Reducing the amount of code we generate in the compiler: We still continue

lib/src/emitters.dart

 // Copyright (c) 2012, 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.
 
 /** Collects several code emitters for the template tool. */
 library emitters;
 
 import 'package:csslib/parser.dart' as css;
 import 'package:csslib/visitor.dart';
 import 'package:html5lib/dom.dart';
 import 'package:html5lib/dom_parsing.dart';
 import 'package:html5lib/parser.dart';
 import 'package:source_maps/span.dart' show Span, FileLocation;
 
+import 'code_printer.dart';
 import 'compiler.dart';
-import 'code_printer.dart';
 import 'dart_parser.dart' show DartCodeInfo;
+import 'html5_utils.dart';
 import 'html_css_fixup.dart';
-import 'html5_utils.dart';
 import 'info.dart';
 import 'messages.dart';
+import 'options.dart';
 import 'paths.dart';
 import 'refactor.dart';
 import 'utils.dart';
 
-/**
- * Context used by an emitter. Typically representing where to generate code
- * and additional information, such as total number of generated identifiers.
- */
-class Context {
-  final Declarations statics;
-  final CodePrinter printer;
-  final bool isClass;
-
-  Context({Declarations statics, CodePrinter printer, bool isClass: false,
-           int indent: 0})
-      : this.statics = statics != null
-            ? statics : new Declarations(indent, staticKeyword: isClass),
-        this.isClass = isClass,
-        this.printer = printer != null
-            ? printer : new CodePrinter(isClass ? indent + 1 : indent);
-}
-
 
 /** Only x-tag name element selectors are emitted as [is="x-"]. */
 class CssEmitter extends CssPrinter {
   final Set _componentsTag;
 
   CssEmitter(this._componentsTag);
 
   /**
    * If element selector is a component's tag name, then change selector to
    * find element who's is attribute's the component's name.
@@ skipping 138 matching lines @@
 String emitComponentStyleSheet(StyleSheet ss, String tagName,
                                CssPolyfillKind polyfillKind) =>
   (new ComponentCssEmitter(tagName, polyfillKind)
       ..visitTree(ss, pretty: true)).toString();
 
 /** Generates the class corresponding to a single web component. */
 class WebComponentEmitter {
   final Messages messages;
   final FileInfo _fileInfo;
   final CssPolyfillKind cssPolyfillKind;
-  Context _context;
 
-  WebComponentEmitter(this._fileInfo, this.messages, this.cssPolyfillKind)
-      : _context = new Context(isClass: true, indent: 1);
+  WebComponentEmitter(this._fileInfo, this.messages, this.cssPolyfillKind);
 
   CodePrinter run(ComponentInfo info, PathMapper pathMapper,
       TextEditTransaction transaction) {
-    var templateNode = info.elementNode;
+    var templateNode = info.element.nodes.firstWhere(
+        (n) => n.tagName == 'template', orElse: () => null);
 
-    // elementNode is pointing at template tag (no attributes).
-    assert(templateNode.tagName == 'element');
-    for (var node in templateNode.nodes) {
-      if (node.tagName == 'template') {
-        templateNode = node;
-        break;
-      }
-    }
-
-    if (info.element.attributes['apply-author-styles'] != null) {
-      _context.printer.addLine('if (__root is autogenerated.ShadowRoot) '
-          '__root.applyAuthorStyles = true;');
-      // TODO(jmesserly): warn at runtime if apply-author-styles was not set,
-      // and we don't have Shadow DOM support? In that case, styles won't have
-      // proper encapsulation.
-    }
-
-    if (templateNode.tagName == 'template') {
+    if (templateNode != null) {
       if (!info.styleSheets.isEmpty && !messages.options.processCss) {
         // TODO(terry): Only one style tag per component.
 
