graphql-compose-mongoose


This is a plugin for graphql-compose, which derives GraphQLType from your mongoose model. Also derives bunch of internal GraphQL Types. Provide all CRUD resolvers, including graphql connection, also provided basic search via operators ($lt, $gt and so on).

Release Notes for v9.0.0 contains a lot of improvements. It's strongly recommended for reading before upgrading from v8.

- Installation
- Intro video
- Example
- Working with Mongoose Collection Level Discriminators
- Customization options
- composeMongoose customization options
- Resolvers' customization options
- connection(opts?: ConnectionResolverOpts)
- count(opts?: CountResolverOpts)
- createMany(opts?: CreateManyResolverOpts)
- createOne(opts?: CreateOneResolverOpts)
- dataLoader(opts?: DataLoaderResolverOpts)
- dataLoaderMany(opts?: DataLoaderManyResolverOpts)
- findById(opts?: FindByIdResolverOpts)
- findByIds(opts?: FindByIdsResolverOpts)
- findMany(opts?: FindManyResolverOpts)
- findOne(opts?: FindOneResolverOpts)
- pagination(opts?: PaginationResolverOpts)
- removeById(opts?: RemoveByIdResolverOpts)
- removeMany(opts?: RemoveManyResolverOpts)
- removeOne(opts?: RemoveOneResolverOpts)
- updateById(opts?: UpdateByIdResolverOpts)
- updateMany(opts?: UpdateManyResolverOpts)
- updateOne(opts?: UpdateOneResolverOpts)
- Description of common resolvers' options
- FilterHelperArgsOpts
- SortHelperArgsOpts
- RecordHelperArgsOpts
- LimitHelperArgsOpts
- FAQ
- Can I get generated vanilla GraphQL types?
- How to add custom fields?
- How to build nesting/relations?
- Reusing the same mongoose Schema in embedded object fields
- Access and modify mongoose doc before save
- How can I restrict access to certain fields or documents?
- How can I push/pop or add/remove values to arrays?
- Is it possible to use several schemas?
- Embedded documents has _id field and you don't need it?
- Can field name in schema have different name in database?
- Backers
- Sponsors
- License

Installation

``bash
npm install graphql graphql-compose mongoose graphql-compose-mongoose --save
`

Modules graphql, graphql-compose, mongoose are in peerDependencies, so should be installed explicitly in your app. They have global objects and should not have ability to be installed as submodule.

Intro video

Viktor Kjartansson created a quite solid intro for graphql-compose-mongoose in comparison with graphql-tools:

(23 mins)

Example

Live demo:

Source code:

Small explanation for variables naming:

- UserSchema - this is a mongoose schema
- User - this is a mongoose model
- UserTC - this is a ObjectTypeComposer instance for User. ObjectTypeComposer has GraphQLObjectType inside, available via method UserTC.getType().
- Here and in all other places of code variables suffix ...TC means that this is ObjectTypeComposer instance, ...ITC - InputTypeComposer, ...ETC - EnumTypeComposer.

`ts
import mongoose from 'mongoose';
import { composeMongoose } from 'graphql-compose-mongoose';
import { schemaComposer } from 'graphql-compose';

// STEP 1: DEFINE MONGOOSE SCHEMA AND MODEL
const LanguagesSchema = new mongoose.Schema({
language: String,
skill: {
type: String,
enum: ['basic', 'fluent', 'native'],
},
});

const UserSchema = new mongoose.Schema({
name: String, // standard types
age: {
type: Number,
index: true,
},
ln: {
type: [LanguagesSchema], // you may include other schemas (here included as array of embedded documents)
default: [],
alias: 'languages', // in schema ln will be named as languages
},
contacts: { // another mongoose way for providing embedded documents
email: String,
phones: [String], // array of strings
},
gender: { // enum field with values
type: String,
enum: ['male', 'female'],
},
someMixed: {
type: mongoose.Schema.Types.Mixed,
description: 'Can be any mixed type, that will be treated as JSON GraphQL Scalar Type',
},
});
const User = mongoose.model('User', UserSchema);

