Document

Get all subdocs (by bfs)

Don't run validation on this path or persist changes to this path.

Example:

doc.foo = null;
doc.$ignore('foo');
doc.save(); // changes to foo will not be persisted and validators won't be run

Checks if a path is set to its default.

Example

MyModel = mongoose.model('test', { name: { type: String, default: 'Val '} });
const m = new MyModel();
m.$isDefault('name'); // true

Getter/setter, determines whether the document was removed or not.

Example:

product.remove(function (err, product) {
  product.$isDeleted(); // true
  product.remove(); // no-op, doesn't send anything to the db

  product.$isDeleted(false);
  product.$isDeleted(); // false
  product.remove(); // will execute a remove against the db
})

Returns true if the given path is nullish or only contains empty objects. Useful for determining whether this subdoc will get stripped out by the minimize option.

Example:

const schema = new Schema({ nested: { foo: String } });
const Model = mongoose.model('Test', schema);
const doc = new Model({});
doc.$isEmpty('nested'); // true
doc.nested.$isEmpty(); // true

doc.nested.foo = 'bar';
doc.$isEmpty('nested'); // false
doc.nested.$isEmpty(); // false

Empty object that you can use for storing properties on the document. This is handy for passing data to middleware without conflicting with Mongoose internals.

Example:

schema.pre('save', function() {
  // Mongoose will set `isNew` to `false` if `save()` succeeds
  this.$locals.wasNew = this.isNew;
});

schema.post('save', function() {
  // Prints true if `isNew` was set before `save()`
  console.log(this.$locals.wasNew);
});

Marks a path as valid, removing existing validation errors.

A string containing the current operation that Mongoose is executing on this document. May be null, 'save', 'validate', or 'remove'.

Example:

const doc = new Model({ name: 'test' });
doc.$op; // null

const promise = doc.save();
doc.$op; // 'save'

await promise;
doc.$op; // null

Alias for parent(). If this document is a subdocument or populated document, returns the document's parent. Returns undefined otherwise.

Getter/setter around the session associated with this document. Used to automatically set session if you save() a doc that you got from a query with an associated session.

Example:

const session = MyModel.startSession();
const doc = await MyModel.findOne().session(session);
doc.$session() === session; // true
doc.$session(null);
doc.$session() === null; // true

If this is a top-level document, setting the session propagates to all child docs.

Alias for set(), used internally to avoid conflicts

Set this property to add additional query filters when Mongoose saves this document and isNew is false.

Example:

// Make sure `save()` never updates a soft deleted document.
schema.pre('save', function() {
  this.$where = { isDeleted: false };
});

Takes a populated field and returns it to its unpopulated state.

Example:

Model.findOne().populate('author').exec(function (err, doc) {
  console.log(doc.author.name); // Dr.Seuss
  console.log(doc.depopulate('author'));
  console.log(doc.author); // '5144cf8050f071d979c118a7'
})

If the path was not provided, then all populated fields are returned to their unpopulated state.

Returns the list of paths that have been directly modified. A direct modified path is a path that you explicitly set, whether via doc.foo = 'bar', Object.assign(doc, { foo: 'bar' }), or doc.set('foo', 'bar').

A path a may be in modifiedPaths() but not in directModifiedPaths() because a child of a was directly modified.

Example

const schema = new Schema({ foo: String, nested: { bar: String } });
const Model = mongoose.model('Test', schema);
await Model.create({ foo: 'original', nested: { bar: 'original' } });

const doc = await Model.findOne();
doc.nested.bar = 'modified';
doc.directModifiedPaths(); // ['nested.bar']
doc.modifiedPaths(); // ['nested', 'nested.bar']

Returns true if this document is equal to another document.

Documents are considered equal when they have matching _ids, unless neither document has an _id, in which case this function falls back to using deepEqual().

Hash containing current validation errors.

Explicitly executes population and returns a promise. Useful for promises integration.

Example:

const promise = doc.
  populate('company').
  populate({
    path: 'notes',
    match: /airline/,
    select: 'text',
    model: 'modelName'
    options: opts
  }).
  execPopulate();

// summary
doc.execPopulate().then(resolve, reject);

// you can also use doc.execPopulate(options) as a shorthand for // doc.populate(options).execPopulate()

Example:

const promise = doc.execPopulate({ path: 'company', select: 'employees' });

// summary promise.then(resolve,reject);

Returns the value of a path.

Example

// path
doc.get('age') // 47

// dynamic casting to a string
doc.get('age', String) // "47"

Returns the changes that happened to the document in the format that will be sent to MongoDB.

Example:

const userSchema = new Schema({
  name: String,
  age: Number,
  country: String
});
const User = mongoose.model('User', userSchema);
const user = await User.create({
  name: 'Hafez',
  age: 25,
  country: 'Egypt'
});

// returns an empty object, no changes happened yet
user.getChanges(); // { }

user.country = undefined;
user.age = 26;

user.getChanges(); // { $set: { age: 26 }, { $unset: { country: 1 } } }

await user.save();

user.getChanges(); // { }

Modifying the object that getChanges() returns does not affect the document's change tracking state. Even if you delete user.getChanges().$set, Mongoose will still send a $set to the server.

