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Document WebFlux FreeMarker macro support in Reference Manual

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Closes gh-23133
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Sam Brannen
2019-06-13 17:37:48 +03:00
parent eef9bc899f
commit c4075cf216
2 changed files with 98 additions and 56 deletions
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55
src/docs/asciidoc/web/webflux-view.adoc
View File

@@ -36,7 +36,7 @@ http://forum.thymeleaf.org/Thymeleaf-3-0-8-JUST-PUBLISHED-td4030687.html[announc
[.small]#<<web.adoc#mvc-view-freemarker, Same as in Spring MVC>>#
https://freemarker.apache.org/[Apache FreeMarker] is a template engine for generating any
kind of text output from HTML to email and others. The Spring Framework has a built-in
kind of text output from HTML to email and others. The Spring Framework has built-in
integration for using Spring WebFlux with FreeMarker templates.
@@ -64,15 +64,15 @@ The following example shows how to configure FreeMarker as a view technology:
@Bean
public FreeMarkerConfigurer freeMarkerConfigurer() {
FreeMarkerConfigurer configurer = new FreeMarkerConfigurer();
configurer.setTemplateLoaderPath("classpath:/templates");
configurer.setTemplateLoaderPath("classpath:/templates/freemarker");
return configurer;
}
}
----
Your templates need to be stored in the directory specified by the `FreeMarkerConfigurer`,
shown in the preceding example. Given the preceding configuration, if your controller returns the view name,
`welcome`, the resolver looks for the
shown in the preceding example. Given the preceding configuration, if your controller
returns the view name, `welcome`, the resolver looks for the
`classpath:/templates/freemarker/welcome.ftl` template.
@@ -82,9 +82,9 @@ shown in the preceding example. Given the preceding configuration, if your contr
[.small]#<<web.adoc#mvc-views-freemarker, Same as in Spring MVC>>#
You can pass FreeMarker 'Settings' and 'SharedVariables' directly to the FreeMarker
`Configuration` object (managed by Spring) by setting the appropriate bean properties on
the `FreeMarkerConfigurer` bean. The `freemarkerSettings` property requires a
`java.util.Properties` object, and the `freemarkerVariables` property requires a
`Configuration` object (which is managed by Spring) by setting the appropriate bean
properties on the `FreeMarkerConfigurer` bean. The `freemarkerSettings` property requires
a `java.util.Properties` object, and the `freemarkerVariables` property requires a
`java.util.Map`. The following example shows how to use a `FreeMarkerConfigurer`:
[source,java,indent=0]
@@ -114,6 +114,47 @@ the `Configuration` object.
[[webflux-view-freemarker-forms]]
=== Form Handling
[.small]#<<web.adoc#mvc-view-freemarker-forms, Same as in Spring MVC>>#
Spring provides a tag library for use in JSPs that contains, among others, a
`<spring:bind/>` element. This element primarily lets forms display values from
form-backing objects and show the results of failed validations from a `Validator` in the
web or business tier. Spring also has support for the same functionality in FreeMarker,
with additional convenience macros for generating form input elements themselves.
[[webflux-view-bind-macros]]
==== The Bind Macros
[.small]#<<web.adoc#mvc-view-bind-macros, Same as in Spring MVC>>#
A standard set of macros are maintained within the `spring-webflux.jar` file for
FreeMarker, so they are always available to a suitably configured application.
Some of the macros defined in the Spring templating libraries are considered internal
(private), but no such scoping exists in the macro definitions, making all macros visible
to calling code and user templates. The following sections concentrate only on the macros
you need to directly call from within your templates. If you wish to view the macro code
directly, the file is called `spring.ftl` and is in the
`org.springframework.web.reactive.result.view.freemarker` package.
For additional details on binding support, see <<web.adoc#mvc-view-simple-binding, Simple
Binding>> for Spring MVC.
[[webflux-views-form-macros]]
==== Form Macros
For details on Spring's form macro support for FreeMarker templates, consult the following
sections of the Spring MVC documentation.
* <<web.adoc#mvc-views-form-macros, Input Macros>>
* <<web.adoc#mvc-views-form-macros-input, Input Fields>>
* <<web.adoc#mvc-views-form-macros-select, Selection Fields>>
* <<web.adoc#mvc-views-form-macros-html-escaping, HTML Escaping>>
[[webflux-view-script]]
== Script Views

99
src/docs/asciidoc/web/webmvc-view.adoc
View File

@@ -35,7 +35,7 @@ See https://www.thymeleaf.org/documentation.html[Thymeleaf+Spring] for more deta
[.small]#<<web-reactive.adoc#webflux-view-freemarker, Same as in Spring WebFlux>>#
https://freemarker.apache.org/[Apache FreeMarker] is a template engine for generating any
kind of text output from HTML to email and others. The Spring Framework has a built-in
kind of text output from HTML to email and others. The Spring Framework has built-in
integration for using Spring MVC with FreeMarker templates.
