waterline
Version:
An ORM for Node.js and the Sails framework
301 lines (256 loc) • 14.3 kB
JavaScript
/**
* Module dependencies
*/
var _ = require('@sailshq/lodash');
var flaverr = require('flaverr');
var parley = require('parley');
var buildOmen = require('../utils/query/build-omen');
var forgeAdapterError = require('../utils/query/forge-adapter-error');
var forgeStageTwoQuery = require('../utils/query/forge-stage-two-query');
var forgeStageThreeQuery = require('../utils/query/forge-stage-three-query');
var getQueryModifierMethods = require('../utils/query/get-query-modifier-methods');
var verifyModelMethodContext = require('../utils/query/verify-model-method-context');
/**
* Module constants
*/
var DEFERRED_METHODS = getQueryModifierMethods('sum');
/**
* sum()
*
* Get the aggregate sum of the specified attribute across all matching records.
*
* ```
* // The cumulative account balance of all bank accounts that have
* // less than $32,000, or that are flagged as "suspended".
* BankAccount.sum('balance').where({
* or: [
* { balance: { '<': 32000 } },
* { suspended: true }
* ]
* }).exec(function (err, total){
* // ...
* });
* ```
*
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*
* Usage without deferred object:
* ================================================
*
* @param {String?} numericAttrName
*
* @param {Dictionary?} criteria
*
* @param {Function?} explicitCbMaybe
* Callback function to run when query has either finished successfully or errored.
* (If unspecified, will return a Deferred object instead of actually doing anything.)
*
* @param {Ref?} meta
* For internal use.
*
* @param {Dictionary} moreQueryKeys
* For internal use.
* (A dictionary of query keys.)
*
* @returns {Ref?} Deferred object if no `explicitCbMaybe` callback was provided
*
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*
* The underlying query keys:
* ==============================
*
* @qkey {String} numericAttrName
* The name of a numeric attribute.
* (Must be declared as `type: 'number'`.)
*
* @qkey {Dictionary?} criteria
*
* @qkey {Dictionary?} meta
* @qkey {String} using
* @qkey {String} method
*
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/
module.exports = function sum( /* numericAttrName?, criteria?, explicitCbMaybe?, meta?, moreQueryKeys? */ ) {
// Verify `this` refers to an actual Sails/Waterline model.
verifyModelMethodContext(this);
// Set up a few, common local vars for convenience / familiarity.
var WLModel = this;
var orm = this.waterline;
var modelIdentity = this.identity;
// Build an omen for potential use in the asynchronous callback below.
var omen = buildOmen(sum);
// Build query w/ initial, universal keys.
var query = {
method: 'sum',
using: modelIdentity
};
// ██╗ ██╗ █████╗ ██████╗ ██╗ █████╗ ██████╗ ██╗ ██████╗███████╗
// ██║ ██║██╔══██╗██╔══██╗██║██╔══██╗██╔══██╗██║██╔════╝██╔════╝
// ██║ ██║███████║██████╔╝██║███████║██║ ██║██║██║ ███████╗
// ╚██╗ ██╔╝██╔══██║██╔══██╗██║██╔══██║██║ ██║██║██║ ╚════██║
// ╚████╔╝ ██║ ██║██║ ██║██║██║ ██║██████╔╝██║╚██████╗███████║
// ╚═══╝ ╚═╝ ╚═╝╚═╝ ╚═╝╚═╝╚═╝ ╚═╝╚═════╝ ╚═╝ ╚═════╝╚══════╝
//
// The `explicitCbMaybe` callback, if one was provided.
var explicitCbMaybe;
// Handle the various supported usage possibilities
// (locate the `explicitCbMaybe` callback, and extend the `query` dictionary)
//
// > Note that we define `args` to minimize the chance of this "variadics" code
// > introducing any unoptimizable performance problems. For details, see:
// > https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#32-leaking-arguments
// > •=> `.length` is just an integer, this doesn't leak the `arguments` object itself
// > •=> `i` is always valid index in the arguments object
var args = new Array(arguments.length);
for (var i = 0; i < args.length; ++i) {
args[i] = arguments[i];
}
// • sum(numericAttrName, explicitCbMaybe, ..., ...)
if (args.length >= 2 && _.isFunction(args[1])) {
query.numericAttrName = args[0];
explicitCbMaybe = args[1];
query.meta = args[2];
if (args[3]) { _.extend(query, args[3]); }
}
// • sum(numericAttrName, criteria, ..., ..., ...)
