Alternate status page

pkg/analysis_server/lib/src/status/ast_writer.dart

+// Copyright (c) 2015, 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.
+
+library analysis_server.src.status.ast_writer;
+
+import 'package:analysis_server/src/status/utilities.dart';
+import 'package:analyzer/src/generated/ast.dart';
+
+/**
+ * A visitor that will produce an HTML representation of an AST structure.
+ */
+class AstWriter extends UnifyingAstVisitor {
+  /**
+   * The buffer on which the HTML is to be written.
+   */
+  final StringBuffer buffer;
+
+  /**
+   * The current level of indentation.
+   */
+  int indentLevel = 0;
+
+  /**
+   * Initialize a newly created element writer to write the HTML representation
+   * of visited nodes on the given [buffer].
+   */
+  AstWriter(this.buffer);
+
+  @override
+  void visitNode(AstNode node) {
+    _writeNode(node);
+    indentLevel++;
+    try {
+      node.visitChildren(this);
+    } finally {
+      indentLevel--;
+    }
+  }
+
+  /**
+   * Return the name of the given [node], or `null` if the given node is not a
+   * declaration.
+   */
+  String _getName(AstNode node) {
+    if (node is ClassTypeAlias) {
+      return node.name.name;
+    } else if (node is ClassDeclaration) {
+      return node.name.name;
+    } else if (node is ConstructorDeclaration) {
+      if (node.name == null) {
+        return node.returnType.name;
+      } else {
+        return node.returnType.name + '.' + node.name.name;
+      }
+    } else if (node is ConstructorName) {
+      return node.toSource();
+    } else if (node is FieldDeclaration) {
+      return _getNames(node.fields);
+    } else if (node is FunctionDeclaration) {
+      SimpleIdentifier nameNode = node.name;
+      if (nameNode != null) {
+        return nameNode.name;
+      }
+    } else if (node is FunctionTypeAlias) {
+      return node.name.name;
+    } else if (node is Identifier) {
+      return node.name;
+    } else if (node is MethodDeclaration) {
+      return node.name.name;
+    } else if (node is TopLevelVariableDeclaration) {
+      return _getNames(node.variables);
+    } else if (node is TypeName) {
+      return node.toSource();
+    } else if (node is TypeParameter) {
+      return node.name.name;
+    } else if (node is VariableDeclaration) {
+      return node.name.name;
+    }
+    return null;
+  }
+
+  /**
+   * Return a string containing a comma-separated list of the names of all of
+   * the variables in the given list of [variables].
+   */
+  String _getNames(VariableDeclarationList variables) {
+    StringBuffer buffer = new StringBuffer();
+    bool first = true;
+    for (VariableDeclaration variable in variables.variables) {
+      if (first) {
+        first = false;
+      } else {
+        buffer.write(', ');
+      }
+      buffer.write(variable.name.name);
+    }
+    return buffer.toString();
+  }
+
+  void _indent([int extra = 0]) {
+    for (int i = 0; i < indentLevel; i++) {
+      buffer.write('&#x250A;&nbsp;&nbsp;&nbsp;');
+    }
+    if (extra > 0) {
+      buffer.write('&#x250A;&nbsp;&nbsp;&nbsp;');
+      for (int i = 1; i < extra; i++) {
+        buffer.write('&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;');
+      }
+    }
+  }
+
+  /**
+   * Write a representation of the given [node] to the buffer.
+   */
+  void _writeNode(AstNode node) {
+    _indent();
+    buffer.write(node.runtimeType);
+    buffer.write(' <span style="color:gray">[');
+    buffer.write(node.offset);
+    buffer.write('..');
+    buffer.write(node.offset + node.length - 1);
+    buffer.write(']</span>');
+    buffer.write('<br>');
+    _writeProperty('name', _getName(node));
+    if (node is BinaryExpression) {
+      _writeProperty('static element', node.staticElement);
+      _writeProperty('static type', node.staticType);
+      _writeProperty('propagated element', node.propagatedElement);
+      _writeProperty('propagated type', node.propagatedType);
+    } else if (node is CompilationUnit) {
+      _writeProperty("element", node.element);
+    } else if (node is ExportDirective) {
+      _writeProperty("element", node.element);
+    } else if (node is FunctionExpressionInvocation) {
+      _writeProperty('static element', node.staticElement);
+      _writeProperty('static type', node.staticType);
+      _writeProperty('propagated element', node.propagatedElement);
+      _writeProperty('propagated type', node.propagatedType);
+    } else if (node is ImportDirective) {
+      _writeProperty("element", node.element);
+    } else if (node is LibraryDirective) {
+      _writeProperty("element", node.element);
+    } else if (node is PartDirective) {
+      _writeProperty("element", node.element);
+    } else if (node is PartOfDirective) {
+      _writeProperty("element", node.element);
+    } else if (node is PostfixExpression) {
+      _writeProperty('static element', node.staticElement);
+      _writeProperty('static type', node.staticType);
+      _writeProperty('propagated element', node.propagatedElement);
+      _writeProperty('propagated type', node.propagatedType);
+    } else if (node is PrefixExpression) {
+      _writeProperty('static element', node.staticElement);
+      _writeProperty('static type', node.staticType);
+      _writeProperty('propagated element', node.propagatedElement);
+      _writeProperty('propagated type', node.propagatedType);
+    } else if (node is SimpleIdentifier) {
+      _writeProperty('static element', node.staticElement);
+      _writeProperty('static type', node.staticType);
+      _writeProperty('propagated element', node.propagatedElement);
+      _writeProperty('propagated type', node.propagatedType);
+    } else if (node is SimpleStringLiteral) {
+      _writeProperty("value", node.value);
+    } else if (node is Expression) {
+      _writeProperty('static type', node.staticType);
+      _writeProperty('propagated type', node.propagatedType);
+    }
+  }
+
+  /**
+   * Write the [value] of the property with the given [name].
+   */
+  void _writeProperty(String name, Object value) {
+    if (value != null) {
+      _indent(2);
+      buffer.write('$name = ');
+      buffer.write(encodeHtml(value.toString()));
+      buffer.write('<br>');
+    }
+  }
+}