org.bridje.web.view.state.StateManager Maven / Gradle / Ivy

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/*
 * Copyright 2016 Bridje Framework.
 *
 * 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 org.bridje.web.view.state;

import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.bridje.el.ElService;
import org.bridje.http.HttpReqParam;
import org.bridje.ioc.Component;
import org.bridje.ioc.Inject;
import org.bridje.ioc.IocContext;
import org.bridje.web.WebScope;
import org.bridje.web.view.ViewUtils;

/**
 * The manager for the states of the web views, this component can create the
 * state map out of the given web request context.
 */
@Component
public class StateManager
{
    private static final Logger LOG = Logger.getLogger(StateManager.class.getName());

    @Inject
    private ElService elServ;

    private Map, Map> stateFields;

    /**
     * Creates a new map with the current state of the web request. All the
     * components that were created during the request that have fields annoted
     * as StateFields will be serialized to the result map, so it can be
     * persisted across multiple HTTP requests.
     *
     * @param ctx The current web request context.
     *
     * @return A map with the names of the fields and the serialized values.
     */
    public Map createViewState(IocContext ctx)
    {
        if (stateFields == null) initStateFields(ctx);
        Map, Object> comps = ctx.find(StateListener.class).getStateComps();
        Map result = new LinkedHashMap<>();
        if (comps != null) comps.forEach((c, i) -> fillStateValues(c, i, result));
        return result;
    }
    
    private void fillStateValues(Class comp, Object inst, Map stateValues)
    {
        Map map = stateFields.get(comp);
        if (map != null) map.forEach((f, s) -> fillStateValues(inst, f, s, stateValues));
    }
    
    private void fillStateValues(Object inst, Field field, String state, Map stateValues)
    {
        try
        {
            Object val = field.get(inst);
            String cv = elServ.convert(val, String.class);
            if (cv != null) stateValues.put(state, cv);
        }
        catch (IllegalArgumentException | IllegalAccessException e)
        {
            LOG.log(Level.SEVERE, e.getMessage(), e);
        }
    }

    /**
     * Injects the state of the HTTP request send to the server, into the given
     * component.
     *
     * @param ctx      The IocContext for the web request.
     * @param clazz    The component class.
     * @param inst     The component instance.
     * @param req      The web request scope.
     */
    protected void injectState(IocContext ctx, Class