Is it useful using WebView whole layout in native Android app? - android

I am currently developing a native android app. My app has a lot of activities. I want to develop native android app. But in some case, I want to use a webview where the entire layout is just a webview. Not linear or relative or another layout, just a webview. All of the images and other things running in HTML. All of screen will run in HTML5.
So, I can partially transfer my app into iphone app or other platforms. This is the benefit of this way to me.
But I don't know. Is this way better? What will the performance be? What is the disadvantages of converting to an HTML5 app?
Can you explain?

There is a very good presentation about this very topic.
Performance: You are adding an additional layer in between, A webkit engine cannot always match native (and sometimes hardware accelerated) rendering performance.
Disadvantages: One is that the API use is limited, you can bind a page's JavaScript to Native code, but not all functionality is available.Though you might want to have a look at capabilities of Cordova project. Another is that emulating complex widgets via JavaScript will slow down the page.
Portability: Indeed is a great advantage, that's why PhoneGap and Cordova are popular. Though many like Facebook App etc have switched to native App for better performance.
The approach you require actually depends on your requirements. This may be my personal rant but IMHO: a markup can be only twisted so far, it can't out-perform industrial grade GUI programming setups as of yet.

Cons WebView
Can't use full performance of device, Since web view form an extra layer.
Web view can't listen all user event.
You can't fully share or save data from your web view to app.
Take more time to load. Other we get all things in a simple API and can be rendered.
Changing a simple fields in page need to load full page again.
Online required, can't extend offline features.
Orientation changes and full screen make difficulties.
Pros of using Web view
One page for both android and IOS.
I think the main advantage is the ability to make changes without the need for each user to update the app on his device, because all the pages are on your server.
No wait for app store approval for updation.
Some Techniques
Native elements TOGETHER with WebView. I think it will be much better, as there are a lot of functions that can't be done with WebView only. The combination of the two is much more recommended.
Rendering from locally, Create an assets directory for HTML files – Android internally maps it to file:///android_asset/ (note singular asset). So you can feed your web view form locally even if you are offline.

I think -by using this way- your app quality will be weak and app will be hard to use because the webview object not having a lot of tools that you can make it be compatible with android. e.g you can't share or save data from your webview to app. whatever that reference on your app what need and what dosen't need, by the way i tried to develop an app with html but it was bad.

Related

React-Native Server Driven ui

I always wonder how apps like Airbnb, Flipkart, and Swiggy update their UI on the fly. Even if I didn’t update the app, Flipkart shows different UIs during festivals, while Swiggy always changes its UI based on the device location.
How I implement this in my react-native-app?
Webview is the solution?
Kindly help me..
Thanks
There are multiple ways you can go about doing this.
One way would be to use WebViews as you've mentioned, this would make it trivial to change the interfaces as it's entierly controled in the servers. But the main issue with this approch will be performance and non native look and feel. These are the two main advantages of using React Native over hybrid frameworks in the first place and therefor, it wouldn't make much sense to use WebViews everywhere. But if there's a small slice of your application that updates regularly(ex - terms of service) you could use a WebView to do the custom views.
A more common way that's low effort would be to have all the code in place for the different looks, but use feature flags to toggle different views. This would work the same way that a dark theme would work. The amount of customization we can do this way is limited because we need to code everything ahead of time.
Another way is to use server driven UIs. With this approch, you will have a pre defined templates in the client that you them populate on run-time with data from the server. For a very simple example, you could have a header image that could be populated with a seasonal greeting image. But instead of simple things like images, this can be much more visible chagnes as well. (ex - List view instead of Grid View)
One more involved way would be to use code push. This would allow things like seasonal UI changes. But this requires a lot more setup and might not provide the best user experience.
Webview is best because this way you can change the UI and the business logic or UI handling logic.
But you have to develop a minimum architecture for that.
Here is my way.
Develop Host layer to use camera, shared preference, file system etc.
Develop a communication layer which will be responsible for communication between your webview and the host layer so that your webview can access all the required device platform(eg. android or ios) features which can not be normally accessed directly from webview.
So now you can render whatever UI(by HTML and CSS) you want, you can put whatever logic you want via javascript also now you can access all the required device features you really need.
So, now you are the king of your app.
Just you have to keep updating the UI or logic in server when you really need.
Some cons are there like
webview in android is different than our normal browser. Some required features are not available.
Its behaviors is different in different API level. So you have to test it very well. For testing, you can use Genymotion.
It does not work well in some old devices/APIs.
Look and feel really matters. But smart design can fix that problem.
If you want your whole app in a single webview then you have to compromise with page transition feature of android or ios. But again smart animation design will fix that.
But this is just a working solution not a smart solution for server driven UI.
I have used some server driven UI frameworks. But they seems to be overhead and lacks some features.
So there should be a framework by which we can render native UI dynamically from server with corresponding business logic change feature and accessibility of all the possible device functionalities.
A few months before I started to develop a Server driven UI framework. I did it little bit. But due to lack of time I really could not complete it.
If someone interested to contribute in this project feel free to contact with me.
I have a solid idea and architecture for this project.
This framework can create a revolution in the world of app development.
email: bedmad82#gmail.com

