/*
 * 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.click.control;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.click.Context;
import org.apache.click.Control;
import org.apache.click.util.ClickUtils;
import org.apache.click.util.ContainerUtils;
import org.apache.click.util.HtmlStringBuffer;

/**
 * Provides a FieldSet container control: &nbsp; &lt;fieldset&gt;.
 *
 * <table style='margin-bottom: 1.25em'>
 * <tr>
 * <td>
 * <fieldset id='form-paymentDetails'>
 * <legend id='form-paymentDetails-legend'>FieldSet</legend>
 * <table class='fields' id='form-paymentDetails-fields'>
 * <tr class='fields'>
 * <td class='fields' align='left'><label>Card Name</label><font color="red">*</font></td>
 * <td align='left'><input type='text' name='cardName' id='form-cardName' value='' size='20'/></td>
 * </tr>
 * <tr class='fields'>
 * <td class='fields' align='left'><label>Card Number</label><font color="red">*</font></td>
 * <td align='left'><input type='text' name='cardNumber' id='form-cardNumber' value='' size='19' onkeypress='javascript:return integerFilter(event);' maxlength='19'/><select name='cardtype' id='form-cardtype' size='1'><option selected='selected' value='VISA'>Visa</option><option value='MASTER'>Master</option><option value='AMEX'>AmEx</option><option value='DINERS'>Diners</option><option value='DISCOVER'>Discover</option></select></td>
 * </tr>
 * <tr class='fields'>
 * <td class='fields' align='left'><label>Expiry</label><font color="red">*</font></td>
 * <td align='left'><input type='text' name='expiry' id='form-expiry' value='' size='4' onkeypress='javascript:return integerFilter(event);' maxlength='4'/></td>
 * </tr>
 * </table>
 * </fieldset>
 * </td>
 * </tr>
 * </table>
 *
 * FieldSet provides a container for laying out form <tt>Field</tt> controls.
 *
 * <h3>FieldSet Example</h3>
 *
 * An FieldSet example containing credit card payment details is provided below:
 *
 * <pre class='codeJava'>
 * <span class='kw'>public class</span> PaymentDetails() {
 *
 *     <span class="kw">public</span> Form form = <span class='kw'>new</span> Form();
 *
 *     <span class='kw'>public</span> PaymentDetails() {
 *         FieldSet paymentFieldSet = <span class='kw'>new</span> FieldSet(<span class='st'>"paymentDetails"</span>);
 *         form.add(paymentFieldSet);
 *
 *         paymentFieldSet.add(<span class='kw'>new</span> TextField(<span class='st'>"cardName"</span>, <span class='kw'>true</span>));
 *         paymentFieldSet.add(<span class='kw'>new</span> CreditCardField(<span class='st'>"cardNumber"</span>, <span class='kw'>true</span>));
 *         IntegerField expiryField = <span class='kw'>new</span> IntegerField(<span class='st'>"expiry"</span>, <span class='kw'>true</span>);
 *         expiryField.setSize(4);
 *         expiryField.setMaxLength(4);
 *         paymentFieldSet.add(expiryField);
 *
 *         form.add(<span class='kw'>new</span> Submit(<span class='st'>"ok"</span>, <span class='st'>"    OK    "</span>, <span class='kw'>this</span>, <span class='st'>"onOkClick"</span>);
 *         form.add(<span class='kw'>new</span> Submit(<span class='st'>"  Cancel  "</span>, <span class='kw'>this</span>, <span class='st'>"onCancelClick"</span>));
 *     }
 * } </pre>
 *
 * When the FieldSet is processed it invokes the <tt>onProcess()</tt> method
 * of its contained Fields. Beyond this the FieldSet performs no server side
 * processing, and should be considered simply as a container for laying out
 * form fields.
 *
 * <p/>
 * See also the W3C HTML reference:
 * <a class="external" target="_blank" title="W3C HTML 4.01 Specification"
 *    href="http://www.w3.org/TR/html401/interact/forms.html#h-17.10">FIELDSET</a>
 */
public class FieldSet extends Field implements Container {

    // Constants --------------------------------------------------------------

    private static final long serialVersionUID = 1L;

    // Instance Variables -----------------------------------------------------

    /** The list of controls. */
    protected List<Control> controls;

    /** The map of controls keyed by field name. */
    protected Map<String, Control> controlMap;

    /** The ordered list of fields, excluding buttons. */
    protected final List<Field> fieldList = new ArrayList<Field>();

    /** The map of field width values. */
    protected Map<String, Integer> fieldWidths;

    /** The FieldSet legend. */
    protected String legend;

    /** The FieldSet legend attributes map. */
    protected Map<String, String> legendAttributes;

    /** The render fieldset border flag, default value is true. */
    protected boolean showBorder = true;

    /**
     * This property serves as a hint to the number of table columns the fieldset
     * is rendered with.
     *<p/>
     * Currently only {@link Form} acts upon this property.
     */
    protected Integer columns;

