> ## Documentation Index
> Fetch the complete documentation index at: https://docs.htmldocs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Template Variables

> Learn how to use template variables and preview props in your document templates

## Overview

Template variables allow you to create dynamic documents by passing data to your templates. This guide shows you how to define and use template variables in your JSX templates.

## Using Template Variables

Create a template component that accepts props for dynamic content:

```tsx theme={null}
import { Document } from "@htmldocs/react";

interface InvoiceProps {
  customerName: string;
  items: {
    name: string;
    quantity: number;
    price: number;
  }[];
}

function Invoice({ customerName, items }: InvoiceProps) {
  return (
    <Document>
      <h1>Invoice for {customerName}</h1>
      <div className="items">
        {items.map((item, index) => (
          <div key={index} className="item">
            <span>{item.name}</span>
            <span>{item.quantity}</span>
            <span>${item.price}</span>
          </div>
        ))}
      </div>
    </Document>
  );
}

export default Invoice;
```

## Preview Props

Define preview data for development and testing using `PreviewProps`:

```tsx theme={null}
Invoice.PreviewProps = {
  customerName: "Acme Corporation",
  items: [
    {
      name: "Premium License",
      quantity: 1,
      price: 999.00
    },
    {
      name: "Support Package",
      quantity: 2,
      price: 299.00
    }
  ]
};
```

## Complex Objects

You can use nested objects and arrays for more complex templates:

```tsx theme={null}
interface CompanyInfo {
  name: string;
  address: {
    street: string;
    city: string;
    state: string;
    zip: string;
  };
  contact: {
    email: string;
    phone: string;
  };
}

interface ReceiptProps {
  orderNumber: string;
  date: string;
  company: CompanyInfo;
  items: {
    name: string;
    quantity: number;
    price: number;
  }[];
}

Receipt.PreviewProps = {
  orderNumber: "ORD-123456",
  date: new Date().toLocaleDateString(),
  company: {
    name: "Acme Corp",
    address: {
      street: "123 Business Ave",
      city: "San Francisco",
      state: "CA",
      zip: "94105"
    },
    contact: {
      email: "info@acme.com",
      phone: "(555) 123-4567"
    }
  },
  items: [
    {
      name: "Product A",
      quantity: 1,
      price: 99.99
    }
  ]
};
```

## Dynamic Values

You can use JavaScript expressions and functions in your preview props:

```tsx theme={null}
Document.PreviewProps = {
  orderNumber: `ORD-${Math.random().toString(36).substr(2, 9).toUpperCase()}`,
  date: new Date().toLocaleDateString('en-US', {
    year: 'numeric',
    month: 'long',
    day: 'numeric'
  }),
  total: calculateTotal(items)
};
```