DependentPicklist.cmp

<!--
 - Created by johnpernock from OpenGate Consulting on 2019-01-09.
 -->

<aura:component description="DependentPicklist" access="global" controller="DependentPicklistController">
    <!-- aura attributes-->
    <aura:attribute access="private" name="listControllingValues" type="list" default="[]" description="to store controller field values"/>
    <aura:attribute access="private" name="listDependingValues" type="list" default="['--- None ---']" description="to store dependent field values"/>
    <aura:attribute access="private" name="depnedentFieldMap" type="String" description="map to store dependent values with controlling value"/>
    <aura:attribute access="private" name="bDisabledDependentFld" type="boolean" default="true"/>
    <aura:attribute name="objDetail" type="sObject" required="true"/>
    <aura:attribute name="requiredField" type="Boolean" default="false" />
    <aura:attribute name="objControlField" type="String" required="true"/>
    <aura:attribute name="objControlLabel" type="String" required="true"/>
    <aura:attribute name="objDependentField" type="String" required="true"/>
    <aura:attribute name="objDependentLabel" type="String" required="true"/>
    <aura:attribute name="controllingFieldAPI" type="string"  description="store field API name of Controller field" required="true"/>
    <aura:attribute name="dependingFieldAPI" type="string" description="store field API name of dependent field" required="true"/>
    <aura:handler name="change" value="{!v.objControlField}" action="{!c.onControllerFieldChange}"/>
    <!-- call doInit function on component load -->
    <aura:handler name="init" value="this" action="{!c.doInit}"/>
    <div aura:id="dependentPicklistDiv" class="slds-is-relative">
    <lightning:spinner variant="brand" size="large" aura:id="loaddependent_spinner" class="slds-hide" />
    <!--Controller Field-->
        <lightning:select name="controllerFld"
                          value="{!v.objControlField}"
                          label="{!v.objControlLabel}"
                          required="{!v.requiredField}">
            <aura:iteration items="{!v.listControllingValues}" var="val">
                <option value="{!val.value}">{!val.label}</option>
            </aura:iteration>
        </lightning:select>

    <!--Dependent Field-->
        <lightning:select name="dependentFld"
                          value="{!v.objDependentField}"
                          label="{!v.objDependentLabel}"
                          disabled="{!v.bDisabledDependentFld}"
                          required="{!v.requiredField}">
            <aura:iteration items="{!v.listDependingValues}" var="val">
                <aura:if isTrue="{!v.objDependentField == val}">
                    <option value="{!val}" selected='selected'>{!val}</option>
                    <aura:set attribute="else">
                        <option value="{!val.value}">{!val.label}</option>
                    </aura:set>
                </aura:if>

            </aura:iteration>
        </lightning:select>
    </div>
</aura:component>