B4J Question Webview per Session/Client at JServer

Magma · Saturday at 10:49 AM

Hi Fam...

I am creating a project... a server with API... that will be used from clients/browsers/apps...

Every time someone using API login https://atmyserver/myapi/login will create a webview for specific session (is it possible?)
thinking to do it something like that:

B4X:

    Public WebViewMap As Map
    WebViewMap.Initialize
....
    Dim wv As WebView
    wv.Initialize("")
    WebViewMap.Put(idofsession, wv)
...when second session will get new idofsession:
    Dim wv As WebView
    wv.Initialize("")
    WebViewMap.Put(idofsession, wv)

With running javascript with javaobject and getEngine... will use dom elements to login...

My silly question is that.... every webview using exclusive cookies? and if not? how to push it use different cookies - and how to have all these webviews open and using them the same time/concurrency without problems ?

Need at any API call - to login at every webview, browse pages, extract data or can split those between api calls ? what do you think ?
or at specific time session/webview will logout me as in standard browser?

Erel · Sunday at 6:37 AM

More information needed. Are you actually serving html? Do you want the mobile app to concurrently show multiple WebViews with different sessions?

Magma · Sunday at 8:05 AM

Well.. no.. let me take it from start..

There is one public website app that is not offering api.. and need to make it simpler for every client .. this is I am doing with a local b4j app... but I need to make it as a web service..

Erel · Sunday at 2:50 PM

You should use jServer for this.

Magma · Sunday at 3:52 PM

Erel said:
You should use jServer for this.

Yes I will serve clients via jserver... but how I will connect for every client at different web view to connect at this public site (not mine, gov) - login with credentials and browse pages.. for them...?

Actually my job is to automate some things... so with one move from their side ..my server will do 10 things.. but the same time for many others too...

Also I will have many works split at handles that will reuse their sessions... how to achieve that ?

Magma · 2025-09-29T10:15:18+0100

I will try to visualize - to understand it better...

This is a public gov site - any user can use... (there are services not offering API - so need to login and make some selections and get some pdf or set appointments and etc):

I ve managed with webview and using dom elements to automate some things - without the user need to make - many selections and etc... minimzed the time of using...

My question is not if i will use jserver ... i know i will use it.. is has to do... how i will have many webviews open the same time without mixxing the "cookies" of different user sessions... is it possible... or need something different to achieve that ?

All these (not just 6, but potentially hundreds) will be WebViews opened concurrently, and they will not be managed by a single jServer handle. Instead, the work will be distributed in jServer by opening sessions and closing them when the user signs out from my web service.

This app/server will be a middleware to automate some things for end user.

aeric · 2025-09-29T11:55:45+0100

Assume the public server returns an access token for each login, you can store all the tokens and then make the subsequent requests.

Magma · 2025-09-29T11:58:40+0100

aeric said:
Assume the public server returns an access token for each login, you can store all the tokens and then make the subsequent requests.

no ... the public "webpages" are just webpages (no api) as i said...

Check the visuals to understand.... a guy just browsing a site with his username/password.. clicking there... there... changing - adding some things... logouts...

no api

* I ve managed locally with b4j - created a program... automate all these... using dom - elements - clicking there and there... and return to guy the pdf needed... but locally - now need to make that "a service" - my web service...

Magma · 2025-09-29T12:04:32+0100

There are two thing making me afraid for the version i want to make...

1. webviews... can i have many, one per user/sessionuser - keep them open, and use them between handles without mixed with other webviews ?
2. my method is something like webextracting, like a bot, a) is it safe? b) is it illegal ?

aeric · 2025-09-29T12:29:06+0100

Magma said:
no ... the public "webpages" are just webpages (no api) as i said...

It is not related to api.
The server should return a token or cookie that store in the browser or client.

Magma · 2025-09-29T12:31:21+0100

aeric said:
It is not related to api.
The server should return a token or cookie that store in the browser or client.

yes - but i am using webview - and soon webviews... how to use those cookies ?

aeric · 2025-09-29T12:33:43+0100

Magma said:
yes - but i am using webview - and soon webviews... how to use those cookies ?

