Goal

Improve the preswald init CLI command to accept a --template flag that lets users choose from a set of curated app templates. Each template bootstraps a different type of Preswald project with example hello.py, preswald.toml, and mock data files tailored to a use case (e.g., CSV dashboard, GeoJSON map, time-series plot, etc).

📌 Motivation

Currently, preswald init <project_name> scaffolds a single generic app with a basic hello.py. This is great for minimalism but misses an opportunity to help new users get started with more realistic examples.

Adding a --template flag will:

• Let users pick a template suited for their data or use case
• Showcase Preswald’s full capability right from the start
• Cut down the time it takes to build a working data app
• Turn the CLI into an educational onboarding tool

✅ Acceptance Criteria

• Add --template <template-name> option to preswald init
• Supported templates:
  • default: basic text() component and scaffold (current behavior)
  • csv-dashboard: Table + plot + slider using a sample CSV
  • geojson-map: Load GeoJSON and render with geo()
  • time-series: Line chart + filter slider
  • comparison: Two plots with shared filters
• Place template contents in preswald/templates/<template-name>/
• Automatically copy files into <project_name> dir:
  • hello.py
  • preswald.toml
  • secrets.toml
  • data/ and images/ as needed
• Provide a helpful error message if template doesn't exist
• Update preswald --help to list available templates

🛠 Implementation Plan

1. Update CLI: preswald/cli.py

@app.command("init")
def init(project_name: str, template: str = "default"):
    from preswald.engine.init import scaffold_project

    scaffold_project(project_name, template)

2. Template Folder Structure

preswald/
  templates/
    default/
      hello.py
      preswald.toml
    csv-dashboard/
      hello.py
      preswald.toml
      data/sample.csv
    geojson-map/
      hello.py
      preswald.toml
      data/map.geojson
    ...

3. In init.py:

def scaffold_project(project_name, template="default"):
    import shutil
    template_path = Path(__file__).parent / "templates" / template
    if not template_path.exists():
        raise Exception(f"Template '{template}' not found.")

    shutil.copytree(template_path, project_name)
    print(f"✅ Project initialized with '{template}' template in ./{project_name}")

🧪 Example Usage

preswald init sales_dashboard --template csv-dashboard
preswald init earthquake_map --template geojson-map
preswald init basic_app --template default

📄 Example: csv-dashboard/hello.py

from preswald import connect, get_df, slider, table, plotly, text
import plotly.express as px

text("# Sales Dashboard")

connect()
df = get_df("sample_csv")

threshold = slider("Min Quantity", min_val=0, max_val=100, default=10)
filtered = df[df["quantity"] > threshold]

fig = px.bar(filtered, x="product", y="quantity")
plotly(fig)

table(filtered)

📚 Docs To Update

• CLI Reference → preswald init
• Quickstart → Mention templates
• Add template previews to website/docs

🔮 Future Ideas

• Add preswald template list to enumerate templates
• Allow remote templates (--template-url)
• Community-contributed template registry
• preswald template publish to create shareable blueprints