    // Constructors -----------------------------------------------------------

    /**
     * Create a FieldSet with the given name.
     *
     * @param name the fieldset name element value
     */
    public FieldSet(String name) {
        super(name);
    }

    /**
     * Create a FieldSet with the given name and legend.
     *
     * @param name the fieldset name
     * @param legend the fieldset legend element value
     */
    public FieldSet(String name, String legend) {
        super(name);
        setLegend(legend);
    }

    /**
     * Create a FieldSet with no name defined.
     * <p/>
     * <b>Please note</b> the control's name must be defined before it is valid.
     */
    public FieldSet() {
    }

    // Public Methods ---------------------------------------------------------

    /**
     * Add a Field to the FieldSet at the specified index and return the added
     * instance.
     * <p/>
     * <b>Please note</b>: if the FieldSet contains a control with the same name
     * as the given control, that control will be
     * {@link #replace(org.apache.click.Control, org.apache.click.Control) replaced}
     * by the given control. If a control has no name defined it cannot be replaced.
     * <p/>
     * Controls can be retrieved from the Map {@link #getControlMap() controlMap}
     * where the key is the Control name and value is the Control instance.
     * <p/>
     * All controls are available on the {@link #getControls() controls} list
     * at the index they were inserted. If you are only interested in Fields,
     * note that fields are available on {@link #getFieldList() fieldList}.
     * <p/>
     * The specified index only applies to {@link #getControls() controls}, not
     * {@link #getFieldList() fieldList}.
     * <p/>
     * <b>Please note</b> if the specified control already has a parent assigned,
     * it will automatically be removed from that parent and inserted into the
     * fieldSet.
     *
     * @see Container#insert(org.apache.click.Control, int)
     *
     * @param control the control to add to the FieldSet and return
     * @param index the index at which the control is to be inserted
     * @return the control that was added to the FieldSet
     * @throws IllegalArgumentException if the control is null, the Field's name
     * is not defined or if the control is neither a Field nor FieldSet
     */
    public Control insert(Control control, int index) {
        // Check if container already contains the control
        String controlName = control.getName();
        if (controlName != null) {
            Control currentControl = getControlMap().get(controlName);

            // If container already contains the control do a replace
            if (currentControl != null
                && !(control instanceof Label)) {

                // Current control and new control are referencing the same object
                // so we exit early
                if (currentControl == control) {
                    return control;
                }

                // If the two controls are different objects, we remove the current
                // control and add the given control
                return replace(currentControl, control);
            }
        }

        ContainerUtils.insert(this, control, index, getControlMap());

        if (control instanceof Field) {
            Field field = (Field) control;

            // Add field to fieldList for fast access
            if (!(field instanceof Button)) {
                getFieldList().add(field);
            }

            Form form = getForm();
            field.setForm(form);

            if (form != null && form.getDefaultFieldSize() > 0) {
                if (field instanceof TextField) {
                    ((TextField) field).setSize(form.getDefaultFieldSize());

                } else if (field instanceof FileField) {
                    ((FileField) field).setSize(form.getDefaultFieldSize());

                } else if (field instanceof TextArea) {
                    ((TextArea) field).setCols(form.getDefaultFieldSize());
                }
            }
        }

        return control;
    }

    /**
     * Replace the current control with the new control.
     *
     * @param currentControl the current control container in the fieldset
     * @param newControl the control to replace the current control
     * @return the new control that replaced the current control
     *
     * @deprecated this method was used for stateful pages, which have been deprecated
     *
     * @throws IllegalArgumentException if the currentControl or newControl is
     * null
     * @throws IllegalStateException if the currentControl is not contained in
     * the fieldset
     */
    public Control replace(Control currentControl, Control newControl) {
        // Current and new control is the same instance - exit early
        if (currentControl == newControl) {
            return newControl;
        }

        int controlIndex = getControls().indexOf(currentControl);
        Control result = ContainerUtils.replace(this, currentControl, newControl,
            controlIndex, getControlMap());

        if (newControl instanceof Field) {
            Field field = (Field) newControl;

            // Replace field in fieldList for fast access
            if (!(field instanceof Button)) {
                int fieldIndex = getFieldList().indexOf(currentControl);
                getFieldList().set(fieldIndex, field);
            }

            // Set parent form
            Form form = getForm();
            field.setForm(form);

            if (currentControl instanceof Field) {
                // Remove form reference from current control
                ((Field) currentControl).setForm(null);
            }

            if (form != null && form.getDefaultFieldSize() > 0) {
                if (field instanceof TextField) {
                    ((TextField) field).setSize(form.getDefaultFieldSize());

                } else if (field instanceof FileField) {
                    ((FileField) field).setSize(form.getDefaultFieldSize());

