topic Re: Help：how to show PNG image of a process using REST api? in Alfresco Archive

Help：how to show PNG image of a process using REST api?

jolly_ian — Sun, 17 Feb 2013 03:00:52 GMT

I want to create an HTML website using the REST APIs with JQuery and Ajax. Till now every thing works fine except that I cannot display the image of a process in HTML client.The problem originates from the fact that the rest API itself is the url to the image, but when I set the source of the image

Re: Help：how to show PNG image of a process using REST api?

jbarrez — Mon, 18 Feb 2013 08:53:49 GMT

I don't understand how an image can be 'too big' to be displayed? Does the server return wrong data?

That being said, Tijs is currently working on integrating a javascript only process diagram viewer in Explorer, might be worthwhile to check that out.

Re: Help：how to show PNG image of a process using REST api?

jolly_ian — Wed, 20 Feb 2013 02:01:19 GMT

I don't understand how an image can be 'too big' to be displayed? Does the server return wrong data?

That being said, Tijs is currently working on integrating a javascript only process diagram viewer in Explorer, might be worthwhile to check that out.

Thanks for your quick reply!~ Too big means that even though some browsers like Chrome is able to display image that written in BASE-64 code, this code can not be too long. Unfortunately, images of processes of Activiti are beyond that limitation.

What I want to know is quite simple: is there any effective javascript or HTML code that can let the browser display the PNG image generated from REST APIs?

Thanks again~

Re: Help：how to show PNG image of a process using REST api?

jbarrez — Wed, 20 Feb 2013 12:12:11 GMT

Ok, I see your problem

One really ugly hack which might work is to load your image with something like image.src = 'http://'+user+':'+pass+'@'+someUrl
But that's not really nice of course as it exposes the user and pass in the open. I did not test this though.

But it raises an interesting question: what is a good solution for this? Definitely not the way it is implemented now.
One way could be we need tokens in the url. Or something else … I'll discuss it with the team.

Re: Help：how to show PNG image of a process using REST api?

jbarrez — Wed, 20 Feb 2013 14:05:17 GMT

Okay, there are two use cases here:

- rest is used by another service (not html): then the security is importent
- rest is used from html/js: in this case the current solution is not workable. So we will remove security from that specific operation.

Hey Facebook also exposes your pics if you know the url! 😉

Re: Help：how to show PNG image of a process using REST api?

jolly_ian — Tue, 26 Feb 2013 02:46:35 GMT

Okay, there are two use cases here:

- rest is used by another service (not html): then the security is importent
- rest is used from html/js: in this case the current solution is not workable. So we will remove security from that specific operation.

Hey Facebook also exposes your pics if you know the url! 😉

Haha~ I see. You mean that the REST APIs were originally designed for another service, not HTML. This is the reason why I cannot load the image in my browser.

Thanks for your kind reply! I hope you could let me know if this security problem is solved.

Re: Help：how to show PNG image of a process using REST api?

jbarrez — Tue, 26 Feb 2013 10:03:03 GMT

Well, we've removed security from that service on master. So in 5.12 it will be possible to fetch without any security.

Re: Help：how to show PNG image of a process using REST api?

sergiolog10 — Wed, 29 Apr 2015 19:50:04 GMT

I have a similar problem with the URL /repository/process-definition/{id}/image. I'd like the use the URL from the processDefinition JSON fetch and let the browser show the image by adding /image to the URL it already have. That URL is still protected, any chance of having it opened ?

Thanks,

Re: Help：how to show PNG image of a process using REST api?

jbarrez — Thu, 07 May 2015 12:28:31 GMT

Not sure what you mean, it's open : https://github.com/Activiti/Activiti/blob/master/modules/activiti-rest/src/main/java/org/activiti/rest/service/api/repository/ProcessDefinitionImageResource.java#L36