org.apache.wicket.markup.html.form.AbstractTextComponent.java Source code

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Here is the source code for org.apache.wicket.markup.html.form.AbstractTextComponent.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.wicket.markup.html.form;

import java.text.SimpleDateFormat;

import org.apache.wicket.Component;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.IObjectClassAwareModel;
import org.apache.wicket.util.string.Strings;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Abstract base class for TextArea and TextField.
 * 
 * @author Jonathan Locke
 * 
 * @param <T>
 *            The model object type
 */
public abstract class AbstractTextComponent<T> extends FormComponent<T> {
    // Flag for the type resolving. FLAG_RESERVED1-3 is taken by form component
    private static final int TYPE_RESOLVED = Component.FLAG_RESERVED4;

    /** Log for reporting. */
    private static final Logger log = LoggerFactory.getLogger(AbstractTextComponent.class);

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    /**
     * Text components that implement this interface are know to be able to provide a pattern for
     * formatting output and parsing input. This can be used by for instance date picker components
     * which are based on JavaScript and need some knowledge as to how to communicate properly via
     * request parameters.
     */
    public interface ITextFormatProvider {
        /**
         * Gets the pattern for printing output and parsing input.
         * 
         * @return The text pattern
         * @see SimpleDateFormat
         */
        String getTextFormat();
    }

    /**
     * @see org.apache.wicket.Component#Component(String)
     */
    public AbstractTextComponent(String id) {
        this(id, null);
    }

    /**
     * @param id
     * @param model
     * @see org.apache.wicket.Component#Component(String, IModel)
     */
    public AbstractTextComponent(final String id, final IModel<T> model) {
        super(id, model);
        setConvertEmptyInputStringToNull(true);
    }

    /**
     * Should the bound object become <code>null</code> when the input is empty?
     * 
     * @return <code>true</code> when the value will be set to <code>null</code> when the input is
     *         empty.
     */
    public final boolean getConvertEmptyInputStringToNull() {
        return getFlag(FLAG_CONVERT_EMPTY_INPUT_STRING_TO_NULL);
    }

    /**
     * TextFields return an empty string even if the user didn't type anything in them. To be able
     * to work nicely with validation, this method returns false.
     * 
     * @see org.apache.wicket.markup.html.form.FormComponent#isInputNullable()
     */
    @Override
    public boolean isInputNullable() {
        return false;
    }

    /**
     * Convert the input respecting the flag convertEmptyInputStringToNull. Subclasses that override
     * this method should test this flag also.
     * 
     * @see org.apache.wicket.markup.html.form.FormComponent#convertInput()
     */
    @Override
    public void convertInput() {
        // Stateless forms don't have to be rendered first, convertInput could be called before
        // onBeforeRender calling resolve type here again to check if the type is correctly set.
        resolveType();
        String[] value = getInputAsArray();
        String tmp = value != null && value.length > 0 ? value[0] : null;
        if (getConvertEmptyInputStringToNull() && Strings.isEmpty(tmp)) {
            setConvertedInput(null);
        } else {
            super.convertInput();
        }
    }

    /**
     * If the type is not set try to guess it if the model supports it.
     * 
     * @see org.apache.wicket.Component#onBeforeRender()
     */
    @Override
    protected void onBeforeRender() {
        super.onBeforeRender();
        resolveType();
    }

    /**
     * 
     */
    private void resolveType() {
        if (!getFlag(TYPE_RESOLVED) && getType() == null) {
            Class<?> type = getModelType(getDefaultModel());
            setType(type);
            setFlag(TYPE_RESOLVED, true);
        }
    }

    /**
     * 
     * @param model
     * @return the type of the model object or <code>null</code>
     */
    private Class<?> getModelType(IModel<?> model) {
        if (model instanceof IObjectClassAwareModel) {
            Class<?> objectClass = ((IObjectClassAwareModel<?>) model).getObjectClass();
            return objectClass;
        } else {
            return null;
        }
    }

    /**
     * Should the bound object become <code>null</code> when the input is empty?
     * 
     * @param flag
     *            the value to set this flag.
     * @return this
     */
    public final FormComponent<T> setConvertEmptyInputStringToNull(boolean flag) {
        setFlag(FLAG_CONVERT_EMPTY_INPUT_STRING_TO_NULL, flag);
        return this;
    };
}