Add JSNative utility class with static methods methods to efficiently manipulate typed JSInterop ob…

sdk/lib/js/dartium/js_dartium.dart

 // Copyright (c) 2013, 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.
 
 /**
  * Support for interoperating with JavaScript.
  *
  * This library provides access to JavaScript objects from Dart, allowing
  * Dart code to get and set properties, and call methods of JavaScript objects
  * and invoke JavaScript functions. The library takes care of converting
@@ skipping 120 matching lines @@
 }
 
 final _allowedMethods = new Map<Symbol, _DeclarationSet>();
 final _allowedGetters = new Map<Symbol, _DeclarationSet>();
 final _allowedSetters = new Map<Symbol, _DeclarationSet>();
 
 final _jsInterfaceTypes = new Set<mirrors.ClassMirror>();
 @Deprecated("Internal Use Only")
 Iterable<mirrors.ClassMirror> get jsInterfaceTypes => _jsInterfaceTypes;
 
+class _StringLiteralEscape {
+  // Character code constants.
+  static const int BACKSPACE       = 0x08;
+  static const int TAB             = 0x09;
+  static const int NEWLINE         = 0x0a;
+  static const int CARRIAGE_RETURN = 0x0d;
+  static const int FORM_FEED       = 0x0c;
+  static const int QUOTE           = 0x22;
+  static const int CHAR_$          = 0x24;
+  static const int CHAR_0          = 0x30;
+  static const int BACKSLASH       = 0x5c;
+  static const int CHAR_b          = 0x62;
+  static const int CHAR_f          = 0x66;
+  static const int CHAR_n          = 0x6e;
+  static const int CHAR_r          = 0x72;
+  static const int CHAR_t          = 0x74;
+  static const int CHAR_u          = 0x75;
+
+  final StringSink _sink;
+
+  _StringLiteralEscape(this._sink);
+
+  void writeString(String string) {
+    _sink.write(string);
+  }
+
+  void writeStringSlice(String string, int start, int end) {
+    _sink.write(string.substring(start, end));
+  }
+
+  void writeCharCode(int charCode) {
+    _sink.writeCharCode(charCode);
+  }
+
+  /// ('0' + x) or ('a' + x - 10)
+  static int hexDigit(int x) => x < 10 ? 48 + x : 87 + x;
+
+  /// Write, and suitably escape, a string's content as a JSON string literal.
+  void writeStringContent(String s) {
+    // Identical to JSON string lieral escaping except that we also escape $.

[sra1, 2016/07/22 20:16:32]

lieral?

[Jacob, 2016/07/25 16:31:58]

Done.

+    int offset = 0;
+    final int length = s.length;
+    for (int i = 0; i < length; i++) {
+      int charCode = s.codeUnitAt(i);
+      if (charCode > BACKSLASH) continue;
+      if (charCode < 32) {
+        if (i > offset) writeStringSlice(s, offset, i);
+        offset = i + 1;
+        writeCharCode(BACKSLASH);
+        switch (charCode) {
+        case BACKSPACE:
+          writeCharCode(CHAR_b);
+          break;
+        case TAB:
+          writeCharCode(CHAR_t);
+          break;
+        case NEWLINE:
+          writeCharCode(CHAR_n);
+          break;
+        case FORM_FEED:
+          writeCharCode(CHAR_f);
+          break;
+        case CARRIAGE_RETURN:
+          writeCharCode(CHAR_r);
+          break;
+        default:
+          writeCharCode(CHAR_u);
+          writeCharCode(CHAR_0);
+          writeCharCode(CHAR_0);
+          writeCharCode(hexDigit((charCode >> 4) & 0xf));
+          writeCharCode(hexDigit(charCode & 0xf));
+          break;
+        }
+      } else if (charCode == QUOTE || charCode == BACKSLASH || charCode == CHAR_$) {

