Meteor Collection Hooks

Extends Meteor.Collection with before/after hooks for insert/update/remove/find/findOne.

Works across both client, server or a mix. Also works when a client initiates a collection method and the server runs the hook, all while respecting the collection validators (allow/deny).

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.before.insert(userId, doc)

Fired before the doc is inserted.

Gives you an opportunity to modify doc as needed, or run additional functionality

• this.transform() obtains transformed version of document, if a transform was defined.

var test = new Meteor.Collection("test");

test.before.insert(function (userId, doc) {
  doc.createdAt = Date.now();
});

---

.before.update(userId, doc, fieldNames, modifier)

Fired before the doc is updated.

Gives you an opportunity to change the modifier as needed, or run additional functionality. Important: note that we are changing modifier, and not doc. Changing doc won't have any effect as the document is a copy and is not what ultimately gets sent down to the real update method.

• this.transform() obtains transformed version of document, if a transform was defined.

test.before.update(function (userId, doc, fieldNames, modifier) {
  modifier.$set.modifiedAt = Date.now();
});

---

.before.remove(userId, doc)

Fired just before the doc is removed.

Gives you an opportunity to affect your system while the document is still in existence -- useful for maintaining system integrity, such as cascading deletes.

• this.transform() obtains transformed version of document, if a transform was defined.

test.before.remove(function (userId, doc) {
  // ...
});

---

.after.insert(userId, doc)

Fired after the doc was inserted.

Gives you an opportunity to run post-insert tasks, such as sending notifications of new document insertions.

• this.transform() obtains transformed version of document, if a transform was defined.

test.after.insert(function (userId, doc) {
  // ...
});

---

.after.update(userId, doc, fieldNames, modifier)

Fired after the doc was updated.

Gives you an opportunity to run post-update tasks, potentially comparing the previous and new documents to take further action.

• this.previous contains the document before it was updated.
• this.transform() obtains transformed version of document, if a transform was defined.

test.after.update(function (userId, doc, fieldNames, modifier) {
  // ...
});

---

.after.remove(userId, doc)

Fired after the doc was removed.

doc contains a copy of the document before it was removed.

Gives you an opportunity to run post-removal tasks that don't necessarily depend on the document being found in the database (external service clean-up for instance).

• this.transform() obtains transformed version of document, if a transform was defined.

test.after.remove: function (userId, doc) {
  // ...
});

---

.before.find(userId, selector, options)

Fired before a find query.

Gives you an opportunity to adjust selector/options on-the-fly.

test.before.find: function (userId, selector, options) {
  // ...
});

---

.after.find(userId, selector, options, cursor)

Fired after a find query.

Gives you an opportunity to act on a given find query. The cursor resulting from the query is provided as the last argument for convenience.

test.after.find: function (userId, selector, options, cursor) {
  // ...
});

---

.before.findOne(userId, selector, options)

Fired before a findOne query.

Gives you an opportunity to adjust selector/options on-the-fly.

test.before.findOne: function (userId, selector, options) {
  // ...
});

---

.after.findOne(userId, selector, options, doc)

Fired after a findOne query.

Gives you an opportunity to act on a given findOne query. The document resulting from the query is provided as the last argument for convenience.

test.after.findOne: function (userId, selector, options, doc) {
  // ...
});

---

Contributors

• Mathieu Bouchard (@matb33)
• Kevin Kaland (@wizonesolutions)
• Andrew Mao (@mizzao)