// STEP 2: CONVERT MONGOOSE MODEL TO GraphQL PIECES
const customizationOptions = {}; // left it empty for simplicity, described below
const UserTC = composeMongoose(User, customizationOptions);

// STEP 3: ADD NEEDED CRUD USER OPERATIONS TO THE GraphQL SCHEMA
// via graphql-compose it will be much much easier, with less typing
schemaComposer.Query.addFields({
userById: UserTC.mongooseResolvers.findById(),
userByIds: UserTC.mongooseResolvers.findByIds(),
userOne: UserTC.mongooseResolvers.findOne(),
userMany: UserTC.mongooseResolvers.findMany(),
userDataLoader: UserTC.mongooseResolvers.dataLoader(),
userDataLoaderMany: UserTC.mongooseResolvers.dataLoaderMany(),
userByIdLean: UserTC.mongooseResolvers.findById({ lean: true }),
userByIdsLean: UserTC.mongooseResolvers.findByIds({ lean: true }),
userOneLean: UserTC.mongooseResolvers.findOne({ lean: true }),
userManyLean: UserTC.mongooseResolvers.findMany({ lean: true }),
userDataLoaderLean: UserTC.mongooseResolvers.dataLoader({ lean: true }),
userDataLoaderManyLean: UserTC.mongooseResolvers.dataLoaderMany({ lean: true }),
userCount: UserTC.mongooseResolvers.count(),
userConnection: UserTC.mongooseResolvers.connection(),
userPagination: UserTC.mongooseResolvers.pagination(),
});

schemaComposer.Mutation.addFields({
userCreateOne: UserTC.mongooseResolvers.createOne(),
userCreateMany: UserTC.mongooseResolvers.createMany(),
userUpdateById: UserTC.mongooseResolvers.updateById(),
userUpdateOne: UserTC.mongooseResolvers.updateOne(),
userUpdateMany: UserTC.mongooseResolvers.updateMany(),
userRemoveById: UserTC.mongooseResolvers.removeById(),
userRemoveOne: UserTC.mongooseResolvers.removeOne(),
userRemoveMany: UserTC.mongooseResolvers.removeMany(),
});

// STEP 4: BUILD GraphQL SCHEMA OBJECT
const schema = schemaComposer.buildSchema();
export default schema;

// STEP 5: DEMO USE OF GraphQL SCHEMA OBJECT
// Just a demo, normally you'd pass schema object to server such as Apollo server.
import { graphql } from 'graphql';

(async () => {
await mongoose.connect('mongodb://localhost:27017/test');
await mongoose.connection.dropDatabase();

await User.create({ name: 'alice', age: 29, gender: 'female' });
await User.create({ name: 'maria', age: 31, gender: 'female' });
const bob = await User.create({ name: 'bob', age: 30, gender: 'male' });

const response1 = await graphql({
schema,
source: 'query { userMany { _id name } }',
});
console.dir(response1, { depth: 5 });

const response2 = await graphql({
schema,
source: 'query($id: MongoID!) { userById(_id: $id) { _id name } }',
variableValues: { id: bob._id },
});
console.dir(response2, { depth: 5 });

const response3 = await graphql({
schema,
source: 'mutation($id: MongoID!, $name: String) { userUpdateOne(filter: {_id: $id}, record: { name: $name }) { record { _id name } } }',
variableValues: { id: bob._id, name: 'bill' },
});
console.dir(response3, { depth: 5 });

mongoose.disconnect();
})();
`

That's all!
You think that is to much code?
I don't think so, because by default internally was created about 55 graphql types (for input, sorting, filtering). So you will need much much more lines of code to implement all these CRUD operations by hands.

$3

Variable Namings

- ...DTC - Suffix for a DiscriminatorTypeComposer instance, which is also an instance of ObjectTypeComposer. All fields and Relations manipulations on this instance affects all registered discriminators and the Discriminator Interface.

