DynamicField Reference Agent: Empty value doesn't work

[StefanAbel-OTOBO]

When you create a Dynamic Field of type (Reference) Agent the Empty value option doesn't work at all, which causes the alphabetically first agent to be selected automatically.

I reproduced ths on ov270

This is my DF configuration:

This is the result (it looks the same e.g. in a Process Activity Dialog or in AgentTicketPhone):

[stefanhaerter]

Related: RotherOSS/ITSMConfigurationManagement#19

[stefanhaerter]

I managed to track the root bug down. There are a number of things which come into play to create the environment, but in the end it boils down to:

Double quote precedes minus precedes alphanumeric character

in regard to perl sort. Please feel free to ask me for further details, but I didn't want to clutter this comment.

I see two possible ways to solve the root cause:

• Insert sorting function ensuring the precedence of the exact combination "" => '-' within selection data
• Insert something like the following to ensure that the empty value is marked as selected if no other information is given:

sub BuildSelection {
    [...]
    if ( !defined $Param{SelectedID} && !defined $Param{SelectedValue} ) {
        $Param{SelectedID} = '';
    }
    [...]
}

[stefanhaerter]

For the interested reader, the place where the mentioned sorting takes place is here:

otobo/Kernel/Output/HTML/Layout.pm

Lines 5920 to 5926 in 9670cb1

	else {
	@SortKeys = sort {
	lc( $DataLocal->{$a} // '' )
	cmp lc( $DataLocal->{$b} // '' )
	} ( keys %{$DataLocal} );
	$OptionRef->{Sort} = 'AlphanumericValue';
	}

[svenoe]

Is reproducible with a standard dropdown dynamic field including "-" as value. (Probably just " suffices.)
See probably:

otobo/var/httpd/htdocs/js/Core.UI.InputFields.js

Line 568 in fecfc99

Selection = [ $SelectObj.val() ];

which, if no option is selected returns the first option, and line 594 where an empty key is skipped. Problem arises when stuff (") is sorted in front of the empty value (-). (See also backend sorting above.)

[MichaelThumes]

steps to reproduce:

• create DF dropdown with 2-3 keys+values like a,b,c
• for one of the fields set value to '-' or '"-"' or '"' (without surrounding single quotes)
• set 'Add empty value' for the dropdown DF to True
• add DF to say AgentTicketPhone
• browse to AgentTicketPhone

Expected Behaviour:

DF dropdown has empty value pre-selected

Observed Behaviour:

DF dropdown has one of the weird values from above pre-selected , eg '"-"'

root cause

Combination of the backend sorting and the way the frontend handles selection (see above comments)

possible approaches

• change backend sorting
• change frontend

[MichaelThumes]

option a) patch the backend Kernel/Output/HTML/Layout.pm

diff --git a/Kernel/Output/HTML/Layout.pm b/Kernel/Output/HTML/Layout.pm
index 86b163855..ae3a6ba35 100644
--- a/Kernel/Output/HTML/Layout.pm
+++ b/Kernel/Output/HTML/Layout.pm
@@ -5919,6 +5919,9 @@ sub _BuildSelectionDataRefCreate {
         }
         else {
             @SortKeys = sort {
+                # assure the empty option, if any, is always sorted first                
+                if($a eq '' ) { return -1; }
+                if($b eq '' ) { return  1; }
                 lc( $DataLocal->{$a} // '' )
                     cmp lc( $DataLocal->{$b} // '' )
             } ( keys %{$DataLocal} );

That seems to work but adds 2 condition checks in the inner sort loop., albeit cheap ones.

Alternative is less condition checks but more typing:

diff --git a/Kernel/Output/HTML/Layout.pm b/Kernel/Output/HTML/Layout.pm
index 86b163855..fa7d013cd 100644
--- a/Kernel/Output/HTML/Layout.pm
+++ b/Kernel/Output/HTML/Layout.pm
@@ -5918,10 +5918,15 @@ sub _BuildSelectionDataRefCreate {
             # already done before the translation
         }
         else {
+            my $EmptyValue = delete $DataLocal->{''};
             @SortKeys = sort {
                 lc( $DataLocal->{$a} // '' )
                     cmp lc( $DataLocal->{$b} // '' )
             } ( keys %{$DataLocal} );
+            if( defined $EmptyValue) {
+                $DataLocal->{''} = $EmptyValue;
+                unshift @SortKeys, '';
+            }
             $OptionRef->{Sort} = 'AlphanumericValue';
         }

option b) - hack the frontend Core.UI.InputFields.js

diff --git a/var/httpd/htdocs/js/Core.UI.InputFields.js b/var/httpd/htdocs/js/Core.UI.InputFields.js
index 431745e85..7273b591e 100644
--- a/var/httpd/htdocs/js/Core.UI.InputFields.js
+++ b/var/httpd/htdocs/js/Core.UI.InputFields.js
@@ -565,7 +565,7 @@ Core.UI.InputFields = (function (TargetNS) {
                 Selection = $.unique($SelectObj.val());
                 SelectionLength = Selection.length;
             } else {
-                Selection = [ $SelectObj.val() ];
+                Selection = [ PossibleNone ? '||-' : $SelectObj.val() ];
                 SelectionLength = 1;
             }