Kendo UI: Conditionally preventing a Tooltip from being displayed on a Grid cell

The tooltip is implemented in a way that makes this difficult. You could call this.hide() wrapped in a setTimeout, but it will have a flicker effect. So you'll probably have to roll your own solution for this. Here's an idea to get you started:

Create a beforeShow pseudo-event which is triggered before the tooltip is shown (this could all be done in a more sophisticated fashion):

// customize the _show method to call options.beforeShow 
// to allow preventing the tooltip from being shown..
kendo.ui.Tooltip.fn._show = function (show) {
    return function (target) {
        var e = {
            sender: this,
            target: target,
            preventDefault: function () {
                this.isDefaultPrevented = true;
            }
        };

        if (typeof this.options.beforeShow === "function") {
            this.options.beforeShow.call(this, e);
        }
        if (!e.isDefaultPrevented) {
            // only show the tooltip if preventDefault() wasn't called..
            show.call(this, target);
        }
    };
}(kendo.ui.Tooltip.fn._show);

Use it like this to conditionally prevent showing the tooltip:

var toolTip = $('#grid').kendoTooltip({
    filter: ".tooltip",
    beforeShow: function (e) {
        if ($(e.target).data("name") === null) {
            // don't show the tooltip if the name attribute contains null
            e.preventDefault();
        }
    },
    content: function (e) {
        var row = $(e.target).closest("tr");
        var dataItem = grid.dataItem(row);

        return "<div>Hi, this is a tool tip for id " + dataItem.Id + "! </div>";
    }
}).data("kendoTooltip");

(demo)

I just came across this and found a solution that works very well. The content event can work like a beforeShow event, because it is actually called before the show event is fired. If we treat it like a beforeShow event we can do this

var grid = $("#myGrid").data("kendoGrid");

grid.table.kendoTooltip({
    width: 300,
    height: 200,
    opacity: 0,
    callout: true,
    position: 'right',
    animation:
    {
        close: {
            effects: "fade:out"
        },
        open: {
            effects: "fade:in",
            duration: 1000
        }
    },
    contentTemplateId: "tooltipTemplate",
    filter: "td",
    show: function (e) {

    },
    content: function (e) {
        var target = e.target,
        currentTarget = target;

        // hide popup as default action
        e.sender.popup.element.css("visibility", "hidden");

        if ($(currentTarget[0]).attr("name") !== undefined) {

           e.sender.popup.element.css("visibility", "visible");

           //Do ajax call, show tool tip
           $.getJSON("SomeUrl").then(function(response) {

               $(target).text(response);

           });

           return "Loading...";
        }

        return "";
    }
});