How an mobile compatible website handles the performance?

As we are now a days fond of bootstrap css which helps in compatiblity. My question is how exactly it deals with the loading as we have more load to the desktop apps and less to mobile. So according to me the css is handling through #media-screen object stylings with toggling of display and alignment. But even if we control the display from client side css or js. Server side will do its task of loading, So whether both desktop website and mobile website are taking the same amount of dataload.
Why am i asking this is if there is same amount of dataload, ill rather choose Android app instead of bootstrap for the fast performance.
Its important to remember that Bootstrap is a client side framework for helping to create responsive websites. You're right in that the same amount of stuff will be sent down the pipe regardless of the device that is used. This is true for any website that just uses client side frameworks to render for mobiles, such as jQuery Mobile.
If your application is big and complex then you may be better off serving up a different page for those mobile devices using Server side technologies. We use the Microsoft .Net stack which can render different views/scripts/css depending on a number of parameters to do with device. You can still use the Bootstrap framework, but maybe render less in the DOM, or have a smaller version of Bootstrap. You could even try a different framework such as the super tiny Pure framework.
Another alternative like you said is to build a native app. This will generally (if you make it right) be faster that what you can achieve in the browser, but you need to be careful that it is actually providing something useful to the user to encourage them to install it. If you are just using it to make it easier to make your website then you're doing it wrong, but if you are building a highly complex app that can leverage some of the extra functionality you can use in a native app then it may be a good way round it.
Without a real question there isn't a huge amount more than my own experience to draw on here, and there is no real right answer to how you go about it, but in answer to the question of how it deals with loading, client side frameworks can't really change what is being loaded without serious customisation or using some server side technology to deliver different pages altogether.

Create a Booklet like app in Phonegap

I am making a Book like app in Phonegap with Quiz... I want to keep 20 chapters for learning C. I am confused on how to use the single page architecture for such an app. I have also made a similar app for Android using JQuery Mobile and Android WebView before I was familiar with Phonegap but the application contained a number of (around 15 ) pages..and the Look & Feel was no more much native.
Any Suggestions on how to follow a single page architecture to create a book accessing its page contents from WebSQL for e.g. Chapter_title, page_heading, topic_contents ... and images if any.
Couple of months back I was in your situation. I experimented with jquery mobile, native application and phonegap. Building a web application at first seemed very attractive at first as the coding is a lot easier compared to native applications.Even though my answer is not very specific to your question it might be helpful to others. Here is my opinion based on my research:
Using phonegap slows your application responses, it loads slowly and together with jquery mobile the response and load time increases. So I didnot use it.
Using jquery alone was no different in Gingerbread mobile and on emulator you can clearly see the lag in switching between one div to another div. I didnot use it either.
What I did was android Webview. I wrote my own javascript and css and placed them on the section of my page. Used .... for changing pages on button click. This approach worked wonders for me and gave nearly native performance.
To follow the single page architecture in html use div element as I have mentioned in step 3 above. You can write a script to convert your WebSql data to json format. Then in your page where you need to call the data using javascript parse the data. Using json in really simple.

