find matched item from document based on regex value in mongidb - node.js

Question

I have to select matched casts item [m_credits_cast] from the Movie collection by using Regex value.
Movie Modal
var mongoose = require('mongoose');
var movieSchema = new mongoose.Schema({
m_tmdb_id: {
type: Number,
unique: true,
index: true
},
m_original_title: {
type: String
},
m_poster_path: {
type: String
},
m_credits_cast: {
type: Array
},
m_release_date: {
type: Date
},
m_title: {
type: String
},
created_at: {
type: Date
},
updated_at: {
type: Date,
default: Date.now
}
});
var MovieModel = mongoose.model('Movie', movieSchema);
module.exports = {
movie: MovieModel
}
Js code
router.post('/casts', function(req, res, next) {
var searchText = req.body.searchtext;
var regexValue = '^' + searchText;
Movie
.aggregate([{
$match: {
'm_credits_cast.name': { '$regex': regexValue, '$options': 'i' }
}
},
{
$project: {
m_credits_cast: {
$filter: {
input: '$m_credits_cast',
as: 'cast',
cond: { $eq: ['$$cast.name', { '$regex': regexValue, '$options': 'i' }] }
}
},
_id: 0
}
}
])
.exec(function(err, casts) {
return res.status(500).json(casts);
}).catch(function(error) {
return res.status(500).json(error);
});
});
The code is not working because i am using $regex inside $project operator.How can i resolve this issue?
Movie Collection
[{
"_id": "5913e96548f1956df16f33a0",
"m_tmdb_id": 401246,
"m_original_title": "The Square",
"m_poster_path": "/g7ifEh3XBKftVA0g1zz9lXORm7l.jpg",
"m_release_date": "2017-08-25T00:00:00.000Z",
"m_runtime": 142,
"m_credits_cast": [{
"cast_id": 2,
"character": "Christian",
"credit_id": "575823d9c3a3687d6f00157f",
"gender": 2,
"id": 150802,
"name": "Claes Bang",
"order": 0,
"profile_path": "/iwPu7hwSj6A9BkO9M13SDkhD7QE.jpg"
},
{
"cast_id": 0,
"character": "Anne",
"credit_id": "575823bec3a3687d6a0016cf",
"gender": 1,
"id": 32798,
"name": "Elisabeth Moss",
"order": 1,
"profile_path": "/iSp2t9GYUUgyqTpz25J6hOHH2An.jpg"
}
],
"m_genres": [{
"id": 18,
"name": "Drama"
}]
}, {
"_id": "5840ebceb386b78c69b56602",
"m_tmdb_id": 336000,
"m_original_title": "The Glass Castle",
"m_poster_path": "/d5fLQ9ZMa1jZ2mODCv5lOWJDugX.jpg",
"m_release_date": "2017-08-11T00:00:00.000Z",
"m_runtime": 0,
"m_credits_cast": [{
"cast_id": 6,
"character": "Jeannette Walls",
"credit_id": "574fbcc6c3a3687950000f7c",
"gender": 1,
"id": 60073,
"name": "Brie Larson",
"order": 1,
"profile_path": "/p66rOUPo1ZFZ7XrAKZ6DjdsvCA2.jpg"
},
{
"cast_id": 7,
"character": "Rose Mary Walls",
"credit_id": "574fbcddc3a36879430011ff",
"gender": 1,
"id": 3489,
"name": "Naomi Watts",
"order": 2,
"profile_path": "/8W02WOJI1pEGh2iqQsgITR5tV0P.jpg"
},
{
"cast_id": 30,
"character": "Miss Bivens",
"credit_id": "58e3d04a925141281902086e",
"gender": 1,
"id": 43259,
"name": "Kyra Harper",
"order": 19,
"profile_path": "/hItQl4CyIC6Www5FQeHVWrv76ap.jpg"
},
{
"cast_id": 31,
"character": "Jeannette Walls (Age 5 and 6)",
"credit_id": "58e3d063c3a36872af01ecaf",
"gender": 0,
"id": 1505453,
"name": "Chandler Head",
"order": 20,
"profile_path": null
},
{
"cast_id": 32,
"character": "Intern",
"credit_id": "58e3d070925141281902089c",
"gender": 0,
"id": 1652138,
"name": "Hamza Haq",
"order": 21,
"profile_path": null
}
],
"m_genres": [{
"id": 18,
"name": "Drama"
}]
}]