XPages sometimes refresh and lose content

Question

I hope someone can help me solve a very serious problem we face at the moment with a business critical application losing data when a user works in it.

This happens randomly - I have never reproduced this but the users are in the system a lot more than me.

A document is created with a load of fields on it, and there are 2 rich text fields. We're using Domino 8.5.3 - there are no extension lib controls in use. The document has workflow built in, and all validation is done by a SSJS function called from the data query save event. There is an insane amount of logging to the sessionscope.log and also this is (now) captured for each user in a notes document so I can review what they are doing.

Sometimes, a user gets to a workflow step where they have to fill in a Rich Text field and make a choice in a dropdown field, then they submit the document with a workflow button. When the workflow button is pressed (does a Full Update) some client side JS runs first

// Process any autogenerated submit listeners
if( XSP._processListeners ){ // Not sure if this is valid in all versions of XPages
    XSP._processListeners( XSP.querySubmitListeners, document.forms[0].id );
}

(I added this to try and prevent the RTF fields losing their values after reading a blog but so far it's not working)

then the Server-side event runs and calls view.save() to trigger QS code (for validation) and PS code to run the workflow agent on the server.

95% of the time, this works fine.

5% of the time however, the page refreshes all the changes made, both to the RFT field (CKEditor) and the dropdown field are reloaded as they were previously, with no content. It's like the save hasn't happened, and the Full Update button has decided to work like a page refresh instead of a submit.

Under normal circumstances, the log shows that when a workflow button is pressed, the QuerySave code starts and returns True. Then the ID of the workflow button pressed is logged (so I can see which ones are being used when I am reviewing problems), then the PostSave code starts and finally returns true.

When there is a problem, The QuerySave event runs, returns true if the validation has passed, or false if it's failed, and then it stops. The ID of the workflow button is also logged. But the code should continue by calling the PostSave function if the QuerySave returns true - it doesn't even log that it's starting the PostSave function.

And to make matters worse, after the failure to call the PostSave code, the next thing that is logged is the beforePageLoad event running and this apparently reloads the page, which hasn't got the recent edits on it, and so the users loses all the information they have typed!

This has to be the most annoying problem I've ever encountered with XPages as I can find no reason why a successful QuerySave (or even a failure because mandatory fields weren't filled in) would cause the page to refresh like this and lose the content. Please please can someone help point me in the right direction??

Answer 1

It sounds as if in the 5% use cases, the document open for > 30mins and the XSP session is timing out - the submit causes the component tree to be re-created, and the now empty page returned back to the user. Try increasing the time out for the application to see if the issue goes away.

Answer 2

I would design the flow slightly different. In JSF/XPages validation belongs into validators, not into a QuerySave event. Also I'd rather use a submit for the buttons, so you don't need to trigger a view.save() in code. This does not interfere with JSF's sequence of things - but that's style not necessarily source of your problem.... idea about that:

As Jeremy I would as a first stop suspect a timeout, then the next stop is a fatal issue in your QuerySave event, that derails the runtime (for whatever reason). You can try something like this:

var qsResult = false;
// your code goes here, no return statements
// please and if you are happy
qsResult = true;
return qsResult;

The pessimistic approach would eventually tell you if something is wrong. Also: if there is an abort and your querySave just returns, then you might run in this trap

function noReturn() {return; }  //nothing comes back!

noReturn() == true;    --> false
noReturn() == false;   --> false
noReturn() != false;   --> true!!!!

What you need to check: what is your performance setting: serialize to disk, keep in memory or keep latest in memory? It could be you running foul of the way JavaScript libraries work.

A SSJS library is loaded whenever it is needed. Variables inside are initialized. A library is unloaded when memory conditions require it and all related variables are discarded. so if you rely on any variable in a JS Function that sits inside a SSJS library between calls you might or might not get the value back, which could describe your error condition. Stuff you want to keep should go into a scope (viewScope seems right here).

To make it a little more trickier: When you use closures and first class functions these functions have access to the variables from the parent function, unless the library had been unloaded. Also functions (you could park them in a scope too) don't serialize (open flaw) so you need to be careful when putting them into a scope.

If your stuff is really complex you might be better off with a backing bean. Did that help?

Answer 3

To create a managed bean (or more) check Per's article. Your validator would sit in a application bean:

<faces-config>
    <managed-bean>
       <managed-bean-name>workflowvalidator</managed-bean-name>
       <managed-bean-class>com.company.WfValidator</managed-bean-class>
       <managed-bean-scope>application</managed-bean-scope>
    </managed-bean>
</faces-config>

Inside you would use a map for the error messages

public Map<String,String> getErrorMessages() {
     if (this.errorStrings == null) { // errorStrings implements the MAP interface
        this.loadErrorDefinitions(); //Private method, loads from Domino
     }
     return this.errorStrings;
}

then you can use EL in the Error message string of your validators:

 workflowvalidator.errorMessage("some-id");

this allows XPages to pick the right one directly in EL, which is faster than SSJS. You could then go and implement your own custom Java validator that talks to that bean (this would allow you bypass SSJS here). Other than the example I wouldn't put the notes code in it, but talk to your WfValidator class. To do that you need to get a handle to it in Java:

private WfValidator getValidatorBean() {
    FacesContext fc = FacesContext.getCurrentInstance();
    return (WfValidator) fc.getApplication()
                           .getVariableResolver()
                           .resolveVariable(fc, "workflowvalidator");
}

Using the resolver you get access to the loaded bean. Hope that helps!

Answer 4

My experience is that this problem is due to keeping page in memory. Sometimes for some reason the page gets wiped out of memory. I'm seeing this when there is a lot of partial refreshes with rather complex backend Java processing. This processing somehow seems to take the space from memory that is used by the XPage.

The problem might have been fixed in later releases but I'm seeing it at least in 8.5.2.

In your case I would figure out some other workaround for the CKEditor bug and use "Keep pages on disk" option. Or if you can upgrade to 9.0.1 it might fix both problems.