How to load data at launching Chrome App? - angularjs

What's the best practice of loading data at launching Chrome App?
The landing page of my Chrome App is dependent on some configuration data, which I've stored in the chrome local storage. However, reading chrome local storage is an asynchronous process. Hence, after the App has launched, there is a period of time when the landing page doesn't show correctly.
To avoid this blank time (due to the asynchronous process of reading local storage), I'm thinking about reading data at background JS. However, I haven't googled out what's the best practice to do it.
Anybody has any comments? Thanks.

just listen to the onLaunched event
chrome.app.runtime.onLaunched.addListener(function() {
// load your data
});

Here's one piece of helpful suggestion I've got from the Google Group. Share here so that someone with the same problem might refer to it:
You can read from chrome.storage in the background page and open the window when the data is ready. However, the user experience might be even worse, because instead of the incorrect landing page, you have no user feedback at all.
The usual (and easy to implement) solution is to show your landing page with some visual feedback during data loading, like a spinning wheel with a "Loading" label. If you UI really requires the data to show up, you can add this visual indicator as an opaque div on top of the whole window.
Some people use splash screens, but I don't think it adds to the user experience.

Related

How to get the current state of the tablet

Is there a way to get the current state of the tablet - if it is in sleep mode, in screen saver mode or if a picture is loaded - to get the name of the loaded picture for example. I didn't find anything in ALTabletService API, but judging on ALTabletService::resetTablet() - Reset the tablet as if no one used it before, i.e. clean the stack of activities, the web browser content, and the web browser cache. there is a stack of tablet activities and perhaps there is what I am looking for.
I don't think you can actually do that. You have to assume it's doing the right thing. If you need to check if your webview is loaded properly, why not raising an Event every 15s from the javascript and subscribe to it from Python? then as soon as Python does not receive this event for 15s, it can reload the page !

How to load a part of application before loading rest of the application in angularjs?

I could not think of a better title, Please suggest one.
I am planning to work on a large web application. It will take time to load the full application before application starts functioning.
Suppose its something like asana.com. If you have a link to the task and you open the link. It loads the application first and then shows the detail of the task.
Note: I have added another example in update 2
I want to do just the opposite. Suppose if I try to open the link directly. It should show me the tasks details first and then load the whole application in background.
What development strategy should I follow to implement such feature. Will angular be good for this? I have worked with angular for small projects and am capable of think in angular :)
I just wanted to be pointed in right direction.
Update 1:
I am using Apache2 PHP5 in backing as ReST API. I am thinking to change to GoLang http server. But that does not matter in this context :)
Update 2:
I have not yet started working on the application, but I know that its size is going to be big and its going to take time to load the application. This will be a javascript application, all the communication to web will be done mostly by API. APIs will be fast and it wont be slowing down the application. My main concern is the javascript library and the approach to the issue that I want to display the content of the page before the application is loaded and load the application in background.
As second example: https://chrome.google.com/webstore/detail/a-journey-through-middle/gjgkjeheegjnnmheaflhdocglkiegoni?utm_source=chrome-ntp-icon
If you open this link in chrome, it will load the application and then load the specific content in a popup. I want to load the content of the popup first and then load the application in background. How should I write my application to achieve that.
My suggestion (and I say this as I start to do similar vs. having proven it successful) would be to make some level of framework fairly static so that users get an almost instant response to the site loaded and then start the angular app with something like this
angular.bootstrap(document.getElementById("container"), ["app"])
Ref for the api - https://docs.angularjs.org/api/ng/function/angular.bootstrap
Ref for a demonstration of this - https://egghead.io/lessons/angularjs-angular-bootstrap-app-init
My expectation then is that you will be able to
Load your static elements quickly (which will just have placeholders for your content/material)
Access the data you want in the order you want to get it to present on the screen
Release any other part of the app you need to chrome it up/decorate or populate side items.

How to integrate payment gateway in applications created using javascript frameworks like ExtJs?