else {
query.numericAttrName = args[0];
query.criteria = args[1];
explicitCbMaybe = args[2];
query.meta = args[3];
if (args[4]) { _.extend(query, args[4]); }
}
// Due to the somewhat unusual variadic usage of this method, and because
// parley doesn't enforce this itself for performance reasons, make sure the
// explicit callback argument is a function, if provided.
if (explicitCbMaybe !== undefined && !_.isFunction(explicitCbMaybe)) {
throw flaverr({
name: 'UsageError',
message:
'`.sum()` received an explicit callback function argument... but it '+
'was not a function: '+explicitCbMaybe
}, omen);
}//•
// ██████╗ ███████╗███████╗███████╗██████╗
// ██╔══██╗██╔════╝██╔════╝██╔════╝██╔══██╗
// ██║ ██║█████╗ █████╗ █████╗ ██████╔╝
// ██║ ██║██╔══╝ ██╔══╝ ██╔══╝ ██╔══██╗
// ██████╔╝███████╗██║ ███████╗██║ ██║
// ╚═════╝ ╚══════╝╚═╝ ╚══════╝╚═╝ ╚═╝
//
// ██╗███╗ ███╗ █████╗ ██╗ ██╗██████╗ ███████╗██╗
// ██╔╝████╗ ████║██╔══██╗╚██╗ ██╔╝██╔══██╗██╔════╝╚██╗
// ██║ ██╔████╔██║███████║ ╚████╔╝ ██████╔╝█████╗ ██║
// ██║ ██║╚██╔╝██║██╔══██║ ╚██╔╝ ██╔══██╗██╔══╝ ██║
// ╚██╗██║ ╚═╝ ██║██║ ██║ ██║ ██████╔╝███████╗██╔╝
// ╚═╝╚═╝ ╚═╝╚═╝ ╚═╝ ╚═╝ ╚═════╝ ╚══════╝╚═╝
//
// ┌┐ ┬ ┬┬┬ ┌┬┐ ┬ ┬─┐┌─┐┌┬┐┬ ┬┬─┐┌┐┌ ┌┐┌┌─┐┬ ┬ ┌┬┐┌─┐┌─┐┌─┐┬─┐┬─┐┌─┐┌┬┐
// ├┴┐│ │││ ││ ┌┼─ ├┬┘├┤ │ │ │├┬┘│││ │││├┤ │││ ││├┤ ├┤ ├┤ ├┬┘├┬┘├┤ ││
// └─┘└─┘┴┴─┘─┴┘ └┘ ┴└─└─┘ ┴ └─┘┴└─┘└┘ ┘└┘└─┘└┴┘ ─┴┘└─┘└ └─┘┴└─┴└─└─┘─┴┘
// ┌─ ┬┌─┐ ┬─┐┌─┐┬ ┌─┐┬ ┬┌─┐┌┐┌┌┬┐ ─┐
// │─── │├┤ ├┬┘├┤ │ ├┤ └┐┌┘├─┤│││ │ ───│
// └─ ┴└ ┴└─└─┘┴─┘└─┘ └┘ ┴ ┴┘└┘ ┴ ─┘
// If an explicit callback function was specified, then immediately run the logic below
// and trigger the explicit callback when the time comes. Otherwise, build and return
// a new Deferred now. (If/when the Deferred is executed, the logic below will run.)
return parley(
function (done){
// Otherwise, IWMIH, we know that it's time to actually do some stuff.
// So...