`ts
import mongoose from 'mongoose';
import { schemaComposer } from 'graphql-compose';
import { composeMongooseDiscriminators } from 'graphql-compose-mongoose';

// pick a discriminatorKey
const DKey = 'type';

const enumCharacterType = {
PERSON: 'Person',
DROID: 'Droid',
};

// DEFINE BASE SCHEMA
const CharacterSchema = new mongoose.Schema({
// _id: field...
type: {
type: String,
required: true,
enum: (Object.keys(enumCharacterType): Array),
description: 'Character type Droid or Person',
},

name: String,
height: Number,
mass: Number,
films: [String],
});

// DEFINE DISCRIMINATOR SCHEMAS
const DroidSchema = new mongoose.Schema({
makeDate: String,
primaryFunction: [String],
});

const PersonSchema = new mongoose.Schema({
gender: String,
hairColor: String,
starships: [String],
});

// set discriminator Key
CharacterSchema.set('discriminatorKey', DKey);

// create base Model
const CharacterModel = mongoose.model('Character', CharacterSchema);

// create mongoose discriminator models
const DroidModel = CharacterModel.discriminator(enumCharacterType.DROID, DroidSchema);
const PersonModel = CharacterModel.discriminator(enumCharacterType.PERSON, PersonSchema);

// create DiscriminatorTypeComposer
const baseOptions = { // regular TypeConverterOptions, passed to composeMongoose
fields: {
remove: ['friends'],
}
}
const CharacterDTC = composeMongooseDiscriminators(CharacterModel, baseOptions);

// create Discriminator Types
const droidTypeConverterOptions = { // this options will be merged with baseOptions -> customizationsOptions
fields: {
remove: ['makeDate'],
}
};
const DroidTC = CharacterDTC.discriminator(DroidModel, droidTypeConverterOptions);
const PersonTC = CharacterDTC.discriminator(PersonModel); // baseOptions -> customizationsOptions applied

// You may now use CharacterDTC to add fields to all Discriminators
// Use DroidTC, PersonTC as any other ObjectTypeComposer.
schemaComposer.Mutation.addFields({
droidCreate: DroidTC.getResolver('createOne'),
personCreate: PersonTC.getResolver('createOne'),
});

const schema = schemaComposer.buildSchema();

describe('createOne', () => {
it('should create child document without specifying DKey', async () => {
const res = await graphql.graphql({
schema,
source: mutation CreateCharacters {
droidCreate(record: {name: "Queue XL", modelNumber: 360 }) {
record {
__typename
type
name
modelNumber
}
}

personCreate(record: {name: "mernxl", dob: 57275272}) {
record {
__typename
type
name
dob
}
}
}
);

expect(res).toEqual({
data: {
droidCreate: {
record: { __typename: 'Droid', type: 'Droid', name: 'Queue XL', modelNumber: 360 },
},
personCreate: {
record: { __typename: 'Person', type: 'Person', name: 'mernxl', dob: 57275272 },
},
},
});
});
});
``

Customization options

$3

When you converting mongoose model const UserTC = composeMongoose(User, opts: ComposeMongooseOpts); you may tune every piece of future derived types – setup name and description for the main type, remove fields or leave only desired fields.

`ts
type ComposeMongooseOpts = {
/**
* Which type registry use for generated types.
* By default is used global default registry.
*/
schemaComposer?: SchemaComposer;
/**
* What should be base type name for generated type from mongoose model.
*/
name?: string;
/**
* Provide arbitrary description for generated type.
*/
description?: string;
/**
* You can leave only whitelisted fields in type via this option.
* Any other fields will be removed.
*/
onlyFields?: string[];
/**
* You can remove some fields from type via this option.
*/
removeFields?: string[];
/**
* You may configure generated InputType
*/
inputType?: TypeConverterInputTypeOpts;
/**
* You can make fields as NonNull if they have default value in mongoose model.
*/
defaultsAsNonNull?: boolean;
};
`

This is opts.inputType options for default InputTypeObject which will be provided to all resolvers for filter and input args.

