Question: Why I'm only getting a white screen while the app is starting up?

[enchev]

From @gaurav-chandra on January 12, 2016 10:11

Why I'm only getting a white screen while the app is starting up? When I click on launcher icon, I get a white screen for sometime and then my application shows.

Copied from original issue: NativeScript/NativeScript#1356

[enchev]

Is this for Android or iOS? Or both?

[enchev]

From @gaurav-chandra on January 12, 2016 12:50

I develop for Android so I have checked it for Android only.

[slavchev]

@gaurav-chandra

Indeed, NativeScript apps could have slow startup. It could be because of the runtime or the app itself. Can you tell us the startup time reported from ActivityManager for the default app created with the following commands?

tns create app1
cd app1
tns platform add android
tns run android --justlaunch

You can find the startup time via the adb logcat command and should look for a line similar the to following one:

I/ActivityManager(XXX): Displayed org.nativescript.app1/com.tns.NativeScriptActivity: +XsXXXms

Also, can you tell us what device/emulator you use?

For splash screen, you can read Splash Screen For Your Android Applications article as well.

[gaurav-chandra]

@slavchev the time is

+4s133ms

@NathanaelA I don't have any major code or cpu intensive task. I just have

exports.navigatingto = function(args) {
    page = args.object;
    //there is a bug so we need to put this here
    page.actionBarHidden=false;
    page.bindingContext = main.$scope;
    main.$scope.set('couponCode',main.couponCode());
    var phoneField = view.getViewById(page,'phoneField');
    //console.dir(phoneField.android);
    var fArray = [];
    fArray[0] = new android.text.InputFilter.LengthFilter(10);
    phoneField.android.setFilters(fArray);
    insomnia.keepAwake().then(function() {
        console.log("Insomnia is active");
    });
};

setTimeout also does not help in my case. Does require() also take time to initialize? Probably if there are no modules to require, I can speed it up.

[gaurav-chandra]

@NathanaelA it is for this app. I wanted to try on the actual app I am building. Yes, there are couple of requires on top of the page.

I don't use an emulator. I directly run on device. Lenovo A6000 with Android 5. I will try by removing and calling requires only when needed.

[gaurav-chandra]

In the new app here is the log:

I/ActivityManager(  864): Displayed org.nativescript.app1/com.tns.NativeScriptActivity: +3s525ms

[slavchev]

@gaurav-chandra

I can confirm that ActivityManager reports ~3.5s for the first startup of a new app on a similar class device. And this is a lot of time indeed. The good news is that we work hard to improve application startup time. We built working prototypes that use V8 code caching and custom startup snapshots features. So far, the results are very promising. Right now it is hard to say when we will ship these improvements but I guess we will be ready for one of the coming releases. I will update this issue once I have more news.

[atanasovg]

Just to add some more info here:

• Significant amount (>1s) of this time is spent in generating the so called "Bindings" - that is the glue code for Java classes extended through JavaScript. You may try to run the tns build android --static-bindings command to pre-generate these.
• On a second+ application runs the loading time should be considerably faster because the file extraction and binding generation is already performed and cached.

Additionally, we are constantly working on improving the loading time of the {N} modules - for example for the 1.5.1 release we improved the require routine - modules are loaded only when/if needed:
NativeScript/NativeScript#1256

The custom startup snapshots feature mentioned by @slavchev also looks promising - we have a POC and it shows nearly 1s ! improvement. Our target is to reduce the loading time up to a maximum of 1.5 seconds for a first (cold) start.

[atanasovg]

@NathanaelA Any research on the matter is more than welcome! Performance, especially the loading time is always with high priority.

[gaurav-chandra]

Is this being looked into actively by core nativescript developers? Hello world NS app is still way slower than Hello world Native Java Android app.

[gaurav-chandra]

hey @NathanaelA thanks for the clarification. I guess you are right, I can show the splash screen.

[slavchev]

@gaurav-chandra

Is this being looked into actively by core nativescript developers?

Good news :) Recently @atanasovg merged PR #341. You will hear more details soon.

[Plamen5kov]

snapshot will optimize loading time:
related to: #425

[alvirtuoso]

Very Disappointing for some trying to decide if NativeScript is the one to learn. Great features BUT a let-down. Im really excited until i came across this app size prob.

[sipacate]

@alvirtuoso I wouldn't worry too much about this because it's under development. While the size is larger than we want right now, the pending solutions will address this in short order.

[alvirtuoso]

I wonder if a few of dependencies in the file be in separate thread or web service. I'm no expert but just a thought.

[Plamen5kov]

Loading time is further boosted, because of the static binding generator that now runs by default.

[gaurav-chandra]

awesome. will give it a try.

[Plamen5kov]

This is implemented, the app ships with splash by default. More information here: https://github.com/NativeScript/docs/blob/master/publishing/creating-launch-screens-android.md