@@ -98,8 +98,9 @@ properties, as the following example shows:
----
Your templates need to be stored in the directory specified by the `FreeMarkerConfigurer`
shown in the preceding example. Given the preceding configuration, if your controller returns a view name
of `welcome`, the resolver looks for the `/WEB-INF/freemarker/welcome.ftl` template.
shown in the preceding example. Given the preceding configuration, if your controller
returns a view name of `welcome`, the resolver looks for the
`/WEB-INF/freemarker/welcome.ftl` template.
@@ -108,10 +109,10 @@ of `welcome`, the resolver looks for the `/WEB-INF/freemarker/welcome.ftl` templ
[.small]#<<web-reactive.adoc#webflux-views-freemarker, Same as in Spring WebFlux>>#
You can pass FreeMarker 'Settings' and 'SharedVariables' directly to the FreeMarker
`Configuration` object (which is managed by Spring) by setting the appropriate bean properties on
the `FreeMarkerConfigurer` bean. The `freemarkerSettings` property requires a
`java.util.Properties` object, and the `freemarkerVariables` property requires a
`java.util.Map`. The following example shows how to do so:
`Configuration` object (which is managed by Spring) by setting the appropriate bean
properties on the `FreeMarkerConfigurer` bean. The `freemarkerSettings` property requires
a `java.util.Properties` object, and the `freemarkerVariables` property requires a
`java.util.Map`. The following example shows how to use a `FreeMarkerConfigurer`:
[source,xml,indent=0]
[subs="verbatim,quotes"]
@@ -145,14 +146,15 @@ with additional convenience macros for generating form input elements themselves
[[mvc-view-bind-macros]]
==== The Bind Macros
[.small]#<<web-reactive.adoc#webflux-view-bind-macros, Same as in Spring WebFlux>>#
A standard set of macros are maintained within the `spring-webmvc.jar` file for both
languages, so they are always available to a suitably configured application.
A standard set of macros are maintained within the `spring-webmvc.jar` file for
FreeMarker, so they are always available to a suitably configured application.
Some of the macros defined in the Spring libraries are considered internal (private), but
no such scoping exists in the macro definitions, making all macros visible to calling
code and user templates. The following sections concentrate only on the macros you need
to directly call from within your templates. If you wish to view the macro code
Some of the macros defined in the Spring templating libraries are considered internal
(private), but no such scoping exists in the macro definitions, making all macros visible
to calling code and user templates. The following sections concentrate only on the macros
you need to directly call from within your templates. If you wish to view the macro code
directly, the file is called `spring.ftl` and is in the
`org.springframework.web.servlet.view.freemarker` package.
@@ -160,27 +162,27 @@ directly, the file is called `spring.ftl` and is in the
[[mvc-view-simple-binding]]
==== Simple Binding
In your HTML forms (vm or ftl templates) that act as a form view for a Spring MVC
In your HTML forms based on FreeMarker templates that act as a form view for a Spring MVC
controller, you can use code similar to the next example to bind to field values and
display error messages for each input field in similar fashion to the JSP equivalent.
The following example shows the `personForm` view that was configured earlier:
display error messages for each input field in similar fashion to the JSP equivalent. The
following example shows a `personForm` view:
[source,xml,indent=0]
[subs="verbatim,quotes"]
----
<!-- freemarker macros have to be imported into a namespace. We strongly
recommend sticking to 'spring' -->
<!-- FreeMarker macros have to be imported into a namespace.
We strongly recommend sticking to 'spring'. -->
<#import "/spring.ftl" as spring/>
<html>
...
<form action="" method="POST">
Name:
<@spring.bind "myModelObject.name"/>
<@spring.bind "personForm.name"/>
<input type="text"
name="${spring.status.expression}"
value="${spring.status.value?html}"/><br>
<#list spring.status.errorMessages as error> <b>${error}</b> <br> </#list>
<br>
value="${spring.status.value?html}"/><br />
<#list spring.status.errorMessages as error> <b>${error}</b> <br /> </#list>
<br />
...
<input type="submit" value="submit"/>
</form>
@@ -189,29 +191,29 @@ The following example shows the `personForm` view that was configured earlier:
----
`<@spring.bind>` requires a 'path' argument, which consists of the name of your command
object (it is 'command', unless you changed it in your `FormController` properties)
followed by a period and the name of the field on the command object to which you wish to bind.
You can also use nested fields, such as `command.address.street`. The `bind` macro assumes
the default HTML escaping behavior specified by the ServletContext parameter
object (it is 'command', unless you changed it in your controller configuration) followed
by a period and the name of the field on the command object to which you wish to bind. You
can also use nested fields, such as `command.address.street`. The `bind` macro assumes the
default HTML escaping behavior specified by the `ServletContext` parameter
`defaultHtmlEscape` in `web.xml`.