`ts
type TypeConverterInputTypeOpts = {
/**
* What should be input type name.
* By default: baseTypeName + 'Input'
*/
name?: string;
/**
* Provide arbitrary description for generated type.
*/
description?: string;
/**
* You can leave only whitelisted fields in type via this option.
* Any other fields will be removed.
*/
onlyFields?: string[];
/**
* You can remove some fields from type via this option.
*/
removeFields?: string[];
/**
* This option makes provided fieldNames as required
*/
requiredFields?: string[];
};
`

Resolvers' customization options

When you are creating resolvers from mongooseResolvers factory, you may provide customizationOptions to it:

`ts
UserTC.mongooseResolvers.findMany(opts);
`

$3

`ts
type ConnectionResolverOpts = {
/ See below /
sort?: ConnectionSortMapOpts;
name?: string;
defaultLimit?: number | undefined;
edgeTypeName?: string;
edgeFields?: ObjectTypeComposerFieldConfigMap;
/ See below /
countOpts?: CountResolverOpts;
/ See below /
findManyOpts?: FindManyResolverOpts;
}
`

The countOpts and findManyOpts props would be used to customize the internally created findMany and count resolver factories used by the connection resolver.
If not provided the default configuration for each of the resolver factories is assumed.

The sort prop is optional. When provided it is used to customize the sorting behaviour of the connection. When not provided, the sorting configuration is derived from the existing indexes on the model.

Please refer to the documentation of the graphql-compose-connection plugin for more details on the sorting customization parameter.

$3

`ts
interface CountResolverOpts {
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize input-type for filter argument. If false then arg will be removed. /
filter?: FilterHelperArgsOpts | false;
}
`

$3

`ts
interface CreateManyResolverOpts {
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize input-type for records argument. /
records?: RecordHelperArgsOpts;
/* Customize payload.recordIds field. If false, then this field will be removed. /
recordIds?: PayloadRecordIdsHelperOpts | false;
/* Customize payload.error field. If true, then this field will be removed. /
disableErrorField?: boolean;
}
`

$3

`ts
interface CreateOneResolverOpts {
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize input-type for record argument /
record?: RecordHelperArgsOpts;
/* Customize payload.recordId field. If false, then this field will be removed. /
recordId?: PayloadRecordIdHelperOpts | false;
/* Customize payload.error field. If true, then this field will be removed. /
disableErrorField?: boolean;
}
`

$3

`ts
interface DataLoaderResolverOpts {
/**
* Enabling the lean option tells Mongoose to skip instantiating
* a full Mongoose document and just give you the plain JavaScript objects.
* Documents are much heavier than vanilla JavaScript objects,
* because they have a lot of internal state for change tracking.
* The downside of enabling lean is that lean docs don't have:
* Default values
* Getters and setters
* Virtuals
* Read more about lean: https://mongoosejs.com/docs/tutorials/lean.html
*/
lean?: boolean;
}
`

$3

`ts
interface DataLoaderManyResolverOpts {
/**
* Enabling the lean option tells Mongoose to skip instantiating
* a full Mongoose document and just give you the plain JavaScript objects.
* Documents are much heavier than vanilla JavaScript objects,
* because they have a lot of internal state for change tracking.
* The downside of enabling lean is that lean docs don't have:
* Default values
* Getters and setters
* Virtuals
* Read more about lean: https://mongoosejs.com/docs/tutorials/lean.html
*/
lean?: boolean;
}
`

$3

`ts
interface FindByIdResolverOpts {
/**
* Enabling the lean option tells Mongoose to skip instantiating
* a full Mongoose document and just give you the plain JavaScript objects.
* Documents are much heavier than vanilla JavaScript objects,
* because they have a lot of internal state for change tracking.
* The downside of enabling lean is that lean docs don't have:
* Default values
* Getters and setters
* Virtuals
* Read more about lean: https://mongoosejs.com/docs/tutorials/lean.html
*/
lean?: boolean;
}
`

$3

`ts
interface FindByIdsResolverOpts {
/**
* Enabling the lean option tells Mongoose to skip instantiating
* a full Mongoose document and just give you the plain JavaScript objects.
* Documents are much heavier than vanilla JavaScript objects,
* because they have a lot of internal state for change tracking.
* The downside of enabling lean is that lean docs don't have:
* Default values
* Getters and setters
* Virtuals
* Read more about lean: https://mongoosejs.com/docs/tutorials/lean.html
*/
lean?: boolean;
limit?: LimitHelperArgsOpts | false;
sort?: SortHelperArgsOpts | false;
}
`

