HashWithIndifferentAccess remove inner hash question

rubyonrails-talk
1

This is probably more of a ruby question, but I'm posting it here as HashWithIndifferentAccess is more of a rails thing.

I have a @morton which is

--- !map:HashWithIndifferentAccess new_lab_data_attributes: - !map:HashWithIndifferentAccess   unit_id: "4"   lab_desc_id: "3"   value: "" - !map:HashWithIndifferentAccess   unit_id: "2"   lab_desc_id: "2"   value: ""

I'd like to delete the new_lab_data_attributes with value = nil

I've tried various incarnations of

@morton[ :new_lab_data_attributes ].each{ |x| x.delete if x[ :value ] == nil }

But nothing seems to be removing those entries. Part of my problem is that I can't quite figure out the key value pairs in this. It almost seems that the inner !map:HashWithIndifferentAccess are symbols for keys--is that right?

Anyway, a method to remove those inner hashes depending on the "value" would be greatly appreciated.

TIA, Craig

2

none of them are nil - they're empty strings....

You could try "blank?" (it might work):   @morton[:new_lab_data_attributes].each{ |x| x.delete if x[:value].blank? }

3

I'm just lost with this syntax :slight_smile: delete complains if it doesn't have an argument, so I tried

@morton[:new_lab_data_attributes].each{ |x| x.delete(x) if x[:value].blank? }

Which still isn't deleting anything...

4

It was your syntax! :slight_smile: I just changed "== nil" to ".blank?" Look at the docs for Hash:

Looks like just dropping the "if" would work...

5

*sigh* no it won't... there's an extra .each iterator in there....

Have a play with "delete_if" instead of the "each"...

6

Oops, you were right about that (I'm so addled by trying different things at this point, that I'm not seeing the obvious) but it still doesn't work:

@morton[:new_lab_data_attributes].each{ |x| x.delete x[ :value ].blank? } raise @morton.to_yaml

--- !map:HashWithIndifferentAccess new_lab_data_attributes: - !map:HashWithIndifferentAccess   unit_id: "4"   lab_desc_id: "3"   value: "" - !map:HashWithIndifferentAccess   unit_id: "2"   lab_desc_id: "2"   value: ""

7

Thou art a genius!

@morton[:new_lab_data_attributes].delete_if{ |x| x[ :value ].blank? }

Works. *Many, many* thanks

8

It ain't me; it's the documentation...

My first port of call is always to type "ruby rails api <my problem>" into Google.

But thanks :slight_smile: