Working with Templates

Learn how to use templates when generating documents via the RenderDoc API.

Overview

Templates in RenderDoc are pre-designed document formats created in the dashboard. When generating documents via API, you reference these templates by their ID and provide variables for personalization.

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Template Management: Templates can be created, updated, and deleted via both the Dashboard UI and JWT-authenticated API endpoints. The Dashboard provides a visual designer for easier template creation, while the API allows programmatic management for automation and integration purposes.

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How Templates Work

1. Create Templates

Templates can be created in two ways:

Option A: Dashboard (Recommended for Design)

• Navigate to Templates in the dashboard
• Click Create Template
• Use the visual drag-and-drop designer
• Define variables for dynamic content
• Save and publish your template

See the Templates User Guide for detailed instructions.

Option B: API (For Automation)

• Use JWT-authenticated API endpoints
• Programmatically create and manage templates
• Ideal for CI/CD pipelines and automated workflows
• Requires template schema knowledge

See the API Reference - Templates for API documentation.

2. Use Templates for Document Generation

Once templates are created, reference them in API calls:

{
  templateId: 'tmpl_invoice',  // Required - references dashboard template
  format: 'pdf',  // or 'xlsx'
  variables: {  // Fills in template placeholders
    invoiceNumber: 'INV-001',
    customerName: 'Acme Corp',
    amount: 1250.00
  }
}

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Template Types

RenderDoc supports two output formats from templates:

PDF Templates

Used for generating professional PDF documents:

• Text, headings, paragraphs
• Images and logos
• Tables for data display
• Conditional blocks
• Loops for repeating content
• Native charts (bar, line, pie, area, scatter)
• Page breaks and headers/footers

Usage:

curl https://api.renderdoc.dev/api/v1/documents/generate \
  -H "Authorization: Bearer rd_sk_abc123..." \
  -H "Content-Type: application/json" \
  -X POST \
  -d '{
    "templateId": "tmpl_invoice",
    "format": "pdf",
    "variables": { "invoiceNumber": "INV-001" }
  }'

Excel Templates

Used for generating Excel spreadsheets:

• All PDF components plus:
• Native charts with Excel interactivity
• Advanced table formatting with calculated columns
• Multiple sheets
• Formula support

Usage:

const result = await client.documents.generate({
  templateId: 'tmpl_monthly_report',
  format: 'xlsx',
  variables: {
    reportMonth: 'January 2025',
    data: [
      { category: 'Sales', amount: 50000 },
      { category: 'Expenses', amount: 30000 }
    ]
  }
});

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Using Template Variables

Variable Syntax

Templates use Handlebars syntax for variables:

Invoice #{{invoiceNumber}}

Customer: {{customerName}}
Total: ${{orderTotal}}

Providing Variable Values

Pass variable values in the variables object:

const response = await fetch('https://api.renderdoc.dev/api/v1/documents/generate', {
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${apiKey}`,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    templateId: 'tmpl_invoice',
    format: 'pdf',
    variables: {
      invoiceNumber: 'INV-001',
      customerName: 'Acme Corp',
      orderTotal: 99.99
    }
  })
});

Variable Types

Templates can use different variable types:

Type	Example	Description
String	{{customerName}}	Text values
Number	{{orderTotal}}	Numeric values
Boolean	{{isPremium}}	True/false values
Array	{{#each items}}...{{/each}}	Lists of items
Object	{{customer.name}}	Nested data

Complex Variables Example

{
  templateId: 'tmpl_invoice',
  format: 'pdf',
  variables: {
    // Simple values
    invoiceNumber: 'INV-12345',
    issueDate: '2025-11-07',

    // Object values
    customer: {
      name: 'John Doe',
      company: 'Acme Corp',
      email: '[email protected]'
    },

    // Array values
    items: [
      { name: 'Product A', quantity: 2, price: 49.99 },
      { name: 'Product B', quantity: 1, price: 29.99 }
    ],

    // Calculated values
    subtotal: 129.97,
    tax: 13.00,
    total: 142.97
  }
}

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Required vs Optional Variables

Required Variables

Templates can define required variables. If you don't provide them, the API will return an error:

{
  "statusCode": 400,
  "code": "ERR_VALID_005",
  "message": "Required field is missing",
  "relatedInfo": {
    "variable": "invoiceNumber",
    "templateId": "tmpl_invoice"
  }
}

Solution: Provide all required variables:

{
  templateId: 'tmpl_invoice',
  format: 'pdf',
  variables: {
    invoiceNumber: 'INV-001',     // Required
    customerName: 'John Doe',     // Required
    amount: 99.99                 // Required
  }
}

Optional Variables

Optional variables can be omitted. The template handles missing values gracefully:

Invoice #{{invoiceNumber}}{{#if poNumber}} (PO: {{poNumber}}){{/if}}

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Conditional Content

Templates support conditional blocks using Handlebars helpers:

Template Design (Dashboard)

{{#if isPremium}}
  <p>Premium Customer - Priority Support Included</p>
{{else}}
  <p>Standard Customer</p>
{{/if}}

API Usage

{
  templateId: 'tmpl_invoice',
  format: 'pdf',
  variables: {
    isPremium: true  // Controls conditional block
  }
}

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Loops and Repeating Content

Templates can loop through arrays of data:

Template Design (Dashboard)

<h2>Line Items</h2>
<table>
  {{#each items}}
    <tr>
      <td>{{this.name}}</td>
      <td>{{this.quantity}}</td>
      <td>${{this.price}}</td>
    </tr>
  {{/each}}
</table>

