# \[ODK Developers\] EvaluationContext error in FormLoaderTask.java

**URL:** <https://forum.getodk.org/t/odk-developers-evaluationcontext-error-in-formloadertask-java/1882>\
**Category:** Development\
**Created:** [January 16, 2013, 7:54pm UTC](https://forum.getodk.org/t/odk-developers-evaluationcontext-error-in-formloadertask-java/1882 "2013-01-16T19:54:23Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Mitch\_S](https://getodk.b-cdn.net/letter_avatar_proxy/v4/letter/m/3ec8ea/32.png) [@Mitch\_S](https://forum.getodk.org/u/Mitch_S)\
**Post date:** [January 16, 2013, 7:54pm UTC](https://forum.getodk.org/t/odk-developers-evaluationcontext-error-in-formloadertask-java/1882/1 "2013-01-16T19:54:23Z")

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ODK Collect is using a javarosa fork: [https://bitbucket.org/m.sundt/javarosa](https://bitbucket.org/m.sundt/javarosa)

I'm not sure what the status of the javarosa-core tree is these days, as  
DiMagi hasn't been doing official javarosa-core library releases, but has  
been adding significant functionality.

The special fork incorporates some of those latest changes.

Mitch

> **···**
>
> On Wed, Jan 16, 2013 at 10:54 AM, Stephanie Ku wrote:
> 
> > Hello Everyone,
> > 
> > I have replaced the javarosa library with the more recent version of  
> > javarosa-core (as I was planning on making some edits to the source code),  
> > however, I keep getting a simple constructor error from line 190 (in the  
> > doInBackground method of FormLoaderTask.java) fd.setEvaluationContext(newEvaluationContext(  
> > null));
> > 
> > The downloaded version of javarosa-core did not have a constructor of that  
> > format (hence the error). Javarosa-core EvaluationContext class here[https://bitbucket.org/javarosa/javarosa-pending/src/96a292dd2664cd9d74b5482c84cdd230e9c44602/core/src/org/javarosa/core/model/condition/EvaluationContext.java?at=default](https://bitbucket.org/javarosa/javarosa-pending/src/96a292dd2664cd9d74b5482c84cdd230e9c44602/core/src/org/javarosa/core/model/condition/EvaluationContext.java?at=default)  
> > .  
> > But, when I changed it to new EvaluationContext(), and ran the ODK  
> > application, I get a nullPointerException and am unable to fill out a blank  
> > form. The logs say that the NullPointerException stems from the constructor.
> > 
> > Any ideas on what's going wrong/how to fix it?
> > 
> > Thank you!
> 
> --  
> Mitch Sundt  
> Software Engineer  
> University of Washington  
> [mitchellsundt@gmail.com](mailto:mitchellsundt@gmail.com)

---

<div class="post-metadata">

**Author:** ![Clayton\_Sims](https://getodk.b-cdn.net/letter_avatar_proxy/v4/letter/c/a4c791/32.png) [@Clayton\_Sims](https://forum.getodk.org/u/Clayton_Sims)\
**Post date:** [January 21, 2013, 6:37pm UTC](https://forum.getodk.org/t/odk-developers-evaluationcontext-error-in-formloadertask-java/1882/2 "2013-01-21T18:37:51Z")

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Stephanie,

Apologies for the confusion. Mitch is correct that JavaRosa has undergone  
major structural changes, but the core committer's group hasn't come to a  
stable point to start doing library releases again.

Is there specific functionality you are looking for in the new libraries  
that isn't supported in Mitch's fork?

-Clayton

> **···**
>
> On Wed, Jan 16, 2013 at 2:54 PM, Mitch S wrote:
> 
> > ODK Collect is using a javarosa fork:  
> > [https://bitbucket.org/m.sundt/javarosa](https://bitbucket.org/m.sundt/javarosa)
> > 
> > I'm not sure what the status of the javarosa-core tree is these days, as  
> > DiMagi hasn't been doing official javarosa-core library releases, but has  
> > been adding significant functionality.
> > 
> > The special fork incorporates some of those latest changes.
> > 
> > Mitch
> > 
> > On Wed, Jan 16, 2013 at 10:54 AM, Stephanie Ku [stephanie.yt.ku@gmail.com](mailto:stephanie.yt.ku@gmail.com)wrote:
> > 
> > > Hello Everyone,
> > > 
> > > I have replaced the javarosa library with the more recent version of  
> > > javarosa-core (as I was planning on making some edits to the source code),  
> > > however, I keep getting a simple constructor error from line 190 (in the  
> > > doInBackground method of FormLoaderTask.java) fd.setEvaluationContext(newEvaluationContext(  
> > > null));
> > > 
> > > The downloaded version of javarosa-core did not have a constructor of  
> > > that format (hence the error). Javarosa-core EvaluationContext class here[https://bitbucket.org/javarosa/javarosa-pending/src/96a292dd2664cd9d74b5482c84cdd230e9c44602/core/src/org/javarosa/core/model/condition/EvaluationContext.java?at=default](https://bitbucket.org/javarosa/javarosa-pending/src/96a292dd2664cd9d74b5482c84cdd230e9c44602/core/src/org/javarosa/core/model/condition/EvaluationContext.java?at=default)  
> > > .  
> > > But, when I changed it to new EvaluationContext(), and ran the ODK  
> > > application, I get a nullPointerException and am unable to fill out a blank  
> > > form. The logs say that the NullPointerException stems from the constructor.
> > > 
> > > Any ideas on what's going wrong/how to fix it?
> > > 
> > > Thank you!
> > 
> > --  
> > Mitch Sundt  
> > Software Engineer  
> > University of Washington  
> > [mitchellsundt@gmail.com](mailto:mitchellsundt@gmail.com)