1 // Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL]
4 import org.mozilla.javascript.*;
10 /** Simple implementation of a JavaScript host object.
12 * If privateVars is set, then any "var" declaration issued on this
13 * scope will create a variable visible only to scripts from the same
14 * directory (package) as the script that made the declaration.
16 * This is implemented by making JSObject.Top the ultimate
17 * parentScope of all privateVars-style JSObjects. Puts to JSObjects
18 * which are var-decls will not climb the scope chain, and will be
19 * put directly to the JSObject. Puts which are <i>not</i> var-decls
20 * will climb the scope chain and will be put to Top, which will then
21 * re-put the value to the JSObject as a global.
23 public class JSObject implements Scriptable {
25 // Static Data ///////////////////////////////////////////////////////////////////////
27 /** helper; retrieves the 'source code filename' (usually the nodeName) of the currently-executing function in this thread */
28 public static String getCurrentFunctionSourceName() {
29 Function cf = Context.getCurrentContext().currentFunction;
30 if (cf == null) return null;
31 return (cf instanceof InterpretedFunction) ?
32 ((InterpretedFunction)cf).getSourceName() : ((InterpretedScript)cf).getSourceName();
35 /** cache for nodeNameToPackageName(); prevents creation of zillions of String objects */
36 private static Hash nodeNameToPackageNameHash = new Hash(1000, 2);
38 /** converts a nodeName (source code filename) into the 'package name' (resource name of its directory) */
39 private static String nodeNameToPackageName(String nodeName) {
40 if (nodeName == null) return null;
41 String ret = (String)nodeNameToPackageNameHash.get(nodeName);
42 if (ret != null) return ret;
44 for(int i=0; i<ret.length() - 1; i++)
45 if (ret.charAt(i) == '.' && (ret.charAt(i + 1) == '_' || Character.isDigit(ret.charAt(i + 1)))) {
46 ret = ret.substring(0, i);
49 if (ret.lastIndexOf('.') != -1)
50 ret = ret.substring(0, ret.lastIndexOf('.'));
52 nodeNameToPackageNameHash.put(nodeName, ret);
56 /** this holds a scope which has been initialized with the standard ECMA objects */
57 public static Scriptable defaultObjects = Context.enter().initStandardObjects(null);
59 // Instance Data ///////////////////////////////////////////////////////////////////////
61 /** The properties that holds our scope */
62 protected Hash properties = null;
64 /** If true, put()s and delete()s are prohibited */
65 boolean sealed = false;
67 /** If true, variables declared with 'var' become visible only to scripts from the same
68 * directory/package as the one which created the variable
70 boolean privateVars = false;
73 public JSObject(boolean privateVars) { this.privateVars = privateVars; }
75 public Object get(String name, Scriptable start) {
76 if (name == null || name.equals("") || properties == null) return null;
78 Object ret = properties.get(name, nodeNameToPackageName(getCurrentFunctionSourceName()));
79 if (ret == NOT_FOUND) return null;
80 if (ret != null) return ret;
81 return properties.get(name, null);
84 /** returns the package-private variable <tt>name</tt> associated with <tt>nodeName</tt> */
85 public Object getPrivately(String name, String nodeName) {
86 return properties == null ? null : properties.get(name, nodeNameToPackageName(nodeName));
89 /** puts a property as a private variable, accessible only to scripts in the source code file <tt>nodeName</tt> */
90 public void putPrivately(String name, Object value, String nodeName) {
92 putGlobally(name, null, value);
95 if (properties == null) properties = new Hash();
97 // we use NOT_FOUND to mark a variable which exists as a script-local, yet has a value of null
98 if (value == null) value = NOT_FOUND;
99 properties.put(name, nodeNameToPackageName(nodeName), value);
102 /** forces a property to be put globally -- accessible to all scripts */
103 public void putGlobally(String name, Scriptable start, Object value) {
104 if (name == null || name.equals("")) return;
105 if (properties == null) properties = new Hash();
106 properties.put(name, null, value);
109 /** if a put is made directly to us (rather than cascading up to Top), it must be a var-declaration */
110 public void put(String name, Scriptable start, Object value) {
112 if (name == null || name.equals("")) return;
113 putPrivately(name, value, getCurrentFunctionSourceName());
116 /** if privateVars is enabled, we always return false, to see if the put propagates up to Top */
117 public boolean has(String name, Scriptable start) {
118 if (!privateVars) return properties != null && properties.get(name) != null;
119 Top.lastByThread.put(Thread.currentThread(), this);
123 public Object[] getIds() {
124 if (properties == null) return new Object[] { };
125 else return properties.keys();
128 /** Parent scope of all JSObjects; we use the has(String) method on this object to determine if a put represents a var-declaration or a plain 'ol put */
129 private static class Top implements Scriptable {
131 /** Last JSObject to perform a has(), keyed by thread.
