Your datagrid can be empty for any number of reasons: you are still fetching the data from the server, the filters
selected by the user are too strict, or simply you didn't find any data to display in it.
In these cases, we display a simple placeholder image, but it can be useful to display a message to the user
explaining what is happening. To do so, simply add a <clr-dg-placeholder>
element next to your rows.