{"action":"created","issue":{"url":"https://api.github.com/repos/PolymerElements/polymer-starter-kit/issues/503","labels_url":"https://api.github.com/repos/PolymerElements/polymer-starter-kit/issues/503/labels{/name}","comments_url":"https://api.github.com/repos/PolymerElements/polymer-starter-kit/issues/503/comments","events_url":"https://api.github.com/repos/PolymerElements/polymer-starter-kit/issues/503/events","html_url":"https://github.com/PolymerElements/polymer-starter-kit/issues/503","id":116396912,"number":503,"title":"Chrome and removing webcomponents.js: bug + question","user":{"login":"wejrowski","id":296987,"avatar_url":"https://avatars.githubusercontent.com/u/296987?v=3","gravatar_id":"","url":"https://api.github.com/users/wejrowski","html_url":"https://github.com/wejrowski","followers_url":"https://api.github.com/users/wejrowski/followers","following_url":"https://api.github.com/users/wejrowski/following{/other_user}","gists_url":"https://api.github.com/users/wejrowski/gists{/gist_id}","starred_url":"https://api.github.com/users/wejrowski/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/wejrowski/subscriptions","organizations_url":"https://api.github.com/users/wejrowski/orgs","repos_url":"https://api.github.com/users/wejrowski/repos","events_url":"https://api.github.com/users/wejrowski/events{/privacy}","received_events_url":"https://api.github.com/users/wejrowski/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":4,"created_at":"2015-11-11T18:48:42Z","updated_at":"2015-12-22T17:13:58Z","closed_at":null,"body":"This is both a question and a potential bug. As stated in [the polymer-perf doc](https://github.com/PolymerElements/polymer-starter-kit/blob/master/docs/polymer-perf.md) to improve performance, you can check to see if web components is implemented in your browser, and only load when needed.\r\n\r\n**Expected Outcome**: As I understand it, I should be able to remove the webcomponents polyfill in Chrome and everything works the same right? \r\nAs a side question, with this check, obviously this cuts down on loadtime, but does this also improve performance (ie. does the polyfill override the native impmenentation and slow things down)?\r\n\r\n**Actual Outcome**: In implementing this check, or simply removing the polyfill, assuming things should work as normal in Chrome, I've noticed on my app and also on the starter-kit example app, iron-pages seems to be having problems—it's not applying the iron-selected class. I haven't narrowed this down. \r\n\r\nCan anyone answer the performance question, as well as have any pointers to what may be missing in iron-pages? This may very well be an iron-pages problem and if so potentially a bug report needs to go there."},"comment":{"url":"https://api.github.com/repos/PolymerElements/polymer-starter-kit/issues/comments/166677697","html_url":"https://github.com/PolymerElements/polymer-starter-kit/issues/503#issuecomment-166677697","issue_url":"https://api.github.com/repos/PolymerElements/polymer-starter-kit/issues/503","id":166677697,"user":{"login":"robdodson","id":1066253,"avatar_url":"https://avatars.githubusercontent.com/u/1066253?v=3","gravatar_id":"","url":"https://api.github.com/users/robdodson","html_url":"https://github.com/robdodson","followers_url":"https://api.github.com/users/robdodson/followers","following_url":"https://api.github.com/users/robdodson/following{/other_user}","gists_url":"https://api.github.com/users/robdodson/gists{/gist_id}","starred_url":"https://api.github.com/users/robdodson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/robdodson/subscriptions","organizations_url":"https://api.github.com/users/robdodson/orgs","repos_url":"https://api.github.com/users/robdodson/repos","events_url":"https://api.github.com/users/robdodson/events{/privacy}","received_events_url":"https://api.github.com/users/robdodson/received_events","type":"User","site_admin":false},"created_at":"2015-12-22T17:13:58Z","updated_at":"2015-12-22T17:13:58Z","body":"I figured out the root problem with iron-pages. Removing the polyfill means the `WebComponentsReady` event never fires (because that comes from the polyfill). That causes [the router to never setup](https://github.com/PolymerElements/polymer-starter-kit/blob/master/app/elements/routing.html#L13), so iron-pages never gets its selected class.\r\n\r\nPlaying around with the updated perf recipe I found a few additional issues that I want to list.\r\n\r\n- paper-scroll-header-panel started throwing errors when it was loaded async. [I raised an issue](https://github.com/PolymerElements/paper-scroll-header-panel/issues/80) and found a workaround (basically use `this.async` inside of the broken handler). Working with the team to see if we can improve this.\r\n\r\n- You should remove the `unresolved` class from the body. This will let you paint a skeleton faster.\r\n- Need to remove 'WebComponentsReady' handler on router\r\n- Need to move routing.html to end of elements.html file\r\n\r\nI think I'm going to need to do a PR to update the PSK recipe with all this guidance :disappointed: The longer term plan is to rebuild PSK with all of these defaults already in place."}}