                } else if (field instanceof TextArea) {
                    ((TextArea) field).setCols(form.getDefaultFieldSize());
                }
            }
        }

        return result;
    }

    /**
     * Add a Control to the fieldset and return the added instance.
     * <p/>
     * <b>Please note</b>: if the FieldSet contains a control with the same name
     * as the given control, that control will be
     * {@link #replace(org.apache.click.Control, org.apache.click.Control) replaced}
     * by the given control. If a control has no name defined it cannot be replaced.
     * <p/>
     * Controls can be retrieved from the Map {@link #getControlMap() controlMap}
     * where the key is the Control name and value is the Control instance.
     * <p/>
     * All controls are available on the {@link #getControls() controls} list
     * in the order they were added. If you are only interested in Fields,
     * note fields are available on {@link #getFieldList() fieldList}.
     *
     * @see org.apache.click.control.Container#add(org.apache.click.Control).
     *
     * @param control the control to add to the container and return
     * @return the control that was added to the container
     *
     * @throws IllegalArgumentException if the control is null, the Field's name
     * is not defined or if the control is neither a Field nor FieldSet
     */
    public Control add(Control control) {
        return insert(control, getControls().size());
    }

    /**
     * Add the field to the fieldSet, and set the fields form property.
     * <p/>
     * <b>Please note</b>: if the FieldSet contains a control with the same name
     * as the given control, that control will be
     * {@link #replace(org.apache.click.Control, org.apache.click.Control) replaced}
     * by the given control. If a control has no name defined it cannot be replaced.
     * <p/>
     * Fields can be retrieved from the Map {@link #getFields() fields} where
     * the key is the Field name and value is the Field instance.
     * <p/>
     * Fields are available on {@link #getFieldList() fieldList}.
     *
     * @see #add(org.apache.click.Control)
     *
     * @param field the field to add to the fieldSet
     * @return the field added to this fieldSet
     * @throws IllegalArgumentException if the field is null or the field name
     * is not defined
     */
    public Field add(Field field) {
        add((Control) field);
        return field;
    }

    /**
     * Add the field to the fieldset and specify the field width in columns.
     * <p/>
     * <b>Please note</b>: if the FieldSet contains a control with the same name
     * as the given control, that control will be
     * {@link #replace(org.apache.click.Control, org.apache.click.Control) replaced}
     * by the given control. If a control has no name defined it cannot be replaced.
     * <p/>
     * Fields can be retrieved from the Map {@link #getFields() fields} where
     * the key is the Field name and value is the Field instance.
     * <p/>
     * Fields are available on {@link #getFieldList() fieldList}.
     * <p/>
     * Note Button and HiddenField types are not valid arguments for this method.
     *
     * @param field the field to add to the fieldset
     * @param width the width of the field in table columns
     * @return the field added to this fieldset
     * @throws IllegalArgumentException if the field is null, field name is
     * not defined, field is a Button or HiddenField or the width &lt; 1
     */
    public Field add(Field field, int width) {
        add((Control) field, width);
        return field;
    }

    /**
     * Add the control to the fieldset and specify the control's width in columns.
     * <p/>
     * <b>Please note</b>: if the FieldSet contains a control with the same name
     * as the given control, that control will be
     * {@link #replace(org.apache.click.Control, org.apache.click.Control) replaced}
     * by the given control. If a control has no name defined it cannot be replaced.
     * <p/>
     * Controls can be retrieved from the Map {@link #getControlMap() controlMap}
     * where the key is the Control name and value is the Control instance.
     * <p/>
     * Controls are available on the {@link #getControls() controls} list.
     * <p/>
     * Note Button and HiddenField types are not valid arguments for this method.
     *
     * @param control the control to add to the fieldSet
     * @param width the width of the control in table columns
     * @return the control added to this fieldSet
     * @throws IllegalArgumentException if the control is null, control is a
     * Button or HiddenField or the width &lt; 1
     */
    public Control add(Control control, int width) {
        if (control instanceof Button || control instanceof HiddenField) {
            String msg = "Not valid a valid field type: " + control.getClass().getName();
            throw new IllegalArgumentException(msg);
        }
        if (width < 1) {
            throw new IllegalArgumentException("Invalid field width: " + width);
        }

        add(control);

        if (control.getName() != null) {
            getFieldWidths().put(control.getName(), width);
        }
        return control;
    }

    /**
     * @see Container#remove(org.apache.click.Control)
     *
     * @param control the control to remove from the container
     * @return true if the control was removed from the container
     * @throws IllegalArgumentException if the control is null
     */
    public boolean remove(Control control) {
        boolean removed = ContainerUtils.remove(this, control, getControlMap());

        if (removed && control instanceof Field) {
            Field field = (Field) control;

            field.setForm(null);

            if (!(field instanceof Button)) {
                getFieldList().remove(field);
            }
        }
        getFieldWidths().remove(control.getName());

        return removed;
    }

    /**
     * Remove the given field from the fieldset.
     *
     * @param field the field to remove from the fieldset
     *
     * @throws IllegalArgumentException if the field is null
     */
    public void remove(Field field) {
        remove((Control) field);
    }