[sra1, 2016/07/22 20:16:32]

line length

[Jacob, 2016/07/25 16:31:58]

done. ran dartfmt

+        if (i > offset) writeStringSlice(s, offset, i);
+        offset = i + 1;
+        writeCharCode(BACKSLASH);
+        writeCharCode(charCode);
+      }
+    }
+    if (offset == 0) {
+      writeString(s);
+    } else if (offset < length) {
+      writeStringSlice(s, offset, length);
+    }
+  }
+
+  /**
+   * Serialize a [num], [String], [bool], [Null], [List] or [Map] value.
+   *
+   * Returns true if the value is one of these types, and false if not.
+   * If a value is both a [List] and a [Map], it's serialized as a [List].

[sra1, 2016/07/22 20:16:32]

This comment is wrong.

+   */
+  bool writeStringLiteral(String str) {

[sra1, 2016/07/22 20:16:32]

Doesn't return anything.

[Jacob, 2016/07/25 16:31:58]

Done.

+    writeString('"');
+    writeStringContent(str);
+    writeString('"');
+  }
+}
+
+String _escapeString(String str) {
+  StringBuffer output = new StringBuffer();
+  new _StringLiteralEscape(output)..writeStringLiteral(str);
+  return output.toString();

[sra1, 2016/07/22 20:16:32]

Could you use the JSON codec rather than copy & paste the code?

[Jacob, 2016/07/25 16:31:58]

Can't easily because of $
JSON doesn't need to escape $ but Dart string literals do.
I could do a two pass approach where I JSON encode and then find and replace $
with \$ but that would be a bit slower and feels a little fragile. 
This code should not live that long so I'm not as worried about a little copy
and pasting than I would be otherwise.

+}
+
 /// A collection of methods where all methods have the same name.
 /// This class is intended to optimize whether a specific invocation is
 /// appropritate for at least some of the methods in the collection.
 class _DeclarationSet {
   _DeclarationSet() : _members = <mirrors.DeclarationMirror>[];
 
   static bool _checkType(obj, mirrors.TypeMirror type) {
     if (obj == null) return true;
     return mirrors.reflectType(obj.runtimeType).isSubtypeOf(type);
   }
@@ skipping 211 matching lines @@
 final _UNDEFINED_VAR = "_UNDEFINED_JS_CONST";
 
 String _accessJsPath(String path) => _accessJsPathHelper(path.split("."));
 
 String _accessJsPathHelper(Iterable<String> parts) {
   var sb = new StringBuffer();
   sb
     ..write('${_JS_LIBRARY_PREFIX}.JsNative.getProperty(' * parts.length)
     ..write("${_JS_LIBRARY_PREFIX}.context");
   for (var p in parts) {
-    sb.write(", '$p')");
+    sb.write(", ${_escapeString(p)})");
   }
   return sb.toString();
 }
 
 // TODO(jacobr): remove these helpers and add JsNative.setPropertyDotted,
 // getPropertyDotted, and callMethodDotted helpers that would be simpler
 // and more efficient.
 String _accessJsPathSetter(String path) {
   var parts = path.split(".");
   return "${_JS_LIBRARY_PREFIX}.JsNative.setProperty(${_accessJsPathHelper(parts.getRange(0, parts.length - 1))
-      }, '${parts.last}', v)";
+      }, ${_escapeString(parts.last)}, v)";
 }
 
 String _accessJsPathCallMethodHelper(String path) {
   var parts = path.split(".");
   return "${_JS_LIBRARY_PREFIX}.JsNative.callMethod(${_accessJsPathHelper(parts.getRange(0, parts.length - 1))
-      }, '${parts.last}',";
+      }, ${_escapeString(parts.last)},";
 }
 
