Allow adding empty strings

Fix #4689

Author: uglide

src/app/models/key-models/stringkey.cpp

@@ -34,8 +34,6 @@ void StringKeyModel::updateRow(int rowIndex, const QVariantMap& row,
 
   QByteArray value = row.value("value").toByteArray();
 
-  if (value.isEmpty()) return;
-
   executeCmd(
       {"SET", m_keyFullPath, value}, [this, c, value](const QString& err) {
         if (err.isEmpty()) {

src/qml/value-editor/AddKeyDialog.qml

@@ -53,6 +53,8 @@ BetterDialog {
 
                 onLoaded: {
                     item.state = "new"
+                    if (item.keyType !== undefined)
+                        item.keyType = typeSelector.model[typeSelector.currentIndex]
                     item.initEmpty()
                 }
             }

src/qml/value-editor/ValueTabs.qml

@@ -802,6 +802,11 @@ Repeater {
                             function clear() {
                                 if (valueEditor.item) {
                                     currentRow = -1
+
+                                    if (valueEditor.item.keyType !== undefined) {
+                                        valueEditor.item.keyType = keyType
+                                    }
+
                                     valueEditor.item.reset()
                                 }
                             }

src/qml/value-editor/editors/SingleItemEditor.qml

@@ -11,6 +11,7 @@ AbstractEditor {
     anchors.fill: parent
 
     property bool active: false
+    property string keyType: ""
 
     MultilineEditor {
         id: textEditor
@@ -22,6 +23,11 @@ AbstractEditor {
         showSaveBtn: root.state == "edit"
         showFormatters: root.state == "edit"
         objectName: "rdm_key_value_field"
+
+        function validationRule(raw) {
+            if (root.keyType === "string") return true;
+            return qmlUtils.binaryStringLength(raw) > 0
+        }
     }
 
     function initEmpty() {