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Bloblang Playground

Quick Start​

Experiment with Bloblang mappings in real-time using our interactive editor.

The playground has three main panels:

  1. Input JSON (top-left): Your source data
  2. Bloblang Mapping (bottom): Your Bloblang logic
  3. Output (top-right): The transformed result

Example Transformations​

Basic Field Mapping​

Try this simple transformation:

Input:

{
  "user": {
    "firstName": "John",
    "lastName": "Doe"
  },
  "timestamp": "2023-12-01T10:00:00Z"
}

Mapping:

root.fullName = this.user.firstName + " " + this.user.lastName
root.date = this.timestamp.format_timestamp("2006-01-02")

Array Processing​

Transform arrays with ease:

Input:

{
  "products": [
    { "name": "Laptop", "price": 999.99, "category": "electronics" },
    { "name": "Book", "price": 19.99, "category": "media" }
  ]
}

Mapping:

root.items = this.products.map_each(item -> {
  "title": item.name.uppercase(),
  "cost": item.price,
  "type": item.category
})

Conditional Logic​

Handle different data scenarios:

Input:

{
  "user": { "age": 25, "country": "US" },
  "product": { "price": 50 }
}

Mapping:

root.user = this.user
root.product = this.product

# Apply discount based on conditions
root.discount = if this.user.age < 30 && this.user.country == "US" {
  this.product.price * 0.1
} else {
  0
}

root.finalPrice = this.product.price - root.discount

Tips & Tricks​

Exploring Functions​

  • Hover over any function in the mapping editor to see its documentation
  • Use auto-completion (Ctrl+Space) to discover available functions
  • Check the function reference for comprehensive documentation

Debugging Mappings​

  • Use root.debug = this to inspect the entire input structure
  • Add temporary fields like root.temp = this.some.field to debug specific paths
  • The error panel shows exactly where syntax errors occur

Common Patterns​

  • Flattening nested objects: root = this.flatten()
  • Filtering arrays: root.filtered = this.items.filter(item -> item.active)
  • Grouping data: root.groups = this.items.group_by(item -> item.category)
  • String manipulation: root.clean = this.text.trim().lowercase()

Local Development​

Want to run the playground locally? Use the Bento CLI:

bento blobl server

This starts a local server with the full playground interface, perfect for development and testing.

Next Steps​