<aura:component implements="force:appHostable,flexipage:availableForAllPageTypes,flexipage:availableForRecordHome,force:hasRecordId,forceCommunity:availableForAllPageTypes,force:lightningQuickAction" access="global" >
    
    <lightning:fileUpload label="Upload Multiple files"
                          multiple="true" 
                          accept=".pdf, .png, .jpeg, .jpg"
                          recordId="{!v.recordId}"
                          aura:id="multipleUpload"
                          onuploadfinished="{!c.handleUploadFinished}" />
</aura:component>

({
    handleUploadFinished: function (cmp, event) {
        // fetch the list of all the files that have been uploaded
        var uploadedFiles = event.getParam('files');
        // show success message – with no of files uploaded
        var toastEvent = $A.get('e.force:showToast');
        toastEvent.setParams({
            'title': 'Success!',
            'type' : 'success',
            'message': uploadedFiles.length + ' files has been updated successfully!'
        });
        toastEvent.fire();
        
        // Refresh the page to that recently uploaded files will display under the object record.
        $A.get('e.force:refreshView').fire();
        
        // Close the quick action panel
        var dismissActionPanel = $A.get('e.force:closeQuickAction');
        dismissActionPanel.fire();
    }    
})