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

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

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'use strict';

const dataModel = require('../Protocol/Stubs/mysqlx_crud_pb').DataModel.TABLE;
const ExprParser = require('../ExprParser');
const Expr = require('./Expr');

/**
 * Factory function to create instances of an informal type that encapsulates
 * a set of projected search column names and optional aliases defined as
 * a string or an X DevAPI expression (computed or not).
 * @private
 * @module ProjectedSearchExprStr
 */

const parser = ExprParser({ mode: dataModel, type: ExprParser.Type.PROJECTED_SEARCH_EXPR });

/**
 * A column name and optional alias to include as part of a result set.
 * @typedef {string|module:Expr} ProjectedSearchExprStr
 * @global
 * @example
 * // string
 * foo as baz
 * bar as qux
 * // X DevAPI expression
 * mysqlx.expr('foo as bar', { mode: mysqlx.Mode.TABLE })
 * mysqlx.expr('bar as qux', { mode: mysqlx.Mode.TABLE })
 * mysqlx.expr('{ "foobar": concat(foo, bar) }', { mode: mysqlx.Mode.TABLE })
 */

/**
 * One or more column names and corresponding optional aliases.
 * @typedef {ProjectedSearchExprStr|ProjectedSearchExprStr[]} ProjectedSearchExprStrList
 * @global
 */

/**
 * @private
 * @alias module:ProjectedSearchExprStr
 * @param {ProjectedSearchExprStr} value - A String or X DevAPI expression
 * instance containing a column name and an optional alias or a computed
 * projection definition.
 * @returns {module:ProjectedSearchExprStr}
 */
function ProjectedSearchExprStr (value) {
    return {
        /**
         * Parses the underlying projected search expression and return
         * the result.
         * @private
         * @function
         * @name module:ProjectedSearchExprStr#getValue
         * @returns {ExpressionTree} An Object that represents an expression
         * tree that results from parsing a given X DevAPI projected search
         * expression string.
         */
        getValue () {
            return parser.parse(Expr({ dataModel, value }).getExpressionString());
        }
    };
}

module.exports = ProjectedSearchExprStr;