org.tinygroup.jspengine.el.parser.AstIdentifier Maven / Gradle / Ivy

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/**
 *  Copyright (c) 1997-2013, www.tinygroup.org ([email protected]).
 *
 *  Licensed under the GPL, Version 3.0 (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.gnu.org/licenses/gpl.html
 *
 *  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 org.tinygroup.jspengine.el.parser;

import org.tinygroup.jspengine.el.lang.ELSupport;
import org.tinygroup.jspengine.el.lang.EvaluationContext;

import javax.el.*;



/**
 * @author Jacob Hookom [[email protected]]
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: tcfujii $
 */
public final class AstIdentifier extends SimpleNode {
    public AstIdentifier(int id) {
        super(id);
    }

    public Class getType(EvaluationContext ctx) throws ELException {
        VariableMapper varMapper = ctx.getVariableMapper();
        if (varMapper != null) {
            ValueExpression expr = varMapper.resolveVariable(this.image);
            if (expr != null) {
                return expr.getType(ctx.getELContext());
            }
        }
        ctx.setPropertyResolved(false);
        Class ret = ctx.getELResolver().getType(ctx, null, this.image);
        if (! ctx.isPropertyResolved()) {
            ELSupport.throwUnhandled(null, this.image);
        }
        return ret;
    }

    public Object getValue(EvaluationContext ctx) throws ELException {
        VariableMapper varMapper = ctx.getVariableMapper();
        if (varMapper != null) {
            ValueExpression expr = varMapper.resolveVariable(this.image);
            if (expr != null) {
                return expr.getValue(ctx.getELContext());
            }
        }
        ctx.setPropertyResolved(false);
        Object ret = ctx.getELResolver().getValue(ctx, null, this.image);
        if (! ctx.isPropertyResolved()) {
            ELSupport.throwUnhandled(null, this.image);
        }
        return ret;
    }

    public boolean isReadOnly(EvaluationContext ctx) throws ELException {
        VariableMapper varMapper = ctx.getVariableMapper();
        if (varMapper != null) {
            ValueExpression expr = varMapper.resolveVariable(this.image);
            if (expr != null) {
                return expr.isReadOnly(ctx.getELContext());
            }
        }
        ctx.setPropertyResolved(false);
        boolean ret = ctx.getELResolver().isReadOnly(ctx, null, this.image);
        if (! ctx.isPropertyResolved()) {
            ELSupport.throwUnhandled(null, this.image);
        }
        return ret;
    }

    public void setValue(EvaluationContext ctx, Object value)
            throws ELException {
        VariableMapper varMapper = ctx.getVariableMapper();
        if (varMapper != null) {
            ValueExpression expr = varMapper.resolveVariable(this.image);
            if (expr != null) {
                expr.setValue(ctx.getELContext(), value);
                return;
            }
        }
        ctx.setPropertyResolved(false);
        ELResolver elResolver = ctx.getELResolver();
        if (value != null) {
            value = ELSupport.coerceToType(value,
                        elResolver.getType(ctx, null, this.image));
        }
        elResolver.setValue(ctx, null, this.image, value);
        if (! ctx.isPropertyResolved()) {
            ELSupport.throwUnhandled(null, this.image);
        }
    }

    private final Object invokeTarget(EvaluationContext ctx, Object target,
            Object[] paramValues) throws ELException {
        if (target instanceof MethodExpression) {
            MethodExpression me = (MethodExpression) target;
            return me.invoke(ctx.getELContext(), paramValues);
        } else if (target == null) {
            throw new MethodNotFoundException("Identity '" + this.image
                    + "' was null and was unable to invoke");
        } else {
            throw new ELException(
                    "Identity '"
                            + this.image
                            + "' does not reference a MethodExpression instance, returned type: "
                            + target.getClass().getName());
        }
    }

    public Object invoke(EvaluationContext ctx, Class[] paramTypes,
            Object[] paramValues) throws ELException {
        return this.getMethodExpression(ctx).invoke(ctx.getELContext(), paramValues);
    }
    

    public MethodInfo getMethodInfo(EvaluationContext ctx, Class[] paramTypes)
            throws ELException {
        return this.getMethodExpression(ctx).getMethodInfo(ctx.getELContext());
    }

    private final MethodExpression getMethodExpression(EvaluationContext ctx)
            throws ELException {
        Object obj = null;

        // case A: ValueExpression exists, getValue which must
        // be a MethodExpression
        VariableMapper varMapper = ctx.getVariableMapper();
        ValueExpression ve = null;
        if (varMapper != null) {
            ve = varMapper.resolveVariable(this.image);
            if (ve != null) {
                obj = ve.getValue(ctx);
            }
        }

        // case B: evaluate the identity against the ELResolver, again, must be
        // a MethodExpression to be able to invoke
        if (ve == null) {
            ctx.setPropertyResolved(false);
            obj = ctx.getELResolver().getValue(ctx, null, this.image);
        }

        // finally provide helpful hints
        if (obj instanceof MethodExpression) {
            return (MethodExpression) obj;
        } else if (obj == null) {
            throw new MethodNotFoundException("Identity '" + this.image
                    + "' was null and was unable to invoke");
        } else {
            throw new ELException(
                    "Identity '"
                            + this.image
                            + "' does not reference a MethodExpression instance, returned type: "
                            + obj.getClass().getName());
        }
    }
}