public interface VisualBuilder
Visual Builder for Functional Design
Visual Builder has several advantages over other tools typically used for functional design:
Instructions for launching Visual Builder are in the Smart GWT FAQ.
Basic usage instructions are embedded in Visual Builder itself, in the "About Visual Builder" pane. Click on it to open it.
Loading and Saving
The "Project" pane within Visual Builder allows screens to be saved and reloaded for further editing. Saved screens can be edited outside of Visual Builder and successfully reloaded, however, as with any design tool that provides a drag and drop, dialog-driven approach to screen creation, Visual Builder cannot work with entirely free-form code. In particular, when a screen is loaded and then re-saved:
The rest of this topic focuses on how Visual Builder can be customized and deployed by developers to make it more effective as a functional design tool for a particular organization.
Adding Custom DataSources to Visual Builder
DataSources placed in the project dataSources directory ([webroot]/shared/ds by default) will be detected by Visual Builder whenever it is started, and appear in the DataSource listing in the lower right-hand corner automatically.
If you have created a custom subclass of DataSource (eg, as a base class for several DataSources that contact the same web service), you can use it with Visual Builder by:
constructorproperty set to the name of your custom DataSource subclass (as described
ComponentXMLunder the heading Custom Components)
Adding Custom Components to Visual Builder
The Component Library on the right hand side of Visual Builder loads component definitions from two XML files in the [webroot]/tools/visualBuilder directory: customComponents.xml and defaultComponents.xml. customComponents.xml is empty and is intended for developers to add their own components. defaultComponents.xml can also be customized, but the base version will change between Smart GWT releases.
As can be seen by looking at defaultComponents.xml, components are specified using a tree structure similar to that shown in the tree XML loading example. The properties that can be set on nodes are:
className: name of the Smart GWT Class on which create() will be called in order to construct the component.
classNamecan be omitted to create a folder that cannot be dropped
title: title for the node
defaults: an Object specifying defaults to be passed to create(). For example, you could add an "EditableGrid" node by using
<defaults canEdit="true"/>NOTE: if you set any defaults that are not Canvas properties, you need to provide explicit type as documented under Custom Properties for
children: components that should appear as children in the tree under this node
icon: icon to show in the Visual Builder component tree (if desired)
iconWidth/Height/Size: dimensions of the icon in pixels ("iconSize" sets both)
showDropIcon: for components that allow children, whether to show a special drop icon on valid drop (like
In order to use custom classes in Visual Builder, you must modify
[webroot]/tools/visualBuilder/globalDependencies.xml to include:
component schemafor the custom component
When you provide
custom schema for a
component, Visual Builder
uses that schema to drive component editing (Component Properties pane) and to drive drag
and drop screen building functionality.
Newly declared fields will appear in the Component Editor in the "Other" category at the bottom by default. You can create your own category by simply setting field.group to the name of a new group and using this on multiple custom fields.
The ComponentEditor will pick a FormItem for a custom field by the
same rules used for ordinary databinding,
including the ability to
set field.editorType to use a custom FormItem.
When the "Apply" button is clicked, Visual Builder will look for an appropriate "setter
function" for the custom field, for example, for a field named "myProp", Visual Builder will
look for "setMyProp". The target component will also be
Event -> Action Bindings
The Component Properties pane contains an Events tab that allows you wire components events to actions on any other component currently in the project.
Events are simply
StringMethods defined on the
order to be considered events, method definitions must have been added to the class via
Class.registerStringMethods and either be publicly documented Smart GWT methods or,
for custom classes, have a methods definition in the
Examples of events are:
Actions are methods on any component that have a method definition in the
component schema and specify action="true".
All available events (stringMethods) on a component are shown in the Events tab of the Component Editor. Clicking the plus (+) sign next to the event name brings up a menu that shows a list of all components currently in the project and their available actions. Selecting an action from this submenu binds the action to the selected event. When an event is bound to an action in this manner, automatic type matching is performed to pass arguments from the event to the action as follows:
typeattribute on the method param in the
component schemadefinition of a custom component.
Component Drag and Drop
Visual Builder uses component schema to determine whether a given drop is allowed and what
methods should be called to accomplish the drop. For example, any Canvas-based component
can be dropped on a VLayout because VLayout has a "members" field of type "Canvas", and an
Because of these rules, any subclass of Canvas will be automatically eligible to be dropped into any container that accepts a Canvas (eg, a Layout or Tab). Any subclass of a FormItem will be, likewise, automatically eligible to be dropped into a DynamicForm.
You can declare custom containment relations, such as a custom class "Wizard" that accepts
instances of the custom class "Pane" by simply declaring a
component schema that says that Wizard has a
"panes" of type "Pane". Then, provide methods that allow components to be added and removed:
multiplefield, provide "add" and "remove" functions based on the name of the field. For example, for a field "panes" of type "Pane", provide "addPane()" that takes a Pane instance, and "removePane()" that takes a pane instance or pane ID
pane), provide a setter method named after the field (eg setContextMenu()) that takes either an instance of the component or null for removal
The "editing" log category can be enabled in the Developer Console to troubleshoot issues with schema-driven drag and drop and automatic lookup of getter/setter and adder/remover methods.
NOTE: after modifying component schema, it may be necessary to restart the servlet engine and reload Visual Builder
Presenting simplified components
Smart GWT components expose many methods and properties. For some environments, it is
more appropriate to provide a simplified list of properties, events, and actions on either
built-in Smart GWT components or your custom components. This can be done by providing a
component schema for an existing
component that exposes
your minimal set. You also need to provide a trivial subclass of the class you're exposing
so that it can be instantiated.
For example, let's say you want to make a simplified button called EButton that exposes only the 'title' property and the 'click' event of a standard Button. The following steps will accomplish this:
1. Edit /tools/visualBuilder/customComponents.xml and add a block similar to the following to make your custom component appear in the Component Library:
<PaletteNode> <title>EButton</title> <className>EButton</className> <icon>button.gif</icon> </PaletteNode>2. Next, create a custom schema: /isomorphic/system/schema/EButton.ds.xml as follows:
<DataSource ID="EButton" inheritsFrom="Button" Constructor="EButton" showLocalFieldsOnly="true" showSuperClassActions="false" showSuperClassEvents="false"> <fields> <field name="title" type="HTML"/> </fields> <methods> <method name="click"> <description>Fires when this button is clicked.</description> </method> </methods> </DataSource>See documentation above and also
component schemafor what the properties above do. 3. Finally, you'll need to define an EButton class as a simple subclass of Button, as follows:
iscInstall deployment instructions apply to Visual Builder except
that the "BuiltinRPCs", which are configured via
enabledBuiltinMethods setting in
must be enabled and include
FilesystemDataSource.enabled should be set to true
in order for Visual Builder to load and save files to the Smart GWT server. This also
means that Visual Builder should only be deployed within trusted environments.
Note that the Visual Builder provides a "live" interface to the provided DataSources. In other words, if a DataSource supports saving and a designer enables inline editing in a grid, real saves will be initiated. The Visual Builder tool should be configured to use the same sample data that developers use during development.