$3

`ts
interface FindManyResolverOpts {
/**
* Enabling the lean option tells Mongoose to skip instantiating
* a full Mongoose document and just give you the plain JavaScript objects.
* Documents are much heavier than vanilla JavaScript objects,
* because they have a lot of internal state for change tracking.
* The downside of enabling lean is that lean docs don't have:
* Default values
* Getters and setters
* Virtuals
* Read more about lean: https://mongoosejs.com/docs/tutorials/lean.html
*/
lean?: boolean;
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize input-type for filter argument. If false then arg will be removed. /
filter?: FilterHelperArgsOpts | false;
sort?: SortHelperArgsOpts | false;
limit?: LimitHelperArgsOpts | false;
skip?: false;
}
`

$3

`ts
interface FindOneResolverOpts {
/**
* Enabling the lean option tells Mongoose to skip instantiating
* a full Mongoose document and just give you the plain JavaScript objects.
* Documents are much heavier than vanilla JavaScript objects,
* because they have a lot of internal state for change tracking.
* The downside of enabling lean is that lean docs don't have:
* Default values
* Getters and setters
* Virtuals
* Read more about lean: https://mongoosejs.com/docs/tutorials/lean.html
*/
lean?: boolean;
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize input-type for filter argument. If false then arg will be removed. /
filter?: FilterHelperArgsOpts | false;
sort?: SortHelperArgsOpts | false;
skip?: false;
}
`

$3

`ts
interface PaginationResolverOpts {
name?: string;
perPage?: number;
countOpts?: CountResolverOpts;
findManyOpts?: FindManyResolverOpts;
}
`

$3

`ts
interface RemoveByIdResolverOpts {
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize payload.recordId field. If false, then this field will be removed. /
recordId?: PayloadRecordIdHelperOpts | false;
/* Customize payload.error field. If true, then this field will be removed. /
disableErrorField?: boolean;
}
`

$3

`ts
interface RemoveManyResolverOpts {
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize input-type for filter argument. If false then arg will be removed. /
filter?: FilterHelperArgsOpts | false;
limit?: LimitHelperArgsOpts | false;
/* Customize payload.error field. If true, then this field will be removed. /
disableErrorField?: boolean;
}
`

$3

`ts
interface RemoveOneResolverOpts {
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize input-type for filter argument. If false then arg will be removed. /
filter?: FilterHelperArgsOpts | false;
sort?: SortHelperArgsOpts | false;
/* Customize payload.recordId field. If false, then this field will be removed. /
recordId?: PayloadRecordIdHelperOpts | false;
/* Customize payload.error field. If true, then this field will be removed. /
disableErrorField?: boolean;
}
`

$3

`ts
interface UpdateByIdResolverOpts {
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize input-type for record argument. /
record?: RecordHelperArgsOpts;
/* Customize payload.recordId field. If false, then this field will be removed. /
recordId?: PayloadRecordIdHelperOpts | false;
/* Customize payload.error field. If true, then this field will be removed. /
disableErrorField?: boolean;
}
`

$3

`ts
interface UpdateManyResolverOpts {
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize input-type for record argument. /
record?: RecordHelperArgsOpts;
/* Customize input-type for filter argument. If false then arg will be removed. /
filter?: FilterHelperArgsOpts | false;
sort?: SortHelperArgsOpts | false;
limit?: LimitHelperArgsOpts | false;
skip?: false;
/* Customize payload.error field. If true, then this field will be removed. /
disableErrorField?: boolean;
}
`

$3

`ts
interface UpdateOneResolverOpts {
/* If you want to generate different resolvers you may avoid Type name collision by adding a suffix to type names /
suffix?: string;
/* Customize input-type for record argument. /
record?: RecordHelperArgsOpts;
/* Customize input-type for filter argument. If false then arg will be removed. /
filter?: FilterHelperArgsOpts | false;
sort?: SortHelperArgsOpts | false;
skip?: false;
/* Customize payload.recordId field. If false, then this field will be removed. /
recordId?: PayloadRecordIdHelperOpts | false;
/* Customize payload.error field. If true, then this field will be removed. /
disableErrorField?: boolean;
}
`

