diff options
Diffstat (limited to 'server/src/com/vaadin/ui/declarative/Design.java')
| -rw-r--r-- | server/src/com/vaadin/ui/declarative/Design.java | 33 |
1 files changed, 22 insertions, 11 deletions
diff --git a/server/src/com/vaadin/ui/declarative/Design.java b/server/src/com/vaadin/ui/declarative/Design.java index 59393a7815..dc96e789bf 100644 --- a/server/src/com/vaadin/ui/declarative/Design.java +++ b/server/src/com/vaadin/ui/declarative/Design.java @@ -184,13 +184,18 @@ public class Design implements Serializable { // taken care of by jsoup. Element root = doc.body(); Elements children = root.children(); - if (children.size() != 1) { + if (children.size() > 1) { throw new DesignException( - "The first level of a component hierarchy should contain exactly one root component, but found " - + children.size()); + "The first level of a component hierarchy should contain at most one root component, but found " + + children.size() + "."); } - Element element = children.first(); + Element element = children.size() == 0 ? null : children.first(); if (componentRoot != null) { + if (element == null) { + throw new DesignException( + "The root element cannot be null when the specified root Component is" + + " not null."); + } // user has specified root instance that may have member fields that // should be bound final FieldBinder binder; @@ -222,7 +227,8 @@ public class Design implements Serializable { designContext.removeComponentCreationListener(creationListener); } else { // createChild creates the entire component hierarchy - componentRoot = designContext.readDesign(element); + componentRoot = element == null ? null : designContext + .readDesign(element); } designContext.setRootComponent(componentRoot); return designContext; @@ -255,8 +261,10 @@ public class Design implements Serializable { // creates the entire component hierarchy rooted at the // given root node. Component root = designContext.getRootComponent(); - Node rootNode = designContext.createElement(root); - body.appendChild(rootNode); + if (root != null) { + Node rootNode = designContext.createElement(root); + body.appendChild(rootNode); + } designContext.writePackageMappings(doc); return doc; } @@ -424,10 +432,11 @@ public class Design implements Serializable { /** * Writes the given component tree in design format to the given output - * stream + * stream. * * @param component - * the root component of the component tree + * the root component of the component tree, null can be used for + * generating an empty design * @param outputStream * the output stream to write the design to. The design is always * written as UTF-8 @@ -446,8 +455,10 @@ public class Design implements Serializable { * and other information not available in the component tree. * * @param designContext - * the DesignContext object specifying the component hierarchy - * and the local id values of the objects + * The DesignContext object specifying the component hierarchy + * and the local id values of the objects. If + * designContext.getRootComponent() is null, an empty design will + * be generated. * @param outputStream * the output stream to write the design to. The design is always * written as UTF-8 |