Develop Reference

Determine if active tab contains an editable Google Doc

Suppose my extension has obtained the URL for the current active tab using the method suggested in How can I get the current tab URL for chrome extension?, e.g.
chrome.tabs.query({
active: true,
lastFocusedWindow: true
}, function (tabs) {
// use first tab to obtain url
var tab = tabs[0];
var url = tab.url
});
How can I determine if the URL refers to a Google Doc to which I have editing rights? The distinction between ownership and being an invited collaborator is not important for this application. I'm interested only in Docs as opposed to Spreadsheets or Forms.
For context on what I'm trying to develop, see: How to manually generate notifications to a Google Doc collaborator?

Alternate answer, based on the Google Drive API rather than the Google Docs UI.
Before doing any of this, make sure to declare permissions in the manifest (to only match URLs that look like docs.google.com/document/*).
Here is a broad overview of the steps you could follow:
GET a
file,
which will return some metadata. You can use the URL you have to extract the relevant ID which is used in the GET request.
Use this metadata file resource to retrieve a permissions resource
In the permissions resource, look at the role attribute: it will be either owner, reader, or writer. You will not have editing rights if you are a reader, but should have editing rights otherwise.

Here is a side by side view of a google doc, where I created a doc, generated a sharing link, and opened it in a browser where I was not signed in to google. I would suggest using a content script to insert a "find" function which would return either true or false if it can locate the "view only" button in the DOM ("view only" meaning you do not have edit permissions). You could make the content script match URLs that look like docs.google.com/document/* only.
Caution: google changes UI pretty frequently so this may not be future-proof. Try inspecting the source of google docs in both situations to look for more clues.
Side by side view:
Source code in the chrome devtools:

Open video URL in native player from Google Chrome

I'm trying to open a remote video (let's say it's located at http://www.example.com/video.mp4) with the default Android player launched directly from Google Chrome, making use of the brand new intent://.
This is the URI I called through an href tag:
intent://www.example.com/video.mp4#Intent;scheme=file;action=android.intent.action.VIEW;end;
Of course, this URI doesn't work, and Chrome returns error "Unable to perform navigation". I've also tried the same URI omitting scheme=file.
Here's the documentation I've been following: https://developer.chrome.com/multidevice/android/intents
Thanks in advance!

A quick browse of the Gallery App in AOSP shows that it can be launched from a browser. It has a category of BROWSABLE and DEFAULT. This means given the correct intent URL you should be able to launch it.
Obviously specifying a package should work, but that is not flexible, what if there are two gallery apps.
The following Intent scheme url works:
intent://www.sample-videos.com/video/mp4/720/big_buck_bunny_720p_1mb.mp4#Intent;action=android.intent.action.VIEW;scheme=http;type=video/mp4;end
Note:
scheme = http (it needs to be that or https),
there is a // before the domain, if that is not there the URL is not constructed correctly in the player
action = android.intent.action.VIEW
type = video/mp4 - if this is not in place the video will open in the browser
I have created a demo that works

Facebook app browser debugging [duplicate]

I'm developing website with a lot of HTML5 and CSS3 features. I'm also using iframe to embed several content on my website. It works fine if I open it using Chrome/Firefox/Safari mobile browser. However, if I share on facebook (post/page) and I opened it up with Facebook application with Facebook Internal Browser, my website is messed up.
Is there any tools or way to debug on Facebook Browser? Thanks.

This is how you can do the debugging yourself. It's painful, but the only way I've come across so far.
tl;dr Get the Facebook App loading a page on your local server so you can iterate quickly. Then print debug statements directly to the page until you figure out what is going on.
Get a link to a page on your local server that you can access on your mobile device (test in mobile safari that it works). See this to find out your local IP address How do you access a website running on localhost from iPhone browser. It will look something like this
http://192.xxx.1.127:3000/facebook-test
Post that link on your Facebook page (you can make it private so your friends aren't all like WTF?)
Click the posted link in the Facebook mobile App and it will open up in Facebook's mobile browser
Since you don't have a console, you basically need to print debug statements directly to the page so it is visible. Put debug statements all over your code. If your problems are primarily related to CSS, then you can iteratively comment out stuff until you've found the issue(s) or print the relevant CSS attributes using JavaScript. Eg something like (using JQuery)
function debug(str){$('body').append("<br>"+str);}
Quite possibly the most painful part. The Facebook browser caches very aggressively. If you are making changes and nothing has happened, it's because the content is cached. You can sometimes resolve this by updating the URLs, eg /facebook-test-1, /facebook-test-2, or adding dummy parameters eg /facebook-test?dummy=1. But if the changes are in external css or js sheets it sometimes will still cache. To 100% clear the cache, delete the Facebook App from your mobile device and reinstall.

The internal browser the Facebook app uses is essentially a uiWebView. Paul Irish has made a simple iOS app that lets you load any URL into a uiWebView which you then can debug using Safari's Developer Tools.
https://github.com/paulirish/iOS-WebView-App

I found a way how to debug it easier. You will need to install the Ghostlab app (You have a 7-day free trial there, however it's totally worth paying for).
In Ghostlab, add the website address (or a localhost address) you want to debug and start the session.
Ghostlab will generate a link for access.
Copy that link and post it on Facebook (as a private post)
Open the link on mobile and that's it! Ghostlab will identify you once you open that link, and will allow you to debug the page.
For debugging, you will have all the same tools as in the Chrome devtools (how cool is that!). For example, you can tweak CSS and see the changes applied live.

