img-top">
  <div class="card-body">
    <h4 class="card-title text-dark">Got .NET?</h5>
    <h5 class="card-title placeholder-glow">
      <span class="placeholder col-6"></span>
    </h5>
    <p class="card-text placeholder-glow">
      <span class="placeholder col-7"></span>
      <span class="placeholder col-4"></span>
      <span class="placeholder col-4"></span>
      <span class="placeholder col-6"></span>
      <span class="placeholder col-8"></span>
    </p>
    <a class="btn btn-warning col-6" href="https://dotnet.microsoft.com/en-us/download" target="_blank">Download Now!</a>
  </div>
</div>
""").Dump();

TextNode.RawText("""
<script>
  (function() {
      setTimeout(() => document.querySelector("#myCard a.btn-warning").classList.replace("btn-warning", "btn-primary"), 2000);
  })();
</script>
""").Dump();

Use a fluent API to construct and dump an Element:

new Element("div").AddClass("badge bg-info").AddText("Hello World!").Dump();

Build an interactive form:

var form = new Element("form")
    .SetAttribute("type", "submit")
    .SetAttribute("onsubmit", "return false;")
    .SetAttribute("style", "max-width: 300px; padding: 1rem; border: 2px solid grey; border-radius: 3px");

form.AddAndGetElement("label")
    .AddClass("form-label")
    .SetAttribute("for", "firstName")
    .AddText("First Name");

form.AddAndGetElement("input")
    .SetId("firstName")
    .AddClass("form-control")
    .SetAttribute("type", "text")
    .SetAttribute("placeholder", "Your first name...");

form.AddAndGetElement("button")
    .SetId("submit-btn")
    .AddClass("btn btn-primary mt-3")
    .AddText("<i class=\"fa fa-solid fa-search\"></i> Submit");

form.AddDivider()
    .AddAndGetElement("p")
    .AddClass("m-3")
    .AddChild(HtmlSerializer.Serialize(new { Name = "John Doe", Age = 35 }));

form.Dump();

TextNode.RawText("""
<script>
  (function() {
      document.getElementById("submit-btn").addEventListener("click", () => {
        const name = document.getElementById("firstName").value;
        if (!name) {
            alert("Please enter your name.");
            return;
        }
        alert("Submitted. Thank you, " + name + "!");
      });
  })();
</script>
""").Dump();

Create an HTML document from scratch and render it inside an iframe:

// Let's start by creating our HTML document
var document = new HtmlDocument();

document.AddStyle("""body {font-family: "Ubuntu"; background: #eee}""");

document.Body
    .AddChild(new Element("h1").AddText("Welcome!"))
    .AddAndGetElement("p").AddText("..from beyond the iFrame.");

// Then add an iframe to host our document inside of, and some JavaScript to load it
TextNode.RawText("""<iframe id="foo"></iframe>""").Dump();

TextNode.RawText($$"""
<script>
(function() {
    const iframe = document.getElementById('foo'),
        iframedoc = iframe.contentDocument || iframe.contentWindow.document;

    iframedoc.body.innerHTML = '{{document.ToHtml()}}';
})();
</script>
""").Dump();

// Let's also print out our HTML to take a look at it
document.ToHtml(O2Html.Formatting.Indented).Dump("HTML", code: "html");

Span<T> and ReadOnlySpan<T>

Dumping Span<T> and ReadOnlySpan<T> values only works if the Span is the value being dumped. If the Span is instead a nested value inside a collection or object, only basic info about the Span will be rendered.

var span = new Span<byte>();
span.Dump(); // will show Span contents

var myObject = new MyObject
{
    SpanProperty = new Span<byte>() // will show basic info about this Span
}.Dump();

Settings

Serialization Depth

When dumping objects there is a limit on how deep the serialization will go. This setting can be configured in Settings > Results > Serialization > Max Depth.

Collection Length

When dumping collections there is a limit on how many items from the collection will be serialized. This setting can be configured in Settings > Results > Serialization > Max Collection Length.

Setting these properties too high might cause performance problems.

Customizing Dump()

While this is not implemented yet, the plan is to give users the ability to customize how certain objects are serialized and rendered.