The optional form of the macro called `<@spring.bindEscaped>` takes a second argument
and explicitly specifies whether HTML escaping should be used in the status error
messages or values. You can set it to `true` or `false` as required. Additional form handling macros
simplify the use of HTML escaping, and you should use these macros wherever possible.
They are explained in the next section.
An alternative form of the macro called `<@spring.bindEscaped>` takes a second argument
that explicitly specifies whether HTML escaping should be used in the status error
messages or values. You can set it to `true` or `false` as required. Additional form
handling macros simplify the use of HTML escaping, and you should use these macros
wherever possible. They are explained in the next section.
[[mvc-views-form-macros]]
==== Input macros
==== Input Macros
Additional convenience macros for both languages simplify both binding and form
generation (including validation error display). It is never necessary to use these
macros to generate form input fields, and you can mix and match them with simple HTML
or direct calls to the spring bind macros that we highlighted previously.
Additional convenience macros for FreeMarker simplify both binding and form generation
(including validation error display). It is never necessary to use these macros to
generate form input fields, and you can mix and match them with simple HTML or direct
calls to the Spring bind macros that we highlighted previously.
The following table of available macros shows the FTL definitions and the
parameter list that each takes:
The following table of available macros shows the FreeMarker Template (FTL) definitions
and the parameter list that each takes:
[[views-macros-defs-tbl]]
.Table of macro definitions
@@ -263,9 +265,9 @@ parameter list that each takes:
| <@spring.showErrors separator, classOrStyle/>
|===
* In FTL (FreeMarker), `formHiddenInput` and `formPasswordInput` are not actually required,
as you can use the normal `formInput` macro, specifying `hidden` or `password` as the
value for the `fieldType` parameter.
NOTE: In FreeMarker templates, `formHiddenInput` and `formPasswordInput` are not actually
required, as you can use the normal `formInput` macro, specifying `hidden` or `password`
as the value for the `fieldType` parameter.
The parameters to any of the above macros have consistent meanings:
@@ -290,8 +292,7 @@ The parameters to any of the above macros have consistent meanings:
element that wraps each error uses. If no information is supplied (or the value is
empty), the errors are wrapped in `<b></b>` tags.
The following sections outline examples of the macros (some in FTL and some in VTL). Where usage
differences exist between the two languages, they are explained in the notes.
The following sections outline examples of the macros.
[[mvc-views-form-macros-input]]
===== Input Fields
@@ -300,7 +301,7 @@ The `formInput` macro takes the `path` parameter (`command.name`) and an additio
parameter (which is empty in the upcoming example). The macro, along with all other form
generation macros, performs an implicit Spring bind on the path parameter. The binding
remains valid until a new bind occurs, so the `showErrors` macro does not need to pass the
path parameter again -- it operates on the field for which a bind was last created.
path parameter again -- it operates on the field for which a binding was last created.
The `showErrors` macro takes a separator parameter (the characters that are used to
separate multiple errors on a given field) and also accepts a second parameter -- this
@@ -333,7 +334,7 @@ The generated HTML resembles the following example:
----
The `formTextarea` macro works the same way as the `formInput` macro and accepts the same
parameter list. Commonly, the second parameter (attributes) is used to pass style
parameter list. Commonly, the second parameter (`attributes`) is used to pass style
information or `rows` and `cols` attributes for the `textarea`.
[[mvc-views-form-macros-select]]
@@ -367,7 +368,7 @@ model under the name 'cityMap'. The following listing shows the example:
The preceding listing renders a line of radio buttons, one for each value in `cityMap`, and uses a
separator of `""`. No additional attributes are supplied (the last parameter to the macro is
missing). The `cityMap` uses the same `String` for each key-value pair in the map. The map's
keys are what the form actually submits as POSTed request parameters. The map values are the
keys are what the form actually submits as `POST` request parameters. The map values are the
labels that the user sees. In the preceding example, given a list of three well known cities
and a default value in the form backing object, the HTML resembles the following:
@@ -414,7 +415,7 @@ user still sees the more user-friendly city names, as follows:
[[mvc-views-form-macros-html-escaping]]
==== HTML Escaping
Default usage of the form macros described earlier results in HTML elemets that are HTML 4.01
Default usage of the form macros described earlier results in HTML elements that are HTML 4.01
compliant and that use the default value for HTML escaping defined in your `web.xml` file, as
used by Spring's bind support. To make the elements be XHTML compliant or to override
the default HTML escaping value, you can specify two variables in your template (or in
@@ -432,8 +433,8 @@ model or context variable named `xhtmlCompliant`, as the following example shows
<#assign xhtmlCompliant = true>
----
After processing
this directive, any elements generated by the Spring macros are now XHTML compliant.
After processing this directive, any elements generated by the Spring macros are now XHTML
compliant.
In similar fashion, you can specify HTML escaping per field, as the following example shows: