rfc6570-expand/lib/expression.js

A template processor for RFC 6570 URI Template

"use strict";
const variables_1 = require('./variables');
const expression_parser_1 = require('./expression-parser');
const parser = expression_parser_1.expressionParser();
const varSpecToString = (allow, ifemp, named, sep, varName, explode, maxLength, value, isEmpty) => {
    if (typeof maxLength !== 'undefined') {
        if (variables_1.isString(value)) {
            return (named ? varName + (isEmpty ? ifemp : '=') : '') +
                allow(value.substring(0, maxLength));
        }
        else {
            throw new Error();
        }
    }
    return (explode
        ? (variables_1.isArray(value)
            ? value.map(v => {
                return (named ? varName + (isEmpty ? ifemp : '=') : '') +
                    allow(v);
            }).join(sep)
            : (variables_1.isString(value)
                ? allow(value)
                : value.map(([k, v]) => {
                    return allow(k) + (isEmpty ? ifemp : '=') + allow(v);
                }).join(sep)))
        : ((named ? varName + (isEmpty ? ifemp : '=') : '') +
            (variables_1.isArray(value)
                ? value.map(allow).join(',')
                : (variables_1.isString(value)
                    ? allow(value)
                    : value.map(([k, v]) => {
                        return allow(k) + ',' + allow(v);
                    }).join(',')))));
};
const expression = (s, variables) => {
    const { operator: { allow, first, ifemp, named, sep }, varSpecs } = parser(s);
    return varSpecs
        .map(varSpec => {
        const { varName } = varSpec;
        const value = variables[varName];
        return { value: value, varSpec: varSpec };
    })
        .filter(({ value }) => {
        return variables_1.isDefined(value) &&
            !(value.length === 0 && (variables_1.isArray(value) || variables_1.isObject(value)));
    })
        .map(({ value, varSpec: { varName, maxLength, explode }, }, index) => {
        const isFirst = index === 0;
        const isEmpty = value.length === 0;
        const firstOrSep = (isFirst ? first : sep);
        return firstOrSep + varSpecToString(allow, ifemp, named, sep, varName, explode, maxLength, value, isEmpty);
    }).join('');
};
exports.expression = expression;