Multiple hazards bug

[Chris B]

Here is an excerpt from an error generated when the software was attempting to add a hazard ...

line 1643, in add_hazard ... chemhazard = ChemicalHazards.objects.get_or_create(

Local Vars

Variable	Value
hazard	<Hazard: H317 Skin sensitization: Category 1: May cause an allergic skin reaction>
hazards	<QuerySet [<Hazard: H317 Skin sensitization: Category 1: May cause an allergic skin reaction>, <Hazard: H317 Skin sensitization: Category 1A: May cause an allergic skin reaction>, <Hazard: H317 Skin sensitization: Category 1B: May cause an allergic skin reaction>]>
hazlabel	'Skin sensitization: Category 1'

In theory this should work in all circumstances because 'get_or_create' should return an existing chemical hazard rather than create one. In practice however, if there is more than one hazard with the same identifying characteristics, the 'get' part of 'get_or_create' complains instead of returning it. As can be seen in the error excerpt, there were three such hazards.

We need to respect user requirements here. Because there can be multiple hazards with the same Hazard Code but different Hazard Category (eg., 2, 2A, 2B etc) we cannot just arbitrarily decide to select one. Even if Australia elects to settle on, say 2A for a category, next week it might be simplified by the regulator to say, Category 2.

The fix will therefore permit as many hazards as desired/added by the user and the software will display them all in reports and permit the user to delete those which are eventually unnecessary.

The software however, will now look separately for the Hazard Code and if discovered, won't try to add another.