Special styling for NULL and EMPTY_STRING

Created by: Henrik tom Wörden

Those two values are special. The should be displayed similarly to TRUE and FALSE. Currently, there is simply nothing...

Imported comments:

By Alexander Schlemmer on 2020-10-21T12:30:36.744Z

I have just submitted a WIP merge request !86 (merged) to work on this solution.

By Alexander Schlemmer on 2020-10-21T11:12:15.448Z

added 11m of time spent at 2020-10-21

By Alexander Schlemmer on 2020-10-21T11:11:52.613Z

The fix could comprise the addition of the following class to webcaosdb.css:

.caosdb-empty-value {
    font-weight: bold;
    font-size: 90%;
    border: 1px solid #bbb;
    padding: 2px 8px;
    border-radius: 8px;
}

and the addition of a text and the class caosdb-empty-value to the span in entity.xsl, line 312:

<xsl:otherwise>
        <!-- DEPRECATED css class .caosdb-property-text-value - Use
             .caosdb-f-property-single-raw-value or introduce new 
             .caosdb-v-property-text-value -->
        <span class="caosdb-f-property-single-raw-value caosdb-property-text-value caosdb-empty-value">EMPTY</span>
      </xsl:otherwise>

I am not pushing this as a merge request, because we have to make sure, that this fix does not break the functionality of the edit mode and caosdb.js. It must be made sure that the EMPTY value is ignored in all js functions reading and writing values and that it is set correctly on writes.

By Alexander Schlemmer on 2020-10-21T11:00:54.838Z

Suggestion analogous to boolean values.

By Alexander Schlemmer on 2020-10-21T10:57:33.263Z

When exactly does NULL occur?