 @Deprecated("Internal Use Only")
 void addMemberHelper(
     mirrors.MethodMirror declaration, String path, StringBuffer sb,
     {bool isStatic: false, String memberName}) {
   if (!declaration.isConstructor) {
     var jsName = _getJsMemberName(declaration);
     path = (path != null && path.isNotEmpty) ? "${path}.${jsName}" : jsName;
   }
@@ skipping 159 matching lines @@
                 sbPatch.write(") {\n"
                     "    var ret = ${_JS_LIBRARY_PREFIX}.JsNative.newObject();\n");
                 i = 0;
                 for (var p in declaration.parameters) {
                   assert(p.isNamed); // TODO(jacobr): throw.
                   var name = args[i];
                   var jsName = _stripReservedNamePrefix(
                       mirrors.MirrorSystem.getName(p.simpleName));
                   sbPatch.write("    if($name != ${_UNDEFINED_VAR}) {\n"
                       "      ${_JS_LIBRARY_PREFIX}.safeForTypedInterop($name);\n"
-                      "      ${_JS_LIBRARY_PREFIX}.JsNative.setProperty(ret, '$jsName', $name);\n"
+                      "      ${_JS_LIBRARY_PREFIX}.JsNative.setProperty(ret, ${_escapeString(jsName)}, $name);\n"
                       "    }\n");
                   i++;
                 }
 
                 sbPatch.write(
                   "  return ret;"
                   "}\n");
               } else if (declaration.isConstructor ||
                   declaration.isFactoryConstructor) {
                 sbPatch.write("  ");
@@ skipping 757 matching lines @@
 
   static toTypedObject(JsObject o) native "JSNative_toTypedObject";
 
   /**
    * Same behavior as new JsFunction.withThis except that JavaScript "this" is not
    * wrapped.
    */
   static JSFunction withThis(Function f) native "JsFunction_withThisNoWrap";
 }
 
-/// Utility methods to efficiently manipulate typed JSInterop objects in cases
-/// where the name to call is not known at runtime. You should only use these
-/// methods when the same effect cannot be achieved with @JS annotations.
-/// These methods would be extension methods on JSObject if Dart supported
-/// extension methods.
-class JSNative {
-   /**
-    * WARNING: performance of this method is much worse than other methods
-    * in JSNative. Only use this method as a last resort.
-    *
-    * Recursively converts a JSON-like collection of Dart objects to a
-    * collection of JavaScript objects and returns a [JsObject] proxy to it.
-    *
-    * [object] must be a [Map] or [Iterable], the contents of which are also
-    * converted. Maps and Iterables are copied to a new JavaScript object.
-    * Primitives and other transferrable values are directly converted to their
-    * JavaScript type, and all other objects are proxied.
-    */
-  static jsify(object) {
-    if ((object is! Map) && (object is! Iterable)) {
-      throw new ArgumentError("object must be a Map or Iterable");
-    }
-    return _jsify(object);
-  }
-
-  static _jsify(object) native "JSObject_jsify";
-  static JSObject newObject() native "JSObject_newObject";
-
-  static hasProperty(JSObject o, name) => o._hasProperty(name);
-  static getProperty(JSObject o, name) => o._operator_getter(name);
-  static setProperty(JSObject o, name, value) => o._operator_setter(name, value);
-  static callMethod(JSObject o, String method, List args) => o._callMethod(method, args);
-  static instanceof(JSObject o, Function type) => o._instanceof(type);
-  static callConstructor(JSObject constructor, List args) native "JSNative_callConstructor";
-}
-
 /**
  * Proxies a JavaScript Function object.
  */
 class JsFunction extends JsObject {
   JsFunction.internal() : super.internal();
 
   /**
    * Returns a [JsFunction] that captures its 'this' binding and calls [f]
    * with the value of this passed as the first argument.
    */
@@ skipping 213 matching lines @@
   } else {
     var ret = _interopCaptureThisExpando[f];
     if (ret == null) {
       // TODO(jacobr): we could optimize this.
       ret = JSFunction._createWithThis(f);
       _interopCaptureThisExpando[f] = ret;
     }
     return ret;
   }
 }