API

import { normalize, schema } from 'normalizr';const myData = { users: [ { id: 1 }, { id: 2 } ] };
const user = new schema.Entity('users');
const mySchema = { users: [ user ] }
const normalizedData = normalize(myData, mySchema);复制代码

{result: { users: [ 1, 2 ] },entities: {users: {'1': { id: 1 },'2': { id: 2 }}}
}复制代码

小心非规范化。 过早将数据还原到大型嵌套对象可能会对React（和其他）应用程序造成性能影响。

If your schema and data have recursive references, only the first instance of an entity will be given. Subsequent references will be returned as the id provided.

如果您的schema和数据具有递归引用，则只会给出实体的第一个实例。 随后的引用将返回给ID。

• input: required The normalized result that should be
  de-normalized
  . Usually the same value that was given in the result key of the output of normalize. 通常在规范化输出的结果键中给出相同的值。
• schema: required A schema definition that was used to get the value for input.
• entities: required An object, keyed by entity schema names that may appear in the denormalized output. Also accepts an object with Immutable data.

Usage

import { denormalize, schema } from 'normalizr';const user = new schema.Entity('users');
const mySchema = { users: [ user ] }
const entities = { users: { '1': { id: 1 }, '2': { id: 2 } } };
const denormalizedData = denormalize({ users: [ 1, 2 ] }, mySchema, entities);复制代码

Output

{ users: [{ id: 1 },{ id: 2 }]
}复制代码

schema

Array(definition, schemaAttribute)

Creates a schema to normalize an array of entities. If the input value is an Object instead of an Array, the normalized result will be an Array of the Object's values.

创建一个schema来规范化实体数组。 如果输入值是Object而不是Array，则归一化结果将是Object的值的Array。

相同的行为可以用速记语法来定义


• definition: required A singular schema that this array contains
  or a mapping of schema to attribute values.

• schemaAttribute:
  optional
  (required if definition is not a singular schema) The attribute on each entity found that defines what schema, per the definition mapping, to use when normalizing.
  Can be a string or a function. If given a function, accepts the following arguments:
  • value: The input value of the entity.
  • parent: The parent object of the input array.
  • key: The key at which the input array appears on the parent object.

Instance Methods

• define(definition): When used, the definition passed in will be merged with the original definition passed to the Array constructor. This method tends to be useful for creating circular references in schema.

Usage

To describe a simple array of a singular entity type:

const data = [ { id: '123', name: 'Jim' }, { id: '456', name: 'Jane' } ];
const userSchema = new schema.Entity('users');const userListSchema = new schema.Array(userSchema);
// or use shorthand syntax:
const userListSchema = [ userSchema ];const normalizedData = normalize(data, userListSchema);复制代码

Output

{entities: {users: {'123': { id: '123', name: 'Jim' },'456': { id: '456', name: 'Jane' }}},result: [ '123', '456' ]
}复制代码

If your input data is an array of more than one type of entity, it is necessary to define a schema mapping.

如果您的输入数据是多个类型的实体的数组，则需要定义一个schema映射。

如果您的数据返回一个未提供映射的对象，则将返回原始对象，并且不会创建一个实体。

For example:

const data = [ { id: 1, type: 'admin' }, { id: 2, type: 'user' } ];const userSchema = new schema.Entity('users');
const adminSchema = new schema.Entity('admins');
const myArray = new schema.Array({admins: adminSchema,users: userSchema
}, (input, parent, key) => `${input.type}s`);const normalizedData = normalize(data, myArray);复制代码

Output

{entities: {admins: { '1': { id: 1, type: 'admin' } },users: { '2': { id: 2, type: 'user' } }},result: [{ id: 1, schema: 'admins' },{ id: 2, schema: 'users' }]
}复制代码

Entity(key, definition = {}, options = {})

• key: required The key name under which all entities of this type will be listed in the normalized response. Must be a string name.
• definition: A definition of the nested entities found within this entity. Defaults to empty object.

• options:
  • idAttribute: The attribute where unique IDs for each of this entity type can be found.
    Accepts either a string key or a function that returns the IDs value. Defaults to 'id'.
    As a function, accepts the following arguments, in order:
    • value: The input value of the entity.
    • parent: The parent object of the input array.
    • key: The key at which the input array appears on the parent object. 输入的数组出现在父对象上的键。
  • mergeStrategy(entityA, entityB): Strategy to use when merging two entities with the same id value. Defaults to merge the more recently found entity onto the previous.

• • processStrategy(value, parent, key): Strategy to use when pre-processing the entity. Use this method to add extra data, defaults, and/or completely change the entity before normalization is complete. Defaults to returning a shallow copy of the input entity.

• value: The input value of the entity.
• parent: The parent object of the input array.
• key: The key at which the input array appears on the parent object.

Instance Methods

• define(definition): When used, the definition passed in will be merged with the original definition passed to the Entity constructor. This method tends to be useful for creating circular references in schema.

Instance Attributes

• key: Returns the key provided to the constructor.
• idAttribute: Returns the idAttribute provided to the constructor in options.

