A conditional tag that displays its contents if the asset in context is the first item in the row in context when publishing a grid of assets (e.g. thumbnails). Grid of assets can be created by specifying assets_per_row attribute value to Assets block tag.

For example, the first, the fourth and the seventh asset are the first assets in row when Assets iterates eight assets and assets_per_row is set to "3".

Example:

    <table>
      <mt:Assets type="image" assets_per_row="4">
        <mt:AssetIsFirstInRow><tr></mt:AssetIsFirstInRow>
          <td><$mt:AssetThumbnailLink$></td>
        <mt:AssetIsLastInRow></tr></mt:AssetIsLastInRow>
      </mt:Assets>
    </table>