gmail - Dave's Blog

Win10 PWA Terminology

Folks familiar with JavaScript UWP apps in Win10 have often been confused by what PWAs in Win10 actually are. TLDR: PWAs in Win10 are simply JavaScript UWP apps. The main difference between these JS UWP Apps and our non-PWA JS UWP apps are our target end developer audience, and how we get Win10 PWAs into the Microsoft Store. See this Win10 blog post on PWAs on Win10 for related info.

Web App

On the web a subset of web sites are web apps. These are web sites that have app like behavior - that is a user might call it an app like Outlook, Maps or Gmail. And they may also have a W3C app manifest.

A subset of web apps are progressive web apps. Progressive web apps are web apps that have a W3C app manifest and a service worker. Various OSes are beginning to support PWAs as first class apps on their platform. This is true for Win10 as well in which PWAs are run as a WWA.

Windows Web App

In Win10 a WWA (Windows Web App) is an unofficial term for a JavaScript UWP app. These are UWP apps so they have an AppxManifest.xml, they are packaged in an Appx package, they run in an App Container, they use WinRT APIs, and are installed via the Microsoft Store. Specific to WWAs though, is that the AppxManifest.xml specifies a StartPage attribute identifying some HTML content to be used as the app. When the app is activated the OS will create a WWAHost.exe process that hosts the HTML content using the EdgeHtml rendering engine.

Packaged vs Hosted Web App

Within that we have a notion of a packaged web app and an HWA (hosted web app). There's no real technical distinction for the end developer between these two. The only real difference is whether the StartPage identifies remote HTML content on the web (HWA), or packaged HTML content from the app's appx package (packaged web app). An end developer may create an app that is a mix of these as well, with HTML content in the package and HTML content from the web. These terms are more like ends on a continuum and identifying two different developer scenarios since the underlying technical aspect is pretty much identical.

Win10 PWA

Win10 PWAs are simply HWAs that specify a StartPage of a URI for a PWA on the web. These are still JavaScript UWP apps with all the same behavior and abilities as other UWP apps. We have two ways of getting PWAs into the Microsoft Store as Win10 PWAs. The first is PWA Builder which is a tool that helps PWA end developers create and submit to the Microsoft Store a Win10 PWA appx package. The second is a crawler that runs over the web looking for PWAs which we convert and submit to the Store using an automated PWA Builder-like tool to create a Win10 PWA from PWAs on the web (see Welcoming PWAs to Win10 for more info). In both cases the conversion involves examining the PWAs W3C app manifest and producing a corresponding AppxManifest.xml. Not all features supported by AppxManifest.xml are also available in the W3c app manifest. But the result of PWA Builder can be a working starting point for end developers who can then update the AppxManifest.xml as they like to support features like share targets or others not available in W3C app manifests.

Easy: Connect your RSS or Atom feed to Google Buzz

It was relatively easy, although still more difficult than I would have guessed, to hook my bespoke website's Atom feed up to Google Buzz. I already have a Google email account and associated profile so Buzz just showed up in my Gmail interface. Setting it up it offered to connect to my YouTube account or my Google Chat account but I didn't see an option to connect to an arbitrary RSS or Atom feed like I expected.

But of course hooking up an arbitrary Atom or RSS feed is documented. You hook it up in the same manner you claim a website as your own via the Google Profile (for some reason they want to ensure you own the feed connected to your Buzz account). You do this via Google's social graph API which uses XFN or FOAF. I used XFN by simply adding a link to my feed to my Google profile (And be sure to check the 'This is a profile page about me' which ensures that a rel="me" tag is added to the HTML on your profile. This is how XFN works.) And by adding a corresponding link in my feed back to my Google profile page with the following:

atom:link rel="me" href="http://www.google.com/profiles/david.risney"

So more difficult than I would have expected (more difficult than just an 'Add your feed' button and textbox) but not super difficult. And yet after reading this Buzz from DeWitt Clinton I feel better about opting-in to Google's Social API.

