{
  total: number,
  filtered: number,
  fields: DField[],
  data: any[],
  summary: { [key: string]: number },
  query: DQuery
}

DField = {
  name: string,
  text?: string,
  sort?: 'asc'|'desc'|'',
  // simple values (one of these may be present)
  string?: string|null,
  number?: number|null,
  numbers?: number[],
  date?: string|null,          // ISO YYYY-MM-DD
  checkbox?: boolean|null,
  select?: { // select-like inputs
    type: 'number'|'date'|'string',
    value?: any|null,
    options: { value: any, text: string }[]
  },
  checkbuttons?: { // select-like inputs
    type: 'number'|'string',
    value?: any|null,
    options: { value: any, text: string }[]
  },
  checkboxes?: { // select-like inputs
    type: 'number'|'date'|'string'|'number[]'|'string[]',
    values?: any[],
    options: { value: any, text: string }[],
    classInput?: string
  },
  range?: { // ranges and validity
    type: 'number'|'date',
    nullable?: boolean,
    from?: number|string|Date|null,
    to?: number|string|Date|null
  },
  valid_until?: {
    type: 'date',
    nullable?: boolean,
    value?: string|Date|null
  }
}

DQuery = {
  from: number,
  size: number,
  init?: number,
  fields: DField[]
}