A question came up the other day in the office: "Everyone keeps saying Web Intents died because of the UX, but no one has actually said what the issues were". I looked back over a bunch of my notes and blog posts and it's correct, I don't think we documented the holistic set of UX issues that we faced.
Wide array of actions and data types
We never optimized for the user intent and all were treated equally: Sharing == Viewing == Picking == Editing == Any other intent, and this caused a number of issues. When the user triggers an action they are presented with a generic box with a list of things that they could click and almost 0 context. There were no affordances for the language and the phrasing of what we wanted the user to do. If they wanted to "pick an image", we could have displayed a little file picker with a photo or something to that effect. Given the scope of all the possible user actions and data types it became impossible for us to make a simple experience for the user. This is one of the reasons why I have suggested in the past that we start small and solve one specific user action (Share perhaps), solve that UX and then focus on another and another and then try to generalize a solution if one is required.
Expecting a return?
One specific issue was with how to wait for data return** — App A opens App B but needs data from a long running operation. If the user closes App A then there is no return path for the data and it will be lost. App B could save the data incrementally or locally but what you really wanted was some sort of stacking conntext so that you could return data from App B and it would be delivered to App A. We didn't solve this.
We could have made it so that apps opened modal, but that required a massive change to Chrome and as we all know modality is bad on the web so that is out.
Knowing to expect data will returned
startActivityForResult which has a very clear meaning for the developer requesting
an action to be completed: Start this and expect a result back. We didn't have this in the API
so we couldn't make any affordences for it in the UI.
We could have also made it explicit in the registration of the service so that it could say "I can return data" so that the system can understand that a service wants to return data and if a calling app expects only show those. I have seen a lot of people have suggesting new APIs to solve this issue: using postMessage, custom protocols etc. The problem os that it creates a lot of choice for developers to make either designing their app or and every new option reduces the chance that a calling app
Which leads on to the next problem.
Open Intents == Lots of Schema and Protocols
By having an open way of registering for and triggering Intents meant that we had as many different new APIs as the user could think of. It turns out standardizing these is incredibly hard.
Take sharing for instance, it seems pretty easy. Wrong. It depends on what you are sharing. If you are sharing a link, a document, a movie or an image. Each have different requirements for how the data should be passed between the apps because every single data type will have different types of meta-data that would be required.
Actually how do you defined the data-type for a link? Is it text/plain, text/uri-list or something else? I won't tell you how much we got caught up in just this one little area.
Best of all because it is an open ecosystem there is no way to enforce it so that neither the apps that made the call or returned the data would have any confidence that any data was delivered. If the app has no confidence the user will have no confidence and there is a massive UX breakdown there.
Always be picking
The user was in control of the app they used to complete an action, but that meant the user needed to make a choice every time an action was made by the users. We had followed Android's model for Intents at the time — it was only later that Android allowed you to pin an Activity to handle an Intent.
In summary, there was a lot of steps to launch an app and the user couldn't set a default handler.
Not being able to set a default app was one problem, another problem that we faced is that unlike on mobile, on desktop lots of users like to control how a site is launched, is it inline, is it replacing a window, is it openging a new tab etc.
We designed a way to target windows and the API then had either open in new window or embed in picker. There was a lot of choice for the developer and no control for the user and the user wouldn't know how any one experience would open, some sharing experiences would open a new window, some would just embed inline in the picker.
We didn't provide a solution to the problem that
also faces: No fallbacks.
If there is no app installed that can handle the users intent, you couldn't tell from the API and there were no clean ways to default to a system experience or a chrome provided experience. When we launched VIEW for RSS feeds intent we got rid of the default handler (which was just display XML) and this incensed the community although massively opened up the RSS reader ecosystem and driving a huge number of installs to a couple of Apps that handled the Intent. Developers need confidence that they are not going to leave their users hanging or that they are going to have to provide a solution themselves.
More specifically we had a way of falling back. We developed a way to query the Chrome Web Store for apps that could handle a certain intent. If there was an app in the Chrome Web Store you could then install it inline (I liked this), there was however, little confidence in the rating of the apps, why it was ranked the way it was or what the App actually did.
Registration of Intents if there was an
The API was a new API thus had 0 ecosystem around it (hence my current looks into intent: URI syntax).
Small piece of trivia. The logo used to indicate that a web app can handle a specific protocol handler was actually the original Web Intents logo.
[Todo: Insert image]
About Me: Paul Kinlan
I lead the Chrome Developer Relations team at Google.
We want people to have the best experience possible on the web without having to install a native app or produce content in a walled garden.
Our team tries to make it easier for developers to build on the web by supporting every Chrome release, creating great content to support developers on web.dev, contributing to MDN, helping to improve browser compatibility, and some of the best developer tools like Lighthouse, Workbox, Squoosh to name just a few.