How to Solve the \'Converting Circular Structure to JSON\' Error in Chrome Extensions?

Error Handling in Chrome Extensions: Resolving the "Converting Circular Structure to JSON" Issue

When working with Chrome extensions, it's common to encounter errors related to data serialization. One such error is "TypeError: Converting circular structure to JSON" encountered while using chrome.extension.sendRequest. This occurs when the request contains an object with circular references, preventing JSON serialization.

In the provided code snippet, the request object contains a pagedoc property. This variable likely represents a DOM node. DOM nodes in JavaScript have circular references, which is problematic for JSON serialization.

Understanding Circular References in the DOM

DOM nodes have inherent circular references due to:

• Each node having an ownerDocument property that refers to the document.
• The document having a reference to the DOM tree through document.body.
• document.body.ownerDocument references back to the document.

As a result, JSON serialization fails because it attempts to traverse the circular references indefinitely.

Solution: Addressing Circular References

To resolve this issue, you can break the circular references in the request object before sending it. Since DOM nodes are hierarchical, you can create a new object representing the hierarchical relationships without circular references:

var newObj = {
  id: pagedoc.id,
  children: []
};
for (var i = 0; i < pagedoc.children.length; i++) {
  newObj.children.push({
    id: pagedoc.children[i].id,
    ... // Continue building the nested structure without circular references
  });
}

Replace pagedoc in the request object with newObj to remove the circular references:

chrome.extension.sendRequest({
  req: "getDocument",
  docu: newObj,
  name: 'name'
}, function(response){
  var efjs = response.reply;
});

By breaking the circular references, you can now successfully serialize the request object and send it to the extension. The extension can then process the request and provide the expected response without encountering the "Converting circular structure to JSON" error.

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