Multiple dropdowns, combination check and filter

Using Ja开发者_JAVA技巧vascript / jQuery, I'm trying to build a "combination checker" that will take the values of three (but can be more) dropdown lists and filter the options based on a supplied list of allowed combinations.

For example:

DROPDOWNS

Field 1:

- value_1

- value_2

Field 2:

- value_3

Field 3:

- value_4

- value_5

COMBINATIONS

- value_1, value_3, value_5

- value_1, value_3, value_4

- value_2, value_3, value_5

When a user selects Field 3 - value_4, the unavailable options will be disabled - ie, Field 1 - value_2 (there is no combination that allows value_2 and value_4 to be selected together).

It would be really great if someone could provide some pointers on how this can be achieved or just provide a fresh perspective - I'm going round in circles on this one!

You can keep the valid combinations in a javascript array.

var combinations = [[value1, value3, value5], [value1, value3, value4], [value2, value3, value5]];

You can then monitor changes with the jQuery change event and remove all entries in the dropdown, and then add the permitted entries only.

There is no way to disable a dropdown entry in particular (you can only disable/enable the whole dropdown), so you'll have to remove the non allowed ones.