Our application is a one-page application created using ExtJs. For any user action, the browser tab is never reloaded and all the actions are performed using ajax. A user can open/close multiple ExtJs windows/panels within the same browser tab, and this way everything remains confined to the same browser tab.
Now, we need to integrate payment gateway in the application, which involves redirecting the user to the bank website and having her brought back to our application.
The issue is that when browser redirects the user, then all the application javascript code along with panels and windows get destroyed, and when the user comes back to the application then she finds it to be different from one she left.
As a solution to this, we were thinking of using following two appraoches:
Option 1. Maintaining the state of application - When user leaves for the bank's website then somehow we maintain the state of application - like which windows are opened carrying what data, which variables have which values etc.. and when user returns back, we generate the same application state for her.
Option 2. Have a browser pop-up window for payment gateway - We intend to provide a button which will open a small pop-up window carrying the transaction details, and in this pop-up window the entire payment gateway process will take place taking care of redirection and everything.
Option 1 is proving to be very cumbersome and complicated as maintaining the exact state is not getting feasible.
For Option 2, we are not sure if this is safe and possible?
Has anyone implemented such an approach earlier. Otherwise, what are the other options which we can go for?
Thanks for any help in advance.
I faced the problem and I implemented it using websocket/polling in the main application while a new window pops up for the payment.
After the payment is successful the main application will be notified.
That way each payment runs in it own sandbox totally unbound from the main application which makes maintenance quite easy. Note that our backend create a new session for each payment using the existing one.
I think it is not uncommon to open new windows for payment that's why I decided to go this.

Populating data in Silverlight App before its sent to he browser

I have a Silverlight App which gets its data from a database. My Silverlight app (running in the browser) retrieves the data through a web service. Pretty standard setup.
But there is some data which has to be there all the time or the App is in an invalid state - think data to fill drop downs etc. So I need this data to be "pre-loaded" into the App before it's sent down to the client so that it's never in an invalid state. Today I load this data via a web service call when my first page is initialized which can some times take a few seconds - during that time my App is in an invalid state.
Is there a way to populate data (from a backend database) in my Silverlight App before it's sent to the browser?
It is valid for an app to start and not be ready to use for a while, so long as the user cannot interact with it (or see the broken bits:))
Better to ensure your app has a splash screen/login page etc that displays until such time as the required resources are loaded. Once loaded you can set an app state to then show the main screen.
I had the same problem with a website that loaded the menu items via a service (as the text was data driven). Wound up running a progress spinner over the top (with a full-screen background).
I don't think you can. The application runtime occurs on the client's machine. I would suggest putting up a loading dialog while you bring those items down from the database.
What HiTech Magic said. Best practice for this is to use a splash screen or login page. You can also have your buttons (and interaction) disabled by default, and after the data is loaded, enable the UI. I would go with the spash screen though..

Progressive rendering of a webpage in Internet Explorer 7

I'm trying to improve the user perception of page load time of some web pages. These web pages take about 5 seconds to complete loading and rendering. The overall time is fine; but on clicking a link to load a page, nothing happens for about 4.5 seconds and then the whole page appears in one shot. This spoils the user experience, since the user is left wondering if anything is happening or not after clicking the link.
As I understand it, browsers are supposed to progressively render web pages as and when the resources available to render portions of the page become available to it. One thing I've seen recommended (by YSlow for eg:) is to put the css in the head and the javascript near the ending body tag - or as near the end of the page as possible. I've done this, but I don't see the initial part of the page rendering and then pausing for the javascript to load. The theory, as I understand it, is that the page will begin rendering progressively once all the CSS is loaded. I also understand that the page will pause rendering when any javascript is being executed/downloaded.
What else can affect progressive rendering on IE, especially on IE7?
I found out that javascript (specifically, some jQuery selectors) were slowing things down and preventing the page from rendering. We first optimized the jQuery code by removing some code which was repeatedly selecting the same elements. Then moved the code down to $.ready so that it executes after the page has loaded.
Overall, this has given us a 2 second boost in page load times as well as allowing more pages to load progressively.
A first step may be to understand what's going on on the network side, a tool like Fiddler will help you. In your case, Timeline display should be a good starting point.
Why not show notifications to users when a link is clicked that the page is currently in loading state.
You can do this:
window.onbeforeunload = function(e){ document.body.innerHTML='loading...';/*or even a better content/* };
I'm having the same load problems because of flash videos on a page. Will somebody tell me why oh my God why can't ie just load pages as nicely as firefox does???
If ie went out of business today, all the hours and days and nights I've wasted would be over.
I think it's about time that ie get with the demands of web maasters in 2009 and change the way they load pages.
If java script is used, people without java will see blank spaces.
Check for unclosed tags.
Check all images have width and height attributes.

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