//
// ███████╗██╗ ██╗███████╗ ██████╗██╗ ██╗████████╗███████╗
// ██╔════╝╚██╗██╔╝██╔════╝██╔════╝██║ ██║╚══██╔══╝██╔════╝
// █████╗ ╚███╔╝ █████╗ ██║ ██║ ██║ ██║ █████╗
// ██╔══╝ ██╔██╗ ██╔══╝ ██║ ██║ ██║ ██║ ██╔══╝
// ███████╗██╔╝ ██╗███████╗╚██████╗╚██████╔╝ ██║ ███████╗
// ╚══════╝╚═╝ ╚═╝╚══════╝ ╚═════╝ ╚═════╝ ╚═╝ ╚══════╝
// ╔═╗╔═╗╦═╗╔═╗╔═╗ ┌─┐┌┬┐┌─┐┌─┐┌─┐ ┌┬┐┬ ┬┌─┐ ┌─┐ ┬ ┬┌─┐┬─┐┬ ┬
// ╠╣ ║ ║╠╦╝║ ╦║╣ └─┐ │ ├─┤│ ┬├┤ │ ││││ │ │─┼┐│ │├┤ ├┬┘└┬┘
// ╚ ╚═╝╩╚═╚═╝╚═╝ └─┘ ┴ ┴ ┴└─┘└─┘ ┴ └┴┘└─┘ └─┘└└─┘└─┘┴└─ ┴
//
// Forge a stage 2 query (aka logical protostatement)
try {
forgeStageTwoQuery(query, orm);
} catch (e) {
switch (e.code) {
case 'E_INVALID_NUMERIC_ATTR_NAME':
return done(
flaverr({
name: 'UsageError',
code: e.code,
details: e.details,
message:
'The numeric attr name (i.e. first argument) to `.sum()` should '+
'be the name of an attribute in this model which is defined with `type: \'number\'`.\n'+
'Details:\n'+
' ' + e.details + '\n'
}, omen)
);
// ^ custom override for the standard usage error. Note that we use `.details` to get at
// the underlying, lower-level error message (instead of logging redundant stuff from
// the envelope provided by the default error msg.)
case 'E_INVALID_CRITERIA':
case 'E_INVALID_META':
return done(
flaverr({
name: 'UsageError',
code: e.code,
details: e.details,
message: e.message
}, omen)
);
// ^ when the standard usage error message is good enough as-is, without any further customization
case 'E_NOOP':
return done(undefined, 0);
default:
return done(e);
// ^ when an internal, miscellaneous, or unexpected error occurs
}
} // >-•
// ╔═╗╔═╗╦═╗╔═╗╔═╗ ┌─┐┌┬┐┌─┐┌─┐┌─┐ ┌┬┐┬ ┬┬─┐┌─┐┌─┐ ┌─┐ ┬ ┬┌─┐┬─┐┬ ┬
// ╠╣ ║ ║╠╦╝║ ╦║╣ └─┐ │ ├─┤│ ┬├┤ │ ├─┤├┬┘├┤ ├┤ │─┼┐│ │├┤ ├┬┘└┬┘
// ╚ ╚═╝╩╚═╚═╝╚═╝ └─┘ ┴ ┴ ┴└─┘└─┘ ┴ ┴ ┴┴└─└─┘└─┘ └─┘└└─┘└─┘┴└─ ┴
try {
query = forgeStageThreeQuery({
stageTwoQuery: query,
identity: modelIdentity,
transformer: WLModel._transformer,
originalModels: orm.collections
});
} catch (e) { return done(e); }
// ┌─┐┌─┐┌┐┌┌┬┐ ┌┬┐┌─┐ ╔═╗╔╦╗╔═╗╔═╗╔╦╗╔═╗╦═╗
// └─┐├┤ │││ ││ │ │ │ ╠═╣ ║║╠═╣╠═╝ ║ ║╣ ╠╦╝
// └─┘└─┘┘└┘─┴┘ ┴ └─┘ ╩ ╩═╩╝╩ ╩╩ ╩ ╚═╝╩╚═
// Grab the appropriate adapter method and call it.
var adapter = WLModel._adapter;
if (!adapter.sum) {
return done(new Error('The adapter used by this model (`' + modelIdentity + '`) doesn\'t support the `'+query.method+'` method.'));
}
adapter.sum(WLModel.datastore, query, function _afterTalkingToAdapter(err, sum) {
if (err) {
err = forgeAdapterError(err, omen, 'sum', modelIdentity, orm);
return done(err);
}//-•
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// FUTURE: Log a warning like the ones in `process-all-records` if
// the sum sent back by the adapter turns out to be something other
// than a number (for example, the naive behavior of a MySQL adapter
// in circumstances where criteria does not match any records); i.e.
// ```
// !_.isNumber(sum) || sum === Infinity || sum === -Infinity || _.isNaN(sum)
// ````
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
return done(undefined, sum);
});//</adapter.sum()>
},
explicitCbMaybe,
_.extend(DEFERRED_METHODS, {
// Provide access to this model for use in query modifier methods.
_WLModel: WLModel,
// Set up initial query metadata.
_wlQueryInfo: query,
})
);//</parley>
};