$3

#### FilterHelperArgsOpts

`ts
type FilterHelperArgsOpts = {
/**
* Add to filter arg only that fields which are indexed.
* If false then all fields will be available for filtering.
* By default: true
*/
onlyIndexed?: boolean;
/**
* You can remove some fields from type via this option.
*/
removeFields?: string | string[];
/**
* This option makes provided fieldNames as required
*/
requiredFields?: string | string[];
/**
* Customize operators filtering or disable it at all.
* By default, for performance reason, graphql-compose-mongoose generates operators
only for indexed* fields.
*
* BUT you may enable operators for all fields when creating resolver in the following way:
* // enables all operators for all fields
* operators: true,
* OR provide a more granular operators configuration to suit your needs:
* operators: {
* // for age field add just 3 operators
* age: ['in', 'gt', 'lt'],
* // for non-indexed amount field add all operators
* amount: true,
* // don't add this field to operators
* indexedField: false,
* }
*
* Available logic operators: AND, OR
* Available field operators: gt, gte, lt, lte, ne, in, nin, regex, exists
*/
operators?: FieldsOperatorsConfig | false;
/**
* Make arg filter as required if this option is true.
*/
isRequired?: boolean;
/**
* Base type name for generated filter argument.
*/
baseTypeName?: string;
/**
* Provide custom prefix for Type name
*/
prefix?: string;
/**
* Provide custom suffix for Type name
*/
suffix?: string;
};
`

#### SortHelperArgsOpts

`ts
type SortHelperArgsOpts = {
/**
* Allow sort arg to be an array of enum values. Example [AGE_DESC, NAME_ASC, _ID_ASC].
Note enum values will only ever be generated for indexed fields*.
*/
multi?: boolean;
/**
* This option set custom type name for generated sort argument.
*/
sortTypeName?: string;
};
`

#### RecordHelperArgsOpts

`ts
type RecordHelperArgsOpts = {
/**
* You can remove some fields from type via this option.
*/
removeFields?: string[];
/**
* This option makes provided fieldNames as required
*/
requiredFields?: string[];
/**
* This option makes all fields nullable by default.
* May be overridden by requiredFields property
*/
allFieldsNullable?: boolean;
/**
* Provide custom prefix for Type name
*/
prefix?: string;
/**
* Provide custom suffix for Type name
*/
suffix?: string;
/**
* Make arg record as required if this option is true.
*/
isRequired?: boolean;
};
`

#### LimitHelperArgsOpts

`ts
type LimitHelperArgsOpts = {
/**
* Set limit for default number of returned records
* if it does not provided in query.
* By default: 100
*/
defaultValue?: number;
};
`

FAQ

$3

`ts
const UserTC = composeMongoose(User);
UserTC.getType(); // returns GraphQLObjectType
UserTC.getInputType(); // returns GraphQLInputObjectType, eg. for args
UserTC.get('languages').getType(); // get GraphQLObjectType for nested field
UserTC.get('fieldWithNesting.subNesting').getType(); // get GraphQL type of deep nested field
`

$3

`ts
UserTC.addFields({
lonLat: ObjectTypeComposer.create('type LonLat { lon: Float, lat: Float }'),
notice: 'String', // shorthand definition
noticeList: { // extended
type: '[String]', // String, Int, Float, Boolean, ID, Json
description: 'Array of notices',
resolve: (source, args, context, info) => 'some value',
},
bio: {
type: GraphQLString,
description: 'Providing vanilla GraphQL type'
}
})
`

$3

Suppose you User model has friendsIds field with array of user ids. So let build some relations:

