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Data arrays

The examples on syntax page describe how to retrieve data for a single instrument. This method may be inconvenient when it comes to obtaining the same type of data for a large number of tools at once. For this purpose, the GraphQL API has interfaces for obtaining data arrays.

Available interfaces​

Specific interfaces are used to obtain data arrays for multiple instruments at once: instruments, bonds, derivatives and stocks.

Example from schema

type Query {
  instruments(
    includeOld: Boolean! = false
    includeNonBaseBoards: Boolean! = false
    first: Int
    after: String
    last: Int
    before: String
    where: InstrumentModelFilterInput
    order: [InstrumentModelSortInput!]
  ): InstrumentsConnection
  bonds(
    includeOld: Boolean! = false
    includeNonBaseBoards: Boolean! = false
    first: Int
    after: String
    last: Int
    before: String
    where: BondFilterInput
    order: [BondSortInput!]
  ): BondsConnection
  derivatives(
    includeOld: Boolean! = false
    includeNonBaseBoards: Boolean! = false
    first: Int
    after: String
    last: Int
    before: String
    where: DerivativeFilterInput
    order: [DerivativeSortInput!]
  ): DerivativesConnection
  stocks(
    includeOld: Boolean! = false
    includeNonBaseBoards: Boolean! = false
    first: Int
    after: String
    last: Int
    before: String
    where: StockFilterInput
    order: [StockSortInput!]
  ): StocksConnection
}

Interface arguments are used for pagination, sorting and filtering of received data. More details about them in the corresponding articles.

Sending requests​

The instruments, bonds, derivatives, and stocks fields are redirected to the same interfaces that are used to retrieve data on an individual instrument (Instrument, Bond, Derivative, and Stock), but combined into nodes. Thus, the body of the operation is similar to the examples above, only lengthened by one path field:

Request example
{
  instruments {
    nodes {
      basicInformation {
        symbol
        exchange
        description
        shortName
        type
        market
      }
    }
  }
}

As a response, the system will return a list of the first 10 instruments with the actual values of the data fields specified in the operation.

Increasing selection​

To get a different number of objects, use one of the two arguments of the path root field:

  • first - returns the first N objects from the beginning of the total list
  • last - returns the first N objects from the end of the total list

Both arguments expect a value in Int format and are mutually exclusive, so only one of them can be stated in a single operation simultaneously.

Request example
{
  instruments(first: 50) {
    nodes {
      basicInformation {
        symbol
        exchange
        description
        shortName
        type
        market
      }
    }
  }
}

n response, the system will return the first 50 records from the beginning of the total list instead of the standard 10.

Edges and nodes​

All fields in the examples above are grouped into nodes, which are interacted with. Referring to a node allows you to get data in arrays without having to specify each instrument of interest separately. However, nodes are not the highest level of field aggregation, as they themselves are part of the edges, which include fields and arguments for further filtering, sorting and pagination of the obtained data.

The proper way to construct a query with an allowance for further operations with the returned data is to add the edges path field between the root path field and the nodes included in it to the already known structure:

Request example
{
  instruments {
    edges {
      node {
        basicInformation {
          symbol
          exchange
          description
          shortName
          type
          market
        }
      }
    }
  }
}

The response from the system to a request in its current form is no different from example above, but this structure opens up possibilities for further transformation of the responses received.

What's next?​

Additionally, we recommend reading the following related articles: