On Fri, May 19, 2017 at 01:50:28PM +0200, Torsten Bergmann wrote:

Alistair Grant wrote

...

This looks really interesting, thanks for making it available. I'm on linux, so I guess it will need some porting.

I added support for Linux and tried on Ubuntu with Chromium. Works - see screenshot

Fantastic, thanks! I did have to change your script for it to work on my laptop: 1. isInDebugMode is false by default, which meant that chrome wasn't launched with remote debugging enabled. 2. Retrieving the remotes in GoogleChrome class>>tabPages failed because the browser hadn't had time to start up. I'll submit a pull request which adds a retry with delay. 3. I initially got a white image. This appears to be because the script doesn't wait for the navigation to complete before taking the screenshot. I just added an ugly delay, but I'm not yet sure what the best solution here is. | chrome page | chrome := GoogleChrome new debugOn; open; yourself. page := chrome tabPages first. page navigateTo: 'http://www.pharo.org'. (Delay forSeconds: 5) wait. page captureScreenshot scaledToSize: 200@300.

You need to load my OSLinux package (instead of OSOSX) from catalog. Or start Chrom manually in debug mode.

In the Pharo settings browser you can set the path to the chrome executable and the debug port to use.

I doubt that the chrome executable is in that many different places. Would you be open accepting a pull request which adds (what I assume is) the Ubuntu 16.04 default location?

Will add Windows support as well (using my OSWindows package)

...

Do you know how the DevTools protocol relates to headless chome, which will be available in Chrome 59? See https://developers.google.com/web/updates/2017/04/headless-chrome

Dont know - just try it.

...

In particular, is it possible to dump the DOM with your package?

I've seen that Brackets editor as well as Netbeans open Chrome to display webpages when editing and refresh when typing. Wanted to find out how it was done.

I have not implemented the full protocol. Only what was needed to show that it is possible and to do things like grabbing screenshots from websites using Pharo.

I've found a page that describes accessing the DOM, so it looks like it should be possible. I'll see what I can do...

There is a DOM domain that one could wrap - basically it is just sending JSON around, see https://chromedevtools.github.io/devtools-protocol

With

chrome := GoogleChrome open. chrome jsProtocolJSON. chrome browseProtocolJSON

you can now even retrieve the Protocol as JSON for the specific browser. With a little bit more work it should be possible to even generate the wrapper classes/methods from such a protocol spec.

Thanks again, Alistair

Hi Torsten, On Fri, May 19, 2017 at 10:50:41PM +0200, Torsten Bergmann wrote:

Hi Alistair,

cant look right now but two things:

- there are also events in the protocol - if we could hook Pharo into them this would solve the problem without abusing delay (because then you will get informed when the page loading is finished)

That would be great. It will be a while before I get a chance to look at this (I want to finish some proposed changes to the FileSystem packages first), but I'll try and include it then.

- you can write "5 seconds wait" in Pharo

Thanks for the tip (I'm still transitioning from VW 2.5 :-)).

Bye T.

...

Gesendet: Freitag, 19. Mai 2017 um 17:51 Uhr Von: "Alistair Grant" <akgrant0710@gmail.com> An: pharo-dev@lists.pharo.org Betreff: Re: [Pharo-dev] Chrome DevTools Protocol and Pharo

On Fri, May 19, 2017 at 01:50:28PM +0200, Torsten Bergmann wrote:

...

Alistair Grant wrote

...

This looks really interesting, thanks for making it available. I'm on linux, so I guess it will need some porting.

I added support for Linux and tried on Ubuntu with Chromium. Works - see screenshot

Fantastic, thanks!

I did have to change your script for it to work on my laptop:

1. isInDebugMode is false by default, which meant that chrome wasn't launched with remote debugging enabled.

2. Retrieving the remotes in GoogleChrome class>>tabPages failed because the browser hadn't had time to start up. I'll submit a pull request which adds a retry with delay.

I've submitted the PR to ping the browser while it starts up, and add /opt/google/chrome/chrome as a known location. Thanks again, Alistair

...

3. I initially got a white image. This appears to be because the script doesn't wait for the navigation to complete before taking the screenshot. I just added an ugly delay, but I'm not yet sure what the best solution here is.

| chrome page |

chrome := GoogleChrome new debugOn; open; yourself. page := chrome tabPages first. page navigateTo: 'http://www.pharo.org'. (Delay forSeconds: 5) wait. page captureScreenshot scaledToSize: 200@300.

...

You need to load my OSLinux package (instead of OSOSX) from catalog. Or start Chrom manually in debug mode.

In the Pharo settings browser you can set the path to the chrome executable and the debug port to use.

I doubt that the chrome executable is in that many different places. Would you be open accepting a pull request which adds (what I assume is) the Ubuntu 16.04 default location?

...

Will add Windows support as well (using my OSWindows package)

...

Do you know how the DevTools protocol relates to headless chome, which will be available in Chrome 59? See https://developers.google.com/web/updates/2017/04/headless-chrome

Dont know - just try it.

...

In particular, is it possible to dump the DOM with your package?

I've seen that Brackets editor as well as Netbeans open Chrome to display webpages when editing and refresh when typing. Wanted to find out how it was done.

I have not implemented the full protocol. Only what was needed to show that it is possible and to do things like grabbing screenshots from websites using Pharo.

I've found a page that describes accessing the DOM, so it looks like it should be possible. I'll see what I can do...

...

There is a DOM domain that one could wrap - basically it is just sending JSON around, see https://chromedevtools.github.io/devtools-protocol

With

chrome := GoogleChrome open. chrome jsProtocolJSON. chrome browseProtocolJSON

you can now even retrieve the Protocol as JSON for the specific browser. With a little bit more work it should be possible to even generate the wrapper classes/methods from such a protocol spec.

Hi Torsten and All, Quick Introduction for those not familiar with Pharo-Chrome: Pharo-Chrome enables Pharo to control and query Chrome / Chromium, in particular to retrieve the DOM of a page. This is useful as many modern pages are just a template which then loads some javascript to asynchronously build the DOM, meaning that the ZnEasy / Soap combination doesn't get the bulk of the information on a page. Pharo-Chrome is now mostly working, i.e. it is possible to open a connection to Chrome, navigate to a requested URL, wait for it to load, retrieve the DOM and then navigate the DOM using a subset of the Soap API, e.g. #findAllStrings:, #findAllTags:, attributeAt:, etc.. GoogleChrome class>>exampleNavigation has been updated to retrieve the DOM from http://pharo.org. GoogleChrome class>>get: is analogous to ZnEasy class>>get:, although it returns a ChromeNode, not an html string. I wasn't able to get rid of the delay while waiting for the page to finish loading. This actually makes sense, since, as mentioned above, many modern pages build the DOM asynchronously, so there's no clear indication of when it is complete. The default delay is currently 2000 milliseconds, which is about twice the maximum I saw needed (983ms), but this can be changed (ChromeTabPage>>pageLoadDelay:). I had three use cases for this library: one which works with ZnEasy+Soap, one that used to work with ZnEasy+Soap, but doesn't due to a page redesign, and one which I hadn't got working before. All three are working now. Unlike Soap, I've currently modelled the nodes as a single class, and have only implemented a subset of Soap's methods, but is enough for what I need. I've introduced a dependency on the Beacon logging framework. I find it useful, but can remove it if you don't want the additional dependency. (I'm planning to add some GoogleChrome specific logging classes and use those to better understand what pageLoadDelay should be). I was focussed on trying to understand the events that Chrome generates, so documentation is still lacking (read "missing" :-)). I'll generate a pull request after some more testing, tweaking and documenting, but if you would like to take a look, the code is available at: https://github.com/akgrant43/Pharo-Chrome/tree/development I haven't yet updated BaselineOfChrome with the Beacon dependency. I did merge in your two commits from May 23. If you, or anyone else, finds this useful, I welcome any feedback. P.S. I've just realised that I need to tidy up #sendMessage:, #sendMessageDictionary and #sendMessageDictionary:wait:. I'll do that as part of the genral tidy up. Cheers, Alistair # vim: tw=72 On Sun, May 21, 2017 at 09:37:56PM +0000, Alistair Grant wrote:

Hi Torsten,

On Fri, May 19, 2017 at 09:20:48PM +0000, Alistair Grant wrote:

...

On Fri, May 19, 2017 at 10:50:41PM +0200, Torsten Bergmann wrote:

...

Hi Alistair,

cant look right now but two things:

- there are also events in the protocol - if we could hook Pharo into them this would solve the problem without abusing delay (because then you will get informed when the page loading is finished)

That would be great. It will be a while before I get a chance to look at this (I want to finish some proposed changes to the FileSystem packages first), but I'll try and include it then.

I've got basic event listening working. It requires that all messages are read asynchronously, so I'll need to change the interface to handle that.

Knowing when a page has finished loading isn't quite as simple as looking for an event - a page can consist of multiple frames, and notifications are delivered for each frame. The page I'm interested in has around 25 frames.

If anyone has a good design pattern for writing an asynchronous WebSocket client please let me know, I don't have anything concrete in mind.

Thanks, Alistair

Thank you guys for your contributions, but I think that this kind of discussions should be done on pharo-users mailing-list, not here. pharo-dev should be use only if you contribute to core-pharo. Thank you Envoyé de mon iPhone

Le 28 mai 2017 à 10:22, askoh <askoh@askoh.com> a écrit :

Wonderful contribution. Having full control of an internet browser will give Smalltalk more freedom to innovate.

Now, can we make Pharo be a web server on demand? Then we can give anyone a URL and they can see the app or info we want to present. Pharo can communicate with anyone using a browser either automatically or under developer control.

All the best, Aik-Siong Koh

...

On May 27, 2017, at 3:23 PM, Alistair Grant [via Smalltalk] <[hidden email]> wrote:

Hi Torsten and All,

Quick Introduction for those not familiar with Pharo-Chrome:

Pharo-Chrome enables Pharo to control and query Chrome / Chromium, in particular to retrieve the DOM of a page. This is useful as many modern pages are just a template which then loads some javascript to asynchronously build the DOM, meaning that the ZnEasy / Soap combination doesn't get the bulk of the information on a page.

Pharo-Chrome is now mostly working, i.e. it is possible to open a connection to Chrome, navigate to a requested URL, wait for it to load, retrieve the DOM and then navigate the DOM using a subset of the Soap API, e.g. #findAllStrings:, #findAllTags:, attributeAt:, etc..

GoogleChrome class>>exampleNavigation has been updated to retrieve the DOM from http://pharo.org.

GoogleChrome class>>get: is analogous to ZnEasy class>>get:, although it returns a ChromeNode, not an html string.

I wasn't able to get rid of the delay while waiting for the page to finish loading. This actually makes sense, since, as mentioned above, many modern pages build the DOM asynchronously, so there's no clear indication of when it is complete. The default delay is currently 2000 milliseconds, which is about twice the maximum I saw needed (983ms), but this can be changed (ChromeTabPage>>pageLoadDelay:).

I had three use cases for this library: one which works with ZnEasy+Soap, one that used to work with ZnEasy+Soap, but doesn't due to a page redesign, and one which I hadn't got working before. All three are working now.

Unlike Soap, I've currently modelled the nodes as a single class, and have only implemented a subset of Soap's methods, but is enough for what I need.

I've introduced a dependency on the Beacon logging framework. I find it useful, but can remove it if you don't want the additional dependency. (I'm planning to add some GoogleChrome specific logging classes and use those to better understand what pageLoadDelay should be).

