JSJson.java

/*
 * � Copyright IBM Corp. 2010
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); 
 * you may not use this file except in compliance with the License. 
 * You may obtain a copy of the License at:
 * 
 * http://www.apache.org/licenses/LICENSE-2.0 
 * 
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" BASIS, 
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 
 * implied. See the License for the specific language governing 
 * permissions and limitations under the License.
 */

package com.ibm.xsp.extlib.util;

import com.ibm.commons.util.io.json.JsonException;
import com.ibm.designer.runtime.DesignerRuntime;
import com.ibm.jscript.InterpretException;
import com.ibm.jscript.json.JsonJavaScriptFactory;
import com.ibm.jscript.std.ArrayObject;
import com.ibm.jscript.std.ObjectObject;
import com.ibm.jscript.types.FBSNull;
import com.ibm.jscript.types.FBSObject;
import com.ibm.jscript.types.FBSUndefined;
import com.ibm.jscript.types.FBSUtility;
import com.ibm.jscript.types.FBSValue;




/**
 * Some utility used to deal with JavaScript objects.
 */
public class JSJson {

    public static final JsonJavaScriptFactory factory = new JsonJavaScriptFactory(DesignerRuntime.getJSContext()); 

    private FBSObject value;
    
    public static final JSJson wrap(Object o) throws JsonException {
        if(o instanceof FBSNull) {
            return new JSJson();
        }
        if(o instanceof FBSUndefined) {
            return new JSJson();
        }
        if(o instanceof FBSObject) {
            return new JSJson((FBSObject)o);
        }
        throw new JsonException(null,"The value {0} is neither a JavaScript object or array"); // $NLX-JSJson.Thevalue0isneitheraJavaScriptobje-1$
    }
    public static final JSJson createObject() throws JsonException {
        return new JSJson(new ObjectObject());
    }
    public static final JSJson createArray() throws JsonException {
        return new JSJson(new ArrayObject());
    }

    // ==================================================================
    // Null value related methods
    
    protected JSJson() {
    }
    protected JSJson(FBSObject value) {
        this.value = value;
    }

    
    // ==================================================================
    // Null value related methods

    public boolean isNull() {
        return value==null;
    }
    public boolean isNotNull() {
        return value!=null;
    }
    
    
    // ==================================================================
    // Object related methods
    
    private FBSObject asObject() throws JsonException {
        if(value!=null) {
            return value;
        }
        throw new JsonException(null,"JavaScript value is not an object"); // $NLX-JSJson.JavaScriptvalueisnotanobject-1$
    }
    private FBSValue getProperty(String propertyName) throws JsonException {
        try {
            return asObject().get(propertyName);
        } catch(InterpretException ex) {
            throw new JsonException(ex,"Error while accessing object property {0}", propertyName); // $NLX-JSJson.Errorwhileaccessingobjectproperty-1$
        }
    }
    private void putProperty(String propertyName, FBSValue v) throws JsonException {
        try {
            asObject().put(propertyName,v);
        } catch(InterpretException ex) {
            throw new JsonException(ex,"Error while setting object property {0}", propertyName); // $NLX-JSJson.Errorwhilesettingobjectproperty0-1$
        }
    }

    public boolean isObject() {
        return value!=null;
    }

    public boolean exists(String propertyName) throws JsonException {
        FBSValue v=getProperty(propertyName);
        return !v.isUndefined(); 
    }
    
    
    public String getString(String propertyName) throws JsonException {
        FBSValue v = getProperty(propertyName);
        if(v.isUndefined() || v.isNull()) {
            return null;
        }
        return v.stringValue();
    }
    public void putString(String propertyName, String v) throws JsonException {
        putProperty(propertyName, FBSUtility.wrap(v));
    }
    
    public int getInt(String propertyName) throws JsonException {
        return getProperty(propertyName).intValue();
    }
    public void putInt(String propertyName, int v) throws JsonException {
        putProperty(propertyName, FBSUtility.wrap(v));
    }
    
    public long getLong(String propertyName) throws JsonException {
        return getProperty(propertyName).longValue();
    }
    public void putLong(String propertyName, long v) throws JsonException {
        putProperty(propertyName, FBSUtility.wrap(v));
    }
    
    public double getDouble(String propertyName) throws JsonException {
        return getProperty(propertyName).doubleValue();
    }
    public void putDouble(String propertyName, double v) throws JsonException {
        putProperty(propertyName, FBSUtility.wrap(v));
    }

    public boolean getBoolean(String propertyName) throws JsonException {
        return getProperty(propertyName).booleanValue();
    }
    public void putBoolean(String propertyName, boolean v) throws JsonException {
        putProperty(propertyName, FBSUtility.wrap(v));
    }

    public JSJson getObject(String propertyName) throws JsonException {
        FBSValue o = getProperty(propertyName);
        if(o.isObject()) {
            return new JSJson((FBSObject)o);
        } else if(o.isArray()) {
            return new JSJson((ArrayObject)o);
        } else if(o.isNull() || o.isUndefined()) {
            return new JSJson();
        }
        throw new JsonException(null,"Property {0} is not an object",propertyName); // $NLX-JSJson.Property0isnotanobject-1$
    }
    public void putObject(String propertyName, JSJson object) throws JsonException {
        if(value!=null) {
            putProperty(propertyName, value);
        } else {
            putProperty(propertyName, FBSNull.nullValue);
        }
    }

    
    
    // ==================================================================
    // Array related methods
    private ArrayObject asArray() throws JsonException {
        if(value instanceof ArrayObject) {
            return (ArrayObject)value;
        }
        throw new JsonException(null,"JavaScript value is not an array"); // $NLX-JSJson.JavaScriptvalueisnotanarray-1$
    }
    private FBSValue getProperty(int index) throws JsonException {
        try {
            return asArray().get(index);
        } catch(InterpretException ex) {
            throw new JsonException(ex,"Error while accessing indexed property {0}", index); // $NLX-JSJson.Errorwhileaccessingindexedpropert-1$
        }
    }
    private void putProperty(int index, FBSValue v) throws JsonException {
        asArray().put(index,v);
    }

    public boolean isArray() {
        return value instanceof ArrayObject;
    }

    public int getArrayLength() throws JsonException {
        return asArray().getArrayLength();
    }
    
    public String getString(int index) throws JsonException {
        return getProperty(index).stringValue();
    }
    public void putString(int index, String v) throws JsonException {
        putProperty(index, FBSUtility.wrap(v));
    }
    
    public int getInt(int index) throws JsonException {
        return getProperty(index).intValue();
    }
    public void putInt(int index, int v) throws JsonException {
        putProperty(index, FBSUtility.wrap(v));
    }
    
    public long getLong(int index) throws JsonException {
        return getProperty(index).longValue();
    }
    public void putLong(int index, long v) throws JsonException {
        putProperty(index, FBSUtility.wrap(v));
    }
    
    public double getDouble(int index) throws JsonException {
        return getProperty(index).doubleValue();
    }
    public void putDouble(int index, double v) throws JsonException {
        putProperty(index, FBSUtility.wrap(v));
    }

    public boolean getBoolean(int index) throws JsonException {
        return getProperty(index).booleanValue();
    }
    public void putBoolean(int index, boolean v) throws JsonException {
        putProperty(index, FBSUtility.wrap(v));
    }

    public JSJson getObject(int index) throws JsonException {
        FBSValue o = getProperty(index);
        if(o.isObject()) {
            return new JSJson((FBSObject)o);
        } else if(o.isArray()) {
            return new JSJson((ArrayObject)o);
        } else if(o.isNull()) {
            return new JSJson();
        }
        throw new JsonException(null,"Index {0} is not an object",index); // $NLX-JSJson.Index0isnotanobject-1$
    }
    public void putObject(int index, JSJson object) throws JsonException {
        if(value!=null) {
            putProperty(index, value);
        } else {
            putProperty(index, FBSNull.nullValue);
        }
    }   
}