From 4fcae9b3f9bdeb5bc69676df1cc58e8beb3db6bf Mon Sep 17 00:00:00 2001
From: Stefan Zermatten <stefanzermatten@gmail.com>
Date: Wed, 25 Sep 2019 14:37:54 +0200
Subject: [PATCH] Fixed a bug where moving documents around deleted docs breaks
 the ordering

---
 app/imports/api/parenting/order.js            | 48 +++++++++++++++++--
 app/imports/api/parenting/organizeMethods.js  |  4 +-
 .../ui/components/tree/TreeNodeList.vue       |  2 +-
 3 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/app/imports/api/parenting/order.js b/app/imports/api/parenting/order.js
index 32172c59..cab63b09 100644
--- a/app/imports/api/parenting/order.js
+++ b/app/imports/api/parenting/order.js
@@ -61,6 +61,8 @@ export function setDocToLastOrder({collection, doc}){
   }) + 1;
 }
 
+// update the order of a doc, and shift the siblings around to suit the new
+// order
 export function updateDocOrder({docRef, order}){
   let doc = fetchDocByRef(docRef, {fields: {
     order: 1,
@@ -116,7 +118,7 @@ export function removedDocAtOrder({collection, doc}){
 }
 
 export function insertedDocAtOrder({collection, parentId, order}){
-  // Decrement the order of all docs after the removed doc
+  // Increment the order of all docs after the inserted doc
   collection.update({
     'parent.id': parentId,
     order: {$gte: order},
@@ -128,6 +130,46 @@ export function insertedDocAtOrder({collection, parentId, order}){
   });
 }
 
+// Update the order a single doc and re-order the entire sibling list
+// with the change
+export function safeUpdateDocOrder({docRef, order}){
+  let collection = getCollectionByName(docRef.collection);
+  let movedDoc = fetchDocByRef(docRef, {fields: {
+    parent: 1, name: 1
+  }});
+  let parentId = movedDoc.parent.id;
+  let bulkWrite = [];
+  let docs = collection.find({
+    'parent.id': parentId,
+    '_id': {$ne: movedDoc._id},
+  }, {
+    fields: {order: 1, name: 1},
+    sort: {order: 1}
+  }).fetch();
+  docs.splice(order, 0, movedDoc);
+  docs.forEach((doc, index) => {
+    if (doc.order !== index){
+      bulkWrite.push({
+        updateOne: {
+          filter: {_id: doc._id},
+          update: {$set: {order: index}},
+        },
+      });
+    }
+  });
+  if (Meteor.isServer){
+    collection.rawCollection().bulkWrite(bulkWrite);
+  } else {
+    bulkWrite.forEach(op => {
+      collection.update(
+        op.updateOne.filter,
+        op.updateOne.update,
+        {selector: {type: 'any'}}
+      );
+    });
+  }
+};
+
 export function reorderDocs({collection, parentId}){
   let bulkWrite = [];
   collection.find({
@@ -137,7 +179,7 @@ export function reorderDocs({collection, parentId}){
     sort: {order: 1}
   }).forEach((doc, index) => {
     if (doc.order !== index){
-      bulkwrite.push({
+      bulkWrite.push({
         updateOne : {
           filter: {_id: doc._id},
           update: {$set: {order: index}},
@@ -149,7 +191,7 @@ export function reorderDocs({collection, parentId}){
     collection.rawCollection().bulkWrite(bulkWrite);
   } else {
     bulkWrite.forEach(op => {
-      collection.update(op.filter, op.update);
+      collection.update(op.updateOne.filter, op.updateOne.update);
     });
   }
 }
diff --git a/app/imports/api/parenting/organizeMethods.js b/app/imports/api/parenting/organizeMethods.js
index 3f9120e2..bce2f889 100644
--- a/app/imports/api/parenting/organizeMethods.js
+++ b/app/imports/api/parenting/organizeMethods.js
@@ -1,6 +1,6 @@
 import SimpleSchema from 'simpl-schema';
 import { updateParent } from '/imports/api/parenting/parenting.js';
-import { insertedDocAtOrder, removedDocAtOrder, updateDocOrder } from '/imports/api/parenting/order.js';
+import { insertedDocAtOrder, removedDocAtOrder, safeUpdateDocOrder } from '/imports/api/parenting/order.js';
 import { RefSchema } from '/imports/api/parenting/ChildSchema.js';
 import { assertDocEditPermission } from '/imports/api/sharing/sharingPermissions.js';
 import fetchDocByRef from '/imports/api/parenting/fetchDocByRef.js';
@@ -48,7 +48,7 @@ const reorderDoc = new ValidatedMethod({
   run({docRef, order}) {
     let doc = fetchDocByRef(docRef);
     assertDocEditPermission(doc, this.userId);
-    updateDocOrder({docRef, order})
+    safeUpdateDocOrder({docRef, order})
   },
 });
 
diff --git a/app/imports/ui/components/tree/TreeNodeList.vue b/app/imports/ui/components/tree/TreeNodeList.vue
index b0fbddd5..93ab46e5 100644
--- a/app/imports/ui/components/tree/TreeNodeList.vue
+++ b/app/imports/ui/components/tree/TreeNodeList.vue
@@ -64,8 +64,8 @@
 		methods: {
 			change({added, moved}){
 				let event = moved || added;
+				let newIndex = this.children[event.newIndex].node.order;
 				if (event){
-					let newIndex = event.newIndex;
 					let doc = event.element.node;
 					if (moved){
 						this.$emit('reordered', {doc, newIndex});