Cast result of getContributionBalance to float to match comment block.

[eileenmcnaughton]

Overview

Fix CRM_Contribute_BAO_Contribution::getContributionBalance to always return a float per the comment block

Before

could be null

After

will be a float - 0 for null

Technical Details

Without this it is possible for it to return 'null' which is not useful / in keeping. I did a bit of an audit & did not find places where this would cause an === comparison to fail

Comments

[civibot]

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[seamuslee001]

I believe this is correct we should be getting a floated value back not 'null'. tests have also passed so merging

[mattwire]

@eileenmcnaughton @seamuslee001 Just a note that I've recently been doing some custom work based (sort of) on the additionalpayment form and realised that there is no easy way via the API to do getContributionBalance which is pretty useful for showing people how much they have left to pay...
So I added this API to my mjwshared extension and thought it might make a useful addition to core at some point: https://lab.civicrm.org/extensions/mjwshared/blob/master/api/v3/Contribution/Getbalance.php

[eileenmcnaughton]

@mattwire we should talk with @colemanw on how to add that to apiv4 - although perhaps on the Order api not contribution. I've been thinking about that & the fact we should start doing some mockups in gitlab on how the apiv4 order api should look. I feel like we can create something with a better developer experience in apiv4