enabling scrolling hstore key/value field

Question

The key/value widget applied on a Postgres hstore field conveniently shows, for a record, a sub-table containing the various keys and values. If there isn't enough space in the form, this sub-table is resized and some key/values are not visible.

How can one scroll this sub-table? I am currently using QGIS 3.4.15 LTR.

Hstore field using the key/value widget:

Sub-table shows an elevator but is not scrollable:

Long enough form allows showing more fields in the sub-table

edit

Let's note that the scrolling works if the layer is being edited and is editable (i.e. it does not work with a read-only user)

Answer 1

A workaround may be to create, in a Drag & Drop Designer a new tab with the Key/Value widget, to access in edit mode if needed.

For read-only mode, add in the main tab, a HtmlWidget with the following code :

<script>
document.write(expression.evaluate(
"'<ul>' || " +
  "with_variable(" +
  "'hstore'," +
  "hstore_to_map(\"tags\")," +
  "array_to_string(" +
    "array_foreach(" +
      "map_akeys(@hstore)," +
      "'<li>' || @element || ': ' || map_get(@hstore, @element) || '</li>'" +
    "), '', ''" +
  ")" +
")" +
"|| '</ul>'"
));
</script>

This will display a Html frame with the tags values as a list like :

• alt_name: Mount King
• wikidata: Q59320
• wikipedia: en:King Peak (Yukon)

---

EDIT

If you want a pretty table styled with mouse hovering, you can add CSS style :

<style>
table {
  font-family: "Trebuchet MS", Arial, Helvetica, sans-serif;
  border-collapse: collapse;
  width: 100%;
}

td, th {
  border: 1px solid #ddd;
  padding: 8px;
}

tr:nth-child(even){background-color: #f2f2f2;}

tr:hover {background-color: #ddd;}

th {
  padding-top: 12px;
  padding-bottom: 12px;
  text-align: left;
  background-color: #4CAF50;
  color: white;
}
</style>
<script>
document.write(expression.evaluate(
"'<table>' || " +
"'<tr><th>Tags</th>' || " +
  "with_variable(" +
  "'hstore'," +
  "hstore_to_map(\"tags\")," +
  "array_to_string(" +
    "array_foreach(" +
      "map_akeys(@hstore)," +
      "'<tr><td>' || @element || ': ' || map_get(@hstore, @element) || '</tr></td>'" +
    "), '', ''" +
  ")" +
")" +
"|| '</table>'"
));
</script>