Complete generator for ebooks

lib/output/base.js

@@ -7,7 +7,6 @@ var pathUtil = require('../utils/path');
 var location = require('../utils/location');
 var PluginsManager = require('../plugins');
 var TemplateEngine = require('../template');
-var gitbook = require('../gitbook');
 
 /*
 Output is like a stream interface for a parsed book
@@ -16,9 +15,13 @@ to output "something".
 The process is mostly on the behavior of "onPage" and "onAsset"
 */
 
-function Output(book) {
+function Output(book, opts) {
     _.bindAll(this);
 
+    this.opts = _.defaults(opts || {}, {
+
+    });
+
     this.book = book;
     this.log = this.book.log;
 
@@ -175,6 +178,17 @@ Output.prototype.onResolveTemplate = function(from, to) {
 
 // ---- Utilities ----
 
+// Return a default context for templates
+Output.prototype.getContext = function() {
+    return _.extend(
+        {},
+        this.book.getContext(),
+        this.book.summary.getContext(),
+        this.book.glossary.getContext(),
+        this.book.config.getContext()
+    );
+};
+
 // Resolve a file path in the context of a specific page
 // Result is an "absolute path relative to the output folder"
 Output.prototype.resolveForPage = function(page, href) {

lib/output/ebook.js

@@ -1,14 +1,155 @@
+var _ = require('lodash');
 var util = require('util');
+var juice = require('juice');
 
+var command = require('../utils/command');
+var fs = require('../utils/fs');
 var WebsiteOutput = require('./website');
 var assetsInliner = require('./assets-inliner');
 
-function EbookOutput() {
+function _EbookOutput() {
     WebsiteOutput.apply(this, arguments);
 }
 util.inherits(EbookOutput, WebsiteOutput);
 
+var EbookOutput = assetsInliner(_EbookOutput);
+
 EbookOutput.prototype.name = 'ebook';
 
+// Finish generation, create ebook using ebook-convert
+EbookOutput.prototype.finish = function() {
+    var that = this;
 