Have you thought not to use Webview?
I think it is a bad idea and make it more complicated.
Maybe it is possible with just OkHttpUtils.

Magma · 2025-09-29T13:36:46+0100

aeric said:
Have you thought not to use Webview?
I think it is a bad idea and make it more complicated.
Maybe it is possible with just OkHttpUtils.

View attachment 167438

Not possible.. need clicking to specific buttons and fill textboxes

Erel · 2025-09-30T06:40:52+0100

Am I right that your server needs to use a WebView to access the gov site? This is a fragile solution as changes to the gov site will break it.

aeric · 2025-09-30T06:46:36+0100

Magma said:
Not possible.. need clicking to specific buttons and fill textboxes

It is possible to make HTTP request of form submit using OkHttpUtils2, Curl or clients like Postman.

Erel · 2025-09-30T06:50:14+0100

Very true. You can use the browser development tools to monitor the requests that are made by the browser. In many cases, these are simple to reproduce with OkHttpUtils2.

See this short tutorial about using OkHttpUtils2 with jServer: https://www.b4x.com/android/forum/threads/server-jokhttputils2-server-version.124350/#content

Magma · 2025-09-30T07:00:02+0100

Erel said:
Am I right that your server needs to use a WebView to access the gov site? This is a fragile solution as changes to the gov site will break it.

Yes, i understand that some "future" changes on "UI" or changing some javascript function names will "break" my code... -->may be<... make my service unstable or totally not working but for now is the only solution..

No, with OKhttputils not possible to work with those webpages... using ajax / javascript... is not just passing some parameters to the next url or post something... need to fill some textboxes, select from options lists (not having the same options every time)...

Apologies for insisting, but I am already using the gov's UI through a WebView. I would like to kindly ask again (hope not being bad guy): is it possible to have multiple WebViews open concurrently, one for each session of my service, without them interfering with each other?

* The reason I want to do this is because I might want to 'prove' that some services should provide an API — and of course, it is also a general question whether B4J supports multiple open WebViews with different cookies.

Magma · 2025-09-30T07:25:26+0100

And to continue... my previous post...

Already.... BIG Accounting Software Companies in Greece... using gov sites to fill forms for accounting tax returns, VAT returns, for 20 years now (using selenium/gecko)! The gov didn't change the way... not providing api...

If you see their software... is like a robot using the webpages and filling/typing to textboxes... and all these in year 2025

Yes you are reading right...

Magma · 2025-09-30T11:11:48+0100

ok i didn't want to share for now, some code... but i will share some to understand that is not possible to use okhttputils... i ve made thousand expirements... i will not say which page is (and i ve changed the javascript elements to not show which gov service using) - but is an example of code i am using...

B4X:

Sub DeleteItemInList(myid As String, myCode As String) As ResumableSub

    wv.LoadUrl("https://xxxxxxxxxxx.gr/xxxform/xxxx/ListItems")
    Wait For wv_PageFinished(URL As String)
    Sleep(2000)
    wait for(RunJavaScript($"deleteItem('${myid}','${myCode}');"$)) complete (result1 As String)  'here i am running javascript of webpage - that returns confirmation window
    Sleep(2000)
    Dim jsConfirm As String
    jsConfirm = "(function() {" & _
            "  try {" & _
            "    var yesBtn = document.querySelector('button.boot-accept');" & _
            "    if (yesBtn) yesBtn.click();" & _
            "    return 'CONFIRMED';" & _
            "  } catch(e) {" & _
            "    return 'ERROR: ' + e.message;" & _
            "  }" & _
            "})()"

    Wait For(RunJavaScript(jsConfirm)) Complete (result2 As String)  'clicking "YES" at confirmation window
    Return result2

End Sub

What is doing...

1. Already showing a list with items from a previous web browsing page...
2. calling function javascript with "deleteItem" name passing myid and myCode
3. waiting for confirmation window
4. clicking Yes to continue...

Then i am calling other page to get all items... to verify if deleted... and all ok...

B4J Question Webview per Session/Client at JServer

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