Class: Console
WebR.Console
Text-based Interactive Console for WebR
A helper application to assist in creating an interactive R REPL based on JavaScript callbacks.
Callback functions stdout
and stderr
are called with a single line of output as the first argument. The default implementation of stdout
and stderr
writes to the console using console.log
and console.error
.
R code can be sent as input by calling the stdin
method with a single line of textual input.
A long running R computation can be interrupted by calling the interrupt
method.
The prompt
callback function is called when webR produces a prompt at the REPL console and is therefore awaiting user input. The prompt character (usually >
or +
) is given as the first argument to the callback function. The default implementation of prompt
shows a JavaScript prompt asking the user for input, and then sends the user input to stdin
.
The canvasExec
callback function is called when webR writes plots to the built-in HTML canvas graphics device.
Once constructed, start the Console using the run
method. The run
method starts an asynchronous infinite loop that waits for output from the webR worker and then calls the relevant callbacks.
Table of contents
Constructors
Properties
Methods
Constructors
constructor
• new Console(callbacks?
, options?
)
Parameters
Name | Type | Description |
---|---|---|
callbacks |
ConsoleCallbacks |
A list of webR Console callbacks to be used for this console. |
options |
WebROptions |
The options to use for the new instance of webR started to support this console. |
Defined in
console/console.ts:65
Properties
canvas
• canvas: undefined
| HTMLCanvasElement
A HTML canvas element
The canvas graphics device writes to this element by default. Undefined when HTML canvas is unsupported.
Defined in
console/console.ts:49
webR
• webR: WebR
The supporting instance of webR
Defined in
console/console.ts:42
Methods
interrupt
▸ interrupt(): void
Interrupt a long running R computation and return to the prompt
Returns
void
Defined in
console/console.ts:98
run
▸ run(): void
Start the webR console
Returns
void
Defined in
console/console.ts:141
stdin
▸ stdin(input
): void
Write a line of input to webR’s REPL through stdin
Parameters
Name | Type | Description |
---|---|---|
input |
string |
A line of input text. |
Returns
void
Defined in
console/console.ts:91