`ts
UserTC.addRelation(
'friends',
{
resolver: () => UserTC.mongooseResolvers.dataLoaderMany(),
prepareArgs: { // resolver findByIds has _ids arg, let provide value to it
_ids: (source) => source.friendsIds,
},
projection: { friendsIds: 1 }, // point fields in source object, which should be fetched from DB
}
);
UserTC.addRelation(
'adultFriendsWithSameGender',
{
resolver: () => UserTC.mongooseResolvers.findMany(),
prepareArgs: { // resolver findMany has filter arg, we may provide mongoose query to it
filter: (source) => ({
_operators : { // Applying criteria on fields which have
// operators enabled for them (by default, indexed fields only)
_id : { in: source.friendsIds },
age: { gt: 21 }
},
gender: source.gender,
}),
limit: 10,
},
projection: { friendsIds: 1, gender: 1 }, // required fields from source object
}
);
`

$3

Suppose you have a common structure you use as embedded object in multiple Schemas.
Also suppose you want the structure to have the same GraphQL type across all parent types.
(For instance, to allow reuse of fragments for this type)
Here are Schemas to demonstrate:

`ts
import { Schema } from 'mongoose';

const ImageDataStructure = Schema({
url: String,
dimensions : {
width: Number,
height: Number
}
}, { _id: false });

const UserProfile = Schema({
fullName: String,
personalImage: ImageDataStructure
});

const Article = Schema({
title: String,
heroImage: ImageDataStructure
});
`

If you want the ImageDataStructure to use the same GraphQL type in both Article and UserProfile you will need create it as a mongoose schema (not a standard javascript object) and to explicitly tell graphql-compose-mongoose the name you want it to have. Otherwise, without the name, it would generate the name according to the first parent this type was embedded in.

Do the following:

`ts
import { schemaComposer } from 'graphql-compose'; // get the default schemaComposer or your created schemaComposer
import { convertSchemaToGraphQL } from 'graphql-compose-mongoose';

convertSchemaToGraphQL(ImageDataStructure, 'EmbeddedImage', schemaComposer); // Force this type on this mongoose schema
`

Before continuing to convert your models to TypeComposers:

`ts
import mongoose from 'mongoose';
import { composeMongoose } from 'graphql-compose-mongoose';

const UserProfile = mongoose.model('UserProfile', UserProfile);
const Article = mongoose.model('Article', Article);

const UserProfileTC = composeMongoose(UserProfile);
const ArticleTC = composeMongoose(Article);
`

Then, you can use queries like this:

`graphql
query {
topUser {
fullName
personalImage {
...fullImageData
}
}
topArticle {
title
heroImage {
...fullImageData
}
}
}
fragment fullImageData on EmbeddedImage {
url
dimensions {
width height
}
}
`

$3

This library provides some amount of ready resolvers for fetch and update data which was mentioned above. And you can create your own resolver of course. However you can find that add some actions or light modifications of mongoose document directly before save at existing resolvers appears more simple than create new resolver. Some of resolvers accepts before save hook which can be provided in resolver params as param named beforeRecordMutate. This hook allows to have access and modify mongoose document before save. The resolvers which supports this hook are:

- createOne
- createMany
- removeById
- removeOne
- updateById
- updateOne

The prototype of before save hook:

`ts
(doc: mixed, rp: ResolverResolveParams) => Promise<*>,
`

The typical implementation may be like this:

`ts
// extend resolve params with hook
rp.beforeRecordMutate = async function(doc, rp) {
doc.userTouchedAt = new Date();

const canMakeUpdate = await performAsyncTask( ...provide data from doc... )
if (!canMakeUpdate) {
throw new Error('Forbidden!');
}

return doc;
}
`

You can provide your implementation directly in type composer:

`ts
UserTC.wrapResolverResolve('updateById', next => async rp => {

// extend resolve params with hook
rp.beforeRecordMutate = async (doc, resolveParams) => { ... };

return next(rp);
});
`

or you can create wrappers for example to protect access:

`ts
function adminAccess(resolvers) {
Object.keys(resolvers).forEach((k) => {
resolvers[k] = resolvers[k].wrapResolve(next => async rp => {

// extend resolve params with hook
rp.beforeRecordMutate = async function(doc, rp) { ... }

return next(rp)
})
})
return resolvers
}

// and wrap the resolvers
schemaComposer.Mutation.addFields({
createResource: ResourceTC.mongooseResolvers.createOne(),
createResources: ResourceTC.mongooseResolvers.createMany(),
...adminAccess({
updateResource: ResourceTC.mongooseResolvers.updateById(),
removeResource: ResourceTC.mongooseResolvers.removeById(),
}),
});
`