    /**
     * Remove the named field from the fieldset, returning true if removed
     * or false if not found.
     *
     * @param name the name of the field to remove from the fieldset
     * @return true if the named field was removed or false otherwise
     */
    public boolean removeField(String name) {
        Control control = ContainerUtils.findControlByName(this, name);

        if (control != null) {
            return remove(control);

        } else {
            return false;
        }
    }

    /**
     * @see org.apache.click.control.Container#getControls()
     *
     * @return the sequential list of controls held by the container
     */
    public List<Control> getControls() {
        if (controls == null) {
            controls = new ArrayList<Control>();
        }
        return controls;
    }

    /**
     * @see org.apache.click.control.Container#getControl(java.lang.String)
     *
     * @param controlName the name of the control to get from the container
     * @return the named control from the container if found or null otherwise
     */
    public Control getControl(String controlName) {
        if (hasControls()) {
            return getControlMap().get(controlName);
        }
        return null;
    }

    /**
     * @see org.apache.click.control.Container#contains(org.apache.click.Control)
     *
     * @param control the control whose presence in this container is to be tested
     * @return true if the container contains the specified control
     */
    public boolean contains(Control control) {
        return getControls().contains(control);
    }

    /**
     * Returns true if this container has existing controls, false otherwise.
     *
     * @see AbstractContainer#hasControls()
     *
     * @return true if the container has existing controls, false otherwise.
     */
    public boolean hasControls() {
        return (controls != null) && !controls.isEmpty();
    }

    /**
     * Return the fieldset's html tag: <tt>fieldset</tt>.
     *
     * @see AbstractControl#getTag()
     *
     * @return this controls html tag
     */
    @Override
    public String getTag() {
        return "fieldset";
    }

    /**
     * Return true if the FieldSet is disabled. The FieldSet will also be
     * disabled if the parent Form is disabled.
     * <p/>
     * <b>Important Note</b>: disabled fieldset also disables all its fields
     * which will not submit their values in a HTML form POST. This may cause
     * validation issues in a form submission. Please note this is a HTML
     * limitation and is not due to Click.
     *
     * @return true if the Field is disabled
     */
    @Override
    public boolean isDisabled() {
        Form form = getForm();
        if (form != null && form.isDisabled()) {
            return true;
        } else {
            return disabled;
        }
    }

    /**
     * Set the FieldSet disabled flag which in turn will disable all its fields.
     * <p/>
     * <b>Important Note</b>: disabled fieldset also disables all its fields
     * which will not submit their values in a HTML form POST. This may cause
     * validation issues in a form submission. Please note this is a HTML
     * limitation and is not due to Click.
     *
     * @param disabled the Field disabled flag
     */
    @Override
    public void setDisabled(boolean disabled) {
        super.setDisabled(disabled);
    }

    /**
     * Return true if the FieldSet is readonly. The FieldSet will also be
     * readonly if the parent Form is readonly.
     *
     * @return true if the FieldSet is a readonly
     */
    @Override
    public boolean isReadonly() {
        Form form = getForm();
        if (form != null && form.isReadonly()) {
            return true;
        } else {
            return readonly;
        }
    }

    /**
     * Set the FieldSet readonly flag which in turn will set all its fields
     * to readonly.
     *
     * @param readonly the FieldSet readonly flag
     */
    @Override
    public void setReadonly(boolean readonly) {
        super.setReadonly(readonly);
    }

    /**
     * Return the number of fieldset layout table columns. This property supplies
     * a hint to the number of table columns the fieldset should be rendered with.
     * <p/>
     * <b>Note</b> currently only {@link Form} acts upon the column value.
     * <p/>
     * By default this property inherits its value from the parent Form, but
     * can be specified to override the form value.
     *
     * @return the number of fieldset layout table columns
     */
    public int getColumns() {
        if (columns != null) {
            return columns;
        } else {
            return getForm().getColumns();
        }
    }

    /**
     * Set the number of fieldset layout table columns. This property supplies
     * a hint to the number of table columns the fieldset should be rendered with.
     * <p/>
     * <b>Note</b> currently only {@link Form} acts upon the column value.
     *
     * @param columns the number of fieldset layout table columns
     */
    public void setColumns(int columns) {
        this.columns = columns;
    }

    /**
     * Return the render fieldset border flag. The border is the HTML
     * &lt;fieldset&gt; element.
     *
     * @return the render the fieldset border flag
     */
    public boolean getShowBorder() {
        return showBorder;
    }

    /**
     * Set the render fieldset border flag. The border is the HTML
     * &lt;fieldset&gt; element.
     *
     * @param value the render the fieldset border flag
     */
    public void setShowBorder(boolean value) {
        this.showBorder = value;
    }

    /**
     * Return the named field if contained in the fieldset, or null if not
     * found.
     *
     * @param name the name of the field
     * @return the named field if contained in the fieldset
     */
    public Field getField(String name) {
        return (Field) getControl(name);
    }

    /**
     * Return the ordered list of FieldSet fields, excluding buttons.
     * <p/>
     * The order of the fields is the same order they were added to the
     * FieldSet.
     * <p/>
     * The returned list only includes fields directly added to the FieldSet.
     *
     * @return the ordered List of fieldset fields
     */
    public List<Field> getFieldList() {
        return fieldList;
    }

    /**
     * Return the Map of fieldset fields, keyed on field name.
     *
     * @return the Map of fieldset fields, keyed on field name
     */
    public Map<String, Control> getFields() {
        return getControlMap();
    }

    /**
     * Return the map of field width values, keyed on field name.
     *
     * @return the map of field width values, keyed on field name
     */
    public Map<String, Integer> getFieldWidths() {
        if (fieldWidths == null) {
            fieldWidths = new HashMap<String, Integer>();
        }
        return fieldWidths;
    }

    /**
     * Set the FieldSet's the parent <tt>Form</tt>.
     *
     * @param form FieldSet's parent <tt>Form</tt>
     */
    @Override
    public void setForm(Form form) {
        this.form = form;

        // Set the specified form on the fieldsSets children. This call is not
        // recursive to children's children
        for (Control control : getControls()) {
            if (control instanceof Field) {
                ((Field) control).setForm(form);
            }
        }
    }

    /**
     * Return the fieldset Legend element value: &lt;legend&gt;
     * <p/>
     * If the legend value is null, this method will attempt to find a
     * localized label message in the parent messages using the key:
     * <blockquote>
     * <tt>getName() + ".title"</tt>
     * </blockquote>
     * If not found then the message will be looked up in the
     * <tt>/click-control.properties</tt> file using the same key.
     * If a value cannot be found in the parent or control messages then the
     * FieldSet name will be converted into a legend using the
     * {@link ClickUtils#toLabel(String)} method.
     *
     * @return the fieldset Legend element value
     */
    public String getLegend() {
        if (legend == null) {
            legend = getMessage(getName() + ".legend");
        }
        if (legend == null) {
            String fsName = getName();
            if (fsName != null) {
                legend = ClickUtils.toLabel(fsName);
            }
        }
        return legend;
    }

    /**
     * Set the fieldset Legend element value: &lt;legend&gt;. If the legend
     * value is a zero length string no legend element will be rendered. You
     * can set a blank zero length string if you want to render the fieldset
     * border but don't want a legend caption.
     *
     * @param legend the fieldset Legend element value
     */
    public void setLegend(String legend) {
        this.legend = legend;
    }

    /**
     * Return the legend HTML attribute with the given name, or null if the
     * attribute does not exist.
     *
     * @param name the name of legend HTML attribute
     * @return the legend HTML attribute
     */
    public String getLegendAttribute(String name) {
        if (legendAttributes != null) {
            return legendAttributes.get(name);
        } else {
            return null;
        }
    }

    /**
     * Set the fieldset HTML attribute with the given attribute name and value.
     *
     * @param name the name of the form HTML attribute
     * @param value the value of the form HTML attribute
     * @throws IllegalArgumentException if name parameter is null
     */
    public void setLegendAttribute(String name, String value) {
        if (name == null) {
            throw new IllegalArgumentException("Null name parameter");
        }

        if (legendAttributes == null) {
            legendAttributes = new HashMap<String, String>(5);
        }

        if (value != null) {
            legendAttributes.put(name, value);
        } else {
            legendAttributes.remove(name);
        }
    }

    /**
     * Return the fieldset attributes Map.
     *
     * @return the fieldset attributes Map
     */
    public Map<String, String> getLegendAttributes() {
        if (legendAttributes == null) {
            legendAttributes = new HashMap<String, String>(5);
        }
        return legendAttributes;
    }

    /**
     * Return true if the fieldset has attributes or false otherwise.
     *
     * @return true if the fieldset has attributes on false otherwise
     */
    public boolean hasLegendAttributes() {
        if (legendAttributes != null && !legendAttributes.isEmpty()) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * Process the request invoking <tt>onProcess()</tt> on the contained
     * <tt>Control</tt> elements.
     *
     * @return true if all Controls were processed, or false if any Control
     * returned false
     */
    @Override
    public boolean onProcess() {
        if (hasControls()) {
            for (Control control : getControls()) {
                String controlName = control.getName();
                if (controlName == null || !controlName.startsWith(
                    Form.SUBMIT_CHECK)) {
                    boolean continueProcessing = control.onProcess();
                    if (!continueProcessing) {
                        return false;
                    }
                }
            }
        }
        dispatchActionEvent();
        return true;
    }

