Models

Concept

Content Type's models

Models are a representation of the database's structure. They are split into two separate files. A JavaScript file that contains the model options (e.g: lifecycle hooks), and a JSON one that represents the data structure stored in the database.

Path — ./api/restaurant/models/Restaurant.js.

module.exports = {
  lifecycles: {
    // Called before an entry is created
    beforeCreate(data) {},
    // Called after an entry is created
    afterCreate(result) {},
  },
};

Path — ./api/restaurant/models/Restaurant.settings.json.

{
  "kind": "collectionType",
  "connection": "default",
  "info": {
    "name": "restaurant",
    "description": "This represents the Restaurant Model"
  },
  "attributes": {
    "cover": {
      "collection": "file",
      "via": "related",
      "plugin": "upload"
    },
    "name": {
      "default": "",
      "type": "string"
    },
    "description": {
      "default": "",
      "type": "text"
    }
  }
}

In this example, there is a Restaurant model which contains the attributes cover, name and description.

Component's models

It also exist another type of models named components. A component is a data structure that can be used in one or many other API's model. There is no lifecycle related, only a JSON file definition

Path — ./components/default/simple.json

{
  "connection": "default",
  "collectionName": "components_default_simples",
  "info": {
    "name": "simple",
    "icon": "arrow-circle-right"
  },
  "options": {},
  "attributes": {
    "name": {
      "type": "string"
    }
  }
}

In this example, there is a Simple component which contains the attributes name. And the component is in the category default.

Where are the models defined?

For Content Types, models are defined in each ./api/**/models/ folder. Every JavaScript or JSON file in these folders will be loaded as a model. They are also available through the strapi.models and strapi.api.**.models global variables. Usable everywhere in the project, they contain the ORM model object that they refer to. By convention, a model's name should be written in lowercase.

For Components, models are defined in ./components folder. Every components has to be under a subfolder (the category name of the component).

How to create a model?

TIP

If you are just starting out it is very convenient to generate some models with the Content Type Builder, directly in the admin interface. You can then review the generated model mappings on the code level. The UI takes over a lot of validation tasks and gives you a feeling for available features.

For Content Types models

Use the CLI, and run the following command strapi generate:model restaurant name:string description:text.
Read the CLI documentation for more information.

This will create two files located at ./api/restaurant/models:

• Restaurant.settings.json: contains the list of attributes and settings. The JSON format makes the file easily editable.
• Restaurant.js: imports Restaurant.settings.json and extends it with additional settings and life cycle callbacks.

TIP

When you create a new API using the CLI (strapi generate:api <name>), a model is automatically created.

For Components models

To create a component you will have to use the Content Type Builder from the Admin panel, there is no generator for components.

Or you can create your component manually by following the file path described previously and by following the file structure described below.

Model settings

Additional settings can be set on models:

• kind (string) - Define if the model is a Collection Type (collectionType) of a Single Type (singleType) - only for Content Types
• connection (string) - Connection name which must be used. Default value: default.
• collectionName (string) - Collection name (or table name) in which the data should be stored.
• globalId (string) - Global variable name for this model (case-sensitive) - only for Content Types
• attributes (object) - Define the data structure of your model. Find available options below.

Path — Restaurant.settings.json.

{
  "kind": "collectionType",
  "connection": "mongo",
  "collectionName": "Restaurants_v1",
  "globalId": "Restaurants",
  "attributes": {}
}

In this example, the model Restaurant will be accessible through the Restaurants global variable. The data will be stored in the Restaurants_v1 collection or table and the model will use the mongo connection defined in ./config/database.js

WARNING

If not set manually in the JSON file, Strapi will adopt the filename as globalId. The globalId serves as a reference to your model within relations and Strapi APIs. If you chose to rename it (either by renaming your file or by changing the value of the globalId), you'd have to migrate your tables manually and update the references. Please note that you should not alter Strapi's models globalId (plugins and core ones) since it is used directly within Strapi APIs and other models' relations.

TIP

The connection value can be changed whenever you want, but you should be aware that there is no automatic data migration process. Also if the new connection doesn't use the same ORM you will have to rewrite your queries.

Model information

The info key on the model-json states information about the model. This information is used in the admin interface, when showing the model.

• name: The name of the model, as shown in admin interface.
• description: The description of the model.
• icon: The fontawesome V5 name - only for Components

Path — Restaurant.settings.json.