The string version of this documents _id.

Note:

This getter exists on all documents by default. The getter can be disabled by setting the id option of its Schema to false at construction time.

new Schema({ name: String }, { id: false });

Initializes the document without setters or marking anything modified.

Called internally after a document is returned from mongodb. Normally, you do not need to call this function on your own.

This function triggers init middleware. Note that init hooks are synchronous.

Helper for console.log

Marks a path as invalid, causing validation to fail.

The errorMsg argument will become the message of the ValidationError.

The value argument (if passed) will be available through the ValidationError.value property.

doc.invalidate('size', 'must be less than 20', 14);

doc.validate(function (err) {
  console.log(err)
  // prints
  { message: 'Validation failed',
    name: 'ValidationError',
    errors:
     { size:
        { message: 'must be less than 20',
          name: 'ValidatorError',
          path: 'size',
          type: 'user defined',
          value: 14 } } }
})

Returns true if path was directly set and modified, else false.

Example

doc.set('documents.0.title', 'changed');
doc.isDirectModified('documents.0.title') // true
doc.isDirectModified('documents') // false

Checks if path was explicitly selected. If no projection, always returns true.

Example

Thing.findOne().select('nested.name').exec(function (err, doc) {
   doc.isDirectSelected('nested.name') // true
   doc.isDirectSelected('nested.otherName') // false
   doc.isDirectSelected('nested')  // false
})

Checks if path is in the init state, that is, it was set by Document#init() and not modified since.

Returns true if any of the given paths is modified, else false. If no arguments, returns true if any path in this document is modified.

If path is given, checks if a path or any full path containing path as part of its path chain has been modified.

Example

doc.set('documents.0.title', 'changed');
doc.isModified()                      // true
doc.isModified('documents')           // true
doc.isModified('documents.0.title')   // true
doc.isModified('documents otherProp') // true
doc.isDirectModified('documents')     // false

Boolean flag specifying if the document is new.

Checks if path was selected in the source query which initialized this document.

Example

Thing.findOne().select('name').exec(function (err, doc) {
   doc.isSelected('name') // true
   doc.isSelected('age')  // false
})

Marks the path as having pending changes to write to the db.

Very helpful when using Mixed types.

Example:

doc.mixed.type = 'changed';
doc.markModified('mixed.type');
doc.save() // changes to mixed.type are now persisted

Returns the list of paths that have been modified.

Overwrite all values in this document with the values of obj, except for immutable properties. Behaves similarly to set(), except for it unsets all properties that aren't in obj.

If this document is a subdocument or populated document, returns the document's parent. Returns undefined otherwise.

Populates document references, executing the callback when complete. If you want to use promises instead, use this function with execPopulate()

Example:

doc
.populate('company')
.populate({
  path: 'notes',
  match: /airline/,
  select: 'text',
  model: 'modelName'
  options: opts
}, function (err, user) {
  assert(doc._id === user._id) // the document itself is passed
})

// summary
doc.populate(path)                   // not executed
doc.populate(options);               // not executed
doc.populate(path, callback)         // executed
doc.populate(options, callback);     // executed
doc.populate(callback);              // executed
doc.populate(options).execPopulate() // executed, returns promise

NOTE:

Population does not occur unless a callback is passed or you explicitly call execPopulate(). Passing the same path a second time will overwrite the previous path options. See Model.populate() for explaination of options.

Gets _id(s) used during population of the given path.

Example:

Model.findOne().populate('author').exec(function (err, doc) {
  console.log(doc.author.name)         // Dr.Seuss
  console.log(doc.populated('author')) // '5144cf8050f071d979c118a7'
})

If the path was not populated, returns undefined.

Sends a replaceOne command with this document _id as the query selector.

Valid options:

• same as in Model.replaceOne

Saves this document by inserting a new document into the database if document.isNew is true, or sends an updateOne operation only with the modifications to the database, it does not replace the whole document in the latter case.

Example:

product.sold = Date.now();
product = await product.save();

If save is successful, the returned promise will fulfill with the document saved.

Example:

const newProduct = await product.save();
newProduct === product; // true

The document's schema.

Sets the value of a path, or many paths.

Example:

// path, value
doc.set(path, value)

// object
doc.set({
    path  : value
  , path2 : {
       path  : value
    }
})

// on-the-fly cast to number
doc.set(path, value, Number)

// on-the-fly cast to string
doc.set(path, value, String)

// changing strict mode behavior
doc.set(path, value, { strict: false });

The return value of this method is used in calls to JSON.stringify(doc).

This method accepts the same options as Document#toObject. To apply the options to every document of your schema by default, set your schemas toJSON option to the same argument.

schema.set('toJSON', { virtuals: true })

See schema options for details.

Converts this document into a plain-old JavaScript object (POJO).

Buffers are converted to instances of mongodb.Binary for proper storage.

