Android Question Button click in B4A WebView

• FileChooserInitialized (FilePathCallback As Object, FileChooserParams1 As FileChooserParams)
• OverrideUrlWithExternalAppIntent (WebResourceRequest1 As WebResourceRequest, ExternalAppIntent As Intent) As Boolean

FrostCodes said:

Use UltimateWebview or WebviewExtra... They would solve most of your issues..

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ilan said:

i am not sure i have understood you question. do you load a website to the webview and the buttons it that website are not working?
or are you trying to run a button click event in your b4a app that should be trigger from a button click inside the webview?

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chaurcey said:

Hi I have a webview that loads a page with a print button on it. But a click does not load the default print functionality as in a browser.
I have the override url but B4A does not go there as when a URL is clicked. It goes to the page_finished but there is no way to tell that it is a button click as the URL field is what is in the browser it seems.

I also loaded a file chooser test page and the file chooser button click does not seem to do anything either.

Any ideas?

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chaurcey said:

The webpage I was loading into webview is https://www.occ.treas.gov/about/who-we-are/history/1866-1913/Index-occ-history-1866-1913.html

Looking at the page source, it has a print button defined by the following code fragment:
<a href="#" role="button" onclick="printFriendly('.occ-grid1-1')">

Was looking at B4A Webview to provide more of an inapp look/feel but for now sticking with providing a button to open page in browser since I am handling arbitrary pages with arbitrary links and arbitrary buttons.

WebView including UltimateWebView does not seem to generate an event when the inputtype/role is "button" with an onclick javascript. it does if it is type "submit with onclick which of course produces the form action.

Looks like it is a limitation of android webview rather than b4a as android webview does not seem to have an onclick event. Also android webview does not seem to support javascript as part of the printmanager per https://developer.android.com/training/printing/html-docs which says "You cannot use JavaScript in a HTML document to trigger printing." in android Webview.

Look like android webview is designed for known custom pages not arbitrary pages but I am not an expert on webview.

UltimateView ShouldInterceptRequest event does receive the above print button click but no way to tell it was that button except searching on the word print but of course the word may not be print for arbitray pages especially when page is in non-English.

UltimateView certainly offer more functionality especially events than Webview so I will incorporate it in future code.

Again, opening page in browser is safest route as I see it for now unless I am missing something.

Again, thanks everyone for the great help.

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chaurcey said:

The webpage I was loading into webview is https://www.occ.treas.gov/about/who-we-are/history/1866-1913/Index-occ-history-1866-1913.html

Looking at the page source, it has a print button defined by the following code fragment:
<a href="#" role="button" onclick="printFriendly('.occ-grid1-1')">

Was looking at B4A Webview to provide more of an inapp look/feel but for now sticking with providing a button to open page in browser since I am handling arbitrary pages with arbitrary links and arbitrary buttons.

WebView including UltimateWebView does not seem to generate an event when the inputtype/role is "button" with an onclick javascript. it does if it is type "submit with onclick which of course produces the form action.

Looks like it is a limitation of android webview rather than b4a as android webview does not seem to have an onclick event. Also android webview does not seem to support javascript as part of the printmanager per https://developer.android.com/training/printing/html-docs which says "You cannot use JavaScript in a HTML document to trigger printing." in android Webview.

Look like android webview is designed for known custom pages not arbitrary pages but I am not an expert on webview.

UltimateView ShouldInterceptRequest event does receive the above print button click but no way to tell it was that button except searching on the word print but of course the word may not be print for arbitray pages especially when page is in non-English.

UltimateView certainly offer more functionality especially events than Webview so I will incorporate it in future code.

Again, opening page in browser is safest route as I see it for now unless I am missing something.

Again, thanks everyone for the great help.

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drgottjr said:

we can talk about

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drgottjr said:

you are mistaken in some of your conclusions. in any case, it was not difficult to print the url you refer to from within a webview (no browsers were harmed) on my local network-attached printer. see attached. we can talk about it unless you've moved on.

