Cell.cross() returns error in Google Refine projects

Question

I'm trying to create a new column based on my main project's Date column that pulls timeline events from another Google Refine project:

cell.cross("Clean5 Timeline", "TimelineDate").cells["TimelineEvent"].value[0]

The dates are in the same format in both Google Refine projects. But it fills no cells, and I get this error:

Error: Cannot retrieve field from null

This —  cell.cross("Clean5 Timeline", "TimelineDate") — returns [ ] for rows where there should be a match.

And this — cell.cross("Clean5 Timeline", "TimelineDate").cells["TimelineEvent"] — returns null for those rows.

I copied the syntax directly from the GREL help files: http://code.google.com/p/google-refine/wiki/GRELOtherFunctions. Can anyone suggest what I may be overlooking?

Thanks.

Answer 1

Without access to your projects it's going to be difficult to answer this, but the first thing I'd suggest is that you trim back your expression to find out exactly where the null is coming from.

Since

cell.cross("Clean5 Timeline", "TimelineDate")

is returning an empty array ([]), nothing based on that result is going to work.

There are three possible problems that I can think of: 1) the project name is wrong, 2) the column name is wrong, 3) the data values don't match (or Refine doesn't think they do), or 4) you are running into a caching bug with cross() that exists in Refine 2.5.

Restarting the Refine server should clear the cache if you're running into the bug and it's also fixed in the current source repository. The fix will be included in OpenRefine 2.6.