How to prepopulate Address field in lightning:inputField

Question

I need to prepopulate fields in lightning:recordEditForm and then get their values to save using Apex (without submitting form itself). What I've already tried:

1. When I setting

   <lightning:inputField value="{!v.contact.MailingAddress} fieldName="MailingAddress"/>
   

It's prepopulated, but I can't access updated values afterwards. Stringified component.find("mAddress").get("v.value") showing nulls everywhere.

2. When trying onload

   let address = component.find("mAddress").get("v.value");
   address["MailingCountryCode"] = "US";
   component.find("mAddress").set("v.value", address);
   

Not prepopulating. But can access updated field value with component.find("mAddress").get("v.value").MailingCountryCode. Same if trying to set after loaded, even on button click.

3. Find fields directly with querySelector - don't have access, maybe since it's on Partner Portal Community. By id - for compound Address each field id generated by Lightning, so I'm not sure if I can use them.
4. Set up aura:attribute with type Address, ConnectedApi.Address, Object - also seems not working.

Is there some other way/option to prepopulate MailingAddress and get updated value on button click?

Answer 1

It seems that for now we don't have any way to directly populate lightning:inputField with compound Address fields. It contains some internal object, which can't be setted. Maybe it has some methods to set/get, but without documentation it's hard to even guess. So for the moment it seems that if we can't use retrieving record by lightning:recordEditForm - we need to make a custom dependent picklist.

Solution which worked for me - https://salesforcespace.blogspot.com/2018/08/salesforce-lightning-dependent-picklist.html

If someone would find better solution - feel free to wrote it here, I would change an Accepted answer.