         // TODO(jmesserly): csslib + html5lib should work together.
         // We shouldn't need to call a different function to serialize CSS.
         // Calling innerHtml on a StyleElement should be enought - like a real
         // browser. CSSOM and DOM should work together in the same tree.
         var styleText = emitComponentStyleSheet(
             info.styleSheets[0], info.tagName, cssPolyfillKind);
 
         templateNode.insertBefore(
             new Element.html('<style>\n$styleText\n</style>'),
             templateNode.hasChildNodes() ? templateNode.children[0] : null);
       }
-
-      _context.statics.add('final', '__shadowTemplate',
-          templateNode.sourceSpan,
-          "new autogenerated.DocumentFragment.html('''"
-          "${escapeDartString(templateNode.innerHtml, triple: true)}"
-          "''')");
-
-      var syntax = templateNode.attributes['syntax'];
-      if (syntax != null) {
-        syntax = escapeDartString(syntax);
-        syntax = ", autogenerated.TemplateElement.syntax['$syntax']";
-      } else {
-        syntax = "";
-      }
-
-      _context.printer
-          ..addLine("__root.nodes.add(cloneTemplate(__shadowTemplate));")
-          ..addLine("autogenerated_mdv.bindModel(__root, this$syntax);");
     }
 
     bool hasExtends = info.extendsComponent != null;
     var codeInfo = info.userCode;
     var classDecl = info.classDeclaration;
     if (classDecl == null) return null;
 
     if (transaction == null) {
       transaction = new TextEditTransaction(codeInfo.code, codeInfo.sourceFile);
     }
 
     // Expand the headers to include polymer imports, unless they are already
     // present.
     var libraryName = (codeInfo.libraryName != null)
         ? codeInfo.libraryName
         : info.tagName.replaceAll(new RegExp('[-./]'), '_');
     var header = new CodePrinter(0);
     header.add(_header(path.basename(info.declaringFile.inputUrl.resolvedPath),
         libraryName));
     emitImports(codeInfo, info, pathMapper, header);
     header.addLine('');
     transaction.edit(0, codeInfo.directivesEnd, header);
 
-    var mangle = cssPolyfillKind == CssPolyfillKind.MANGLED_POLYFILL;
-    var cssMapExpression = createCssSelectorsExpression(info, mangle);
     var classBody = new CodePrinter(1)
         ..add('\n')
-        ..addLine('/** Autogenerated from the template. */')
-        ..addLine('')
-        // TODO(terry): Remove [_css]; after migrating to getScopedCss.
-        ..addLine('autogenerated.ScopedCssMapper _css;')
-        ..addLine('')
-        ..addLine('/** This field is deprecated, use getShadowRoot instead. */')
-        ..addLine('get _root => getShadowRoot("${info.tagName}");')
-        ..add(_context.statics)
-        ..addLine('')
-        ..addLine('void initShadow() {')
-        ..addLine(hasExtends ? '  super.initShadow();' : null)
-        ..addLine('  var __root = createShadowRoot("${info.tagName}");')
-        ..addLine('  shadowRootReady(__root, "${info.tagName}");')
-        ..addLine('  setScopedCss("${info.tagName}", '
-            'new autogenerated.ScopedCssMapper($cssMapExpression));')
-        // TODO(terry): Remove assignment after migrating to getScopedCss.
-        ..addLine('  _css = getScopedCss("${info.tagName}");')
-        ..add(_context.printer)
-        ..addLine('}')
-        ..addLine('')
         ..addLine('/** Original code from the component. */');
 
     var pos = classDecl.leftBracket.end;
     transaction.edit(pos, pos, classBody);
 
     // Emit all the code in a single printer, keeping track of source-maps.
     return transaction.commit();
   }
 }
 
-/** Generates the class corresponding to the main html page. */
-class EntryPointEmitter {
-  final GlobalInfo global;
-  final FileInfo _fileInfo;
-  Context _context;
+/** The code that will be used to bootstrap the application. */
+CodePrinter generateBootstrapCode(
+    FileInfo info, FileInfo userMainInfo, GlobalInfo global,
+    PathMapper pathMapper, CompilerOptions options) {
 
