@mysql/xdevapi/lib/DevAPI/ExprOrLiteral.js

MySQL Connector/Node.js - A Node.js driver for MySQL using the X Protocol and X DevAPI.

/*
 * Copyright (c) 2022, Oracle and/or its affiliates.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2.0, as
 * published by the Free Software Foundation.
 *
 * This program is also distributed with certain software (including
 * but not limited to OpenSSL) that is licensed under separate terms,
 * as designated in a particular file or component or in included license
 * documentation.  The authors of MySQL hereby grant you an
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 *
 * Without limiting anything contained in the foregoing, this file,
 * which is part of MySQL Connector/Node.js, is also subject to the
 * Universal FOSS Exception, version 1.0, a copy of which can be found at
 * http://oss.oracle.com/licenses/universal-foss-exception.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License, version 2.0, for more details.
 *
 * You should have received a copy of the GNU General Public License
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 */

'use strict';

const Expr = require('./Expr');

/**
 * Factory function to create instances of an informal type that represents a
 * unified version for a JavaScript primitive or an X DevAPI expression
 * literal.
 * @private
 * @module ExprOrLiteral
 */

/**
 * A document definition as represented by a plain JavaScript object, a JSON
 * string or an X DevAPI expression instance.
 * @typedef {string|number|boolean|module:Expr} ExprOrLiteral
 * @global
 * @example
 * // primitive JavaScript values
 * 'foo'
 * true
 * false
 * 3
 * 1.234
 * // X DevAPI expression literal
 * mysqlx.expr('{"foo":"bar"}')
 */

/**
 * @private
 * @alias module:ExprOrLiteral
 * @param {DataModel} [dataModel] - The data model to use for parsing the
 * value when determining between document fields and column identifiers.
 * @param {ExprOrLiteral} value - A plain JavaScript object, JSON string or
 * an X DevAPI expression instance that represents a document definition.
 * @returns {module:ExprOrLiteral}
 */
function ExprOrLiteral ({ dataModel, value }) {
    return {
        /**
         * Parses the underlying expression and return the result.
         * @private
         * @function
         * @name module:DocumentOrJSON#getValue
         * @returns {ExprOrLiteral|ExpressionTree} A primitive JavaScript
         * value which represents the expression literal. The object can be an
         * expression tree that results from parsing a given X DevAPI
         * expression instance.
         */
        getValue () {
            if (this.isLiteral()) {
                return value;
            }

            return Expr({ dataModel, value }).getValue();
        },

        /**
         * Checks if the underlying expression is a literal string or an X
         * DevAPI expression.
         * @private
         * @function
         * @name module:DocumentOrJSON#isLiteral
         * @returns {boolean}
         */
        isLiteral () {
            return Expr({ dataModel, value }).isLiteral();
        }
    };
}

module.exports = ExprOrLiteral;