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 '} });
var 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.

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

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 populated, this is a no-op.

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 the Document stores the same data as doc.

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 ES2015 integration.

Example:

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

// summary
doc.execPopulate().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"

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 was initialized.

Returns true if this document was modified, else false.

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.

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, undefined is returned.

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

Valid options:

• same as in Model.replaceOne

Saves this document.

Example:

product.sold = Date.now();
product.save(function (err, product) {
  if (err) ..
})

The callback will receive two parameters

1. err if an error occurred
2. product which is the saved product

As an extra measure of flow control, save will return a Promise.

Example:

product.save().then(function(product) {
   ...
});

The documents 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 javascript object, ready for storage in MongoDB.

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

Options:

• getters apply all getters (path and virtual getters), defaults to false
• 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)

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;
}

var 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: '[email protected]',
  members: [{ name: 'Val', email: '[email protected]' }]
});

// 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

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:

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