flutter web loading first page size - lazy-loading

I am programming a large web site.
My main problem is the volume of the web at the end of the work
When the user enters the website address, are all the designed web pages loaded or only the first page is loaded and other pages are loaded according to the user's request?
Because in other programming languages, the entire website is not loaded, but this happens in web applications.

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What is a progressive web app in layman's terms?

I have been a dev for some years now, but I can't wrap my head around what exactly is a PWA.
For example, if an app runs on a mobile phone it is a native app. I can point to it and tell people that "look it is a native app."
In a similar sense, what is a PWA? Where does it run? Which app can I point to and tell that it is a PWA?
From what I have read on the web I feel that a PWA is a website that has modern technologies and gives a "native app like" experience to the user.
Is my understanding correct?
All in all, it is a website that has native-like experience?
If so how does a user separate a normal website form a PWA?
The concept of the progressive web app (PWA) was approached by Google in late 2015. They are basically web applications (Website) but have look and feel like other native mobile apps. The progressive web app enabled websites can offer functionalities such as working offline, push notifications, and device hardware access.
Benefits of the progressive web app:
1. Smaller and Faster:
The progressive web apps are much smaller in size than native apps. They don’t even need to install. That’s they are not wasting disc space and load very fast.
2. Responsive Interface:
Progressive web app (PWA) supported web pages are capable to fit in every screen sizes automatically. It could be a smartphone, tablet, desktop or laptop.
3. No Updates Required:
Most of the mobile apps need regular weekly updates. Like the normal website, progressive web apps (PWA) are always loaded latest updated version whenever the user interaction happens and no App or Play Store approval required.
4. Cost Effective:
Native mobile apps need to be developed for both Android and iOS devices separately and their development cost is very high. On the other hand, progressive web apps are had the same features but the fraction of the prior price.
5. SEO Advantage:
Progressive web apps are discoverable by search engines and load super-fast. Just like other websites, their links are sharable too. This, in other words, gives good user experience and result in SEO rank boost.
6. Offline capabilities:
Due to the support of service worker API, PWAs are accessible in offline or low internet connections.
7. Security:
PWAs are delivered over HTTPS connection and secure user-data over each interaction.
8. Push Notifications:
By the support of push notifications, PWAs can interact easily with the users and provide a really amazing user experience.
9. Bypass the app stores:
PWAs don’t need the App store or Google play store support. Their updated version can be directly loaded from the web server without the requirement of app store approval. On the other hand, native apps need days of approval if any new update required. There are possibilities of getting rejected or banned.
10. Zero installation:
During browsing, progressive web app gets its own icon on phones and tablets, just like a mobile application, but without the need to go through the tedious and slow App Store installation process.
Disadvantages of the progressive web app:
1. Less access to system features:
Currently, Progressive Web Apps have limited access to native system features than native apps. Also, all browsers are not supporting its full features but maybe in near future, it will be the new standard of development.
2. More Android – Less Apple’s iOS:
progressive web apps are currently, most supported by Android devices. Apple’s iOS is only partially supporting.
3. No review standard:
progressive web apps don’t need any kind of review system which is applicable for native apps from the app store. It may make the process faster but lack of promotional benefits from the app store.
Progressive web app checklist:
The checklist for the progressive web app is extensive. I have described its main few items here.
1. HTTPS
2. Web app manifest - manifest.json
3. Service worker
4. Responsive design
5. App icon
6. First load fast even on 3G
Conclusions:
There are huge possibilities offered for the progressive web app. Although there are lots of features and browser adaptability expected in near future. But, whatever already exists in the market is enough to show a strong mobile presence.
Visit the video blog: https://www.youtube.com/watch?v=NVXP-RzA0Eo
A PWA is a website with certain progressive features, most notably the ability to load offline or in areas with spotty connection, load quickly, display push notifications, and have other native app qualities. The benefits of a PWA is that they run on any browsers (since they're a normal website, if the browser doesn't support PWAs then the user gets a normal website experience), even desktop browsers. On mobile devices, the user will often get prompted to install the web app to the home screen, which happens almost instantaneously and uses barely any data since the website is already loaded. This allows for way more "downloads" than a native app, leading to higher engagement. For another brief overview of what a PWA, Google has some great articles about them.
Technically speaking, a PWA is a website that has two things: a web app manifest file and a service worker.
A manifest is a JSON file (usually called manifest.json) with some information about the progressive web app. It contains information similar to what you would include with a native app. It has the name, the short name for display on home screens, icons, orientation, etc. A web app manifest can be used on any site (even non-PWAs) to give the browser more information and allow the site to create a shortcut on the user's homescreen, but it's required for a PWA. You can read more about it over on the Google Developer's site.
A service worker is a JavaScript file that can be installed by the browser to do certain tasks. This file will be run in the background of the site and can do things like caching resources, intercepting network requests (to do stuff like return data from the cache), receiving push notifications, background synchronization, etc. When a user first visits your site this JS file gets installed and starts running. This is the file that allows for things like offline functionality. You can read more about service workers on the Google Developer's site as well.
Roughly speaking PWA is a web app that has native feeling and can be installed to the users' home screen and can start & work offline with an optional sync to server when Internet connection gets available.
To be considered a Progressive Web App, your app must be:
Progressive - Work for every user, regardless of browser choice,
because they are built with progressive enhancement as a core tenet.
Responsive - Fit any form factor, desktop, mobile, tablet, or whatever
is next.
Connectivity independent - Enhanced with service workers to work
offline or on low quality networks.
App-like - Use the app-shell model to provide app-style navigation and
interactions.
Fresh - Always up-to-date thanks to the service worker update process.
Safe - Served via HTTPS to prevent snooping and ensure content has not
been tampered with.
Discoverable - Are identifiable as “applications” thanks to W3C
manifests and service worker registration scope allowing search
engines to find them.
Re-engageable - Make re-engagement easy through features like push
notifications.
Installable - Allow users to “keep” apps they find most useful on
their home screen without the hassle of an app store.
Linkable - Easily share via URL and not require complex installation.
I think PWA is quite a broad term. I say broad because there are many ways of developing and distributing a PWA. In Layman's terms a Progressive Web App is a 'web site' that is effectively used/displayed like a native app. I believe an example of this would be something like phonegap? where phonegap built an app 'surrounding/scaffolding' and displayed a webpage with some custom CSS over the top. (Editorial Note: Phonegap is not related to progressive web apps. Phonegap creates actual, native applications. Wrapping a website in a native application is very different from progressive web apps.)
Most recently though I've been working on a lot of react only based website which I believe is the closest to PWA you can get at the moment (especially for IOS who only support minimal feature to encourage you to build native apps for their app store).
But yea it's basically an app like app that's not an app; rendering from a web page :thumbsup:
Progressive Web Apps (PWAs) are web apps that follow a set of guidelines
Starts fast, stays fast
Performance plays a significant role in the success of any online experience, because high performing sites engage and retain users better than poorly performing ones. Sites should focus on optimizing for user-centric performance metrics.
Works in any browser
Users can use any browser they choose to access your web app before it's installed.
Responsive to any screen size
Users can use your PWA on any screen size and all of the content is available at any viewport size.
Provides a custom offline page
When users are offline, keeping them in your PWA provides a more seamless experience than dropping back to the default browser offline page.
Is installable
Users who install or add apps to their device tend to engage with those apps more.
For more details see What makes a good Progressive Web App?

How to make reactjs serve static pages for SEO

I have this reactjs webapp - http://52.26.51.120/
It loads a single page and then you can click links to dynamically load other boards on the same page... such as 52.26.51.120/#/b, 52.26.51.120/#/g
Now the thing is, I want each of these to be an individual page, for the purpose of seo. I want you to be able to google "my-site.com g", and you will see the result 52.26.51.120/#/g. This obviously cant work if you are using reactjs and it is all on one page. Google will only render and cache that main page (can it even render that page? does google execute javascript?)
Even more specifically, id want something like my-site.com/g/1234 to load a thread. There could be a thousand threads every day, so im not sure how to handle that.
Are there any solutions to this? to allow react to possibly serve up static pages as html so that they can be cached on google? I am using expressjs and webpack as my server right now, and all the code is executed in jsx files.
Thanks
You can use Prerender.io service. In a nutshell you will need to connect your server app or web server with prerender service and do little setup (see documentation). After that search engines and crawlers will be served with a static (prerendered) content while users will get classic React.js (or any other single page) app.
There is a hosted service with free tier or open source version
I suspect you could do some smart configuration with nginx and it could convert a url of domain/board to a redirection of domain/#/board when detecting the user-agent as a bot instead of a typical user.

Issue with rending an MVC 4 website inside an iFrame

We have an existing live MVC 4 website that works exactly as it supposed to, running in an Azure Web Role.
A third party want to embed our site in an iFrame on their site (a small part of it anyway, one form really)
I'm no fan of iFrames but this is what they want to do and our business are happy for them to do it.
Except it doesn't seem to work at all.
So I tested it myself with an html page just running on my machine.=, with just an iFrame and a link to the site.
The default page loads fine. It is a forms login screen, when I submit a login, the site crashes into the exception handing and it doesn't provide much useful information.
I then tried pointing the iFrame at the site running in my dev environment. Submitting the login and debugging into the action, the code flows through correctly, no error and tries to return the correct view, but iframe refreshes to the login screen again.
What could be causing this? What am I missing?

What is the difference between Apache NetUI and Struts?

What is the difference between JPF (Apache netUI) and Struts? When should I use JPF in web applications? What are the pros and cons about JPF?
Apache Struts is an open-source framework that provides support to Model-View-Controller
implementations of web-pages. Its goal is to separate these three parts of the project: the model (application logic that interacts with a database) from the view (HTML pages presented to the client) and the controller (instance that passes information between view and model). It has a tag library
that eases the production of form-based applications with server pages.
NetUI is also a MVC framework that is part of Beehive Project, which aims for the reduction of the necessary code on J2EE projects
by using JSR-175 java annotations.
NetUI was built atop Struts, and it provides a Page Flow Controller class that separates navigational control from presentation
of the web-project, keeping a clean JSP code and enabling the reuse of navigational/flow logic (also, it provides a set of JSP tags for rendering HTML/XHTML).
Now, regarding your other question about when to use JPF: Page flows control all of the major features of a web application: how users navigate from page to page, user requests, and access to the web application's back-end resources. You should use them when you need this kind of control for your application.
For example, with normal HTML pages, each page is linked directly to other pages.
page > page > page > page
When using page flows, pages and actions are interwoven, transparently.
page > action > page > action > page > action > page
Here is an image to illustrate this situation. The .jsp squares are static pages, while the other ones are JPF controllers.
You can read more about all of this in the apache beehive documentation, where I got the most of these information.

Windows 8 App - Loading an external Page

Is there a way to load an external page within a WinJS Windows 8 App? I wanted to load something similar to the following;
http://www.highcharts.com/demo/line-ajax
You can reference the external page in an iframe, which will load that page in the web context (giving it different access than pages you might load that are part of your app).
Check How to link to external web pages for a full discussion of the various options.