Options:

• getters apply all getters (path and virtual getters), defaults to false
• aliases apply all aliases if virtuals=true, defaults to true
• virtuals apply virtual getters (can override getters option), defaults to false
• minimize remove empty objects, defaults to true
• transform a transform function to apply to the resulting document before returning
• depopulate depopulate any populated paths, replacing them with their original refs, defaults to false
• versionKey whether to include the version key, defaults to true
• flattenMaps convert Maps to POJOs. Useful if you want to JSON.stringify() the result of toObject(), defaults to false
• useProjection set to true to omit fields that are excluded in this document's projection. Unless you specified a projection, this will omit any field that has select: false in the schema.

Getters/Virtuals

Example of only applying path getters

doc.toObject({ getters: true, virtuals: false })

Example of only applying virtual getters

doc.toObject({ virtuals: true })

Example of applying both path and virtual getters

doc.toObject({ getters: true })

To apply these options to every document of your schema by default, set your schemas toObject option to the same argument.

schema.set('toObject', { virtuals: true })

Transform

We may need to perform a transformation of the resulting object based on some criteria, say to remove some sensitive information or return a custom object. In this case we set the optional transform function.

Transform functions receive three arguments

function (doc, ret, options) {}

• doc The mongoose document which is being converted
• ret The plain object representation which has been converted
• options The options in use (either schema options or the options passed inline)

Example

// specify the transform schema option
if (!schema.options.toObject) schema.options.toObject = {};
schema.options.toObject.transform = function (doc, ret, options) {
  // remove the _id of every document before returning the result
  delete ret._id;
  return ret;
}

// without the transformation in the schema
doc.toObject(); // { _id: 'anId', name: 'Wreck-it Ralph' }

// with the transformation
doc.toObject(); // { name: 'Wreck-it Ralph' }

With transformations we can do a lot more than remove properties. We can even return completely new customized objects:

if (!schema.options.toObject) schema.options.toObject = {};
schema.options.toObject.transform = function (doc, ret, options) {
  return { movie: ret.name }
}

// without the transformation in the schema
doc.toObject(); // { _id: 'anId', name: 'Wreck-it Ralph' }

// with the transformation
doc.toObject(); // { movie: 'Wreck-it Ralph' }

Note: if a transform function returns undefined, the return value will be ignored.

Transformations may also be applied inline, overridding any transform set in the options:

function xform (doc, ret, options) {
  return { inline: ret.name, custom: true }
}

// pass the transform as an inline option
doc.toObject({ transform: xform }); // { inline: 'Wreck-it Ralph', custom: true }

If you want to skip transformations, use transform: false:

schema.options.toObject.hide = '_id';
schema.options.toObject.transform = function (doc, ret, options) {
  if (options.hide) {
    options.hide.split(' ').forEach(function (prop) {
      delete ret[prop];
    });
  }
  return ret;
}

const doc = new Doc({ _id: 'anId', secret: 47, name: 'Wreck-it Ralph' });
doc.toObject();                                        // { secret: 47, name: 'Wreck-it Ralph' }
doc.toObject({ hide: 'secret _id', transform: false });// { _id: 'anId', secret: 47, name: 'Wreck-it Ralph' }
doc.toObject({ hide: 'secret _id', transform: true }); // { name: 'Wreck-it Ralph' }

If you pass a transform in toObject() options, Mongoose will apply the transform to subdocuments in addition to the top-level document. Similarly, transform: false skips transforms for all subdocuments.

Note that this is behavior is different for transforms defined in the schema

if you define a transform in schema.options.toObject.transform, that transform will not apply to subdocuments.

const memberSchema = new Schema({ name: String, email: String });
const groupSchema = new Schema({ members: [memberSchema], name: String, email });
const Group = mongoose.model('Group', groupSchema);

const doc = new Group({
  name: 'Engineering',
  email: 'dev@mongoosejs.io',
  members: [{ name: 'Val', email: 'val@mongoosejs.io' }]
});

// Removes `email` from both top-level document **and** array elements
// { name: 'Engineering', members: [{ name: 'Val' }] }
doc.toObject({ transform: (doc, ret) => { delete ret.email; return ret; } });

Transforms, like all of these options, are also available for toJSON. See this guide to JSON.stringify() to learn why toJSON() and toObject() are separate functions.

See schema options for some more details.

During save, no custom options are applied to the document before being sent to the database.

Helper for console.log

Gets all populated documents associated with this document.

Clears the modified state on the specified path.

Example:

doc.foo = 'bar';
doc.unmarkModified('foo');
doc.save(); // changes to foo will not be persisted

Sends an update command with this document _id as the query selector.

Example:

weirdCar.update({$inc: {wheels:1}}, { w: 1 }, callback);

Valid options:

• same as in Model.update

Sends an updateOne command with this document _id as the query selector.

Example:

weirdCar.updateOne({$inc: {wheels:1}}, { w: 1 }, callback);

Valid options:

• same as in Model.updateOne

Executes registered validation rules for this document.

Note:

This method is called pre save and if a validation rule is violated, save is aborted and the error is returned to your callback.

Example:

doc.validate(function (err) {
  if (err) handleError(err);
  else // validation passed
});

Executes registered validation rules (skipping asynchronous validators) for this document.

Note:

This method is useful if you need synchronous validation.

Example:

const err = doc.validateSync();
if (err) {
  handleError(err);
} else {
  // validation passed
}