API Usage

{
  templateId: 'tmpl_invoice',
  format: 'pdf',
  variables: {
    items: [
      { name: 'Product A', quantity: 2, price: 49.99 },
      { name: 'Product B', quantity: 1, price: 29.99 },
      { name: 'Product C', quantity: 3, price: 19.99 }
    ]
  }
}

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Finding Template IDs

Via Dashboard

1. Navigate to Templates in the dashboard
2. Click on a template to view details
3. Copy the Template ID from the details page

Template IDs follow the format: tmpl_xxxxxxxxxx

Naming Convention

Use descriptive template IDs for clarity:

• tmpl_invoice - Invoice generation
• tmpl_monthly_report - Monthly report
• tmpl_contract - Contract document
• tmpl_receipt - Receipt generation

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Template Errors

Template Not Found

{
  "statusCode": 404,
  "code": "ERR_TMPL_001",
  "message": "Template not found",
  "relatedInfo": {
    "templateId": "tmpl_invalid"
  }
}

Solution: Verify the template ID exists in your dashboard.

Template Not Published

{
  "statusCode": 400,
  "code": "ERR_TMPL_021",
  "message": "Template has no published version",
  "relatedInfo": {
    "templateId": "tmpl_invoice",
    "status": "draft"
  }
}

Solution: Publish the template in the dashboard before using it via API.

Missing Required Variable

{
  "statusCode": 400,
  "code": "ERR_VALID_005",
  "message": "Required field is missing",
  "relatedInfo": {
    "variable": "invoiceNumber",
    "templateId": "tmpl_invoice"
  }
}

Solution: Provide all required variables in the variables object.

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Best Practices

1. Use Descriptive Template Names

Good:

• tmpl_invoice_standard
• tmpl_report_monthly
• tmpl_contract_service

Bad:

• tmpl_001
• tmpl_test
• tmpl_doc

2. Define Clear Variable Names

Good:

{
  variables: {
    customerFirstName: 'John',
    invoiceNumber: '12345',
    totalAmount: 99.99
  }
}

Bad:

{
  variables: {
    fn: 'John',
    in: '12345',
    t: 99.99
  }
}

3. Validate Variable Data

Always validate data before generating:

function validateInvoiceData(invoice) {
  if (!invoice.number) throw new Error('Invoice number required');
  if (!invoice.customer.name) throw new Error('Customer name required');
  if (invoice.items.length === 0) throw new Error('Invoice must have items');
  return true;
}

// Use it
validateInvoiceData(invoiceData);

await client.documents.generate({
  templateId: 'tmpl_invoice',
  format: 'pdf',
  variables: invoiceData
});

4. Use Template Versioning

When templates are updated in the dashboard, the API automatically uses the latest published version. To ensure consistency:

• Test template changes in a non-production environment first
• Use separate templates for different environments (e.g., tmpl_invoice_dev, tmpl_invoice_prod)
• Document template changes in your version control system

5. Handle Missing Optional Variables

Design templates to handle missing optional variables gracefully:

{{#if companyLogo}}
  <img src="{{companyLogo}}" />
{{/if}}

6. Keep Templates Simple

• Break complex documents into smaller, reusable templates
• Use consistent naming conventions
• Document required and optional variables
• Test templates with various data combinations

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Testing Templates

Test with Real Data

Always test templates with realistic data:

// Production-like test data
const testVariables = {
  invoiceNumber: 'INV-TEST-001',
  customer: {
    name: 'Test Customer',
    company: 'Test Corp'
  },
  items: [
    { name: 'Product A', quantity: 2, price: 49.99 },
    { name: 'Product B', quantity: 1, price: 29.99 }
  ],
  total: 129.97
};

// Generate test document
const result = await client.documents.generate({
  templateId: 'tmpl_invoice',
  format: 'pdf',
  variables: testVariables
});

console.log('Test document:', result.downloadUrl);

Testing Tips

When testing templates:

• Use the template preview in the dashboard
• Generate documents with various data combinations
• Test edge cases (empty arrays, long text, special characters)
• Verify formatting across different output formats

See Authentication for API key details.

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Common Use Cases

Invoice Generation

{
  templateId: 'tmpl_invoice',
  format: 'pdf',
  variables: {
    invoiceNumber: 'INV-12345',
    issueDate: '2025-01-15',
    customer: {
      name: 'John Doe',
      company: 'Acme Corp',
      address: '123 Main St, New York, NY'
    },
    items: [
      { name: 'Product A', quantity: 2, price: 49.99 },
      { name: 'Product B', quantity: 1, price: 29.99 }
    ],
    subtotal: 129.97,
    tax: 13.00,
    total: 142.97
  }
}

Monthly Report

{
  templateId: 'tmpl_monthly_report',
  format: 'xlsx',
  variables: {
    reportMonth: 'January 2025',
    department: 'Sales',
    metrics: [
      { category: 'Revenue', value: 150000, change: '+12%' },
      { category: 'Orders', value: 523, change: '+8%' },
      { category: 'Customers', value: 89, change: '+15%' }
    ],
    summary: 'Strong growth across all metrics.'
  }
}

Contract Document

{
  templateId: 'tmpl_service_contract',
  format: 'pdf',
  variables: {
    contractNumber: 'CON-2025-001',
    effectiveDate: '2025-02-01',
    clientName: 'Acme Corporation',
    serviceTerm: '12 months',
    monthlyFee: 5000,
    services: [
      'Consulting Services',
      'Technical Support',
      'Training Sessions'
    ]
  }
}

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Next Steps

• Create Templates: Learn how to design templates in the Templates User Guide
• Generate Documents: See complete API documentation in Generating Documents
• Handle Errors: Learn about error handling in Error Handling
• Batch Generation: Generate documents at scale with Batch Generation

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Related: Generating Documents | Authentication | Templates User Guide