@contexture/export

@contexture/export

Contexture Export is a set of contexture utilities to get all of the records from a given tree.

This is accomplished by inserting a node in the tree that gets the data for you over one or more iterations. To do this correctly and efficiently, the tree is wrapped in an AND group (in case the root was an OR) and recursively marked filterOnly (to prevent getting results for any other nodes on the tree).

Usage

Simple usage

import { results } from '@contexture/export'

let service = Contexture({
  /*...*/
})
let tree = {
  schema: 'someCollection',
  children: [
    /*...*/
  ],
}

let report = results({ tree, service, pageSize: 10 })

// Count results
let totalCount = await report.getTotalRecords()

// Stream
let stream = createWriteStream('someFile.txt')
for await (let record of report) stream.write(record)
stream.end()

// To Array
let array = []
for await (let record of report) array = array.concat(record)

// To array with it-all
import all from 'it-all'
let array = await all(report)

CSV Usage

Using our fast-csv wrapper, you can pass it a write stream, async iterable, and transforms based on contexture schemas

import _ from 'lodash/fp'
import { createWriteStream } from 'fs'
import { results, csv } from '@contexture/export'

let service = Contexture({/*...*/})
let tree = { schema: 'someCollection', children: [/*...*/] }
let schema = { field1: {/*...*/} }

await csv(
  stream: createWriteStream('./test/actualFile.csv'),
  iterableData: results({ service, tree }),
  transform: [
    {key: 'name', label: 'THE,NAME', display: _.capitalize},
    {key: 'value', label: 'Value', display: _.identity},
  ],
)

API

• nodes: Correspond to contexture nodes

  • results: This strategy extracts the records out of the node with results type. It's not affected by the position of the results node.
    • args:
      • options: object
        • service: (REQUIRED) An async function that will receive a single parameter: the Contexture DSL with the changes required to retrieve only the necessary data for the results strategy.
        • tree: (REQUIRED) The Contexture DSL! It must contain a node with the results type. It doesn't matter where!
        • include: An array with the list of fields that will be included on each retrieved record. This is relevant to the results type. It's undefined by default (which is valid).
        • sortField: Specifies what field will be used to sort the data. This is relevant to the results type. It's undefined by default (which is valid).
        • sortDir: Specifies in which direction the data will be sorted (asc or desc). This is relevant to the results type. It's undefined by default (which is valid).
        • pageSize: It allows you to specify how many records per page (per call of getNext) are returned. It defaults to 100.
        • page: Indicates the starting page of the specified search. Defaults to 1.
    • return:
      • iterableObject
        • getTotalRecords: function, returns the number of total records
  • terms_stats:
    • args:
      • options: object
        • service: (REQUIRED) An async function that will receive a single parameter: the Contexture DSL with the changes required to retrieve only the necessary data for the results strategy.
        • tree: (REQUIRED) The Contexture DSL! It must contain a node with the results type. It doesn't matter where!
        • key_field: The field to calculate stats for
        • size: the number of records to perfom the stats on

• csv: writes csv data to a stream. The parameter it receives are:

  • args:
    • options: object
      • stream, // writable stream target stream
      • iterableData: an iterable data object where each iteraction yields an object
      • transform: order list of which indicates the header label, display function for the field,and key of the record. [{ key: string, label: string, display: funciton}...]
      • onWrite: function to intercept writing a records, recieves {recordsWriten: int, record: object}
  • return:
    • object
      • cancel: function, stops the writing to the stream
      • promise: resolves when the writing is complete