LDS Error Example

LDSErrorTest.cmp

<aura:component implements="forceCommunity:availableForAllPageTypes,force:appHostable,flexipage:availableForAllPageTypes,force:hasRecordId" access="public">
	
	<aura:attribute name="contactRecord" type="Contact"/>
    <aura:attribute name="recordError" type="String"/>
    <aura:attribute name="returnedError" type="String"/>


	
	<force:recordData aura:id="recordLoader"
		recordId="{!v.recordId}"
	   	mode="EDIT"
	   	targetFields="{!v.contactRecord}"
        targetError="{!v.recordError}"
	   	fields="FirstName, My_Test_Formula__c"/>
    
    <!-- Display Lightning Data Service errors, if any -->
    <aura:if isTrue="{!not(empty(v.recordError))}">
        <div class="recordError">
            <ui:message title="Error" severity="error" closable="true">
                {!v.recordError}
            </ui:message>
        </div>
    </aura:if>
    
    <div>
    	{!v.contactRecord.FirstName}
	   	<lightning:button class="slds-button" onclick="{!c.changeNameToSusie}">Change Name</lightning:button>
		
    </div>

    <aura:if isTrue="{!not(empty(v.returnedError))}">
        {!v.returnedError}
    </aura:if>
	   	
    

</aura:component>