| // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| /// Bootstrap to initialize polymer applications. This library is will be |
| /// replaced by boot.dart in the near future (see dartbug.com/18007). |
| /// |
| /// This script contains logic to bootstrap polymer apps during development. It |
| /// internally discovers special Dart script tags through HTML imports, and |
| /// constructs a new entrypoint for the application that is then launched in an |
| /// isolate. |
| /// |
| /// For each script tag found, we will load the corresponding Dart library and |
| /// execute all methods annotated with `@initMethod` and register all classes |
| /// labeled with `@CustomTag`. We keep track of the order of imports and execute |
| /// initializers in the same order. |
| /// |
| /// All polymer applications use this bootstrap logic. It is included |
| /// automatically when you include the polymer.html import: |
| /// |
| /// <link rel="import" href="packages/polymer/polymer.html"> |
| /// |
| /// There are two important changes compared to previous versions of polymer |
| /// (0.10.0-pre.6 and older): |
| /// |
| /// * Use 'application/dart;component=1' instead of 'application/dart': |
| /// Dartium already limits to have a single script tag per document, but it |
| /// will be changing semantics soon and make them even stricter. Multiple |
| /// script tags are not going to be running on the same isolate after this |
| /// change. For polymer applications we'll use a parameter on the script tags |
| /// mime-type to prevent Dartium from loading them separately. Instead this |
| /// bootstrap script combines those special script tags and creates the |
| /// application Dartium needs to run. |
| /// |
| // If you had: |
| /// |
| /// <polymer-element name="x-foo"> ... |
| /// <script type="application/dart" src="x_foo.dart'></script> |
| /// |
| /// Now you need to write: |
| /// |
| /// <polymer-element name="x-foo"> ... |
| /// <script type="application/dart;component=1" src="x_foo.dart'></script> |
| /// |
| /// * `initPolymer` is gone: we used to initialize applications in two |
| /// possible ways: using `init.dart` or invoking initPolymer in your main. Any |
| /// of these initialization patterns can be replaced to use an `@initMethod` |
| /// instead. For example, If you need to run some initialization code before |
| /// any other code is executed, include a "application/dart;component=1" |
| /// script tag that contains an initializer method with the body of your old |
| /// main, and make sure this tag is placed above other html-imports that load |
| /// the rest of the application. Initialization methods are executed in the |
| /// order in which they are discovered in the HTML document. |
| (function() { |
| // Only run in Dartium. |
| if (navigator.userAgent.indexOf('(Dart)') === -1) return; |
| |
| // Extract a Dart import URL from a script tag, which is the 'src' attribute |
| // of the script tag, or a data-url with the script contents for inlined code. |
| function getScriptUrl(script) { |
| var url = script.src; |
| if (url) { |
| // Normalize package: urls |
| var index = url.indexOf('packages/'); |
| if (index == 0 || (index > 0 && url[index - 1] == '/')) { |
| url = "package:" + url.slice(index + 9); |
| } |
| return url; |
| } |
| |
| // TODO(sigmund): change back to application/dart: using application/json is |
| // wrong but it hides a warning in Dartium (dartbug.com/18000). |
| return "data:application/json;base64," + window.btoa(script.textContent); |
| } |
| |
| // Creates a Dart program that imports [urls] and passes them to |
| // startPolymerInDevelopment, which in turn will invoke methods marked with |
| // @initMethod, and register any custom tag labeled with @CustomTag in those |
| // libraries. |
| function createMain(urls, mainUrl) { |
| var imports = Array(urls.length + 1); |
| for (var i = 0; i < urls.length; ++i) { |
| imports[i] = 'import "' + urls[i] + '" as i' + i + ';'; |
| } |
| imports[urls.length] = 'import "package:polymer/src/mirror_loader.dart";'; |
| var arg = urls.length == 0 ? '[]' : |
| ('[\n "' + urls.join('",\n "') + '"\n ]'); |
| return (imports.join('\n') + |
| '\n\nmain() {\n' + |
| ' startPolymerInDevelopment(' + arg + ');\n' + |
| '}\n'); |
| } |
| |
| function discoverScripts(content, state) { |
| if (!state) { |
| // internal state tracking documents we've visited, the resulting list of |
| // scripts, and any tags with the incorrect mime-type. |
| state = {seen: {}, scripts: [], badTags: []}; |
| } |
| if (!content) return state; |
| |
| // Note: we visit both script and link-imports together to ensure we |
| // preserve the order of the script tags as they are discovered. |
| var nodes = content.querySelectorAll('script,link[rel="import"]'); |
| for (var i = 0; i < nodes.length; i++) { |
| var node = nodes[i]; |
| if (node instanceof HTMLLinkElement) { |
| // TODO(jmesserly): figure out why ".import" fails in content_shell but |
| // works in Dartium. |
| if (node.import && node.import.href) node = node.import; |
| |
| if (state.seen[node.href]) continue; |
| state.seen[node.href] = node; |
| discoverScripts(node.import, state); |
| } else if (node instanceof HTMLScriptElement) { |
| if (node.type == 'application/dart;component=1') { |
| state.scripts.push(getScriptUrl(node)); |
| } |
| if (node.type == 'application/dart') { |
| state.badTags.push(node); |
| } |
| } |
| } |
| return state; |
| } |
| |
| // TODO(jmesserly): we're using this function because DOMContentLoaded can |
| // be fired too soon: https://www.w3.org/Bugs/Public/show_bug.cgi?id=23526 |
| HTMLImports.whenImportsReady(function() { |
| // Append a new script tag that initializes everything. |
| var newScript = document.createElement('script'); |
| newScript.type = "application/dart"; |
| |
| var results = discoverScripts(document); |
| if (results.badTags.length > 0) { |
| console.warn('Dartium currently only allows a single Dart script tag ' |
| + 'per application, and in the future it will run them in ' |
| + 'separtate isolates. To prepare for this all the following ' |
| + 'script tags need to be updated to use the mime-type ' |
| + '"application/dart;component=1" instead of "application/dart":'); |
| for (var i = 0; i < results.badTags.length; i++) { |
| console.warn(results.badTags[i]); |
| } |
| } |
| newScript.textContent = createMain(results.scripts); |
| document.body.appendChild(newScript); |
| }); |
| })(); |