js/datas/todo/data_query.js
// NPM IMPORTS
import assert from 'assert'
// import {Map} from 'immutable'
// COMMON IMPORTS
import T from '../utils/types'
let context = 'common/data/data_record'
/**
* @file DataRecord class.
*
* @author Luc BORIES
*
* @license Apache-2.0
*/
export default class DataQuery
{
/**
* Data record class, contains one collection item attributes.
*
* API:
* ->constructor(arg_model)
*
* ->get_model():DataModel - get record model.
* ->hash():string - get query hash string.
*
* ->set_fields(arg_fields_names:array):nothing - set query fields.
* ->get_fields():array - get query fields names.
*
* ->set_limit(arg_offset:integer, arg_length:integer):nothing - set query limit with offset and length.
* ->set_range(arg_first:integer, arg_last:integer):nothing - set query limit with first and last index.
* ->get_limit():object - get query limit as { offset:..., length:..., first:..., last:...}
* ->set_page(arg_page_size, arg_page_index):nothing - set query limit with a page index.
* ->get_page(arg_page_size):integer - get query page.
*
* ->set_where(arg_where:object):nothing - set query where clause.
* ->get_where():object - get query where clause.
* ->and():this
* ->or():this
* ->not():this
* ->field(arg_field_name):this
* ->lt():this
* ->gt():this
* ->lte():this
* ->gte():this
* ->equal():this
* ->notequal():this
* ->like():this
* ->value(arg_string):this
*
* ->set_orderby(arg_orderby:array):nothing - set query orderby clause.
* ->get_orderby():array - get query orderby clause.
*
* ->set_groupby(arg_groupby:array):nothing - set query groupby clause.
* ->get_groupby():array - get query groupby clause.
*
* @param {DataModel} arg_model - data model: contains schema.
*
* @returns {nothing}
*/
constructor(arg_model)
{
assert( T.isObject(arg_model) && arg_model.is_data_model, context + ':constructor:bad model object')
this.is_data_query = true
this._model = arg_model
this._hash = undefined
this._hash_is_dirty = true
this._fields = []
this._limit = { offset:0, length:1000, first:0, last:999 }
this._where = {}
this._where_cursor = undefined
this._orderby = []
this._groupby = []
}
/**
* Emit on event.
* @private
*
* @param {string} arg_event - event name.
* @param {any} arg_datas - event datas (optional, default:undefined).
*
* @returns {nothing}
*/
/* eslint no-unused-vars: "off" */
_emit(arg_event, arg_datas=undefined) // TODO
{
}
/**
* Get record model.
*
* @returns {DataModel}
*/
get_model()
{
return this._model
}
/**
* Calculate query hash string.
*
* @returns {string}
*/
_calculate_hash()
{
const model = this._model.get_name()
const fields = this.fields.joins(',')
const limit = this._limit.offset + ',' + this._limit.length
const where = this._where.hash// TODO
const groupby = this._groupby.hash // TODO
const orderby = this._orderby.hash // TODO
this._hash = 'QUERY[' + model + ':' + fields + ':' + limit + ':' + where + ':' + groupby + ':' + orderby + ']'
this._hash_is_dirty = false
return this._hash
}
/**
* Get hash string.
*
* @returns {string}
*/
hash()
{
return this._hash_is_dirty ? this._calculate_hash() : this._hash
}
/**
* Set query fields.
*
* @param {array} arg_fields_names - query fields names
*
* @returns {nothing}
*/
set_fields(arg_fields_names)
{
assert( T.isArray(arg_fields_names), context + ':set_fields:bad fields array')
arg_fields_names.forEach(
(field_name, index)=>{
assert( T.isString(field_name), context + ':set_fields:bad field string at [' + index + '] for [' + field_name + ']')
assert( this._model.check_field_name(field_name), context + ':set_fields:bad field name at [' + index + '] for [' + field_name + ']')
}
)
this._fields = arg_fields_names
}
/**
* Get query fields.
*
* @returns {array}
*/
get_fields()
{
return this._fields
}
/**
* Get query limit as { offset:..., length:..., first:..., last:...}.
*
* @returns {object}
*/
get_limit()
{
return this._limit
}
/**
* Set query limit with offset and count.
*
* @param {integer} arg_offset - query limit offset.
* @param {integer} arg_length - query limit length.
