43. spring JSP Tag Library

43.1 Introduction

One of the view technologies you can use with the Spring Framework is Java Server Pages (JSPs). To help you implement views using Java Server Pages the Spring Framework provides you with some tags for evaluating errors, setting themes and outputting internationalized messages.

Please note that the various tags generated by this form tag library are compliant with the XHTML-1.0-Strict specification and attendant DTD.

This appendix describes the spring.tld tag library.

43.2 The argument tag

Argument tag based on the JSTL fmt:param tag. The purpose is to support arguments inside the message and theme tags.

Table 43.1. Attributes

AttributeRequired?Runtime Expression?Description

value

false

true

The value of the argument.


43.3 The bind tag

Provides BindStatus object for the given bind path. The HTML escaping flag participates in a page-wide or application-wide setting (i.e. by HtmlEscapeTag or a "defaultHtmlEscape" context-param in web.xml).

Table 43.2. Attributes

AttributeRequired?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


43.4 The escapeBody tag

Escapes its enclosed body content, applying HTML escaping and/or JavaScript escaping. The HTML escaping flag participates in a page-wide or application-wide setting (i.e. by HtmlEscapeTag or a "defaultHtmlEscape" context-param in web.xml).

Table 43.3. Attributes

AttributeRequired?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.

javaScriptEscape

false

true

Set JavaScript escaping for this tag, as boolean value. Default is false.


43.5 The eval tag

Evaluates a Spring expression (SpEL) and either prints the result or assigns it to a variable.

Table 43.4. Attributes

AttributeRequired?Runtime Expression?Description

expression

true

true

The expression to evaluate.

htmlEscape

false

true

Set HTML escaping for this tag, as a boolean value. Overrides the default HTML escaping setting for the current page.

javaScriptEscape

false

true

Set JavaScript escaping for this tag, as a boolean value. Default is false.

scope

false

true

The scope for the var. 'application', 'session', 'request' and 'page' scopes are supported. Defaults to page scope. This attribute has no effect unless the var attribute is also defined.

var

false

true

The name of the variable to export the evaluation result to. If not specified the evaluation result is converted to a String and written as output.


43.6 The hasBindErrors tag

Provides Errors instance in case of bind errors. The HTML escaping flag participates in a page-wide or application-wide setting (i.e. by HtmlEscapeTag or a "defaultHtmlEscape" context-param in web.xml).

Table 43.5. Attributes

AttributeRequired?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.

name

true

true

The name of the bean in the request, that needs to be inspected for errors. If errors are available for this bean, they will be bound under the 'errors' key.


43.7 The htmlEscape tag

Sets default HTML escape value for the current page. Overrides a "defaultHtmlEscape" context-param in web.xml, if any.

Table 43.6. Attributes

AttributeRequired?Runtime Expression?Description

defaultHtmlEscape

true

true

Set the default value for HTML escaping, to be put into the current PageContext.


43.8 The message tag

Retrieves the message with the given code, or text if code isn’t resolvable. The HTML escaping flag participates in a page-wide or application-wide setting (i.e. by HtmlEscapeTag or a "defaultHtmlEscape" context-param in web.xml).

Table 43.7. Attributes

AttributeRequired?Runtime Expression?Description

arguments

false

true

Set optional message arguments for this tag, as a (comma-)delimited String (each String argument can contain JSP EL), an Object array (used as argument array), or a single Object (used as single argument).

argumentSeparator

false

true

The separator character to be used for splitting the arguments string value; defaults to a 'comma' (',').

code

false

true

The code (key) to use when looking up the message. If code is not provided, the text attribute will be used.

htmlEscape

false

true

Set HTML escaping for this tag, as boolean value. Overrides the default HTML escaping setting for the current page.

javaScriptEscape

false

true

Set JavaScript escaping for this tag, as boolean value. Default is false.

message

false

true

A MessageSourceResolvable argument (direct or through JSP EL). Fits nicely when used in conjunction with Spring’s own validation error classes which all implement the MessageSourceResolvable interface. For example, this allows you to iterate over all of the errors in a form, passing each error (using a runtime expression) as the value of this 'message' attribute, thus effecting the easy display of such error messages.

scope

false

true

The scope to use when exporting the result to a variable. This attribute is only used when var is also set. Possible values are page, request, session and application.

text

false

true

Default text to output when a message for the given code could not be found. If both text and code are not set, the tag will output null.

var

false

true

The string to use when binding the result to the page, request, session or application scope. If not specified, the result gets outputted to the writer (i.e. typically directly to the JSP).