132 * Assumes that every Top.has() is immediately preceded by a JSObject.has() in the same thread
134 public static Hash lastByThread = new Hash();
136 public static Top singleton = new Top();
139 public boolean has(String name, Scriptable start) { return true; }
140 public void put(String name, Scriptable start, Object value) {
141 JSObject last = (JSObject)lastByThread.get(Thread.currentThread());
142 if (last.properties != null && last.properties.get(name, nodeNameToPackageName(getCurrentFunctionSourceName())) != null)
143 last.put(name, start, value);
144 else last.putGlobally(name, start, value);
147 public Object get(String name, Scriptable start) {
149 // hack since Rhino needs to be able to grab these functions to create new objects
150 if (name.equals("Object")) return JSObject.defaultObjects.get("Object", null);
151 if (name.equals("Array")) return JSObject.defaultObjects.get("Array", null);
152 if (name.equals("Function")) return JSObject.defaultObjects.get("Function", null);
153 if (name.equals("TypeError")) return JSObject.defaultObjects.get("TypeError", null);
154 return ((JSObject)lastByThread.get(Thread.currentThread())).get(name, start);
158 public String getClassName() { return "Top"; }
159 public Scriptable construct(Context cx, Scriptable scope, java.lang.Object[] args) { return null; }
160 public void delete(String name) { }
161 public Scriptable getParentScope() { return null; }
162 public void setParentScope(Scriptable p) { }
163 public boolean hasInstance(Scriptable value) { return false; }
164 public Scriptable getPrototype() { return null; }
165 public void setPrototype(Scriptable p) { }
166 public void delete(int i) { }
167 public Object getDefaultValue(Class hint) { return "Top"; }
168 public void put(int i, Scriptable start, Object value) { }
169 public Object get(int i, Scriptable start) { return null; }
170 public boolean has(int i, Scriptable start) { return false; }
171 public Object[] getIds() { return new Object[] { }; }
176 // Trivial Methods ///////////////////////////////////////////////////////////
178 public void setSeal(boolean doseal) { sealed = doseal; }
179 public void flush() { if (properties != null) properties.clear(); }
180 public void delete(String name) { if (Log.on) Log.log(this, "JSObject.delete() should not be reachable"); }
181 public void delete(int i) { if (Log.on) Log.log(this, "JSObject.delete() should not be reachable"); }
182 public Scriptable getParentScope() { return privateVars ? Top.singleton : null; }
183 public void setParentScope(Scriptable p) { }
184 public boolean hasInstance(Scriptable value) { return false; }
185 public Scriptable getPrototype() { return null; }
186 public void setPrototype(Scriptable p) { }
187 public String getClassName() { return this.getClass().getName(); }
188 public Object getDefaultValue(Class hint) { return toString(); }
189 public void put(int i, Scriptable start, Object value) { }
190 public Object get(int i, Scriptable start) { return null; }
191 public boolean has(int i, Scriptable start) { return false; }