-  EntryPointEmitter(this._fileInfo, this.global)
-      : _context = new Context(indent: 1);
+  var printer = new CodePrinter(0)
+      ..addLine('library app_bootstrap;')
+      ..addLine('')
+      ..addLine("import 'package:polymer/polymer.dart' as polymer;");
 
-  CodePrinter run(PathMapper pathMapper, TextEditTransaction transaction,
-      bool rewriteUrls) {
+  if (userMainInfo.userCode != null) {
+    printer..addLine('')
+        ..addLine("import '${pathMapper.importUrlFor(info, userMainInfo)}' "
+            "as userMain;\n");
+  }
 
-    var filePath = _fileInfo.inputUrl.resolvedPath;
+  for (var c in global.components.values) {
+    if (c.hasConflict) continue;
+    printer.addLine("import '${pathMapper.importUrlFor(info, c)}';");
+  }
 
-    var codeInfo = _fileInfo.userCode;
-    if (codeInfo == null) {
-      assert(transaction == null);
-      codeInfo = new DartCodeInfo(null, null, [], 'main(){\n}', null);
-    }
+  printer..addLine('')
+      ..addLine('void main() {')
+      ..indent += 1;
 
-    if (transaction == null) {
-      transaction = new TextEditTransaction(codeInfo.code, codeInfo.sourceFile);
-    }
+  if (userMainInfo.userCode != null) printer.addLine('userMain.main();');
 
-    var libraryName = codeInfo.libraryName != null
-        ? codeInfo.libraryName : _fileInfo.libraryName;
-    var header = new CodePrinter(0);
-    header.add(_header(path.basename(filePath), libraryName));
-    emitImports(codeInfo, _fileInfo, pathMapper, header, global);
-    header..addLine('')
-          ..addLine('')
-          ..addLine('// Original code');
-    transaction.edit(0, codeInfo.directivesEnd, header);
+  for (var c in global.components.values) {
+    if (c.hasConflict) continue;
+    var tagName = escapeDartString(c.tagName);
+    var cssMapExpression = createCssSelectorsExpression(c,
+        CssPolyfillKind.of(options, c));
+    printer
+        ..addLine("polymer.setScopedCss('$tagName', $cssMapExpression);")
+        ..addLine("polymer.registerPolymerElement("
+            "'$tagName', () => new ${c.className}());");
+  }
 
-    var printer = (transaction.commit())
-        ..addLine('')
-        ..addLine('// Additional generated code')
-        ..addLine('void init_autogenerated() {')
-        ..indent += 1;
+  return printer
+      ..indent -= 1
+      ..addLine('}');
+}
 
-    for (var c in global.components.values) {
-      if (c.hasConflict) continue;
-      var tagName = escapeDartString(c.tagName);
 
-      printer.addLine("autogenerated.registerPolymerElement("
-        "new autogenerated.Element.html("
-            "'${escapeDartString(c.elementNode.outerHtml)}')"
-        ", () => new ${c.className}());");
-    }
-
-    return printer
-        ..add(_context.statics)
-        ..add(_context.printer)
-        ..indent -= 1
-        ..addLine('}');
-  }
-}
 
 /**
  * List of HTML4 elements which could have relative URL resource:
  *
  * <body background=url>, <img src=url>, <input src=url>
  *
  * HTML 5:
  *
  * <audio src=url>, <command icon=url>, <embed src=url>,
  * <source src=url>, <video poster=url> and <video src=url>
@@ skipping 59 matching lines @@
   var file = codeInfo.sourceFile;
   for (var d in codeInfo.directives) {
     addUnique(d.toString(), file != null ? file.location(d.offset) : null);
   }
 }
 
 final shadowDomJS = new RegExp(r'shadowdom\..*\.js', caseSensitive: false);
 
