tools/bin/augment_toc.js

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

"use strict";

var fs   = require("fs");
var path = require("path");

var yaml     = require("js-yaml");
var optimist = require("optimist");

var util = require("./util");

// constants
var DEFAULT_PREFIX     = "";
var VERBOSE_BY_DEFAULT = false;

// globals
var verbose = VERBOSE_BY_DEFAULT;

// helpers
function augmentEntry(originalEntry, prefix) {
    var augmentedEntry = {};

    // skip entries that have no URI
    if (!originalEntry.url) {
        return originalEntry;
    }

    // get the path to the file to which this entry points
    var filePath = path.join(prefix, originalEntry.url).replace('.html', '.md');

    // skip entries that don't point to a valid file
    if (!fs.existsSync(filePath)) {
        console.warn("WARNING! Possible 404 in ToC: \"" + filePath + "\"");
        return originalEntry;
    }

    // read in the referenced file and get its front matter
    var fileContents      = fs.readFileSync(filePath).toString();
    var frontMatterString = util.getFrontMatterString(fileContents);
    var frontMatter       = yaml.load(frontMatterString);

    augmentedEntry.name = decideOnName(originalEntry, frontMatter);
    augmentedEntry.url  = originalEntry.url;

    if (frontMatter.description) {
        augmentedEntry.description = frontMatter.description;
    }

    return augmentedEntry;
}

function decideOnName(originalEntry, frontMatter) {

    // raise a warning for old-style ToC entry names
    if (originalEntry.name && verbose === true) {
        console.warn("'name' property will be ignored");
    }

    // error out if there is no name
    if (!frontMatter.toc_title && !frontMatter.title) {
        throw Error("can't find out name for ToC entry");
    }

    // use entry's name, and if it's not defined use the front matter name
    return frontMatter.toc_title || frontMatter.title;
}

// public API
function augmentToc(originalToc, prefix) {

    var augmentedToc = [];

    if (typeof prefix === "undefined") {
        throw new Error("missing prefix for ToC");
    }

    // go through all original entries
    for (var i = 0; i < originalToc.length; i++) {
        var originalEntry  = originalToc[i];
        var augmentedEntry = {};

        // recurse for entries with children, replacing their children with
        // their augmented equivalents
        if (originalEntry.children) {

            if (typeof originalEntry.name === "undefined") {
                throw new Error("entries with children must have a name");
            }

            augmentedEntry.name     = originalEntry.name;
            augmentedEntry.children = augmentToc(originalEntry.children, prefix);

        // replace regular entries with their augmented equivalents
        } else {
            augmentedEntry = augmentEntry(originalEntry, prefix);
        }

        augmentedToc.push(augmentedEntry);
    }

    return augmentedToc;
}

function augmentString(srcTocString, prefix) {
    var srcToc             = yaml.load(srcTocString);
    var augmentedToc       = augmentToc(srcToc, prefix);
    var augmentedTocString = yaml.dump(augmentedToc, {indent: 4});

    return augmentedTocString;
}

function main () {

    // get args
    var argv = optimist
        .usage("Usage: $0 [options]")
        .demand("srcToc").describe("srcToc", "the source ToC for the given directory")
        .demand("srcRoot").describe("srcRoot", "the directory containing files described by the ToC")
        .boolean("verbose").describe("verbose", "if true, print more helpful information").default("verbose", VERBOSE_BY_DEFAULT)
        .alias("v", "verbose")
        .argv;

    var srcTocPath  = argv.srcToc;
    var srcRootPath = argv.srcRoot;

    // set globals
    verbose = argv.verbose;

    // get augmented ToC
    var srcTocString       = fs.readFileSync(srcTocPath);
    var augmentedTocString = augmentString(srcTocString, srcRootPath);

    console.log(util.generatedBy(__filename));
    console.log(augmentedTocString);
}

if (require.main === module) {
    main();
}

module.exports = {
    augmentToc:    augmentToc,
    augmentString: augmentString,
};