[siber-biber]

http://docs.sencha.com/extjs/6.2.1/c...ipManager.html
http://docs.sencha.com/extjs/6.2.1/c...l#cfg-renderer

var myRenderer = function(value, metaData, record, rowIndex, colIndex) {
    if (colIndex === 0) {
        metaData.tdAttr = 'data-qtip=' + value;
    }
    // additional logic to apply to values in all columns
    return value;
}

// using the same renderer on all columns you can process the value for
// each column with the same logic and only set a tooltip on the first column
renderer: myRenderer