Clarification needed on URL channel

ckacoroski

Hi,

I am considering using the URL channel to communicate with some external processes. A few questions:

What are the limits on the parameters sent (e.g. length, etc.)
Do all attributes of the object get sent as parameters or just some of them
How does the successURL work? Is this a page the AwareIM will display if the external request was successful? How does AwareIM determine if it was sucessful? Does it scan the return page text?
Is the failure URL parameter, 'failureURL=returnURL'. Same questions as #3 apply here.
Can I return data into an awareim object with this approach?
Are there any examples that use this type of service.

Thanks,

ski

aware_support

There are no limits
All attributes get sent
The concept is this:
Some web sites require that you sent a parameter that identifies the URL that the site should return to upon successful fulfilment of the service. So it's not Aware IM that determines whether the service has been successful, but the web site that you are calling. If Aware IM knows the name of the parameter to be sent it takes care of providing the right value for this parameter (i.e. the predefined Aware IM page that handles success of the service). The only thing that Aware IM requires you to provide is the name of the parameter and it will take care about the value of the parameter.
Exactly the same concept as in 3. but for the failure of the service
Yes, the data that is sent back from the web site is written into the notification that you define for the service (it must have exactly the same names for the attributes as parameters being sent by the web site). Once you have the notification you can store some or all of its attributes in a business object.
Yes, Library sample application - interaction with PayPal

ckacoroski

Ok, I need to get this working with a simple site so I understand it. I have a simple perl script running under apache that displays a form asking for two numbers, adds the numbers, and then returns the result. It works fine by going directly to the web page.

In AwareIM I created:

BO: AddNumService which has failureURL and sucessURL as text attributes (this is probably wrong, but I am not using them yet). This BO has a URL service "http://localhost/cgi-bin/qa.pl" with both the success and failure fields left blank. I have a service called addnum which takes AddNumParams as the input and has a custom reply called AddNumReply which has one attribute num3 (matches up with the perl script).

The AddNumParams object just has two attributes num1 and num2.

I then have an AddNumbers process which is:

Enter NEW AddNumParams
Request Service addnum of AddNumService using AddNumParams

I get the following errors in the logs:
2007-07-02 14:45:57,090 ERROR Reply#3 -Execution Exception after resuming a process message Operation error. Invalid service provider in the following rule:
REQUEST SERVICE addnum OF AddNumService USING AddNumParams
2007-07-02 14:45:57,093 ERROR Reply#3 -18 Resumed process AddNumbers has failed. Message is Operation error. Invalid service provider in the following rule:
REQUEST SERVICE addnum OF AddNumService USING AddNumParams Sending failure reply

Thanks for your help.

ski

ckacoroski

Duh, I have to create the service, not just define it. Ok I have the service created and I can access it just fine, but I am unclear about how to get the results back into AwareIM. Currently, I get the page that the site puts up (the entry form + the result). If I hit the back arrow on the browser, I get back to AwareIM where I can see the process still running. I have tried the standard reply and a custom reply where I create something (not sure what as it does not show up as an object or notification with an attribute. I will keep poking at it, but are there any examples that we can run through (paypal doesn't really work as it does not return data).

ski

aware_support

When you are saying that your Perl script "returns the result", how does it do it?

The URL channel assumes that the web site you call returns the result by calling the URL that is specified in the "success URL" parameter. For example, let's say the web site you are calling has "http:/www.website.php" URL and the "success URL" parameter is called "onSuccess". Aware IM automatically makes the following call:

http://www.website.php?onSuccess=AwareIMReturnURL&param1=value1&param2=value2...

where param1, param2 etc are attributes of the parameter object.
Aware IM automatically sets the value of "AwareIMReturnURL" and expects the web site to call this URL upon successful completion of its user interface, i.e. it expects it to make the following call:

http://AwareIMReturnURL?returnParam1=value1&returnParam2=value2 etc

where returnParam1, returnParam2 etc are parameters that the web site returns. You must have a custom reply notification defined with attributes "returnParam1, returnParam2" etc. After you call the service you can get the return values like so:

REQUEST SERVICE MyService OF MyProvider USING...
MyObject.ReturnAttribute1 = MyCustomReplyNotification.returnParam1
MyObject.ReturnAttribute2 = MyCustomReplyNotification.returnParam2

etc

ckacoroski

Getting close, but I now get an internal server error on the AwareIM side. This is from the perl website log:

Starting
http://localhost:8080/AwareIM/urlChannelSuccess.do, 1, 3, 4
4

Posting to: http://localhost:8080/AwareIM/urlChannelSuccess.do?num3=4

Response back:
<html><head><title>Apache Tomcat/5.0.28 - Error report</title><style></style> </head><body><h1>HTTP Status 500 - </h1><HR size=" 1" noshade="noshade"><p><b>type</b> Exception report</p><p><b>message</b> <u></u ></p><p><b>description</b> <u>The server encountered an internal error () that p revented it from fulfilling this request.</u></p><p><b>exception</b> <pre>java.l ang.NullPointerException
org.apache.struts.util.RequestUtils.forwardURL(RequestUtils.java:824)
org.apache.struts.util.RequestUtils.forwardURL(RequestUtils.java:747)
com.cc.framework.adapter.struts.FWRequestProcessor.processForwardConfig( Unknown Source)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java: 231)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
</pre></p><p><b>note</b> <u>The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.</u></p><HR size="1" noshade="noshade"><h3>Apac he Tomcat/5.0.28</h3></body></html>