*
* @returns {nothing}
*/
set_limit(arg_offset, arg_length)
{
assert( T.isNumber(arg_offset) && arg_offset >= 0, context + ':set_limit:bad offset number [' + arg_offset + ']')
assert( T.isNumber(arg_length) && arg_length > 0, context + ':set_limit:bad length number [' + arg_length + ']')
this._limit = {
offset:arg_offset,
length:arg_length,
first: arg_offset,
last: arg_offset + arg_offset - 1,
hash:'LIMIT[' + this._limit.offset + ':' + this._limit.length + ']'
}
}
/**
* Set query limit with first and last indices.
*
* @param {integer} arg_first - query limit first index.
* @param {integer} arg_last - query limit last index.
*
* @returns {nothing}
*/
set_range(arg_first, arg_last)
{
assert( T.isNumber(arg_first) && arg_first >= 0, context + ':set_limit:bad first index number [' + arg_first + ']')
assert( T.isNumber(arg_last) && arg_last > 0 && arg_last >= arg_first, context + ':set_limit:bad last index number [' + arg_last + ']')
this._limit = {
offset:arg_first,
length:arg_last - arg_first + 1,
first: arg_first,
last: arg_last,
hash:'LIMIT[' + this._limit.offset + ':' + this._limit.length + ']'
}
}
/**
* Set query limit with page size and page index.
*
* @param {integer} arg_page_size - query page size.
* @param {integer} arg_page_index - query page index.
*
* @returns {nothing}
*/
set_page(arg_page_size, arg_page_index)
{
assert( T.isNumber(arg_page_size) && arg_page_size > 0, context + ':set_limit:bad page size number [' + arg_page_size + ']')
assert( T.isNumber(arg_page_index) && arg_page_index >= 0, context + ':set_limit:bad page index number [' + arg_page_index + ']')
this._limit = {
offset:arg_page_size * (arg_page_index == 0 ? 0 : (arg_page_index - 1) ),
length:arg_page_size,
first: arg_page_size * (arg_page_index == 0 ? 0 : (arg_page_index - 1) ),
last: arg_page_size * arg_page_index,
hash:'LIMIT[' + this._limit.offset + ':' + this._limit.length + ']'
}
}
/**
* Get query limit page index.
*
* @param {integer} arg_page_size - query page size.
*
* @returns {integer}
*/
get_page(arg_page_size)
{
assert( T.isNumber(arg_page_size) && arg_page_size > 0, context + ':set_limit:bad page size number [' + arg_page_size + ']')
const size = this._limit.offset + this._limit.length
const rest = size % arg_page_size
const pages = ( size - rest ) / arg_page_size
return pages + (rest > 0 ? 1 : 0)
}
}
/*
* ->set_where(arg_where:object):nothing - set query where clause.
* ->get_where():object - get query where clause.
* ->and():this
* ->or():this
* ->not():this
* ->field(arg_field_name):this
* ->lt():this
* ->gt():this
* ->lte():this
* ->gte():this
* ->equal():this
* ->notequal():this
* ->like():this
* ->value(arg_string):this
*
* ->set_orderby(arg_orderby:array):nothing - set query orderby clause.
* ->get_orderby():array - get query orderby clause.
*
* ->set_groupby(arg_groupby:array):nothing - set query groupby clause.
* ->get_groupby():array - get query groupby clause.
* ->set_credentials(arg_crentials:object) - set credentials to use with some adapters.
* ->get_credentials():object - get credentials to use with some adapters.
Query modifiers include filters:
where
limit
skip
sort
select
distinct
Boolean logic:
and
or
not
As well as groupBy and the aggregators:
count
sum
min
max
average
IN queries: Adapters which implement where should recognize a list of values (e.g. name: ['Gandalf', 'Merlin']) as an IN query. In other words, if name is either of those values, a match occured.
Sub-attribute modifiers: You are also responsible for sub-attribute modifiers, (e.g. { age: { '>=' : 65 } }) with the notable exception of contains, startsWith, and endsWith, since support for those modifiers can be derived programatically by leveraging your definition of like.
like (SQL-style, with % wildcards)
'>' (you can also opt to use the more verbose .greaterThan(), etc.)
'<'
'>='
'<='
TODO: range queries (e.g. { '<':4, >= 2 })
*/
