Add a tooltip to a lightning datatable

Question

I'm trying to add a tooltip as showsn in the picture above. But I don't see anything out of the box that comes with the lightning:datatable that would help us do it,

Any ideas on how to get this tool tip added to the header column.

Component code

<aura:component implements="flexipage:availableForRecordHome,force:hasRecordId" access="global" >

<aura:attribute name="mydata" type="Object"/>
<aura:attribute name="mycolumns" type="List"/>
<aura:handler name="init" value="{! this }" action="{! c.init }"/>
<lightning:datatable data="{! v.mydata }" 
    columns="{! v.mycolumns }" 
    keyField="id" />

   </aura:component>

Controller code

({
  init: function (cmp, event, helper) {

cmp.set('v.mycolumns', [
            {label: 'Opportunity name', fieldName: 'opportunityName', type: 'text'},
            {label: 'Confidence', fieldName: 'confidence', type: 'percent', cellAttributes:
             { iconName: { fieldName: 'trendic' }, iconPosition: 'right' }},
            {label: 'Amount', fieldName: 'amount', type: 'currency', typeAttributes: { currencyCode: 'EUR'}},
            {label: 'Contact Email', fieldName: 'contact', type: 'email'},
            {label: 'Contact Phone', fieldName: 'phone', type: 'phone'}

        ]);
    cmp.set('v.mydata', [{
            id: 'a',
            opportunityName: 'Cloudhub',
            confidence: 0.2,
            amount: 25000,
            contact: 'jrogers@cloudhub.com',
            phone: '2352235235',
            trendic:'utility:info',

        },
        {
            id: 'b',
            opportunityName: 'Quip',
            confidence: 0.78,
            amount: 740000,
            contact: 'quipy@quip.com',
            phone: '2352235235',
            trendic:'utility:info',

        }]);
}, })

Answer 1

I'm trying to figure out this same thing.

I have discovered that if you use the following, you can get the icon to appear in the header only instead of every cell.

{label:'MyLabel', fieldName:'myfield', iconName:'utility:info'}

Note: iconName is a param on the column, not within cellAttributes.

I'm still trying to add helptext and will update if I figure out how.