43.9 The nestedPath tag

Sets a nested path to be used by the bind tag’s path.

Table 43.8. Attributes

AttributeRequired?Runtime Expression?Description

path

true

true

Set the path that this tag should apply. E.g. 'customer' to allow bind paths like 'address.street' rather than 'customer.address.street'.


43.10 The param tag

Parameter tag based on the JSTL c:param tag. The sole purpose is to support params inside the url tag.

Table 43.9. Attributes

AttributeRequired?Runtime Expression?Description

name

true

true

The name of the parameter.

value

false

true

The value of the parameter.


43.11 The theme tag

Retrieves the theme message with the given code, or text if code isn’t resolvable. The HTML escaping flag participates in a page-wide or application-wide setting (i.e. by HtmlEscapeTag or a "defaultHtmlEscape" context-param in web.xml).

Table 43.10. Attributes

AttributeRequired?Runtime Expression?Description

arguments

false

true

Set optional message arguments for this tag, as a (comma-)delimited String (each String argument can contain JSP EL), an Object array (used as argument array), or a single Object (used as single argument).

argumentSeparator

false

true

The separator character to be used for splitting the arguments string value; defaults to a 'comma' (',').

code

false

true

The code (key) to use when looking up the message. If code is not provided, the text attribute will be used.

htmlEscape

false

true

Set HTML escaping for this tag, as boolean value. Overrides the default HTML escaping setting for the current page.

javaScriptEscape

false

true

Set JavaScript escaping for this tag, as boolean value. Default is false.

message

false

true

A MessageSourceResolvable argument (direct or through JSP EL).

scope

false

true

The scope to use when exporting the result to a variable. This attribute is only used when var is also set. Possible values are page, request, session and application.

text

false

true

Default text to output when a message for the given code could not be found. If both text and code are not set, the tag will output null.

var

false

true

The string to use when binding the result to the page, request, session or application scope. If not specified, the result gets outputted to the writer (i.e. typically directly to the JSP).


43.12 The transform tag

Provides transformation of variables to Strings, using an appropriate custom PropertyEditor from BindTag (can only be used inside BindTag). The HTML escaping flag participates in a page-wide or application-wide setting (i.e. by HtmlEscapeTag or a 'defaultHtmlEscape' context-param in web.xml).

Table 43.11. Attributes

AttributeRequired?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.

scope

false

true

The scope to use when exported the result to a variable. This attribute is only used when var is also set. Possible values are page, request, session and application.

value

true

true

The value to transform. This is the actual object you want to have transformed (for instance a Date). Using the PropertyEditor that is currently in use by the 'spring:bind' tag.

var

false

true

The string to use when binding the result to the page, request, session or application scope. If not specified, the result gets outputted to the writer (i.e. typically directly to the JSP).


43.13 The url tag

Creates URLs with support for URI template variables, HTML/XML escaping, and Javascript escaping. Modeled after the JSTL c:url tag with backwards compatibility in mind.

Table 43.12. Attributes

AttributeRequired?Runtime Expression?Description

value

true

true

The URL to build. This value can include template {placeholders} that are replaced with the URL encoded value of the named parameter. Parameters must be defined using the param tag inside the body of this tag.

context

false

true

Specifies a remote application context path. The default is the current application context path.

var

false

true

The name of the variable to export the URL value to. If not specified the URL is written as output.

scope

false

true

The scope for the var. 'application', 'session', 'request' and 'page' scopes are supported. Defaults to page scope. This attribute has no effect unless the var attribute is also defined.

htmlEscape

false

true

Set HTML escaping for this tag, as a boolean value. Overrides the default HTML escaping setting for the current page.

javaScriptEscape

false

true

Set JavaScript escaping for this tag, as a boolean value. Default is false.