If I try the following code:

chrome.bookmarks.getTree(function(items) {
  items.forEach(function(item) {
    document.write(item.url);
  });
});

it returns undifined. But when I write:

chrome.bookmarks.getRecent(20, function(items) {
  items.forEach(function(item) {
    document.write(item.url);
  });
});

it works.

Why does it differ?

If I try the following code:

chrome.bookmarks.getTree(function(items) {
  items.forEach(function(item) {
    document.write(item.url);
  });
});

it returns undifined. But when I write:

chrome.bookmarks.getRecent(20, function(items) {
  items.forEach(function(item) {
    document.write(item.url);
  });
});

it works.

Why does it differ?

• javascript
• google-chrome-extension

3 Answers 3

Both chrome.bookmarks.getTree and chrome.bookmarks.getRecent return an array of BookmarkTreeNodes, but BookmarkTreeNodes do not necessarily have a url property. In the case of getTree, the top nodes of the tree are folders and do not have URLs:

If you use getTree, you'll have to traverse the tree recursively using each node's children array. It helps to know that every BookmarkTreeNode either has a children attribute (if it's a folder) or a url attribute (if it's an actual bookmark). Try something like:

chrome.bookmarks.getTree(function(itemTree){
    itemTree.forEach(function(item){
        processNode(item);
    });
});

function processNode(node) {
    // recursively process child nodes
    if(node.children) {
        node.children.forEach(function(child) { processNode(child); });
    }

    // print leaf nodes URLs to console
    if(node.url) { console.log(node.url); }
}

Before modifying your code try this!

Check if the extension has the persimo 'bookmarks'. You can see it in chrome://extensions/, 'Details' button, 'Permissions' section.

If it doesn't say 'Read and change favorites', then delete the Chrome extension and reload it unpackaged.

In my case, I loaded the extension and worked on it, updating it to incorporate the changes, then I realized that I hadn't requested the 'bookmarks' permission in the manifest.json, so I added it and updated the extension. Then chrome.bookmarks gave me 'undefined'.

It took me more than a couple of hours to realize that the manifest.json is not updated when you update the extension, it is only updated when you delete and reupload the extension.

D'oh!

chrome.bookmarks needs permission to use. Try to use it in page chrome://bookmarks.