{
  "info": {
    "name": "restaurant",
    "description": ""
  }
}

Model options

The options key on the model-json states.

• timestamps: This tells the model which attributes to use for timestamps. Accepts either boolean or Array of strings where first element is create date and second element is update date. Default value when set to true for Bookshelf is ["created_at", "updated_at"] and for MongoDB is ["createdAt", "updatedAt"].

• privateAttributes: This configuration allows to treat a set of attributes as private, even if they're not actually defined as attributes in the model. Accepts an Array of strings. It could be used to remove from API responses timestamps or _v when using MongoDB. The set of privateAttributes defined in the model are merged with the privateAttributes defined in the global Strapi configuration.

Path — User.settings.json.

{
  "options": {
    "timestamps": true,
    "privateAttributes": ["id", "created_at"]
  }
}

Define the attributes

The following types are currently available:

• string
• text
• richtext
• email
• password
• integer
• biginteger
• float
• decimal
• date
• time
• datetime
• boolean
• enumeration
• json
• uid

Validations

You can apply basic validations to the attributes. The following supported validations are only supported by MongoDB connection. If you're using SQL databases, you should use the native SQL constraints to apply them.

• required (boolean) — If true, adds a required validator for this property.
• unique (boolean) — Whether to define a unique index on this property.
• index (boolean) — Adds an index on this property, this will create a single field index that will run in the background. Only supported by MongoDB.
• max (integer) — Checks if the value is greater than or equal to the given maximum.
• min (integer) — Checks if the value is less than or equal to the given minimum.

Security validations

To improve the Developer Experience when developing or using the administration panel, the framework enhances the attributes with these "security validations":

• private (boolean) — If true, the attribute will be removed from the server response (it's useful to hide sensitive data).
• configurable (boolean) - if false, the attribute isn't configurable from the Content Type Builder plugin.

Exceptions

uid

• targetField(string) — The value is the name of an attribute that has string of text type.
• options (string) — The value is a set of options passed to the underlying uid generator. A caveat is that the resulting uid must abide to the following RegEx /^[A-Za-z0-9-_.~]*$.

Example

Path — Restaurant.settings.json.

{
  ...
  "attributes": {
    "title": {
      "type": "string",
      "min": 3,
      "max": 99,
      "unique": true
    },
    "description": {
      "default": "My description",
      "type": "text",
      "required": true
    },
    "slug": {
      "type": "uid",
      "targetField": "title"
    }
    ...
  }
}

Relations

Relations let you create links (relations) between your Content Types.

One-way relationships are useful to link an entry to another. However, only one of the models can be queried with its populated items.

Example

A pet can be owned by someone (a user).

Path — ./api/pet/models/Pet.settings.json.

{
  "attributes": {
    "owner": {
      "model": "user"
    }
  }
}

Example

// Create a pet
const xhr = new XMLHttpRequest();
xhr.open('POST', '/pets', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    owner: '5c151d9d5b1d55194d3209be', // The id of the user you want to link
  })
);

One-to-One relationships are useful when you have one entity that could be linked to only one other entity. And vice versa.

Example

A user can have one address. And this address is only related to this user.

Path — ./api/user/models/User.settings.json.

{
  "attributes": {
    "address": {
      "model": "address",
      "via": "user"
    }
  }
}

Path — ./api/address/models/Address.settings.json.

{
  "attributes": {
    "user": {
      "model": "user"
    }
  }
}

Example

// Create an address
const xhr = new XMLHttpRequest();
xhr.open('POST', '/addresses', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    user: '5c151d9d5b1d55194d3209be', // The id of the user you want to link
  })
);

One-to-Many relationships are useful when an entry can be linked to multiple entries of another Content Type. And an entry of the other Content Type can be linked to only one entry.

Example

A user can have many articles, and an article can be related to one user (author).

Path — ./api/user/models/User.settings.json.

{
  "attributes": {
    "articles": {
      "collection": "article",
      "via": "author"
    }
  }
}

Path — ./api/article/models/Article.settings.json.

{
  "attributes": {
    "author": {
      "model": "user"
    }
  }
}

Examples

// Create an article
const xhr = new XMLHttpRequest();
xhr.open('POST', '/articles', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    author: '5c151d9d5b1d55194d3209be', // The id of the user you want to link
  })
);

// Update an article
const xhr = new XMLHttpRequest();
xhr.open('PUT', '/users/5c151d9d5b1d55194d3209be', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    articles: ['5c151d51eb28fd19457189f6', '5c151d51eb28fd19457189f8'], // Set of ALL articles linked to the user (existing articles + new article or - removed article)
  })
);

Many-to-Many relationships are useful when an entry can be linked to multiple entries of another Content Type. And an entry of the other Content Type can be linked to many entries.

Example

A product can be related to many categories, so a category can have many products.

Path — ./api/product/models/Product.settings.json.

{
  "attributes": {
    "categories": {
      "collection": "category",
      "via": "products",
      "dominant": true,
      "collectionName": "products_categories__categories_products" // optional
    }
  }
}

NOTE: (NoSQL databases only) The dominant key defines which table/collection should store the array that defines the relationship. Because there are no join tables in NoSQL, this key is required for NoSQL databases (e.g. MongoDB).

NOTE: (NoSQL databases only) The collectionName key defines the name of the join table. It has to be specified once, in the dominant attribute of the relation. If it is not specified, Strapi will use a generated default one. It is useful to define the name of the join table when the name generated by Strapi is too long for the database you use.

Path — ./api/category/models/Category.settings.json.

{
  "attributes": {
    "products": {
      "collection": "product",
      "via": "categories"
    }
  }
}

Example

// Update a product
const xhr = new XMLHttpRequest();
xhr.open('PUT', '/products/5c151d9d5b1d55194d3209be', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    categories: ['5c151d51eb28fd19457189f6', '5c151d51eb28fd19457189f8'], // Set of ALL categories linked to the product (existing categories + new category or - removed category).
  })
);

The polymorphic relationships are the solution when you don't know which kind of model will be associated to your entry. A common use case is an Image model that can be associated to many others kind of models (Article, Product, User, etc.).

Single vs Many

Let's stay with our Image model which might belong to a single Article or Product entry.

NOTE: In other words, it means that an Image entry can be associated to one entry. This entry can be a Article or Product entry.

Path — ./api/image/models/Image.settings.json.

{
  "attributes": {
    "related": {
      "model": "*",
      "filter": "field"
    }
  }
}

Also, our Image model which might belongs to many Article or Product entries.

NOTE: In other words, it means that an Article entry can relate to the same image as a Product entry.

Path — ./api/image/models/Image.settings.json.

{
  "attributes": {
    "related": {
      "collection": "*",
      "filter": "field"
    }
  }
}

Filter

The filter attribute is optional (but we highly recommend to use it every time). If it's provided it adds a new match level to retrieve the related data.

For example, the Product model might have two attributes which are associated to the Image model. To distinguish which image is attached to the cover field and which images are attached to the pictures field, we need to save and provide this to the database.

Path — ./api/article/models/Product.settings.json.

{
  "attributes": {
    "cover": {
      "model": "image",
      "via": "related"
    },
    "pictures": {
      "collection": "image",
      "via": "related"
    }
  }
}

The value is the filter attribute is the name of the column where the information is stored.

Example

A Image model might belongs to many either Article models or a Product models.

Path — ./api/image/models/Image.settings.json.

{
  "attributes": {
    "related": {
      "collection": "*",
      "filter": "field"
    }
  }
}

Path — ./api/article/models/Article.settings.json.

{
  "attributes": {
    "avatar": {
      "model": "image",
      "via": "related"
    }
  }
}

Path — ./api/article/models/Product.settings.json.

{
  "attributes": {
    "pictures": {
      "collection": "image",
      "via": "related"
    }
  }
}

Database implementation

If you're using MongoDB as a database, you don't need to do anything. Everything is natively handled by Strapi. However, to implement a polymorphic relationship with SQL databases, you need to create two tables.

Path — ./api/image/models/Image.settings.json.

{
  "attributes": {
    "name": {
      "type": "string"
    },
    "url": {
      "type": "string"
    },
    "related": {
      "collection": "*",
      "filter": "field"
    }
  }
}

The first table to create is the table which has the same name as your model.

CREATE TABLE `image` (
  `id` int(11) NOT NULL,
  `name` text NOT NULL,
  `text` text NOT NULL
)

NOTE: If you've overridden the default table name given by Strapi by using the collectionName attribute. Use the value set in the collectionName to name the table.

The second table will allow us to associate one or many others entries to the Image model. The name of the table is the same as the previous one with the suffix _morph.

