docs: function renderCell (record, field, model, cb) {
  
      let fieldName = (typeof field === 'object') ? field.fieldName : field,
          renderer = (model.schema.tree[fieldName] && model.schema.tree[fieldName].ref && linz.api.model.getObjectIdFromRefField(record[fieldName]) instanceof linz.mongoose.Types.ObjectId) ?
              'reference' :
              (record[fieldName] && linz.api.model.getObjectIdFromRefField(record[fieldName]) instanceof linz.mongoose.Types.ObjectId && linz.mongoose.models[record[fieldName].ref]) ? 'referenceValue' :
                  'text';
  
      // Users can supply their own renderer fields (use it if provided).
      (field.renderer || cellRenderers[renderer])(record[fieldName], record, fieldName, model, function (err, value) {
  
          if (err) {
              return cb(err);
          }
  
          return cb(null, {
              label: field.label ? field.label : model.linz.formtools.labels[fieldName],
              value: value
          });
  
      });
  
  }