First, you need to get all data.
Then serialize the result.
Finally, offer it as a download to the user.
chrome.storage.local.get(null, function(items) { // null implies all items
// Convert object to a string.
var result = JSON.stringify(items);
// Save as file
var url = 'data:application/json;base64,' + btoa(result);
chrome.downloads.download({
url: url,
filename: 'filename_of_exported_file.json'
});
});
To use the chrome.downloads.download
method, you need to declare the "downloads"
permission in addition to the storage
permission in the manifest file.