Custom Case Deflection in Lightning Community [aura]

SampleController.js

({
 itemsChange : function(component, event, helper) {           
        var appEvent = $A.get("e.selfService:caseCreateFieldChange");
        appEvent.setParams({
            "modifiedField": event.getSource().get("v.fieldName"),
            "modifiedFieldValue": event.getSource().get("v.value")
        });

        appEvent.fire();
})

SampleForm.cmp

<aura:component implements="forceCommunity:availableForAllPageTypes" access="global" >
    <aura:registerEvent name="appEvent" type="selfService:caseCreateFieldChange"/>
    <lightning:recordEditForm aura:id="recordEditForm" objectApiName="Case">
    <lightning:messages />
    <lightning:inputField fieldName="Subject" onchange="{!c.itemsChange}"/>
    <lightning:inputField fieldName="Description" onchange="{!c.itemsChange}"/>
    <lightning:button class="slds-m-top_small" type="submit" label="Create new" />
</lightning:recordEditForm>
</aura:component>