$3

This library allows modifying the query before it is executed using the beforeQuery hook. This lets us prevent certain fields or documents from being read. Here's an example of restricting access to specific fields:

`ts
schemaComposer.Query.addFields({
userOne: UserTC.mongooseResolvers.findOne().wrapResolve((next) => (rp) => {
const { role } = rp.context;

rp.beforeQuery = (query: Query) => {
if (role === 'admin') {
// Don't change the projection and still allow all fields to be read
} else if (role === 'moderator') {
// Only allow the name, age, and gender fields to be read
query.projection({ name: 1, age: 1, gender: 1 });
} else if (role === 'public') {
// Only allow the name field to be read
query.projection({ name: 1 });
}
};

return next(rp);
}),
});
`

Note that fields that are sometimes restricted should not be marked as required in the mongoose schema. Otherwise, when you query them you will get a "Cannot return null for non-nullable field" error because the database query didn't return a value for the field.

You can also use beforeQuery to hide certain documents from the query. Here's an example:

`ts
schemaComposer.Query.addFields({
postMany: PostTC.mongooseResolvers.findMany().wrapResolve((next) => (rp) => {
const { userId } = rp.context;

rp.beforeQuery = (query: Query) => {
// Only allow users to see their own posts
query.where('authorId', userId);
};

return next(rp);
}),
});
`

Both of these examples require putting extra data in the resolver context. Here's how to attach context data in Apollo Server:

`ts
const server = new ApolloServer({
schema: schemaComposer.buildSchema(),
context() {
// This role should actually come from a JWT or something
return { role: 'admin' };
},
});
`

Other GraphQL servers are likely similar.

$3

The default resolvers, by design, will replace (overwrite) any supplied array object when using e.g. updateById. If you want to push or pop a value in an array you can use a custom resolver with a native MongoDB call.

For example (push):

`ts
schemaComposer.Mutation.addFields({
userPushToArray: {
type: UserTC,
args: { userId: 'MongoID!', valueToPush: 'String' },
resolve: async (source, args, context, info) => {
const user = await User.update(
{ _id: args.userId },
{ $push: { arrayToPushTo: args.valueToPush } }
);
if (!user) return null // or gracefully return an error etc...
return User.findOne({ _id: args.userId }) // return the record
}
}
})
`

User is the corresponding Mongoose model. If you do not wish to allow duplicates in the array then replace $push with $addToSet. Read the graphql-compose docs on custom resolvers for more info: https://graphql-compose.github.io/docs/en/basics-resolvers.html

NB if you set unique: true on the array then using the update $push approach will not check for duplicates, this is due to a MongoDB bug: https://jira.mongodb.org/browse/SERVER-1068. For more usage examples with $push and arrays see the MongoDB docs here https://docs.mongodb.com/manual/reference/operator/update/push/. Also note that $push will preserve order in the array (append to end of array) whereas $addToSet will not.

$3

By default composeMongoose uses global schemaComposer for generated types. If you need to create different GraphQL schemas you need create own schemaComposers and provide them to customizationOptions:

`ts
import { SchemaComposer } from 'graphql-compose';

const schema1 = new SchemaComposer();
const schema2 = new SchemaComposer();

const UserTCForSchema1 = composeMongoose(User, { schemaComposer: schema1 });
const UserTCForSchema2 = composeMongoose(User, { schemaComposer: schema2 });
`

$3

Just turn them off in mongoose:

`ts
const UsersSchema = new Schema({
_id: { type: String }
emails: [{
_id: false, // <-- disable id addition in mongoose
address: { type: String },
verified: Boolean
}]
});
`

$3

Yes, it can. This package understands mongoose alias option for fields. Just provide alias: 'country' for field c and you get country field name in GraphQL schema and Mongoose model but c field in database:

`ts
const childSchema = new Schema({
c: {
type: String,
alias: 'country'
}
});
``

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License

MIT