    001/*
    002    Licensed to the Apache Software Foundation (ASF) under one
    003    or more contributor license agreements.  See the NOTICE file
    004    distributed with this work for additional information
    005    regarding copyright ownership.  The ASF licenses this file
    006    to you under the Apache License, Version 2.0 (the
    007    "License"); you may not use this file except in compliance
    008    with the License.  You may obtain a copy of the License at
    009
    010       http://www.apache.org/licenses/LICENSE-2.0
    011
    012    Unless required by applicable law or agreed to in writing,
    013    software distributed under the License is distributed on an
    014    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015    KIND, either express or implied.  See the License for the
    016    specific language governing permissions and limitations
    017    under the License.
    018 */
    019package org.apache.wiki.forms;
    020
    021import org.apache.wiki.api.core.Context;
    022import org.apache.wiki.api.plugin.Plugin;
    023
    024/**
    025 */
    026public abstract class FormElement implements Plugin {
    027
    028    /**
    029     * In order to make the form-to-handler parameter transfer easier,
    030     * we prefix all user-specified FORM element names with HANDLERPARAM_PREFIX
    031     * the HTML output. This lets us differentiate user-defined FormHandler
    032     * parameters from Form parameters.
    033     * The submit handler must then use MapUtil.requestToMap() to
    034     * strip them before executing the handler itself.
    035     */
    036    public static final String HANDLERPARAM_PREFIX = "nbf_";
    037
    038    /**
    039     * The submit servlet may decide to store a FormInfo with user-entered
    040     * form values in the Session. It should use this name, and this class
    041     * checks for it to pre-fill fields from a previous form submit.
    042     */
    043    public static final String FORM_VALUES_CARRIER = "nbpf_values";
    044
    045    /** Show values.  Value is <tt>{@value}</tt>. */
    046    public static final String HIDE_SUCCESS = "onsuccess";
    047
    048    // Parameter names:
    049    /** Plugin parameter, optional, indicates servlet to post to. */
    050    public static final String PARAM_SUBMITHANDLER = "submit";
    051    /** Plugin parameter, mandatory, indicates what form element to insert. */
    052    public static final String PARAM_ELEMENT    = "element";
    053    /** Plugin parameter, mandatory in output element, indicates Plugin to use to handle form submitted data. */
    054    public static final String PARAM_HANDLER    = "handler";
    055    /** Plugin parameter, mandatory in open/output: name of the form. */
    056    public static final String PARAM_FORM       = "form";
    057    /** Plugin parameter, mandatory in input elements: name of an element. */
    058    public static final String PARAM_INPUTNAME  = "name";
    059    /** Plugin parameter, optional: default value for an input. */
    060    public static final String PARAM_VALUE      = "value";
    061    /** Experimental: hide the form if it was submitted successfully. */
    062    public static final String PARAM_HIDEFORM   = "hide";
    063
    064    /** If set to 'handler' in output element, the handler plugin is
    065     * called even on first invocation (no submit). The plugin can
    066     * then place values into its parameter map, and these are seen by
    067     * subsequent Form elements. (Store a value in the plugin with the
    068     * same key as an input element, and the value will be visible in
    069     * the initial form.)
    070     */
    071    public static final String PARAM_POPULATE = "populate";
    072    /** HTTP parameter, inserted as hidden variable into the generated form. */
    073    public static final String PARAM_FORMNAMEHIDDEN   = "formname";
    074
    075    // Key to store the form info container in the context by:
    076    //public static final String CONTEXT_FORMINFO = "FormPluginInfo";
    077
    078    /**
    079     * Utility method stores a FormInfo object into the Context.
    080     *
    081     * @param ctx The Context to store it in
    082     * @param info The FormInfo to store.
    083     */
    084    protected void storeFormInfo( final Context ctx, final FormInfo info ) {
    085        ctx.setVariable( FORM_VALUES_CARRIER, info );
    086    }
    087
    088    /**
    089     * Attempts to retrieve information on the currently handled form from the Context.
    090     *
    091     * @param ctx The Context
    092     * @return The FormInfo from the context
    093     */
    094    protected FormInfo getFormInfo( final Context ctx ) {
    095        return ( FormInfo )ctx.getVariable( FORM_VALUES_CARRIER );
    096    }
    097
    098}