How to filter one list from another to display a shorter list on form.

Q&A
1

I have two imported tables/lists from an external DB, 

One for companies and another for contacts. Companies can have multiple contact persons, they are related by company ID.  

In an instantiation form, I would like to be able to select a company from a list (this is working already), and then only allow the user to choose from the contacts (in a separate list field) that relate to the company. 

I feel like this should be as simple as a js asset but can't seem to implement one correctly (I'm beginner). Any help and advice appreciated.

2

Hi, you could do it using the UID variables.

First, you need to have your companies data have a certain form. You need an array that has multiple objects. Something like this :

[{displayKey: "company1", returnKey: "company1"}, {displayKey: "company2", returnKey: "company2"}]

Then, use this data in the companies dropdown, Display key is displayKey and Return key is returnKey.
Have the value of your companies dropdown be assigned to a UID variable (ex: companiesValue).
Then, create a UID variable (let's say it's called controller) that will have a function that will filter the contacts data depending on the selected companiesValue. The value of the controller variable will be something like this:

return {
    filterDataDependingOnCompanySelected: function(companySelected) {
        $data.contacts.filter(function (contact) {
            contact.company = companySelected;
        });
    }
};

Or create a list that can be used in a dropdown (through displayKey, returnKey). Now, all you need to do is call "controller.filterDataDependingOnCompanySelected(companiesValue)"and you will get a list of contacts that are part of the company. You can always change how you filter the contacts if your data differs.

 

Hope this helps,
Dumitru

3

Hi!

Watch this video: https://www.youtube.com/watch?v=hk_SHNKPPd8

At minute 28:49 you can see how you can do what you need.

I hope that helps!

4

Solved thanks, didn't even think about that route

5

What do you mean here by contact.company? 

I assume in $data.contacts you mean the list of contacts. Then contact.company refers to what? 
contactsList.companyID? 

Also I call this 'controller.filterDataDependingOnCompanySelected(companiesValue)' in available values, yes? 

6

Solved by comment of walo2014.