srp_jsonx_go & go_back

AusMarkB · February 13

This is the first time I've attempted to use these two commands and I don't know whether I'm misunderstanding something or I've just done it wrong, which I guess is the same thing. But it's not doing what I'm expecting at least.
I have a json array with six objects.
I loop through the array using go and back the way I think they're intended to be used, but I only retrieve the data of the odd numbered rows.
iteration 1 worked just fine and the data I wanted was retrieved.
Then I went go back and went through iteration 2 and everything returned null so I thought, Ok, I've got it wrong.
But then iteration 3 went through and all the correct data was returned.
Iteration 4 - nulls
Iteration 5 - data
Iteration 6 - nulls.

			For itemCnt = 1 to numItems
				SRP_JsonX_Go('[':itemCnt:']')
				orderId		= SRP_JsonX_Get('id')
				orderDate	= SRP_JsonX_Get('date_created')
				custID		= SRP_JsonX_Get('customer_id')
				custName	= SRP_JsonX_Get('billing.first_name'):" ":SRP_JsonX_Get('billing.last_name')
				orderNo		= SRP_JsonX_Get('number')
				orderStatus	= SRP_JsonX_Get('status')
				custNote	= SRP_JsonX_Get('customer_note')
				total		= SRP_JsonX_Get('total')
				numLineItems	= SRP_JsonX_Count('line_items')		; //
				for liCount = 1 to numLineItems
					SRP_JsonX_Go('line_items[':liCount:']')
					itemWebId	= SRP_JsonX_Get('product_id')
					thisItem	= SRP_JsonX_Get('sku')
					itemQty		= SRP_JsonX_Get('quantity')
					itemPrice	= SRP_JsonX_Get('price')
					itemTotal	= SRP_JsonX_Get('total')
					SRP_JsonX_GoBack()		; // go back to the parent item (the line_items object)
				next liCount 
				SRP_JsonX_GoBack()		; // go back to the parent item (the array object)
			Next itemCnt

The code is so much nicer to read then the long way round but I'm missing something. Well, 3 things - rows 2,4 and 6.

In typing this, I tested the code without the inner line_items loop. Without that loop, I get all six rows so the inner goback must be screwing me over somehow. But only every second time.

DonBakke · February 13

Mark,

I've fallen into this trap before. The problem is with your inner "Go" command:
SRP_JsonX_Go('line_items[':liCount:']')
This works, but you are technically jumping forward two levels from the current element. The "GoBack" command doesn't revert to where you started, it "changes the current element to the parent of the current element." The solution is to add a second "GoBack".

AusMarkB · February 13

So my first GoBack takes me back to 'line_items' and then I'm saying Go to 'line_items.line_items[':liCount:']' but because that doesn't work, the GoBack on the 2nd iteration takes me to where I thought I was?

DonBakke · February 13

Something like that...:) Did you test with the additional "GoBack" yet?

AusMarkB · February 13

Just did and I was about to tell you it didn't work....

But someone changed the source data on me and there was only 3 items to extract this time. I was debugging and thinking, well at least I didn't get any null rows. :)

Looks like it works, thanks.
Each of the inner loops only had one item so fingers crossed it still works if there are multiple iterations for that loop

KevinFournier · February 13

I admit that I severely misnamed this routine. The docs explain it, but GoBack means "Go up to parent node". It does not go back to your previous position. Maybe I should create an alias called GoUp.

DonBakke · February 13

A "GoUp" alias would be useful. I would say, however, that part of the problem (for me at least) was not recognizing that performing a "Go" into a specific element of an array is jumping two levels deep rather than one level. That's why I intuitively expected the "GoBack" to work.

KevinFournier · February 13

I think it's a valid intuition. If Go can "go anywhere" like when I use the web, then GoBack should be equivalent to Back on the browser. I could update GoBack to do this, but it would break stuff.

KevinFournier · February 13

Funnily enough, I was just using JsonX this week and ran into this same issue and was mad at myself for choosing such a bad name.

AusMarkB · February 14

Kev, the docs do explain it and I read them and "understood".
My issue was essentially the same as Dons. I was forgetting that the array node is the parent of the array element.
So I read the docs and thought I was going back to the parent but thinking that the parent was the outer array element.
Same same I guess, in not recognising that I'd gone two nodes down.
I guess what I'm saying here is even if you had a GoUp to do what the GoBack currently does, I still would have found myself in the same hole.

AusMarkB · February 14

Perhaps instead of trying to "fix" the GoBack, maybe add an "SRP_JsonX_Return" that does what you're now thinking GoBack should be doing.
GoBack - goes back up one node
Return - returns you to where you were before you said Go.

That way we get both worlds and don't break anything.

DonBakke · February 14

SRP_JsonX_ReadMyMindAndGoThere() works for me.

AusMarkB · February 14

Oh that's right, you've met my wife.

DonBakke · February 14

KevinFournier · February 14

I'm gonna stick with poor naming conventions and call it SRP_JsonX_UnGo.

srp_jsonx_go & go_back

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