The presentation library

Storm includes a library for creating presentations in a declarative manner. It is located in the presentations package. The file root/presentation/test/ includes the following example that illustrates how the library is used.

use presentation;
use layout;

// Declare the presentation. Uses an extension implemented in the package 'presentation'.
presentation Simple "My presentation" {
    // Generate a random caption for the first slide.
    Str caption = "Presentation number " + rand(1, 10).toS;

    // Create a slide.
    slide title caption, "By myself" {}

    // Another one, with an animation!
    slide FadeIn => content "Hello!" {
        list [ "Welcome to " + title, "In Storm!" ] {}

void simple() {;

The presentation block declares a function named Simple that returns a Presentation instance that describes the presentation. The function is then called inside main to produce the instance and show it using the show member. Since the presentation block is essentially a function, it may contain regular Basic Storm code, but also declarative declarations of slides using the layout DSL as described here, as shown in the example.

The file root/presentation/test/ contains a larger example that shows more complex layout and also the picture block, which allows creation of more advanced figures in the presentation.

Live reloading

To improve the experience when creating presentations, the presentation library supports live reloading of presentations. For this to work, the presentation library must be informed of the location of the presentation's definition. This is done by using the showDebug function rather than the show function to show the presentation as follows:

use presentation;
use lang:bs:macro;

void develop() {

The named{} syntax evaluates to the Function object inside the compiler that represents the presentation function itself. The presentation library then executes the function to retrieve the presentation itself, and is able to use the Function object to reload the function when the user presses the F5 key.

Exporting to PDF

Exporting presentations to PDF is also supported using the export function provided in the library. The PDF writer library in the ui.pdf package is used for this. This library is not entirely complete, and may produce corrupt PDF at times, but works well in most cases. Please read the README for that library using help ui:pdf in the Basic Storm interactive prompt before using this ability.

The example above can be exported as follows:

use presentation;
use core:io;

void export() {
    Simple.export(cwdUrl / "export.pdf");