CREATE TABLE `image_morph` (
  `id` int(11) NOT NULL,
  `image_id` int(11) NOT NULL,
  `related_id` int(11) NOT NULL,
  `related_type` text NOT NULL,
  `field` text NOT NULL
)

• image_id is using the name of the first table with the suffix _id.
  • Attempted value: It corresponds to the id of an Image entry.
• related_id is using the attribute name where the relation happens with the suffix _id.
  • Attempted value: It corresponds to the id of an Article or Product entry.
• related_type is using the attribute name where the relation happens with the suffix _type.
  • Attempted value: It corresponds to the table name where the Article or Product entry is stored.
• field is using the filter property value defined in the model. If you change the filter value, you have to change the name of this column as well.
  • Attempted value: It corresponds to the attribute of an Article, Product with which the Image entry is related.

id	image_id	related_id	related_type	field
1	1738	39	product	cover
2	4738	58	article	avatar
3	1738	71	article	avatar

Components

Component field let your create a relation between your Content Type and a Component structure.

Example

Lets say we created an openinghours component in restaurant category.

Path — ./api/restaurant/models/Restaurant.settings.json.

{
  "attributes": {
    "openinghours": {
      "type": "component",
      "repeatable": true,
      "component": "restaurant.openinghours"
    }
  }
}

• repeatable (boolean): Could be true or false that let you create a list of data.
• component (string): It follows this format <category>.<componentName>.

Create a restaurant with non-repeatable component

const xhr = new XMLHttpRequest();
xhr.open('POST', '/restaurants', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    openinghour: {
      opening_at: '10am',
      closing_at: '6pm',
      day: 'monday',
    },
  })
);

Create a restaurant with repeatable component

const xhr = new XMLHttpRequest();
xhr.open('POST', '/restaurants', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    openinghours: [
      {
        opening_at: '10am',
        closing_at: '6pm',
        day: 'monday',
      },
      {
        opening_at: '10am',
        closing_at: '6pm',
        day: 'tuesday',
      },
    ],
  })
);

Update a restaurant with non-repeatable component

const xhr = new XMLHttpRequest();
xhr.open('PUT', '/restaurants/1', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    openinghour: {
      id: 1, // the ID of the entry
      opening_at: '11am',
      closing_at: '7pm',
      day: 'wednesday',
    },
  })
);

Update a restaurant with repeatable component

const xhr = new XMLHttpRequest();
xhr.open('PUT', '/restaurants/2', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    openinghours: [
      {
        "id": 1 // the ID of the entry you want to update
        "opening_at": "10am",
        "closing_at": "6pm",
        "day": "monday"
      },
      {
        "id": 2, // you also have to put the ID of entries you don't want to update
        "opening_at": "10am",
        "closing_at": "6pm",
        "day": "tuesday"
      }
    ]
  })
);

NOTE if you don't specify the ID it will delete and re-create the entry the entry, you will see the ID value change.

Delete a restaurant with non-repeatable component

const xhr = new XMLHttpRequest();
xhr.open('PUT', '/restaurants/1', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    openinghour: null,
  })
);

Delete a restaurant with repeatable component

const xhr = new XMLHttpRequest();
xhr.open('PUT', '/restaurants/2', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    openinghours: [
      {
        "id": 1 // the ID of the entry you want to keep
        "opening_at": "10am",
        "closing_at": "6pm",
        "day": "monday"
      }
    ]
  })
);

Dynamic Zone

Dynamic Zone fields let you create a flexible space, in which to compose content, based on a mixed list of components.

Example

Lets say we created an slider and content component in article category.

Path — ./api/article/models/Article.settings.json.

{
  "attributes": {
    "body": {
      "type": "dynamiczone",
      "components": ["article.slider", "article.content"]
    }
  }
}

• components (array): Array of components, that follows this format <category>.<componentName>.

const xhr = new XMLHttpRequest();
xhr.open('POST', '/articles', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    body: [
      {
        __component: 'article.content',
        content: 'This is a content',
      },
      {
        __component: 'article.slider',
        name: 'Slider name',
      },
    ],
  })
);

const xhr = new XMLHttpRequest();
xhr.open('PUT', '/restaurant/2', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    body: [
      {
        "id": 1 // the ID of the entry you want to update
        "__component": "article.content",
        "content": "This is an updated content",
      },
      {
        "id": 2, // you also have to put the ID of entries you don't want to update
        "__component": "article.slider",
        "name": "Slider name",
      }
    ]
  })
);

NOTE if you don't specify the ID it will delete and re-create the entry the entry, you will see the ID value change.

