org.springframework.web.servlet.tags.BindTag Maven / Gradle / Ivy
/*
* Copyright 2002-2018 the original author or authors.
*
* 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
*
* https://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.springframework.web.servlet.tags;
import java.beans.PropertyEditor;
import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.PageContext;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.validation.Errors;
import org.springframework.web.servlet.support.BindStatus;
/**
* The {@code } tag supports evaluation of binding errors for a certain
* bean or bean property. Exposes a "status" variable of type
* {@link org.springframework.web.servlet.support.BindStatus},
* to both Java expressions and JSP EL expressions.
*
* Can be used to bind to any bean or bean property in the model.
* The specified path determines whether the tag exposes the status of the
* bean itself (showing object-level errors), a specific bean property
* (showing field errors), or a matching set of bean properties
* (showing all corresponding field errors).
*
*
The {@link org.springframework.validation.Errors} object that has
* been bound using this tag is exposed to collaborating tags, as well
* as the bean property that this errors object applies to. Nested tags
* such as the {@link TransformTag} can access those exposed properties.
*
*
* Attribute Summary
*
*
* Attribute
* Required?
* Runtime Expression?
* Description
*
*
*
*
* htmlEscape
false
true
Set HTML escaping for this tag, as boolean value. Overrides the default
* HTML escaping setting for the current page.
*
* ignoreNestedPath
false
true
Set whether to ignore a nested path, if any.
* Default is to not ignore.
*
* path
true
true
The path to the bean or bean property to bind status information for.
* For instance account.name, company.address.zipCode or just employee. The status
* object will exported to the page scope, specifically for this bean or bean
* property
*
*
*
* @author Rod Johnson
* @author Juergen Hoeller
* @see #setPath
*/
@SuppressWarnings("serial")
public class BindTag extends HtmlEscapingAwareTag implements EditorAwareTag {
/**
* Name of the exposed variable within the scope of this tag: "status".
*/
public static final String STATUS_VARIABLE_NAME = "status";
private String path = "";
private boolean ignoreNestedPath = false;
@Nullable
private BindStatus status;
@Nullable
private Object previousPageStatus;
@Nullable
private Object previousRequestStatus;
/**
* Set the path that this tag should apply. Can be a bean (e.g. "person")
* to get global errors, or a bean property (e.g. "person.name") to get
* field errors (also supporting nested fields and "person.na*" mappings).
* "person.*" will return all errors for the specified bean, both global
* and field errors.
* @see org.springframework.validation.Errors#getGlobalErrors
* @see org.springframework.validation.Errors#getFieldErrors
*/
public void setPath(String path) {
this.path = path;
}
/**
* Return the path that this tag applies to.
*/
public String getPath() {
return this.path;
}
/**
* Set whether to ignore a nested path, if any.
* Default is to not ignore.
*/
public void setIgnoreNestedPath(boolean ignoreNestedPath) {
this.ignoreNestedPath = ignoreNestedPath;
}
/**
* Return whether to ignore a nested path, if any.
*/
public boolean isIgnoreNestedPath() {
return this.ignoreNestedPath;
}
@Override
protected final int doStartTagInternal() throws Exception {
String resolvedPath = getPath();
if (!isIgnoreNestedPath()) {
String nestedPath = (String) this.pageContext.getAttribute(
NestedPathTag.NESTED_PATH_VARIABLE_NAME, PageContext.REQUEST_SCOPE);
// only prepend if not already an absolute path
if (nestedPath != null && !resolvedPath.startsWith(nestedPath) &&
!resolvedPath.equals(nestedPath.substring(0, nestedPath.length() - 1))) {
resolvedPath = nestedPath + resolvedPath;
}
}
try {
this.status = new BindStatus(getRequestContext(), resolvedPath, isHtmlEscape());
}
catch (IllegalStateException ex) {
throw new JspTagException(ex.getMessage());
}
// Save previous status values, for re-exposure at the end of this tag.
this.previousPageStatus = this.pageContext.getAttribute(STATUS_VARIABLE_NAME, PageContext.PAGE_SCOPE);
this.previousRequestStatus = this.pageContext.getAttribute(STATUS_VARIABLE_NAME, PageContext.REQUEST_SCOPE);
// Expose this tag's status object as PageContext attribute,
// making it available for JSP EL.
this.pageContext.removeAttribute(STATUS_VARIABLE_NAME, PageContext.PAGE_SCOPE);
this.pageContext.setAttribute(STATUS_VARIABLE_NAME, this.status, PageContext.REQUEST_SCOPE);
return EVAL_BODY_INCLUDE;
}
@Override
public int doEndTag() {
// Reset previous status values.
if (this.previousPageStatus != null) {
this.pageContext.setAttribute(STATUS_VARIABLE_NAME, this.previousPageStatus, PageContext.PAGE_SCOPE);
}
if (this.previousRequestStatus != null) {
this.pageContext.setAttribute(STATUS_VARIABLE_NAME, this.previousRequestStatus, PageContext.REQUEST_SCOPE);
}
else {
this.pageContext.removeAttribute(STATUS_VARIABLE_NAME, PageContext.REQUEST_SCOPE);
}
return EVAL_PAGE;
}
/**
* Return the current BindStatus.
*/
private BindStatus getStatus() {
Assert.state(this.status != null, "No current BindStatus");
return this.status;
}
/**
* Retrieve the property that this tag is currently bound to,
* or {@code null} if bound to an object rather than a specific property.
* Intended for cooperating nesting tags.
* @return the property that this tag is currently bound to,
* or {@code null} if none
*/
@Nullable
public final String getProperty() {
return getStatus().getExpression();
}
/**
* Retrieve the Errors instance that this tag is currently bound to.
* Intended for cooperating nesting tags.
* @return the current Errors instance, or {@code null} if none
*/
@Nullable
public final Errors getErrors() {
return getStatus().getErrors();
}
@Override
@Nullable
public final PropertyEditor getEditor() {
return getStatus().getEditor();
}
@Override
public void doFinally() {
super.doFinally();
this.status = null;
this.previousPageStatus = null;
this.previousRequestStatus = null;
}
}