This document outlines the functionality and usage of the JSON Reader node, which enables extracting specific values from JSON data.

​
Node Inputs

  • JSON String: A string containing valid JSON data from which values will be extracted
  • Keys: A comma-separated list of keys to extract from the JSON structure (e.g., ‘name,email,id’)

​
Node Output

  • Key Values: Each key defined in the input is exposed as a separate output value

​
Node Functionality

The JSON Reader node extracts specified pieces of information from a JSON structure. It takes a JSON string and a list of keys as input, then outputs the values associated with those keys. The node processes one level of the JSON structure at a time.

​
When to Use

Use the JSON Reader node when you need to:

  • Extract specific fields from API responses
  • Process JSON data from files or other sources
  • Convert JSON values into individual outputs for further processing
  • Filter specific keys from larger JSON structures

​
Working with Nested JSON

For nested JSON structures, you’ll need to use multiple JSON Reader nodes in sequence. Each node can process one level of the JSON structure.

​
Example: Processing Nested JSON

Given this JSON structure from an API response:

{
  "success": true,
  "data": {
    "title": "Product Update",
    "content": "New features released",
    "metadata": {
      "author": "John Doe",
      "date": "2024-01-30"
    }
  }
}

To access nested values, create a chain of JSON Reader nodes:

  1. First JSON Reader:

    • Input: Original JSON string
    • Keys: “data”
    • Output: The entire data object

  2. Second JSON Reader:

    • Input: Output from first reader
    • Keys:
      1. title
      2. content
    • Output: Individual title and content values

  3. Third JSON Reader (for metadata):

    • Input: Output from second reader’s metadata
    • Keys:
      1. author
      2. date
    • Output: Individual author and date values

​
Example Use Cases

​
1. API Response Processing

{
  "status": "success",
  "results": {
    "userId": "12345",
    "username": "johndoe",
    "email": "john@example.com"
  }
}

Keys to extract: “status”

​
2. Configuration Data

{
  "settings": {
    "theme": "dark",
    "language": "en",
    "notifications": true
  },
  "version": "2.0.0"
}

Keys to extract: “version”

​
Working with Arrays

When dealing with JSON arrays, use the List Operations nodes in conjunction with the JSON Reader:

  1. Use JSON Reader to extract the array
  2. Use Get List Item to access specific array elements
  3. Use another JSON Reader to extract values from each array element

​
Important Considerations

  1. Key Sensitivity: Keys are case-sensitive
  2. Invalid JSON: Ensure your JSON string is valid before processing
  3. Nested Structures: Use multiple JSON Reader nodes for nested data
  4. Array Handling: Combine with List Operations nodes for array processing

​
Tips for Success

  1. Validate JSON First: Use the If/Else node to check if the JSON is valid
  2. Chain Readers: For nested structures, chain multiple JSON Reader nodes
  3. Use with Error Shield: Wrap JSON operations in Error Shield nodes to handle invalid JSON gracefully
  4. Preview Data: Use the debugger to preview JSON structure before setting keys
  • Write JSON Value: For modifying JSON data
  • Call API: For fetching JSON from APIs
  • If/Else: For conditional JSON processing
  • Error Shield: For handling JSON parsing errors
  • Custom Node: For creating a customized JSON parser that can handle:
    • Nested key extraction using dot notation
    • Complex array operations
    • Dynamic key mapping
    • Custom parsing logic
    • Automatic type conversion
Email ValidatorJSON Writer