Goal
Add a tab() component that enables developers to organize UI content into labeled tabs within their Preswald apps—ideal for sectioning long dashboards, multiple views, or split data insights.

📌 Motivation

Many dashboards and tools created with Preswald contain multiple logical sections (e.g., charts, tables, filters). Scrolling through all at once creates cognitive overload. A tab() component provides:

• Better user experience through organized navigation
• A way to switch between related views in-place
• Clean separation of logic (e.g., Overview vs. Details)

This aligns with the existing layout vision (e.g., size, collapsible()), and will significantly improve interface design for real-world dashboards.

✅ Acceptance Criteria

• Add tab() component to preswald/interfaces/components.py
• Frontend implementation using ShadCN’s Tabs from @/components/ui/tabs.tsx
• Create TabWidget.jsx to render tabs and dynamic child content
• Register component in DynamicComponents.jsx
• Tab component should accept:
  • label: str – Label for the tab container
  • tabs: list[dict] – Each item with title: str, components: list
  • size: float = 1.0 – For layout sizing
• Ensure tabs support rendering other registered components (e.g., text, plotly, table) inside them
• Fully documented in SDK

🛠 Implementation Plan

1. Backend – Component Definition

In preswald/interfaces/components.py:

def tab(
    label: str,
    tabs: list[dict],
    size: float = 1.0,
) -> None:
    service = PreswaldService.get_instance()
    component_id = f"tab-{hashlib.md5(label.encode()).hexdigest()[:8]}"
    
    component = {
        "type": "tab",
        "id": component_id,
        "label": label,
        "size": size,
        "tabs": tabs,
    }

    service.append_component(component)

Register it in __init__.py:

from .components import tab

2. Frontend – UI Component

Create: frontend/src/components/widgets/TabWidget.jsx

import React from 'react';
import { Tabs, TabsList, TabsTrigger, TabsContent } from '@/components/ui/tabs';
import { Card } from '@/components/ui/card';

const TabWidget = ({ _label, tabs = [] }) => {
  const [activeTab, setActiveTab] = React.useState(tabs?.[0]?.title || '');

  return (
    <Card className="mb-4 p-4 rounded-2xl shadow-md">
      <h2 className="font-semibold text-lg mb-2">{_label}</h2>
      <Tabs value={activeTab} onValueChange={setActiveTab}>
        <TabsList className="mb-2 flex space-x-2">
          {tabs.map((tab) => (
            <TabsTrigger key={tab.title} value={tab.title}>
              {tab.title}
            </TabsTrigger>
          ))}
        </TabsList>
        {tabs.map((tab) => (
          <TabsContent key={tab.title} value={tab.title}>
            {/* Render nested components */}
            {tab.components?.map((child, i) => (
              <div key={i}>{window.renderDynamicComponent(child)}</div>
            ))}
          </TabsContent>
        ))}
      </Tabs>
    </Card>
  );
};

export default TabWidget;

3. DynamicComponents.jsx – Register tab

import TabWidget from '@/components/widgets/TabWidget';

case 'tab':
  return (
    <TabWidget
      {...commonProps}
      _label={component.label}
      tabs={component.tabs}
    />
  );

Ensure renderDynamicComponent() is accessible globally or passed through props to render children.

🧪 Testing Plan

• Add a test in examples/iris/hello.py:

from preswald import tab, text, table, get_df, connect

connect()
df = get_df("sample_csv")

tab(
    label="Data Views",
    tabs=[
        {"title": "Intro", "components": [text("Welcome to the Iris app.")]},
        {"title": "Table", "components": [table(df)]},
    ]
)

• Run with preswald run and confirm:
  • Tab titles appear
  • Content switches correctly
  • Styling matches Tailwind theme

🧾 SDK Usage Example

tab(
    label="Navigation",
    tabs=[
        {"title": "Overview", "components": [text("Summary goes here")]},
        {"title": "Data", "components": [table(df)]},
        {"title": "Chart", "components": [plotly(fig)]}
    ]
)

📚 Docs To Update

• /docs/sdk/tab.mdx – Full parameters and example
• /docs/layout/guide.mdx – Add layout pattern for tab()

🧩 Files Involved

• preswald/interfaces/components.py
• frontend/src/components/widgets/TabWidget.jsx
• frontend/src/components/ui/tabs.tsx
• DynamicComponents.jsx

💡 Future Ideas

• Allow dynamic content loading (lazy tabs)
• Optional icon support per tab
• Persist selected tab state across sessions