Moved a lot of functionality to mixins, improved parenting

app/imports/api/order/order.js

@@ -0,0 +1,78 @@
+import SimpleSchema from 'simpl-schema';
+
+export function getHighestOrder({collection, charId}){
+  const highestOrderedDoc = collection.findOne({
+    charId
+  }, {
+    fields: {order: 1},
+    sort: {order: -1},
+  });
+  return (highestOrderedDoc && highestOrderedDoc.order) || 0;
+}
+
+export function setDocToLastOrder({collection, doc}){
+  doc.order = getHighestOrder({
+    collection,
+    charId: doc.charId,
+  }) + 1;
+}
+
+export function setDocOrder({collection, doc, order}){
+  const currentOrder = doc.order;
+  if (currentOrder === order){
+    return;
+  } else {
+    // Move the document to its new order
+    collection.update(doc._id, {$set: {order}});
+    let inBetweenSelector, increment;
+    if (order > currentOrder){
+      // Move in-between docs backward
+      inBetweenSelector = [
+        {$gt: currentOrder},
+        {$lte: order},
+      ];
+      increment = -1;
+    } else if (order < currentOrder){
+      // Move in-between docs forward
+      inBetweenSelector = [
+        {$lt: currentOrder},
+        {$gte: order},
+      ];
+      increment = 1;
+    }
+    collection.update({
+      order: {$and: inBetweenSelector},
+      charId: doc.charId,
+    }, {
+      $inc: {order: increment},
+    }, {
+      multi: true,
+    });
+  }
+}
+
+export function reorderDocs({collection, charId}){
+  let bulkWrite = [];
+  collection.find({
+    charId
+  }, {
+    fields: {order: 1},
+    sort: {order: 1}
+  }).forEach((doc, index) => {
+    if (doc.order !== index){
+      bulkwrite.push({
+        updateOne : {
+          filter: {_id: doc._id},
+          update: {$set: {order: index}},
+        },
+      });
+    }
+  });
+  if (Meteor.isServer){
+    collection.rawCollection().bulkWrite(bulkWrite);
+  } else {
+    bulkWrite.forEach(op => {
+      collection.update(op.filter, op.update);
+    });
+  }
+}