FieldChangeHandlerManagerImpl.java

/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates.
 *
 * 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.kie.workbench.common.forms.processing.engine.handling.impl;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.enterprise.context.Dependent;

import org.jboss.errai.common.client.api.Assert;
import org.kie.workbench.common.forms.processing.engine.handling.FieldChangeHandler;
import org.kie.workbench.common.forms.processing.engine.handling.FieldChangeHandlerManager;
import org.kie.workbench.common.forms.processing.engine.handling.FormValidator;

@Dependent
public class FieldChangeHandlerManagerImpl implements FieldChangeHandlerManager {

    private FormValidator validator;

    private Map<String, FieldChangeProcessor> fieldExecutors = new HashMap<>();
    private List<FieldChangeHandler> defaultChangeHandlers = new ArrayList<>();

    @Override
    public void setValidator(FormValidator validator) {
        this.validator = validator;
    }

    @Override
    public void registerField(String fieldName) {
        registerField(fieldName,
                      false);
    }

    @Override
    public void registerField(String fieldName,
                              boolean validateOnChange) {
        fieldExecutors.put(fieldName,
                           new FieldChangeProcessor(fieldName,
                                                    validateOnChange));
    }

    @Override
    public void addFieldChangeHandler(FieldChangeHandler changeHandler) {
        defaultChangeHandlers.add(changeHandler);
    }

    @Override
    public void addFieldChangeHandler(String fieldName,
                                      FieldChangeHandler changeHandler) {
        Assert.notNull("FieldName cannot be null",
                       fieldName);
        Assert.notNull("FieldChangeHandler cannot be null",
                       changeHandler);

        FieldChangeProcessor executor = fieldExecutors.get(fieldName);

        if (executor != null) {
            executor.addFieldChangeHandler(changeHandler);
        }
    }

    @Override
    public void processFieldChange(String fieldName,
                                   Object newValue,
                                   Object model) {
        assert fieldName != null;

        String realFieldName = fieldName;

        if (realFieldName.indexOf(".") != -1) {
            realFieldName = realFieldName.substring(0,
                                                    realFieldName.indexOf("."));
        }

        FieldChangeProcessor executor = fieldExecutors.get(realFieldName);

        if (executor != null) {
            if (executor.isRequiresValidation()) {
                if (validator != null && !validator.validate(realFieldName,
                                                             model)) {
                    return;
                }
            }
            doProcess(executor.getChangeHandlers(),
                      fieldName,
                      newValue);
            doProcess(defaultChangeHandlers,
                      fieldName,
                      newValue);
        }
    }

    protected void doProcess(Collection<FieldChangeHandler> handlers,
                             String fieldName,
                             Object newValue) {
        for (FieldChangeHandler handler : handlers) {
            handler.onFieldChange(fieldName,
                                  newValue);
        }
    }

    @Override
    public void clear() {
        fieldExecutors.clear();
        defaultChangeHandlers.clear();
    }
}