-module.exports = assetsInliner(EbookOutput);
+    return Promise()
+    .then(function() {
+        return EbookOutput.super_.prototype.finish.apply(that);
+    })
+
+    // Generate SUMMARY.html
+    .then(function() {
+        return that.render('summary', that.getContext())
+        .then(function(html) {
+            return that.writeFile(
+                that.resolve('SUMMARY.html'),
+                html
+            );
+        });
+    })
+
+    // Start ebook-convert
+    .then(function() {
+        return that.ebookConvertOption();
+    })
+
+    .then(function(options) {
+        var cmd = [
+            'ebook-convert',
+            that.resolve('SUMMARY.html'),
+            that.resolve('index.'+that.opts.format),
+            command.optionsToShellArgs(options)
+        ].join(' ');
+
+        return command.exec(cmd)
+        .fail(function(err) {
+            if (err.code == 127) {
+                err = new Error('Need to install ebook-convert from Calibre');
+            }
+
+            throw err;
+        });
+    });
+};
+
+// Generate header/footer for PDF
+EbookOutput.prototype.getPDFTemplate = function(tpl) {
+    var that = this;
+    var context = _.extend(
+        {
+            // Nunjucks context mapping to ebook-convert templating
+            page: {
+                num: '_PAGENUM_',
+                title: '_TITLE_'
+            }
+        },
+        this.getContext()
+    );
+
+    return this.render('pdf_'+tpl, context)
+
+    // Inline css, include css relative to the output folder
+    .then(function(output) {
+        return Promise.nfcall(juice.juiceResources, tpl, {
+            webResources: {
+                relativeTo: that.root()
+            }
+        });
+    });
+};
+
+// Generate options for ebook-convert
+EbookOutput.prototype.ebookConvertOption = function() {
+    var that = this;
+    var cover = this.book.config.get('cover');
+
+    if (!cover && fs.existsSync(this.resolve('cover.jpg'))) {
+        cover = this.resolve('cover.jpg');
+    }
+
+    var options = {
+        '--cover': cover,
+        '--title': this.book.config.get('title'),
+        '--comments': this.book.config.get('description'),
+        '--isbn': this.book.config.get('isbn'),
+        '--authors': this.book.config.get('author'),
+        '--language': this.book.config.get('language'),
+        '--book-producer': 'GitBook',
+        '--publisher': 'GitBook',
+        '--chapter': 'descendant-or-self::*[contains(concat(\' \', normalize-space(@class), \' \'), \' book-chapter \')]',
+        '--level1-toc': 'descendant-or-self::*[contains(concat(\' \', normalize-space(@class), \' \'), \' book-chapter-1 \')]',
+        '--level2-toc': 'descendant-or-self::*[contains(concat(\' \', normalize-space(@class), \' \'), \' book-chapter-2 \')]',
+        '--level3-toc': 'descendant-or-self::*[contains(concat(\' \', normalize-space(@class), \' \'), \' book-chapter-3 \')]',
+        '--no-chapters-in-toc': true,
+        '--max-levels': '1',
+        '--breadth-first': true
+    };
+
+    if (this.opts.format == 'epub') {
+        options = _.extend(options, {
+            '--dont-split-on-page-breaks': true
+        });
+    }
+
+    if (this.opts.format != 'pdf') return Promise(options);
+
+    var pdfOptions = this.book.config.get('pdf');
+
+    options = _.extend(options, {
+        '--chapter-mark': String(pdfOptions.chapterMark),
+        '--page-breaks-before': String(pdfOptions.pageBreaksBefore),
+        '--margin-left': String(pdfOptions.margin.left),
+        '--margin-right': String(pdfOptions.margin.right),
+        '--margin-top': String(pdfOptions.margin.top),
+        '--margin-bottom': String(pdfOptions.margin.bottom),
+        '--pdf-default-font-size': String(pdfOptions.fontSize),
+        '--pdf-mono-font-size': String(pdfOptions.fontSize),
+        '--paper-size': String(pdfOptions.paperSize),
+        '--pdf-page-numbers': Boolean(pdfOptions.pageNumbers),
+        '--pdf-header-template': that.getPDFTemplate('header'),
+        '--pdf-footer-template': that.getPDFTemplate('footer'),
+        '--pdf-sans-family': String(pdfOptions.fontFamily)
+    });
+
+    return this.getPDFTemplate('header')
+    .then(function(tpl) {
+        options['--pdf-header-template'] = tpl;
+
+        return that.getPDFTemplate('footer');
+    })
+    .then(function(tpl) {
+        options['--pdf-footer-template'] = tpl;
+
+        return options;
+    });
+};
+
+module.exports = EbookOutput;

lib/utils/command.js

@@ -1,3 +1,4 @@
+var _ = require('lodash');
 var childProcess = require('child_process');
 var Promise = require('./promise');
 
@@ -37,8 +38,27 @@ function spawn(command, args, options) {
     return d.promise;
 }
 
+// Transform an option object to a command line string
+function escapeShellArg(s) {
+    s = s.replace(/"/g, '\\"');
+    return '"' + s + '"';
+}
+
+function optionsToShellArgs(options) {
+    return _.chain(options)
+    .map(function(value, key) {
+        if (value === null || value === undefined || value === false) return null;
+        if (value === true) return key;
+        return key + '=' + escapeShellArg(value);
+    })
+    .compact()
+    .value()
+    .join(' ');
+}
+
 module.exports = {
     isAvailable: isAvailable,
     exec: exec,
-    spawn: spawn
+    spawn: spawn,
+    optionsToShellArgs: optionsToShellArgs
 };

package.json

@@ -37,7 +37,7 @@
         "dom-serializer": "0.1.0",
         "spawn-cmd": "0.0.2",
         "escape-string-regexp": "1.0.3",
-        "juice": "1.5.0",
+        "juice": "1.9.0",
         "jsonschema": "1.0.2",
         "json-schema-defaults": "0.1.1",
         "merge-defaults": "0.2.1",