Otdfbt

I'm looking for getting a dynamically assigned Aura:id. Below is my attempt to read it in Lightning:recordEditForm.

Component markup:

<aura:component >
 <aura:handler name="init" value="!this" action="!c.init" />
 <aura:attribute name="conid" type="Id" default="null" />

 <aura:attribute name="fields" type="String[]" default="['Email','Birthdate']" />

 <lightning:recordEditForm aura:id="conRecEdit" objectApiName="Contact" recordid="!v.conid" >
 <lightning:messages />
 <lightning:inputField aura:id="fname" fieldName="FirstName"/> 
 <lightning:inputField aura:id="lname" fieldName="LastName"/> 

 <aura:iteration items="!v.fields" var="f" >
 <lightning:inputField aura:id="!f" fieldName="!f"/>
 </aura:iteration>

 <lightning:button type="button" label="test" onclick="!c.checkValue" />
 </lightning:recordEditForm>
</aura:component>

JS Controller:

(
 init : function(component, event, helper) 
 var fld = component.find('fname');
 console.log('fld '+fld);
 if (fld!=null)
 fld.set('v.value', 'new name');

 var fld1 = component.find('Email');
 console.log('fld1 '+fld1);
 if (fld1!=null)
 fld1.set('v.value', 'test@test.com');
 ,

 checkValue: function(component, event, helper)
 var fld1 = component.find('Email');
 console.log('fld1 '+fld1);

 if (fld1!=null)
 fld1.set('v.value', 'test@test.com');

 ,
)

If we assign aura:id hard-coding it, it works perfectly fine. But if the id is assigned dynamically, seems it's not possible to find here.

Any clues, suggestions to workaround reading the aura:id in above working example. Much Appreciated!
Thanks!

aura:id can't be populated dynamically:

aura:id doesn't support expressions. You can only assign literal string values to aura:id.

Instead, give all of your <lightning:inputField> components a common aura:id so that you can find them, and then filter by the fieldName attribute:

<aura:iteration items="!v.fields" var="f" >
 <lightning:inputField aura:id="contactField" fieldName="!f"/>
</aura:iteration>

then

let emailField = component.find('contactField').filter(x => x.get('v.fieldName') === 'Email')[0];
emailField.set('v.value', 'test@test.com');