If you want to debug a possible error, you can try to catch it and display it.
Put this at the very top of your code:
window.onerror = function (msg, url, lineNo, columnNo, error) {
var string = msg.toLowerCase();
var substring = "script error";
if (string.indexOf(substring) > -1){
alert('Script Error: See Browser Console for Detail');
} else {
var message = [
'Message: ' + msg,
'URL: ' + url,
'Line: ' + lineNo,
'Column: ' + columnNo,
'Error object: ' + JSON.stringify(error)
].join(' - ');
alert(message);
}
}
(Source: MDN)
This will catch and alert your errors.
Share a link on Facebook (privately), or send yourself a message on Facebook Messenger (easier). To break the cache, create a new URL every time, e.g. by appending a random string to the URL.
Follow the link and see if you can find any errors.

With help of ngrok create temporary http & https adress instead of your ordinary localhost:3000(or other port) and you could run your app on any devices. It is super easy to use.
and as it was written above all other useful information you should write somewhere inside div element (in case of React I recommend to put onClick on that div with force update or other function for getting info, sometimes it helps because JS in FB could be executed erlier than your information appears). Keep in mind that alerts are not reliable, sometimes they are blocked
bonus from ngrok that in console you will see which files was
requested and response code (it will replace lack of network tab)
and about iFrame.If you use it on other domain and you rely on cookies - you should know that facebook in-app browser blocks 3rd party cookies
test on Android and iOS separately because technicaly they use different browsers

Opening a new window that needs to make ajax calls to another domain

Background
We have two web applications hosted on different sub-domains. Application 1 is an internal admin system. Application 2 is a helpdesk system.
We can modify the source code of Application 1 but we have no access to modify Application 2.
The Goal
To display a link against an order in Application 1 that will open a new window, the URL of which is that of a ticket in Application 2.
The idea being that our staff can see that an order has a helpdesk ticket raised against it and simply needs to click a link on the order to view the ticket and reply to it.
The problem
Regardless of how I open the new window (window.open, target="_blank", etc.) the ticket in the new window is unable to make any ajax requests back to the helpdesk system where it is hosted.
The URL of the new window is part of Application 2.
In Google dev tools it tells me "The frame requesting access has a protocol of "http", the frame being accessed has a protocol of "https". Protocols must match." even when I open it using _blank.
If I go to the exact same URL manually everything works... but this doesn't help when I need it to work from the link.
Is there any way to achieve the above?
If not, is there any way I can open a new window that is "detached" from the window that opened it so that same origin policy no longer applies?
Edit 2014-03-28 10:23
I have no access to App2's code at all. I cannot make any changes to App2. Any answer must take this into account.
I am trying to open a new window from my application (App1) where the target URL of that window is a page in App2. That page inside App2 then needs to be able to use ajax to communicate with other areas of App2. This is where the problem lies. Because App1 opened the window the same origin policy is preventing that window from making it's ajax requests.

I suspect that JavaScript on the second (helpdesk) app is trying to access the first app via window.opener (which could lead to the cross-origin error you're seeing) and subsequent JavaScript (fetching stuff via AJAX) is then not getting executed. You can probably narrow things down by setting appropriate breakpoints in the second app.
If this is the cause and you can't modify the source for the helpdesk app, how about going to a URL in the internal domain that would then redirect to the help desk? The redirect should cause the window.opener property to become null (same as manually typing in the URL).
Assuming https://admin.mydomain.co.uk and http://helpdesk.mydomain.co.uk, clicking on the "Help Ticket" link would go to a URL in the internal app, e.g. https://admin.mydomain.co.uk/getHelp?ticketId, which would respond with a 301 response and an appropriate Location: http://helpdesk.domain.uk/help/ticketId header taking the user to the actual helpdesk URL.

You could use a proxy server or iframe proxying.

Use the following url //app2.mydomain.co.uk without the http or https.

It's not only a cross domain problem but a protocol issue :
You can't embed https into http page without this warning.
Consider using iframe inside your App1 :
<iframe src="https://app2.mydomain.co.uk" ></iframe>
Or maybe you can use CORS to access data between your two domains ( but i think it's not the point, you want the whole App2 page, isn't it ? )
Edit : By re-reading your question, i'm pretty sure of two thing :
You're not looking at the right direction. You say App2 don't use SSL, and that obviously false when Chrome say "Protocols must match"
It's not a "attach" or "detached" problem. If you put a link (blank or not) in a page, it can be load the new page without any problem, nor link with the referal page.
So my guess is : Your are calling App2 without SSL ( no https), BUT inside the App2, there is some https involved ( certainly some ajax query). So here is the problem : When you open the page without https, it's seem to load, but when the first https Ajax fires, it fail.
Try using https when calling your App2 url, and give us the result

My solution is this: in Application 1 you create a method your method that calling Application 2 on the server side, then you can use AJAX calling your method which will return result of Application 2.

How to open email by x-gm-msgid in Gmail with Javascript

I'm writing an extension which surfaces links to gmail messages. As the UI loads right in Gmail, I should be able to click on one of these links and have Gmail load it (without refreshing). I have "x-gm-msgid" available and theoretically, I should just be able to navigate to "https://mail.google.com/mail/u/0/#inbox/[x-gm-msgid]".
I've tried using
location.hash = "#inbox/[x-gm-msgid]"
I've tried using
history.pushState(null, null, "/mail/u/0/#inbox/[x-gm-msgid]")
Neither of which works. Gmail just thwarts any attempt to change the URL (unless it is done via user interaction)
Any thoughts on how to get around this restriction?

chrome.tabs.update should work.
Modifies the properties of a tab. Properties that are not specified in updateProperties are not modified. Note: This function can be used without requesting the 'tabs' permission in the manifest.