Thoughts on registerProtocolHandler in HTML 5

I'm a big fan of the concept of registerProtocolHandler in HTML 5 and in FireFox 3, but not quite the implementation. From a high level, it allows web apps to register themselves as handlers of an URL scheme so for (the canonical) example, GMail can register for the mailto URL scheme. I like the concept:

• Better integration of web apps with your system.
• Its easy for web apps to do.
• Links to URNs can now take the user to the sites the user prefers for the sort of thing identified by the URN. For example, if I have a physical address in HTML, instead of making that an http link to Yahoo Maps, I can make the link a geo scheme URI and those who follow the link will get their preferred mapping site that has registered for that scheme. Actually, looking at the geo scheme's RFC, maybe I'd rather use some other URN scheme to represent the physical location, but you get the point.

• There's no way to know if you are the handler for a particular URL scheme which is an important question for web app URL protocol handler authors.
• There's no way to fallback to an http URL in the case that a particular URL scheme isn't registered. A suggested solution to testing the registration of a scheme is for browsers to provide an additional script method to check if a scheme is registered. I don't like the idea of writing script that walks over all my page's links and rewrites them based on that method. I'd much rather see a declarative and backwards compatible fallback mechanism, although I don't know what that would look like.
• There's no way to register for a namespace within the urn scheme URI, the info scheme URI, or the tag scheme URI. I want to register info:lccn/... (Library of Congress Card Number identifiers) to LibraryThing or Amazon and I want to register urn:duri:... (dated URIs) to the Web Archive, among other things.


• Will this result in a proliferation of unregistered URL schemes with clashing namespaces? The ESW Wiki notes why this would be bad.
• And last, although this is nitpickier than the rest, I don't like the '%s' syntax used in the registration method. I'd much rather pass in an URL template, like the URL template used in OpenSearch. If an URL template is used for matching rather than registering against a particular URL scheme, this could also allow for registering a namespace within a URN. For example something along the lines of: registerProtocolHandler("info:lccn/{lccnID}", "htttp://www.librarything.com/search_works.php?q={lccnID}", "LibraryThing LCCN")

Investigation of a Few Application Protocols (Updated)

Windows allows for application protocols in which, through the registry, you specify a URL scheme and a command line to have that URL passed to your application. Its an easy way to hook a webbrowser up to your application. Anyone can read the doc above and then walk through the registry and pick out the application protocols but just from that info you can't tell what the application expects these URLs to look like. I did a bit of research on some of the application protocols I've seen which is listed below. Good places to look for information on URI schemes: Wikipedia URI scheme, and ESW Wiki UriSchemes.

Gmail integration with Internet Explorer 8

With the new features of IE8 there's several easy ways to integrate Gmail, Google's web mail service, for mail composition, searching, and monitoring that I enjoy using.

Composition

I made a Send via Gmail activity that allows you to select some text, a document, or link and via the activity menu open a new tab to compose a new message with the selection. Go to my activity page and click "Send via Gmail" (source) to install it. I found info on the gmail composition URL in the comments of this gmail howto article and used that in the activity. I talked about activities previously.

Search

I've made a search provider that searches your gmail account. See my search provider page and select 'Gmail' (source) to install the Gmail search provider. Search providers aren't new to IE8 but this fits in with Gmail integration in IE. Again in the comments of another howto I found information on a Gmail search URL.

Monitor

New to IE8 is authenticated feed support and favorites bar monitoring which combined with the Gmail inbox feed means you can see when you get new mail in your favorites bar in IE. To do this, navigate to the feed https://mail.google.com/mail/feed/atom, click 'Subscribe to this feed', then click on the Add button in the upper left (the star with plus icon) and select 'Monitor on Favorites Bar' to add this as a monitored item in the favorites bar. Next, right click on the new item in your favorites bar, open the properties dialog, and enter your Gmail username and password into the new username and password fields. Now when you get new mail the Gmail feed item will shine and bold and you'll be able to get to new messages in the dropdown. I described monitored feed items previously.