    001    //  Copyright 2007, 2008, 2009 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    //     http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5;
    016
    017    /**
    018     * Constants for the built-in binding prefixes.  These are often used with the {@link
    019     * org.apache.tapestry5.annotations.Parameter#defaultPrefix()} annotation attribute.
    020     */
    021    public class BindingConstants
    022    {
    023        /**
    024         * Binding expression prefix used for literal strings.
    025         */
    026        public static final String LITERAL = "literal";
    027        /**
    028         * Binding expression prefix used to bind to a property of the component. When {@link
    029         * org.apache.tapestry5.annotations.Parameter#defaultPrefix()} is not specified, the default is PROP.
    030         */
    031        public static final String PROP = "prop";
    032
    033        /**
    034         * A way of selecting a named {@link org.apache.tapestry5.NullFieldStrategy} contributed to {@link
    035         * org.apache.tapestry5.services.NullFieldStrategySource}.
    036         */
    037        public static final String NULLFIELDSTRATEGY = "nullfieldstrategy";
    038
    039        /**
    040         * A reference to a component within the container's template, by local component id.
    041         */
    042        public static final String COMPONENT = "component";
    043
    044        /**
    045         * A reference to a localized message from the component's message catalog (including message keys inherited from
    046         * the application global message catalog).
    047         */
    048        public static final String MESSAGE = "message";
    049
    050        /**
    051         * References (and configures) one ore more named {@link org.apache.tapestry5.Validator}s contributed to the {@link
    052         * org.apache.tapestry5.services.FieldValidatorSource} service.
    053         *
    054         * @see org.apache.tapestry5.services.FieldValidatorSource
    055         */
    056        public static final String VALIDATE = "validate";
    057
    058        /**
    059         * References a named {@link org.apache.tapestry5.Translator} contributed to the {@link
    060         * org.apache.tapestry5.services.TranslatorSource} service. The binding is of type {@link
    061         * org.apache.tapestry5.FieldTranslator}.
    062         */
    063        public static final String TRANSLATE = "translate";
    064
    065        /**
    066         * References a named block within the template.
    067         */
    068        public static final String BLOCK = "block";
    069
    070        /**
    071         * References a localized asset.  The asset will be relative to the component's class file, unless a prefix
    072         * (typically, "context:") is used on the expression.    Typically, this is used for classpath assets relative to
    073         * the component class, and {@link #CONTEXT} is used for context assets.
    074         *
    075         * @see org.apache.tapestry5.Asset
    076         * @see org.apache.tapestry5.services.AssetSource
    077         */
    078        public static final String ASSET = "asset";
    079
    080        /**
    081         * Allows for temporary storage of information during the render only (may not currently be used during form
    082         * submission processing).  This is often used to store the current object iterated over by a {@link
    083         * org.apache.tapestry5.corelib.components.Loop} component.
    084         */
    085        public static final String VAR = "var";
    086
    087        /**
    088         * Binding factory for context assets specifically. The expression is the path from the root of the web
    089         * application.
    090         *
    091         * @since 5.1.0.0
    092         */
    093        public static final String CONTEXT = "context";
    094
    095
    096        /**
    097         * References a value of a symbol.
    098         *
    099         * @since 5.2.0
    100         */
    101        public static final String SYMBOL = "symbol";
    102    }