Fix cross function example

[wetneb]

It looks like the only example of the cross function we had in the docs was actually wrong… Can anyone confirm?

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[thadguidry]

Yes, the example is wrong in the sense that an Array might be the result, or it might not. Depends on if it returns an [ [ object Row ] ] Array technically? For now that's not likely to change? Until we introduce storing Arrays in cells?

The original expression syntax was to get the 1st Row from the Array
cell.cross("TestCross","Name")[0] et.al. @dfhuynh
But dunno if there is always 1 Row or Record only now after @antoine2711 's changes...which is slightly concerning, but we'll figure it out.

[antoine2711]

@wetneb : yes, the documentation is wrong.

cell.cross("People","Name").cells["Address"].value[0]

should of course be

cell.cross("People","Name")[0].cells["Address"].value

Regards, A.

[antoine2711]

But dunno if there is always 1 Row or Record only now after @antoine2711 's changes... which is slightly concerning, but we'll figure it out.

No, this has not changed with the fix 3 years ago. Somehow, the doc got broken. Sad, but good thing it's now fixed.

Regards,
Antoine

[ostephens]

In fact both expressions work. Although cross (as it has always done afaik) returns an array of rows, it seems that .cells[] will iterate of the array of rows and and value will iterate over the array of rows. So:

cell.cross("People","Name") -> array of row objects
cell.cross("People","Name").cells["Address"] -> array of cell objects
cell.cross("People","Name").cells["Address"].value -> array of values

So
cell.cross("People","Name").cells["Address"].value[0]
and
cell.cross("People","Name").cells["Address"][0].value
and
cell.cross("People","Name")[0].cells["Address"].value

all give the same result

I'm not sure if this has always been the case, but I always use (and teach) the last of these as it makes most sense to me, but I guess the other options provide some convenience if you just need a single value

[wetneb]

Ah, good point. Actually, I find it really messy that GREL silently applies a computation to the elements of an array as a map.

[tfmorris]

All of these examples deemphasize the fact that cross() can return multiple rows. I think it would be better for the example to using join() to highlight handling of multiple values.