loop/webui: swtich to web components impl (#1)
* loop/webui: swtich to web components impl
This change reorganizes the original vibe-coded
frontend code into a structure that's much
easier for a human to read and reason about,
while retaining the user-visible functionality
of its vibe-coded predecessor. Perhaps most
importantly, this change makes the code testable.
Some other notable details:
This does not use any of the popular large web
frameworks, but instead follows more of an
"a la carte" approach: leverage features
that already exist in modern web browsers,
like custom elements and shadow DOM.
Templating and basic component lifecycle
management are provided by lit.
State management is nothing fancy. It
doesn't use any library or framework, just
a basic "Events up, properties down"
approach.
* fix bad esbuild.go merge
* loop/webui: don't bundle src/web-components/demo
* loop/webui: don't 'npm ci' dev deps in the container
* rebase to main, undo README.md changes, add webuil.Build() call to LaunchContainer()
diff --git a/loop/webui/src/web-components/vega-embed.ts b/loop/webui/src/web-components/vega-embed.ts
new file mode 100644
index 0000000..04f0087
--- /dev/null
+++ b/loop/webui/src/web-components/vega-embed.ts
@@ -0,0 +1,86 @@
+import { css, html, LitElement } from "lit";
+import { customElement, property, query } from "lit/decorators.js";
+import vegaEmbed from "vega-embed";
+import { VisualizationSpec } from "vega-embed";
+
+/**
+ * A web component wrapper for vega-embed.
+ * Renders Vega and Vega-Lite visualizations.
+ *
+ * Usage:
+ * <vega-embed .spec="${yourVegaLiteSpec}"></vega-embed>
+ */
+@customElement("vega-embed")
+export class VegaEmbed extends LitElement {
+ /**
+ * The Vega or Vega-Lite specification to render
+ */
+ @property({ type: Object })
+ spec?: VisualizationSpec;
+
+ static styles = css`
+ :host {
+ display: block;
+ width: 100%;
+ height: 100%;
+ }
+
+ #vega-container {
+ width: 100%;
+ height: 100%;
+ min-height: 200px;
+ }
+ `;
+
+ @query("#vega-container")
+ protected container?: HTMLElement;
+
+ protected firstUpdated() {
+ this.renderVegaVisualization();
+ }
+
+ protected updated() {
+ this.renderVegaVisualization();
+ }
+
+ /**
+ * Renders the Vega/Vega-Lite visualization using vega-embed
+ */
+ private async renderVegaVisualization() {
+ if (!this.spec) {
+ return;
+ }
+
+ if (!this.container) {
+ return;
+ }
+
+ try {
+ // Clear previous visualization if any
+ this.container.innerHTML = "";
+
+ // Render new visualization
+ await vegaEmbed(this.container, this.spec, {
+ actions: true,
+ renderer: "svg",
+ });
+ } catch (error) {
+ console.error("Error rendering Vega visualization:", error);
+ this.container.innerHTML = `<div style="color: red; padding: 10px;">
+ Error rendering visualization: ${
+ error instanceof Error ? error.message : String(error)
+ }
+ </div>`;
+ }
+ }
+
+ render() {
+ return html`<div id="vega-container"></div> `;
+ }
+}
+
+declare global {
+ interface HTMLElementTagNameMap {
+ "vega-embed": VegaEmbed;
+ }
+}