    /**
     * @see org.apache.click.Control#onDestroy()
     */
    @Override
    public void onDestroy() {
        if (hasControls()) {
            for (int i = 0, size = getControls().size(); i < size; i++) {
                Control control = getControls().get(i);
                try {
                    control.onDestroy();
                } catch (Throwable t) {
                    ClickUtils.getLogService().error("onDestroy error", t);
                }
            }
        }
    }

   /**
    * @see org.apache.click.Control#onInit()
    */
    @Override
    public void onInit() {
        super.onInit();
        if (hasControls()) {
            for (int i = 0, size = getControls().size(); i < size; i++) {
                Control control = getControls().get(i);
                control.onInit();
            }
        }
    }

   /**
    * @see org.apache.click.Control#onRender()
    */
    @Override
    public void onRender() {
        if (hasControls()) {
            for (int i = 0, size = getControls().size(); i < size; i++) {
                Control control = getControls().get(i);
                control.onRender();
            }
        }
    }

    /**
     * Return the FieldSet state. The following state is returned:
     *
     * <ul>
     * <li>all the input Field values and other FieldSets contained in this
     * FieldSet and child containers.</li>
     * </ul>
     *
     * @return the state of input Fields and FieldSets contained in this FieldSet
     */
    @Override
    public Object getState() {
        List<Field> fields = new ArrayList<Field>();
        addStatefulFields(this, fields);
        Map<String, Object> stateMap = new HashMap<String, Object>();
        for (Field field : fields) {
            Object state = field.getState();
            if (state != null) {
                stateMap.put(field.getName(), state);
            }
        }

        if (stateMap.isEmpty()) {
            return null;
        }
        return stateMap;
    }

    /**
     * Set the FieldSet state. The state will be applied to all the input Fields
     * and FieldSets contained in the FieldSet or child containers.
     *
     * @param state the FieldSet state to set
     */
    @Override
    public void setState(Object state) {
        if (state == null) {
            return;
        }

        Map stateMap = (Map) state;
        List<Field> fields = new ArrayList<Field>();
        addStatefulFields(this, fields);

        for (Field field : fields) {
            String fieldName = field.getName();
            if (stateMap.containsKey(fieldName)) {
                Object fieldState = stateMap.get(fieldName);
                field.setState(fieldState);
            }
        }
    }

    /**
     * Render the HTML representation of the FieldSet.
     * <p/>
     * The size of buffer is determined by {@link #getControlSizeEst()}.
     *
     * @param buffer the specified buffer to render the control's output to
     */
    @Override
    public void render(HtmlStringBuffer buffer) {

        if (getShowBorder()) {
            buffer.elementStart(getTag());

            buffer.appendAttribute("id", getId());

            appendAttributes(buffer);

            if (isDisabled()) {
                buffer.appendAttributeDisabled();
            }

            buffer.closeTag();
            buffer.append("\n");

            String legend = getLegend();
            if (legend != null && legend.length() > 0) {
                buffer.elementStart("legend");
                if (hasLegendAttributes()) {
                    Object legendId = getLegendAttributes().get("id");
                    if (legendId != null) {
                        buffer.appendAttribute("id", legendId);
                    } else {
                        buffer.appendAttribute("id", getId() + "-legend");
                    }
                    buffer.appendAttributes(getLegendAttributes());
                } else {
                    buffer.appendAttribute("id", getId() + "-legend");
                }
                buffer.closeTag();
                buffer.append(getLegend());
                buffer.elementEnd("legend");
                buffer.append("\n");
            }
        }

        // Render Controls
        renderFields(buffer);

        // Render Buttons
        renderButtons(buffer);

        if (getShowBorder()) {
            buffer.elementEnd(getTag());
            buffer.append("\n");
        }
    }

    /**
     * Remove the FieldSet state from the session for the given request context.
     *
     * @see #saveState(org.apache.click.Context)
     * @see #restoreState(org.apache.click.Context)
     *
     * @param context the request context
     */
    @Override
    public void removeState(Context context) {
        ClickUtils.removeState(this, getName(), context);
    }

    /**
     * Restore the FieldSet state from the session for the given request context.
     * <p/>
     * This method delegates to {@link #setState(java.lang.Object)} to set the
     * field restored state.
     *
     * @see #saveState(org.apache.click.Context)
     * @see #removeState(org.apache.click.Context)
     *
     * @param context the request context
     */
    @Override
    public void restoreState(Context context) {
        ClickUtils.restoreState(this, getName(), context);
    }

    /**
     * Save the FieldSet state to the session for the given request context.
     * <p/>
     * * This method delegates to {@link #getState()} to retrieve the field state
     * to save.
     *
     * @see #restoreState(org.apache.click.Context)
     * @see #removeState(org.apache.click.Context)
     *
     * @param context the request context
     */
    public void saveState(Context context) {
        ClickUtils.saveState(this, getName(), context);
    }

