ZUML Reference/ZUML/Processing Instructions/import

Import Classes

Syntax to Import Classes

<?import class-name1 class-name2 ?>

[6.0.0]

It imports a class or a package of classes. It works like Java's import statement. For example,

<?import com.foo.composer.FooComposer?>
<?import com.foo.init.*?>

<?init class="FooInit"?><!-- it will look for com.foo.init.FooInit  -->
<window apply="FooComposer"><!-- com.foo.composer.FooComposer will be used -->
...

[Since 8.0.0]

After import, we can invoke the static method or field defined in imported class with el statement. For example,

<?import com.foo.FooClass ?>
<!-- or we can import com.foo.* -->
<label value="${FooClass.staticMethod()}"></label>
<label value="${FooClass.staticField}"></label>

Import Directives

Syntax to Import Directives

<?import uri="..."?>
<?import uri="..." directives="..."?>

It imports the directives, such as component definitions (<?component?>) and initiators (<?init?>), defined in another ZUML page.

A typical use is that you put a set of component definitions in one ZUML page, and then import it in other ZUML pages, such that they share the same set of component definitions, additional to the system default.

 <!-- special.zul: Common Definitions -->
 <?init zscript="/WEB-INF/macros/special.zs"?>
 <?component name="special" macroURI="/WEB-INF/macros/special.zuml" class="Special"?>
 <?component name="another" macroURI="/WEB-INF/macros/another.zuml"?>

where the Special class is assumed to be defined in /WEB-INF/macros/special.zs.

Then, other ZUML pages can share the same set of component definitions as follows.

 <?import uri="special.zul"?>
 ...
 <special/><!-- you can use the component defined in special.zul -->

Notes

• Unlike other directives, the import directives must be at the topmost level, i.e., at the the same level as the root element.
• The imported directives in the imported page are also imported. For example, if A imports B and B imports C, then A imports both C and B component definitions. If there is a name conflict, A overrides B, while B overrides C.
• Once the directives are imported, they won't be changed until the importing page is change, no matter the imported page is changed or not.

class

[Required if importing a class]

The name of a class, or a wildcard, such as com.foo.app.*.

uri

[Required if importing directives]

The URI of a ZUML page which the component definitions will be imported from.

directives

[Optional]

If the directives attribute is omitted, only the component, init and import (with class) directives are imported. If you want to import particular directives, you can specify a list of the names of the directives separated by comma. For example,

 <?import uri="/template/taglibs.zul" directives="taglib, xel-method"?>
 <?import uri="/template/java.zul" directives="import"?><!-- only <?import class="..."?> -->

The directives that can be imported include component, init, meta, taglib, variable-resolver, and xel-method. If you want to import them all, specify * to the directives attribute. Notice that meta implies both the meta, link and script directives.

Version History

Version	Date	Content
6.0.0	July, 2011	The import of classes was introduced.