Added argument for adding additional scripts to a document

This allows to render documents with special handlers without modifying
the HTML before generation.

README.md

@@ -17,22 +17,23 @@ pagedjs-cli ./path/to/index.html -o result.pdf
 ## Options
 
 ```
--h, --help                  output usage information
--V, --version               output the version number
--i, --inputs [inputs]       Inputs
--o, --output [output]       Output
--d, --debug                 Show Electron Window to Debug
--l, --landscape             Landscape printing
--s, --page-size [size]      Print to Page Size [size]
--w, --width [size]          Print to Page Width [width]
--h --height [size]          Print to Page Height [weight]
--m, --page-margin [margin]  Print with margin [margin]
--n, --hyphenate [lang]      Hyphenate with language [language], defaults to "en-us"
--hi, --hypher_ignore [str]  Ignore passed element selectors, such as ".class_to_ignore, h1"
--ho, --hypher_only [str]    Only hyphenate passed elements selector, such as ".hyphenate, aside"
--e, --encoding [type]       Set the encoding of the input html, defaults to "utf-8"
--t, --timeout [ms]          Set a max timeout of [ms]
---outline-tags [tags]       Specifies that an outline should be generated for the resulting PDF document. [tags] specifies which HTML tags should be considered for that outline. "h1,h2" will trigger an outline with "h1" tags as root elements and "h2" elements as their childs.
+-h, --help                    output usage information
+-V, --version                 output the version number
+-i, --inputs [inputs]         Inputs
+-o, --output [output]         Output
+-d, --debug                   Show Electron Window to Debug
+-l, --landscape               Landscape printing
+-s, --page-size [size]        Print to Page Size [size]
+-w, --width [size]            Print to Page Width [width]
+-h --height [size]            Print to Page Height [weight]
+-m, --page-margin [margin]    Print with margin [margin]
+-n, --hyphenate [lang]        Hyphenate with language [language], defaults to "en-us"
+-hi, --hypher_ignore [str]    Ignore passed element selectors, such as ".class_to_ignore, h1"
+-ho, --hypher_only [str]      Only hyphenate passed elements selector, such as ".hyphenate, aside"
+-e, --encoding [type]         Set the encoding of the input html, defaults to "utf-8"
+-t, --timeout [ms]            Set a max timeout of [ms]
+--outline-tags [tags]         Specifies that an outline should be generated for the resulting PDF document. [tags] specifies which HTML tags should be considered for that outline. "h1,h2" will trigger an outline with "h1" tags as root elements and "h2" elements as their childs.
+--additional-script <script>  Additional script tags which are added to the HTML document before rendering. This is useful for adding custom pagedjs handlers. The option can be repeated. (default: [])
 ```
 
 ## Hyphenation

bin/paged

@@ -31,8 +31,16 @@ program
           "HTML tags should be considered for that outline. " +
           "\"h1,h2\" will trigger an outline with \"h1\" tags as root elements " +
           "and \"h2\" elements as their childs.")
+  .option("--additional-script <script>", "Additional script tags which are " +
+          "added to the HTML document before rendering. This is useful for " +
+          "adding custom pagedjs handlers. The option can be repeated.",
+          collect, [])
   .parse(process.argv);
 
+function collect(value, previous) {
+  return previous.concat(value);
+}
+
 
 let input = program.inputs || program.args[0];
 
@@ -96,7 +104,7 @@ if (typeof input === "string") {
 }
 
 (async () => {
-  let printer = new Printer(headless, allowLocal);
+  let printer = new Printer(headless, allowLocal, program.additionalScript);
 
   printer.on("page", (page) => {
     if (page.position === 0) {

src/printer.js

@@ -14,11 +14,12 @@ let scriptPath = paths[0] + "node_modules" + paths[paths.length-1];
 const PostProcesser = require("./postprocesser");
 
 class Printer extends EventEmitter {
-  constructor(headless, allowLocal) {
+  constructor(headless, allowLocal, additionalScripts) {
     super();
     this.headless = headless !== false;
     this.allowLocal = allowLocal;
     this.pages = [];
+    this.additionalScripts = additionalScripts;
   }
 
   async setup() {
@@ -98,6 +99,12 @@ class Printer extends EventEmitter {
       path: scriptPath
     });
 
+    for (const script of this.additionalScripts) {
+      await page.addScriptTag({
+        path: script
+      });
+    }
+
     // await page.exposeFunction("PuppeteerLogger", (msg) => {
     //   console.log(msg);
     // });