    /**
     * Returns the HTML representation of the FieldSet.
     * <p/>
     * The rendering of the FieldSet is delegated to
     * {@link #render(org.apache.click.util.HtmlStringBuffer)}. The size of buffer
     * is determined by {@link #getControlSizeEst()}.
     *
     * @see Object#toString()
     *
     * @return the HTML representation of this control
     */
    @Override
    public String toString() {
        HtmlStringBuffer buffer = new HtmlStringBuffer(getControlSizeEst());
        render(buffer);
        return buffer.toString();
    }

    // Protected methods -------------------------------------------------------

    /**
     * Return the map of controls where each map's key / value pair will consist
     * of the control name and instance.
     *
     * @see org.apache.click.control.AbstractContainer#getControlMap()
     *
     * @return the map of controls
     */
    protected Map<String, Control> getControlMap() {
        if (controlMap == null) {
            controlMap = new HashMap<String, Control>();
        }
        return controlMap;
    }

    /**
     * @see org.apache.click.control.AbstractControl#getControlSizeEst()
     *
     * @return the estimated rendered control size in characters
     */
    @Override
    protected int getControlSizeEst() {
        int size = 20;

        if (getTag() != null && hasAttributes()) {
            size += 20 * getAttributes().size();
        }

        if (hasControls()) {
            size += getControls().size() * size;
        }

        return size;
    }

    /**
     * Render the fieldset's form fields to the string buffer. This method will
     * apply the parent Forms properties to the layout and rendering of fields.
     *
     * @param buffer the StringBuffer to render to
     */
    protected void renderFields(HtmlStringBuffer buffer) {
        if (getControls().isEmpty()) {
            return;
        }

        buffer.elementStart("table");
        buffer.appendAttribute("class", "fields");
        buffer.appendAttribute("id", getId() + "-fields");
        buffer.closeTag();
        buffer.append("<tbody>\n");

        int column = 1;
        boolean openTableRow = false;

        if (!hasControls()) {
            return;
        }

        for (Control control : getControls()) {

            // Buttons are rendered separately
            if (control instanceof Button) {
                continue;
            }

            if (!isHidden(control)) {

                // Field width
                Integer width = getFieldWidths().get(control.getName());

                if (column == 1) {
                    buffer.append("<tr class=\"fields\">\n");
                    openTableRow = true;
                }

                if (control instanceof Label) {
                    Label label = (Label) control;
                    buffer.append("<td align=\"");
                    buffer.append(getForm().getLabelAlign());
                    buffer.append("\" class=\"fields");

                    String cellStyleClass = label.getParentStyleClassHint();
                    if (cellStyleClass != null) {
                        buffer.append(" ");
                        buffer.append(cellStyleClass);
                    }
                    buffer.append("\"");

                    buffer.appendAttribute("style", label.getParentStyleHint());

                    if (width != null) {
                        int colspan = (width.intValue() * 2);
                        buffer.appendAttribute("colspan", colspan);
                    } else {
                        buffer.appendAttribute("colspan", 2);
                    }

                    if (label.hasAttributes()) {
                        Map<String, String> labelAttributes = label.getAttributes();
                        for (Map.Entry<String, String> entry : labelAttributes.entrySet()) {
                            String labelAttrName = entry.getKey();
                            if (!labelAttrName.equals("id") && !labelAttrName.equals("style")) {
                                buffer.appendAttributeEscaped(labelAttrName, entry.getValue());
                            }
                        }
                    }
                    buffer.append(">");
                    label.render(buffer);
                    buffer.append("</td>\n");

                } else if (control instanceof Field) {
                    Field field = (Field) control;
                    Form form = getForm();
                    // Write out label
                    if (Form.POSITION_LEFT.equals(form.getLabelsPosition())) {
                        buffer.append("<td class=\"fields");
                        String cellStyleClass = field.getParentStyleClassHint();
                        if (cellStyleClass != null) {
                            buffer.append(" ");
                            buffer.append(cellStyleClass);
                        }
                        buffer.append("\"");
                        buffer.appendAttribute("align", form.getLabelAlign());
                        String cellStyle = field.getParentStyleHint();
                        if (cellStyle == null) {
                            cellStyle = form.getLabelStyle();
                        }
                        buffer.appendAttribute("style", cellStyle);
                        buffer.append(">");
                    } else {
                        buffer.append("<td valign=\"top\" class=\"fields");
                        String cellStyleClass = field.getParentStyleClassHint();
                        if (cellStyleClass != null) {
                            buffer.append(" ");
                            buffer.append(cellStyleClass);
                        }
                        buffer.append("\"");
                        String cellStyle = field.getParentStyleHint();
                        if (cellStyle == null) {
                            cellStyle = form.getLabelStyle();
                        }
                        buffer.appendAttribute("style", cellStyle);
                        buffer.append(">");
                    }

