winnow/lib/sql-query-builder/create-sql-params.js

Apply sql-like filters to GeoJSON

const isDifferentCrs = require('./is-different-crs')

function params (features, {
  returnGeometry,
  inputCrs,
  outputCrs,
  aggregates,
  geometry,
  geometryPrecision
} = {}) {
  const params = []
  // NOTE: order matters here
  // select fragment: transform function parameters here
  if (shouldAddCrsParams({ aggregates, returnGeometry, inputCrs, outputCrs })) {
    params.push(getCrsString(inputCrs), getCrsString(outputCrs))
  }

  if (geometryPrecision) {
    params.push(geometryPrecision)
  }

  // from fragment: features parameter here
  params.push(Array.isArray(features) ? features : [features])

  // where fragment: geometry filter parameter here
  if (geometry) {
    params.push(geometry)
  }
  return params
}

function shouldAddCrsParams ({
  aggregates,
  returnGeometry,
  inputCrs,
  outputCrs
} = {}) {
  return !aggregates && returnGeometry !== false && isDifferentCrs(inputCrs, outputCrs)
}

function getCrsString ({ wkt, wkid } = {}) {
  return wkt || `EPSG:${wkid}`
}

module.exports = params