Shared State

Shared State allows developers to store and retrieve data within and across Modify Request Body and Modify API Response rules. This functionality is facilitated by $sharedState, a JavaScript object where you can assign key-value pairs to enhance rule customisation.

Use Cases for Shared State

1. Conditional Request/Response Modification: Use shared state to modify requests or responses dynamically based on conditions stored in prior requests. For example, you can conditionally fail requests based on request counts.

2. Data Aggregation Across Requests: Collect and aggregate data from multiple requests to use within a rule. For instance, you can store API responses and utilize them for further processing across different Requestly rules.

3. Token Management Across API Requests: Manage shared values such as tokens or other critical data across various API interactions, streamlining complex workflows.

How to Use Shared State

Copyfunction modifyResponse(args) {
  const {
    method, url, response, 
    responseType, requestHeaders, 
    requestData, responseJSON
    } = args;

  const [urlPath, queryParams] = url.split('?');

  // Store Request URLs and their responses
  const urlMap = $sharedState.urlMap || {};
  urlMap[urlPath] = response;
  $sharedState.urlMap = urlMap;
  
  // Block all subsequent requests if a specific URL was accessed
  if ($sharedState.urlMap && 
        "https://mock.redq.io/api/products" in $sharedState.urlMap) {
    console.log("Blocked: "+urlPath);
    return null;
  }
  
  return response;
}

Best Practices

• Namespace Your Keys: Use structured keys (e.g., "moduleX.keyY") to avoid overwriting shared data.

• Clean Up When Done: Remove unnecessary data to prevent memory bloat.

• Test Thoroughly: Ensure that shared state logic doesn’t introduce unintended side effects.

Frequently Asked Questions