[SalesForce] Lightning:input format currency

"fieldLevelHelp" attribute works for lightning:input component too even though it's not been documented. It's documented for lightning-input and aura components use LWC under the covers.

<lightning:input label="Custom Label" 
             value="Custom Text" 
             fieldLevelHelp="Help text goes here" />

You can also create your own field with custom rendering using the below code without the need for any CSS:

<lightning:layoutItem>
 <span class="slds-form-element">
     <label for="textInput" 
            class="slds-form-element__label slds-no-flex">
         Custom Label
     </label>
     <lightning:helptext content="{!v.fieldLevelHelp}" />
     <div class="slds-form-element__control slds-grow">
         <!--Custom rendered element -->
         <a id="textInput" 
            target="_blank" 
            href="{/lightning/r/'+v.recordId + '/view'}"> 
            Custom Link Label
         </a>
     </div>
</span>
</lightning:layoutItem>

we had a similar requirement and the way we fixed it was to put the entire form inside an aura:if and changed the Boolean condition. this essentially meant the dom got re-created again but we were able to reset 4 to 5 fields in one condition.

<aura:component >
    <aura:attribute name="truthy" default="true" type="boolean"/>
    <lightning:button label="Click Me" onclick="{!c.clickMe}" />
     <aura:if isTrue="{!v.truthy}">
    <lightning:input type="text" name="firstName" required="true" aura:id="firstName" label="First Name" value="{!v.firstName}" 
    messageWhenValueMissing="First name is required"/>
    </aura:if>     
</aura:component>

Helpercode:

compCreate:function(com,eve,helper){
   com.set('v.truthy',false);
      com.set('v.truthy',true);
}

We also did not have the need to touch each field this way instead controlled everything through an aura:if.Not the cleanest or most-efficient solution but till we get a reset function in lightning-input in the future we will use this :)