Custom filter is not called for null values

[ebq-m]

Bootstraptable version(s) affected

latest (online editor)

Description

I'm using a custom filter control function
I think a user (currently me) might need a filter to search for empty/null values as well

Example(s)

<table
  id="table"
  data-filter-control="true"
  data-show-search-clear-button="true">
  <thead>
    <tr>
      <th data-field="id">ID</th>
      <th data-field="price" data-filter-control="select" data-filter-custom-search="final_cat_custom_filter">Item Price</th>
    </tr>
  </thead>
</table>

<script>
  $(function() {
    var data = [
    {
    "id": 1,
    "price": 1
    },
    {
    "id": 1,
    "price": null
    }
    ]
    $('#table').bootstrapTable({'data': data})
  })
  
  function final_cat_custom_filter(...x) {
    alert(JSON.stringify(x))
  }
  
  
</script>

Possible Solutions

I think this commit introduced this bug: #4494?
Not sure

Additional Context

No response

[wenzhixin]

Online example: https://live.bootstrap-table.com/code/wenzhixin/17502

[ebq-m]

Looks like the same code to me?

[ebq-m]

When you change the select filter, it only alerts one time when it should've done 2 times because there are two rows

[wenzhixin]

Yes, I saved your code to the online editor.

[ebq-m]

Thank you! It wasn't formatted properly as well

[nubbeldupp]

I'd like to chime in on this. :)
I ran into the same issue having NULL Values in my Table.

I'm using

while ($row = oci_fetch_array($stmt, OCI_ASSOC+OCI_RETURN_NULLS)) {
    echo "<tr>";
    foreach ($row as $item) {
        echo "    <td>" . ($item !== null ? htmlentities($item, ENT_QUOTES) : "&nbsp;") . "</td>\n";
    }
    echo "</tr>";
}

to break down the Array and replace NULL with  
With BT 1.15.5 this prompted an "empty" Option in the Select-Filter.

It doesn't look nice, but it worked. :)

With 1.24.0 this doesn't work anymore but it would be nice if it did.
For now as a workaround I replaced the   with a hyphen.