Secure Send documented, and the machine form stops re-creating a controlling-PC link that already exists

plugins/machines/frontend/views/MachineForm.vue

@@ -379,6 +379,7 @@ import PrinterAssignmentPicker from '@/components/PrinterAssignmentPicker.vue'
 import { currentTheme } from '@/stores/theme'
 import { useIdentifierFlags } from '@/composables/identifierSettings'
 import { apiError } from '@/utils/apiError'
+import { planControllingPcChange } from './controllingPc'
 
 const { isEnabled } = useIdentifierFlags()
 
@@ -440,6 +441,9 @@ const relationshipTypes = ref([])
 const controllingPcId = ref(null)
 const relationshipTypeId = ref(null)
 const existingRelationshipId = ref(null)
+// Which PC the link named when the form loaded, so an unchanged one can be left
+// alone. Editing a machine is mostly editing something else about it.
+const loadedControllingPcId = ref(null)
 const currentMachine = ref(null)
 
 // Filter models by selected machine vendor
@@ -575,7 +579,16 @@ onMounted(async () => {
             if (rel.sourceasset?.assettypename === 'computer' && (rel.relationshiptypename || '').toLowerCase() === 'controls') {
               controllingPcId.value = rel.sourceasset.assetid
               relationshipTypeId.value = rel.relationshiptypeid
-              existingRelationshipId.value = rel.assetrelationshipid
+              // relationshipid. `assetrelationshipid` is not a key the API has
+              // ever emitted - to_dict serialises the column names and the
+              // column is relationshipid - so this read undefined every time,
+              // and saveRelationship then took the "there is nothing to
+              // replace" path on a machine that had a controlling PC. Saving
+              // ANY change, a map position included, re-POSTed the link that
+              // was already there and the server correctly answered 409 "this
+              // relationship already exists".
+              existingRelationshipId.value = rel.relationshipid
+              loadedControllingPcId.value = rel.sourceasset.assetid
               break
             }
           }
@@ -693,31 +706,40 @@ async function saveMachine() {
 }
 
 async function saveRelationship(assetId) {
-  // If no PC selected and no existing relationship, nothing to do
-  if (!controllingPcId.value && !existingRelationshipId.value) {
+  // The decision lives in controllingPc.js, where it is covered by tests.
+  // See that file for why "is there a link" and "do I know its id" are two
+  // different questions and what happened when they were treated as one.
+  const plan = planControllingPcChange({
+    selected: controllingPcId.value,
+    loaded: loadedControllingPcId.value,
+    existingRelationshipId: existingRelationshipId.value,
+  })
+
+  if (plan.action === 'none') {
     return
   }
 
-  // If clearing the relationship
-  if (!controllingPcId.value && existingRelationshipId.value) {
-    await assetsApi.deleteRelationship(existingRelationshipId.value)
+  if (plan.deleteId !== null) {
+    await assetsApi.deleteRelationship(plan.deleteId)
+    existingRelationshipId.value = null
+    loadedControllingPcId.value = null
+  }
+
+  if (plan.action === 'unlink') {
     return
   }
 
-  // If PC is selected
-  if (controllingPcId.value) {
-    // If there's an existing relationship, delete it first
-    if (existingRelationshipId.value) {
-      await assetsApi.deleteRelationship(existingRelationshipId.value)
-    }
+  // PC controls Machine, so the PC is the source and the machine the target.
+  const created = await assetsApi.createRelationship({
+    sourceassetid: controllingPcId.value,
+    targetassetid: assetId,
+    relationshiptypeid: relationshipTypeId.value
+  })
 
-    // Create new relationship (PC controls Machine, so PC is source, Machine is target)
-    await assetsApi.createRelationship({
-      sourceassetid: controllingPcId.value,
-      targetassetid: assetId,
-      relationshiptypeid: relationshipTypeId.value
-    })
-  }
+  // Keep the form honest about what is now stored, so a second save without a
+  // reload does not repeat the create it just did.
+  existingRelationshipId.value = created?.data?.data?.relationshipid ?? null
+  loadedControllingPcId.value = controllingPcId.value
 }
 </script>