Queries

Queries are used to get and filter records through a Queryable object. Which uses lodash to work with Array records. The following contents are a list of available query methods.

Work with Queryable

Queryable contains a set of immutable records and separated from the Document records. The following code demonstrates how to create a Queryable object.

import { Queryable } from 'vasern';

const queryObj = new Queryable(data);

Get record

Find and return a record that match with lookupQuery.

Queryable.get(lookupQuery)

Arguments

• lookupQuery ( string | Object )
  • (string): match record id with string value
  • (Object): match record properties and values with Object properties and values

Return

• Object: object that match with lookupQuery
• undefined if not found

Example

var foundRecord = Queryable.get({ id: "5bc592cacdAsassfs000ddddBBdbcdfb" });

Filter records

Find and return a list of records that match with lookupQuery.

Queryable.filter(lookupQuery)

Arguments

• lookupQuery ( Object ): match record properties and values with Object properties and values

Return

• Array<Object>: a list of records that match with lookupQuery

Example

var records = Queryable.filter({ completed: true });

Exclude records

Excludes records that match with lookupQuery from current Queryable dataset.

Queryable.exclude(lookupQuery)

Arguments

• lookupQuery ( Object ): match record properties and values with Object properties and values

Return

• Array<Object>: a list of records that match with lookupQuery

Example

var records = Queryable.exclude({ completed: true });

Order records

Re-order records list by key.

Queryable.order(key, asc = true)

Arguments

• key ( string ): property name
• asc (boolean): allow order ascending, set to false for decending order.

Return

• Array<Object>: a list of reorderd records

Example

var records = Queryable.filter({ completed: true });

What's next?

Learn about Event listeners