Get all defined Variables in the current context programatically?

[efficienthacks]

Is there any way to get the Variables programatically (i.e. in a C# cell)? (I know you see it in the Polyglot Notebook: Variables pane)

I want to run a different code path depending on whether a variable exists in the Notebook.

Thanks

[jonsequitur]

Here's an example of the API used to query for which variables are declared in a given kernel:

using Microsoft.DotNet.Interactive;
using Microsoft.DotNet.Interactive.Commands;

var result = await Kernel.Root.SendAsync(new RequestValueInfos("csharp"));
result.Events

The RequestValueInfos command will respond with a ValueInfosProduced event that provides the names and a summary formatting of the value for every variable in the specified subkernel. This is the same command used by the Variables pane.

To get the value of a specific variable you can use the RequestValue command:

var result = await Kernel.Root.SendAsync(new RequestValue("x", mimeType: "application/json", targetKernelName: "csharp"));
result.Events

It's also worth noting that the ValueProduced event has a Value property that's not visible here because it's not serialized. When handling events from an in-process subkernel, this property contains a reference to the actual, unserialized value.