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drgottjr said:

what works in this particular case will not necessarily work in others.
you don't necessarily need the libraries you refer to, although in a
different case, you might.

you need a few lines of inline java, an event sub in the app, and
familiarity with webview and b4a that you do not have yet.

we were expecting an error to be thrown when javascript's window.print()
is called. we do not actually get that far; two different errors are thrown
both are reported back to b4a. one holds the key. window.print() might
have held the key too, but you'll have to wait for another day and a
different webpage to find out (or generate it yourself in a dummy webpage.)

the "key" is a reference (in the literal sense, not the programming one) to
the .js file in which it occurred. that tells you the print button has been
clicked on. once you know that, you can print the page.

if you add a chromeclient (via a library), you will see errors seen by the
webview and sent to the console. you see them in the b4a log, but
they are not helpful, except in a post mortem. under normal circumstances,
you can't do anything that affects how the app behaves. however, if you
create your own chromeclient and override its onconsole() method, you
can raise an event in b4a (exactly like the pagefinished or overrideurl
events raised by webview and webviewextras, etc). so now, instead of
seeing errors in the log, you'll see them in the new event sub. now
you can control your destiny. if a console message refers to a
printing error, you launch your own page print. the user thinks he's
printing the page.

attached is the project. it should work out of the box. i tried it twice
before archiving. when you say you know how to print the page, i
assume you're referring to the Printing library. if not, you'll either
need to find it somewhere in the bowels of b4x or you need to
remove the few references to it and replace them with your own
print function. when i was initially trying to solve your problem,
i used my own webpage printing library, having forgotten b4a
already had one. so i used the Printing library in my example to
keep things simple. if you don't have the library, you'll get an
error as soon as you load the project. otherwise, all you need
is the javaobject library

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Ivica Golubovic said:

Your example works for that particular webpage, but not every webpage will contain printer-frendly in its URL. If you read my answer above, you will see that it indicates exactly what you did in your example. I repeat, your solution will only work for websites that contain printer-friendly text in their URL. In any other case, your solution will not start printing. Cheers.

Click to expand...

drgottjr said:

i stated quite clearly that my solution works in this particular case. thank you for repeating that. twice. but let's repeat it again: my solution works in this case. this case is, after all, what we are talking about. i was hoping to engage the OP in a discussion of why a solution to his problem would be unique.

solutions to given problems are sometimes discovered by various people independently of one other. if you had wanted to help the OP, you could have presented a solution. next time, provide the solution so as to avoid the perception that others are taking your ideas.

when it was clear the OP did not know how to follow your answer, i provided a my solution. by the way, did i mention that my solution is for this particular case?

cheers.

Click to expand...

drgottjr said:

what works in this particular case will not necessarily work in others.
you don't necessarily need the libraries you refer to, although in a
different case, you might.

you need a few lines of inline java, an event sub in the app, and
familiarity with webview and b4a that you do not have yet.

we were expecting an error to be thrown when javascript's window.print()
is called. we do not actually get that far; two different errors are thrown
both are reported back to b4a. one holds the key. window.print() might
have held the key too, but you'll have to wait for another day and a
different webpage to find out (or generate it yourself in a dummy webpage.)

the "key" is a reference (in the literal sense, not the programming one) to
the .js file in which it occurred. that tells you the print button has been
clicked on. once you know that, you can print the page.

if you add a chromeclient (via a library), you will see errors seen by the
webview and sent to the console. you see them in the b4a log, but
they are not helpful, except in a post mortem. under normal circumstances,
you can't do anything that affects how the app behaves. however, if you
create your own chromeclient and override its onconsole() method, you
can raise an event in b4a (exactly like the pagefinished or overrideurl
events raised by webview and webviewextras, etc). so now, instead of
seeing errors in the log, you'll see them in the new event sub. now
you can control your destiny. if a console message refers to a
printing error, you launch your own page print. the user thinks he's
printing the page.

attached is the project. it should work out of the box. i tried it twice
before archiving. when you say you know how to print the page, i
assume you're referring to the Printing library. if not, you'll either
need to find it somewhere in the bowels of b4x or you need to
remove the few references to it and replace them with your own
print function. when i was initially trying to solve your problem,
i used my own webpage printing library, having forgotten b4a
already had one. so i used the Printing library in my example to
keep things simple. if you don't have the library, you'll get an
error as soon as you load the project. otherwise, all you need
is the javaobject library

Click to expand...

Ivica Golubovic said:

Your example works for that particular webpage, but not every webpage will contain printer-frendly in its URL. If you read my answer above, you will see that it indicates exactly what you did in your example. I repeat, your solution will only work for websites that contain printer-friendly text in their URL. In any other case, your solution will not start printing. Cheers.

Click to expand...