 /** Trim down the html for the main html page. */
 void transformMainHtml(Document document, FileInfo fileInfo,
-    PathMapper pathMapper, bool hasCss, bool rewriteUrls, Messages messages) {
+    PathMapper pathMapper, bool hasCss, bool rewriteUrls,
+    Messages messages, GlobalInfo global) {
   var filePath = fileInfo.inputUrl.resolvedPath;
 
   bool dartLoaderFound = false;
   bool shadowDomFound = false;
   for (var tag in document.queryAll('script')) {
     var src = tag.attributes['src'];
     if (src != null) {
       var last = src.split('/').last;
       if (last == 'dart.js' || last == 'testing.js') {
         dartLoaderFound = true;
       } else if (shadowDomJS.hasMatch(last)) {
         shadowDomFound = true;
       }
     }
     if (tag.attributes['type'] == 'application/dart') {
       tag.remove();
     } else if (src != null && rewriteUrls) {
       tag.attributes["src"] = pathMapper.transformUrl(filePath, src);
     }
   }
+
   for (var tag in document.queryAll('link')) {
     var href = tag.attributes['href'];
     var rel = tag.attributes['rel'];
     if (rel == 'component' || rel == 'components' || rel == 'import') {
       tag.remove();
     } else if (href != null && rewriteUrls && !hasCss) {
       // Only rewrite URL if rewrite on and we're not CSS polyfilling.
       tag.attributes['href'] = pathMapper.transformUrl(filePath, href);
     }
   }
@@ skipping 20 matching lines @@
     for (var i = styles.length - 1; i > 0 ; i--) {
       styles[i].remove();
     }
   }
 
   // TODO(jmesserly): put this in the global CSS file?
   // http://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/templates/index.html#css-additions
   document.head.nodes.insert(0, parseFragment(
       '<style>template { display: none; }</style>'));
 
+  // Move all <element> declarations to the main HTML file
+  // TODO(sigmund): remove this once we have HTMLImports implemented.
+  for (var c in global.components.values) {
+    document.body.nodes.insert(0, new Text('\n'));
+    var fragment = c.element;
+    for (var tag in fragment.queryAll('script')) {
+      // TODO(sigmund): leave script tags around when we start using "boot.js"
+      if (tag.attributes['type'] == 'application/dart') {
+        tag.remove();
+      }
+    }
+    document.body.nodes.insert(0, fragment);
+  }
+
+
   if (!shadowDomFound) {
     // TODO(jmesserly): we probably shouldn't add this automatically.
     document.body.nodes.add(parseFragment('<script type="text/javascript" '
         'src="packages/shadow_dom/shadow_dom.debug.js"></script>\n'));
   }
   if (!dartLoaderFound) {
     // TODO(jmesserly): turn this warning on.
     //messages.warning('Missing script to load Dart. '
     //    'Please add this line to your HTML file: $dartLoader',
     //    document.body.sourceSpan);
+    // TODO(sigmund): switch to 'boot.js'
     document.body.nodes.add(parseFragment('<script type="text/javascript" '
         'src="packages/browser/dart.js"></script>\n'));
   }
 
   // Insert the "auto-generated" comment after the doctype, otherwise IE will
   // go into quirks mode.
   int commentIndex = 0;
   DocumentType doctype = find(document.nodes, (n) => n is DocumentType);
   if (doctype != null) {
     commentIndex = document.nodes.indexOf(doctype) + 1;
@@ skipping 20 matching lines @@
 // Auto-generated from $filename.
 // DO NOT EDIT.
 $lib
 import 'dart:html' as autogenerated;
 import 'dart:svg' as autogenerated_svg;
 import 'package:mdv/mdv.dart' as autogenerated_mdv;
 import 'package:observe/observe.dart' as __observe;
 import 'package:polymer/polymer.dart' as autogenerated;
 """;
 }