I was focussed on trying to understand the events that Chrome generates, so documentation is still lacking (read "missing" :-)).

I'll generate a pull request after some more testing, tweaking and documenting, but if you would like to take a look, the code is available at:

https://github.com/akgrant43/Pharo-Chrome/tree/development

I haven't yet updated BaselineOfChrome with the Beacon dependency. I did merge in your two commits from May 23.

If you, or anyone else, finds this useful, I welcome any feedback.

P.S. I've just realised that I need to tidy up #sendMessage:, #sendMessageDictionary and #sendMessageDictionary:wait:. I'll do that as part of the genral tidy up.

Cheers, Alistair

# vim: tw=72 On Sun, May 21, 2017 at 09:37:56PM +0000, Alistair Grant wrote:

...

Hi Torsten,

On Fri, May 19, 2017 at 09:20:48PM +0000, Alistair Grant wrote:

...

On Fri, May 19, 2017 at 10:50:41PM +0200, Torsten Bergmann wrote:

...

Hi Alistair,

cant look right now but two things:

- there are also events in the protocol - if we could hook Pharo into them this would solve the problem without abusing delay (because then you will get informed when the page loading is finished)

That would be great. It will be a while before I get a chance to look at this (I want to finish some proposed changes to the FileSystem packages first), but I'll try and include it then.

I've got basic event listening working. It requires that all messages are read asynchronously, so I'll need to change the interface to handle that.

Knowing when a page has finished loading isn't quite as simple as looking for an event - a page can consist of multiple frames, and notifications are delivered for each frame. The page I'm interested in has around 25 frames.

If anyone has a good design pattern for writing an asynchronous WebSocket client please let me know, I don't have anything concrete in mind.

Thanks, Alistair

If you reply to this email, your message will be added to the discussion below: http://forum.world.st/Chrome-DevTools-Protocol-and-Pharo-tp4947589p4948458.h... To unsubscribe from Chrome DevTools Protocol and Pharo, click here. NAML

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If you are up to a Smalltalk internet browser then check the old Scamper from Squeak and H. Hirzels post + screenshot on squeak-dev from this month: http://lists.squeakfoundation.org/pipermail/squeak-dev/2017-May/194481.html If you want a simple morphic based internet browser I guess this could be ported to Pharo. There was also "WithStyle" in VisualWorks Smalltalk, an XML based UI browser built back in the days by an (australian?) company. I guess it is still included in the commercial VisualWorks distribution. Dont know about the license http://forum.world.st/VW-7-5-and-WithStyle-td1408557.html Building a webbrowser in Smalltalk would be cool - but lots of work (HTML + CSS parsing, JavaScript layer, drawing, ...) that would require time. Thx T.

Gesendet: Freitag, 19. Mai 2017 um 03:30 Uhr Von: askoh <askoh@askoh.com> An: pharo-dev@lists.pharo.org Betreff: Re: [Pharo-dev] Chrome DevTools Protocol and Pharo

Torsten:

Excellent. This is a great start towards the Smalltalk Internet Browser I had envisioned. Hopefully, this integration can be made standard in Pharo and other Smalltalks in many platforms. Perhaps, someone can connect all Smalltalk IDEs to a cloud where the different dialects can really work together in synergy - share and pool code from all sources, minimize duplications, integrate local and external search, etc. Smalltalk has pioneered many things in the past and there is no reason for it to stop. Smalltalk makes it easier to do so and we can live up to the quote by Bob Martin "Smalltalkers will, eventually, win. So says this old C++ programmer".

Thanks, Aik-Siong Koh

-- View this message in context: http://forum.world.st/Chrome-DevTools-Protocol-and-Pharo-tp4947589p4947609.h... Sent from the Pharo Smalltalk Developers mailing list archive at Nabble.com.