                    // Store the field id and label (the values could be null)
                    String fieldId = field.getId();
                    String fieldLabel = field.getLabel();

                    // Only render a label if the fieldId and fieldLabel is set
                    if (fieldId != null && fieldLabel != null) {
                        if (field.isRequired()) {
                            buffer.append(form.getMessage("label-required-prefix"));
                        } else {
                            buffer.append(form.getMessage("label-not-required-prefix"));
                        }
                        buffer.elementStart("label");
                        buffer.appendAttribute("for", field.getId());
                        buffer.appendAttribute("style", field.getLabelStyle());
                        if (field.isDisabled()) {
                            buffer.appendAttributeDisabled();
                        }
                        String cellClass = field.getLabelStyleClass();
                        if (field.getError() == null) {
                            buffer.appendAttribute("class", cellClass);
                        } else {
                            buffer.append(" class=\"error");
                            if (cellClass != null) {
                                buffer.append(" ");
                                buffer.append(cellClass);
                            }
                            buffer.append("\"");
                        }
                        buffer.closeTag();
                        buffer.append(field.getLabel());
                        buffer.elementEnd("label");
                        if (field.isRequired()) {
                            buffer.append(form.getMessage("label-required-suffix"));
                        } else {
                            buffer.append(form.getMessage("label-not-required-suffix"));
                        }
                    }

                    if (Form.POSITION_LEFT.equals(form.getLabelsPosition())) {
                        buffer.append("</td>\n");
                        buffer.append("<td");
                        buffer.appendAttribute("class", field.getParentStyleClassHint());
                        buffer.appendAttribute("align", "left");
                        String cellStyle = field.getParentStyleHint();
                        if (cellStyle == null) {
                            cellStyle = form.getFieldStyle();
                        }
                        buffer.appendAttribute("style", cellStyle);

                        if (width != null) {
                            int colspan = (width.intValue() * 2) - 1;
                            buffer.appendAttribute("colspan", colspan);
                        }

                        buffer.append(">");
                    } else {
                        buffer.append("<br/>");
                    }

                    // Write out field
                    field.render(buffer);
                    buffer.append("</td>\n");
                } else {
                    buffer.append("<td class=\"fields\"");

                    if (width != null) {
                        int colspan = (width.intValue() * 2);
                        buffer.appendAttribute("colspan", colspan);
                    } else {
                        buffer.appendAttribute("colspan", 2);
                    }
                    buffer.append(">\n");
                    control.render(buffer);

                    buffer.append("</td>\n");
                }

                if (width != null) {
                    if (control instanceof Label || !(control instanceof Field)) {
                        column += width.intValue();

                    } else {
                        column += (width.intValue() - 1);
                    }
                }

                if (column >= getColumns()) {
                    buffer.append("</tr>\n");
                    openTableRow = false;
                    column = 1;
                } else {
                    column++;
                }

            }
        }

        if (openTableRow) {
            buffer.append("</tr>\n");
        }

        buffer.append("</tbody>");
        buffer.elementEnd("table");
        buffer.append("\n");
    }

    /**
     * Render the fieldset buttons to the string buffer.
     *
     * @param buffer the StringBuffer to render to
     */
    protected void renderButtons(HtmlStringBuffer buffer) {
        List<Button> buttons = ContainerUtils.getButtons(this);

        if (!buttons.isEmpty()) {
            buffer.append("<table class=\"buttons\" id=\"");
            buffer.append(getId());
            buffer.append("-buttons\"><tbody>\n");
            buffer.append("<tr class=\"buttons\">");

            Form form = getForm();
            for (Button button : buttons) {
                buffer.append("<td class=\"buttons\"");
                buffer.appendAttribute("style", form.getButtonStyle());
                buffer.closeTag();

                button.render(buffer);

                buffer.append("</td>");
            }

            buffer.append("</tr>\n");
            buffer.append("</tbody></table>\n");
        }
    }

    // Private Methods --------------------------------------------------------

    /**
     * Return true if the control is hidden, false otherwise.
     *
     * @param control control to check hidden status
     * @return true if the control is hidden, false otherwise
     */
    private boolean isHidden(Control control) {
        if (!(control instanceof Field)) {
            // Non-Field Controls can not be hidden
            return false;
        } else {
            return ((Field) control).isHidden();
        }
    }

    /**
     * Add fields for the given Container to the specified field list,
     * recursively including any Fields contained in child containers.
     *
     * @param container the container to obtain the fields from
     * @param fields the list of contained fields
     */
    private void addStatefulFields(final Container container, final List<Field> fields) {
        for (Control control : container.getControls()) {
            if (control instanceof Label || control instanceof Button) {
                // Skip buttons and labels
                continue;
            }

            if (control instanceof Field) {
                fields.add((Field) control);
            } else if (control instanceof Container) {
                Container childContainer = (Container) control;
                addStatefulFields(childContainer, fields);
            }
        }
    }
}