const xhr = new XMLHttpRequest();
xhr.open('PUT', '/restaurant/2', true);
xhr.setRequestHeader('Content-Type', 'application/json');
xhr.send(
  JSON.stringify({
    body: [
      {
        "id": 1 // the ID of the entry you want to keep
        "__component": "article.content",
        "content": "This is an updated content",
      }
    ]
  })
);

Lifecycle hooks

The lifecycle hooks are functions that get triggered when the Strapi queries are called. They will get triggered automatically when you manage your content in the Admin Panel or when you develop custom code using queries·

To configure a ContentType lifecycle hooks you can set a lifecycles key in the {modelName}.js file located at ./api/{apiName}/models/{modelName}.js folder.

Available Lifecycle hooks

beforeFind(params, populate)

Parameters:

Name	Type	Description
params	Object	Find params (e.g: limit, filters)

---

afterFind(results, params, populate)

Parameters:

Name	Type	Description
results	Array{Object}	The results found for the find query
params	Object	Find params (e.g: limit, filters)
populate	Array{string}	Populate specific relations

beforeFindOne(params, populate)

Parameters:

Name	Type	Description
params	Object	Find params (e.g: filters)

---

afterFindOne(result, params, populate)

Parameters:

Name	Type	Description
result	Object	The results found for the findOne query
params	Object	Find params (e.g: filters)
populate	Array{string}	Populate specific relations

beforeCreate(data)

Parameters:

Name	Type	Description
data	Object	Input data to the entry was created with

---

afterCreate(result, data)

Parameters:

Name	Type	Description
result	Object	Created entry
data	Object	Input data to the entry was created with

beforeUpdate(params, data)

Parameters:

Name	Type	Description
params	Object	Find params (e.g: filters)
data	Object	Input data to the entry was created with

---

afterUpdate(result, params, data)

Parameters:

Name	Type	Description
result	Object	Updated entry
params	Object	Find params (e.g: filters)
data	Object	Input data to the entry was created with

beforeDelete(params)

Parameters:

Name	Type	Description
params	Object	Find params (e.g: filters)

---

afterDelete(result, params)

Parameters:

Name	Type	Description
result	Object	Deleted entry
params	Object	Find params (e.g: filters)

beforeCount(params)

Parameters:

Name	Type	Description
params	Object	Find params (e.g: filters)

---

afterCount(result, params)

Parameters:

Name	Type	Description
result	Integer	The count matching entries
params	Object	Find params (e.g: filters)

beforeSearch(params, populate)

Parameters:

Name	Type	Description
params	Object	Find params (e.g: filters)
populate	Array{string}	Populate specific relations

---

afterSearch(result, params)

Parameters:

Name	Type	Description
results	Array{Object}	The entries found
params	Object	Find params (e.g: filters)
populate	Array{string}	Populate specific relations

beforeCountSearch(params)

Parameters:

Name	Type	Description
params	Object	Find params (e.g: filters)

---

afterCountSearch(result, params)

Parameters:

Name	Type	Description
result	Integer	The count matching entries
params	Object	Find params (e.g: filters)

Example

Path — ./api/user/models/User.js.

module.exports = {
  /**
   * Triggered before user creation.
   */
  lifecycles: {
    async beforeCreate(data) {
      const passwordHashed = await strapi.api.user.services.user.hashPassword(data.password);
      data.password = passwordHashed;
    },
  },
};

TIP

You can mutate one of the parameters to change its properties. Make sure not to reassign the parameter as it will have no effect:

This will Work

module.exports = {
  lifecycles: {
    beforeCreate(data) {
      data.name = 'Some fixed name';
    },
  },
};

This will NOT Work

module.exports = {
  lifecycles: {
    beforeCreate(data) {
      data = {
        ...data,
        name: 'Some fixed name',
      };
    },
  },
};

Custom use

When you are building custom ORM specific queries the lifecycles will not be triggered. You can however call a lifecycle function directly if you wish.

Bookshelf example

Path - ./api/{apiName}/services/{serviceName}.js

module.exports = {
  async createCustomEntry() {
    const ORMModel = strapi.query(modelName).model;

    const newCustomEntry = await ORMModel.forge().save();

    // trigger manually
    ORMModel.lifecycles.afterCreate(newCustomEntry.toJSON());
  },
};

TIP

When calling a lifecycle function directly, you will need to make sure you call it with the expected parameters.