campaignListItem.cmp

<aura:component >
    <aura:attribute name="item" type="Camping_Item__c" required="true" />
    <aura:attribute name="packed" type="Boolean" default="false"/>
    <ui:outputText value="{!v.item.Name}" />
    <ui:outputCheckbox value="{!v.item.Packed__c}" />
    <ui:outputCurrency value="{!v.item.Price__c}" />
    <ui:outputNumber value="{!v.item.Quantity__c}" />
    <ui:button label="Packed!" press="{!c.packItem}" disabled="{!v.Packed}" />
</aura:component>

campaignListItemController.js

({
    packItem: function(component, event, helper) {
        var a = component.get("v.item",true);
        a.Packed__c = true;
        component.set("v.item",a);
        var btnClicked = event.getSource();
        btnClicked.set("v.disabled",true);
    }
})