Tomcat log is:
2007-07-05 10:27:12 StandardWrapperValve[action]: Servlet.service() for servlet action threw exception
java.lang.NullPointerException
at org.apache.struts.util.RequestUtils.forwardURL(RequestUtils.java:824)
at org.apache.struts.util.RequestUtils.forwardURL(RequestUtils.java:747)
at com.cc.framework.adapter.struts.FWRequestProcessor.processForwardConfig(Unknown Source)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:231)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198-)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118-)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Unknown Source)

ckacoroski

Tried by hand with no luck, but did not get the java error. What I did was to comment out the post from the perl code and just enter the url into my browser (e.g. http://localhost:8080/AwareIM/urlChannelSuccess.do?num3=3). It still does not work though. I am still confused about how to set up AwareIM to recieve the data back. Here is what I have:

BO: AddNumParams with num1 and num2 attributes, no rules

BO: AddNumReply with num3 attribute, no rules

BO: AddNumService with name attribute. no rules, marked as intelligent. URL communication channel active and the default. URL of service provider is http://localhost/cgi-bin/awareim.pl. success return url is successURL. fail return url is blank. it provides 1 service (addnum) with a custom reply called AddNumNotification that as Attributes num3.

Process: AddNumbers with 3 rules.
Rule1: create AddNumReply create AddNumNotification
Rule2: Enter new AddNumParameters
Rule3: Request service addnum of AddNumService using AddNumParams
AddNumReply.num3 = AddNumNotification.num3

One thing that doesn't make sense is that when I create the notification on AddNumService from the Service dialog, it doesn't show up as a notification in the left hand list. Why? I also tried creating a notification in the left side list separate from the AddNumServices BO and then just listing that in the services dialog. This did not work either.

ski

ckacoroski

I also tried creating the AddNumNotification with a string variable and using the rule: AddNumReply.num3 = as_number(AddNumNotification.num3). No luck.

In the log viewer, I see the request service action get triggered and then when I enter the return url in my browser, I see the next step (e.g. setting of the AddNumReply) action get triggered. It doesn't do anything because the AddNumNotification.num3 variable is null.

aware_support

Ski,

I see a couple of problems in what you are doing:

You should not create custom reply notification (AddNumNotification) yourself - it will be created automatically by Aware IM. So your rules should be:

Rule1: Enter NEW AddNumParameters
Rule2: Request service addnum of AddNumService using AddNumParams
Rule3: CREATE AddNumReply WITH AddNumReply.num3 = AddNumNotification.num3

You should not try to call Aware IM success URL explicitly - let Aware IM provide you with the value of the success URL in the "success URL" parameter and then call the URL that Aware IM provides.

ckacoroski

Ok, making progress. I was able to get values back into AwareIM. What threw me off was when you create the process, it will have a warning that the notification is possibly the wrong object because this is not a normal notification, but one that is created on the fly.

My last problem is accessing the URL that AwareIM provides programmatically. I have the perl web site script log everything so I know the URL. If I cut and paste the URL into a browser it works perfectly. However, if I try perl, wget, curl or any command line tool I get the following:

<html><head><title>Apache Tomcat/5.0.28 - Error report</title><style></style> </head><body><h1>HTTP Status 500 - </h1><HR size="1" noshade="noshade"><p><b>type</b> Exception report</p><p><b>message</b> <u></u></p><p><b>description</b> <u>The server encountered an internal error () that prevented it from fulfilling this request.</u></p><p><b>exception</b> <pre>java.lang.NullPointerException
org.apache.struts.util.RequestUtils.forwardURL(RequestUtils.java:824)
org.apache.struts.util.RequestUtils.forwardURL(RequestUtils.java:747)
com.cc.framework.adapter.struts.FWRequestProcessor.processForwardConfig(Unknown Source)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:231)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:397)
javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
</pre></p><p><b>note</b> <u>The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.</u></p><HR size="1" noshade="noshade"><h3>Apache Tomcat/5.0.28</h3></body></html>

The Tomcat logs have:

2007-07-06 15:57:37 StandardWrapperValve[action]: Servlet.service() for servlet action threw exception
java.lang.NullPointerException
at org.apache.struts.util.RequestUtils.forwardURL(RequestUtils.java:824)
at org.apache.struts.util.RequestUtils.forwardURL(RequestUtils.java:747)
at com.cc.framework.adapter.struts.FWRequestProcessor.processForwardConfig(Unknown Source)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:231)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:397)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198-)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118-)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java: at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Unknown Source)

Appreciate your ideas on why this only works with a web browser and not with any command line tool.

ski

ckacoroski

I think I may have found the problem by watching the packets with ethereal. It looks like AwareIM expects to have a cookie passed back to it when you hit the successURL return. The cookie is set in the browser when the person is in operation mode. This is why when I put the url into the browser it would work.

Problem is that my test perl website has not logged into AwareIM so it does not have a cookie.

Thanks for letting me know if this is the problem and what, if anything, can be done about it.

cheers,

ski

aware_support

Yes, Aware IM expects a cookie that stores its session info and there is no way around it.

I am not sure I understand why this is a problem for you. Communication with your Perl based site must have been initiated by a user working in a browser, so the cookie would have been created already when this user logged in. Or am I missing something?

ckacoroski

Whoops, I did not explain what I was trying to do well. I am starting from an AwareIM application and trying to call out to a perl function. For example, in my AwareIM application I create a new staff member. I then want to call a perl function that creates the directory on the file server. In the case of students, this entire process is automated in that the students are created in the student records system, I have an AwareIM process that runs at night an creates new students in AwareIM app, then I need to call out to perl to create the directories on disk.

I guess I will go back to the xml-rpc idea.

cheers,

ski

cchappell

You've got me curious. 🙂

How are you planning to use xml-rpc with Aware IM?