Usage

const data = { id_str: '123', url: 'https://twitter.com', user: { id_str: '456', name: 'Jimmy' } };const user = new schema.Entity('users', {}, { idAttribute: 'id_str' });
const tweet = new schema.Entity('tweets', { user: user }, { idAttribute: 'id_str',// Apply everything from entityB over entityA, except for "favorites"mergeStrategy: (entityA, entityB) => ({...entityA,...entityB,favorites: entityA.favorites}),// Remove the URL field from the entityprocessStrategy: (entity) => omit(entity, 'url')
});const normalizedData = normalize(data, tweet);复制代码

Output

{entities: {tweets: { '123': { id_str: '123', user: '456' } },users: { '456': { id_str: '456', name: 'Jimmy' } }},result: '123'
}复制代码

idAttribute Usage

When passing the idAttribute a function, it should return the IDs value.

idAttribute作为key

For Example:

const data = [{ id: '1', guest_id: null, name: 'Esther' },{ id: '1', guest_id: '22', name: 'Tom' },
];const patronsSchema = new schema.Entity('patrons', undefined, {// idAttribute *functions* must return the ids **value** (not key)idAttribute: value => value.guest_id ? `${value.id}-${value.guest_id}` : value.id,
});normalize(data, [patronsSchema]);复制代码

Output

{entities: {patrons: {'1': { id: '1', guest_id: null, name: 'Esther' },'1-22': { id: '1', guest_id: '22', name: 'Tom' },}},result: ['1', '1-22']
}复制代码

Object(definition)

Define a plain object mapping that has values needing to be normalized into Entities.

定义一个普通对象映射，它需要将值归一化为Entities。

• definition: required A definition of the nested entities found within this object. Defaults to empty object.
  You do not need to define any keys in your object other than those that hold other entities. All other values will be copied to the normalized output.

Instance Methods

• define(definition): When used, the definition passed in will be merged with the original definition passed to the Object constructor. This method tends to be useful for creating circular references in schema.

Usage

// Example data response
const data = { users: [ { id: '123', name: 'Beth' } ] };const user = new schema.Entity('users');
const responseSchema = new schema.Object({ users: new schema.Array(user) });
// or shorthand
const responseSchema = { users: new schema.Array(user) };const normalizedData = normalize(data, responseSchema);复制代码

Output

{entities: {users: { '123': { id: '123', name: 'Beth' } }},result: { users: [ '123' ] }
}复制代码

Union(definition, schemaAttribute)

Describe a schema which is a union of multiple schemas. This is useful if you need the polymorphic behavior provided by schema.Array or schema.Values but for non-collection fields.

描述一个多个schema的并集的schema。 如果您需要由schema.Array或schema.Values提供的多态性行为，但对于非收集字段，这是非常有用的。

• definition: required An object mapping the definition of the nested entities found within the input array
• schemaAttribute: required The attribute on each entity found that defines what schema, per the definition mapping, to use when normalizing.
  Can be a string or a function. If given a function, accepts the following arguments:
  • value: The input value of the entity.
  • parent: The parent object of the input array.
  • key: The key at which the input array appears on the parent object.

Instance Methods

• define(definition): When used, the definition passed in will be merged with the original definition passed to the Union constructor. This method tends to be useful for creating circular references in schema.

Usage

const data = { owner: { id: 1, type: 'user', name: 'Anne' } };const user = new schema.Entity('users');
const group = new schema.Entity('groups');
const unionSchema = new schema.Union({user: user,group: group
}, 'type');const normalizedData = normalize(data, { owner: unionSchema });复制代码

Output

{entities: {users: { '1': { id: 1, type: 'user', name: 'Anne' } }},result: { owner: { id: 1, schema: 'user' } }
}复制代码

Values(definition, schemaAttribute)

Describes a map whose values follow the given schema.

• definition: required A singular schema that this array contains
  or a mapping of schema to attribute values.
• schemaAttribute:
  optional
  (required if definition is not a singular schema) The attribute on each entity found that defines what schema, per the definition mapping, to use when normalizing.
  Can be a string or a function. If given a function, accepts the following arguments:
  • value: The input value of the entity.
  • parent: The parent object of the input array.
  • key: The key at which the input array appears on the parent object.

Instance Methods

• define(definition): When used, the definition passed in will be merged with the original definition passed to the Values constructor. This method tends to be useful for creating circular references in schema.

Usage

const data = { firstThing: { id: 1 }, secondThing: { id: 2 } };const item = new schema.Entity('items');
const valuesSchema = new schema.Values(item);const normalizedData = normalize(data, valuesSchema);复制代码

Output

{entities: {items: { '1': { id: 1 }, '2': { id: 2 } }},result: { firstThing: 1, secondThing: 2 }
}复制代码

If your input data is an object that has values of more than one type of entity, but their schema is not easily defined by the key, you can use a mapping of schema, much like schema.Union and schema.Array.

For example:

const data = {'1': { id: 1, type: 'admin' }, '2': { id: 2, type: 'user' }
};const userSchema = new schema.Entity('users');
const adminSchema = new schema.Entity('admins');
const valuesSchema = new schema.Values({admins: adminSchema,users: userSchema
}, (input, parent, key) => `${input.type}s`);const normalizedData = normalize(data, valuesSchema);复制代码

Output

{entities: {admins: { '1': { id: 1, type: 'admin' } },users: { '2': { id: 2, type: 'user' } }},result: {'1': { id: 1, schema: 'admins' },'2': { id: 2, schema: 'users' }}
}复制代码