Create Android Client For Website

As a beginner wanting to become more familiar with the android platform, I wanted to create a web client for a website.
Something similar to https://play.google.com/store/apps/details?id=com.krinsen.javadocreader&hl=en
However, I am confused about how the author created the custom UI for the java docs.
To my understanding, there are 2 ways to do this.
One approach is with WebViews. I quickly prototyped a sample of this but I believe (correct me if I'm wrong) that I can't change the UI of the WebView and will have to view the page from the perspective of a browser. Unfortunately, this does not look very well as the website was not mobile optimized and there are inconsistent spacings and odd whitespace.
The second approach is to manually create each View using the different layouts provided by android (LinearLayout, TableLayout, etc). This should create a more custom mobile experience as I can manually construct how each page will look. However, this seems time-consuming as I will need to manually create a different UI page for each page of the website. Also I am confused as to how to pull the data from the website as each new view in the new UI will need the content from the website. Do I need to do HTML parsing to pull the content or is there a better way in the android sdk? What is a good approach that android developers take to extract the different forms of content from a website to redisplay on a android client?
Finally, since I have a very beginner understanding of this situation, am I correct in assuming that most likely the creator of the application mentioned above did something similar to the second approach I mentioned?
What is a good approach that android developers take to extract the different forms of content from a website to redisplay on a android client?
I think the best way is to provide an API for native application. Parsing HTML might look nice untill you need to suppport every change in your HTML page. But if you are not the owner of web-site there is no other choise if only you don't contact owners and ask for an API.

Hard to choose between native or cross platform for mobile application

I would like to create an application that support in both Android and iPhone.
It will be a interactive system for people to chat,share photos, etc.
So, it will consist lo-gin system, and all information for users will stored in mysql.
The question is here, should I write two sets of code for Android and iPhone or use some cross platform tools such as Phonegap + jQueryMobile for development.
1)I am wondering if html + css + javascript can complete all the functions that I want to include in this application if I use Phonegap.For example, how to handle the data transfer when loading data from db, should I create many .html for different pages. And the performance of using Phonegap...
2)Also, how about the time of development. Suppose there is one developer for Android, and one for iPhone. If we develop separately, we cannot help each other. On the other hand, web may be easier and we can research on this together.
3)Then, for the UI, it is easier for native language. But it is much difficult for web to make the things like mobile application.
I have asked a lot of questions. But I really think about this kind of issue for a long time and this is the time for me to have the decision.
Can anyone help me and give me some idea? Really thx....
Consider these Factors & Make your own wise decision,
which coding technique are you familiar with (HTML, CSS, JS) or (Java, C#).
For your First Question about data transfer from db,(your question is not clear internal db or server side db) if internal db Here is My QuestionI couldn't find the solution with the given answers, Help me if you can solve the same.(if you are talking about server side db) both for native & Cross platform it has to be achieved by API's
Time of Development is less in PhoneGap, when consider for both platforms since you are coding for both platforms simultaneously.
UI is Easier in Native ONLY when you go with Default styles,
For example consider yourself adding a Customized Button in *.png format.
you are gonna add single button multiple times in multiple sizes. If you wanna achieve clicked or Hover Effect you are Gonna add 2 more Customized Buttons. Which makes totally 3 images for single click for single Screen & Single Orientation, to achieve Correct Quality, u have to add same image in different sizes in ldpi, mdpi, hdpi, x-hdpi, no-dpi which finally brings you 5x3=15 images for single Button.(imagine the size of your app). Finally you have to add few lines of Codes to achieve Clicked effect
The same can be achieved in CSS with few lines of Codes(hardly 5 KB). Many animations also can be achieved easily with js.
UI can be changed when ever you want with change in few lines of codes.UI - PhoneGap Wins your app runs in Browser, both Android & iOS use the same browser engine Webkit, but still significant differences even in Webkit
Here are few more issues in PhoneGap,
Performance Native wins. In PhoneGap your browser has to load js, CSS which gives you notable delay, which cannot be ignored. If you want awesome UI go with CrossPlatform. To achieve performance choose Native.
Finally time to take decision.
It depends on what your requirements are. Evaluate if all your requirements are possible with Phonegap. For a list of supported features see: http://phonegap.com/about/features
Note that you can only use the native phone functionality that phonegap provides.
The development time depends on various factors, such as complexity, size of project and developer skill. I think the main difference here is developer skill, as the complexity and size of project are the same.
This is a tradeoff you have to make. An example phonegap application can be found here:
http://coenraets.org/blog/2011/10/sample-application-with-jquery-mobile-and-phonegap/
1.If you build application using cordova with more page, you app will get slow and some time it will get more bugs of design. So it
is better if you use single html page with different dives for each
pages and use "display: none;" from your java script or JQuery to
show and hide you current pages.then your application will more
fast.
there a lot of plugins in cordova those are supporting for both iOS and android so you don't need a iOS developer or android
developer if you have proper html and css design like responsive web
site.
UI won't be problem if you build a responsive html pages using bootstrap

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