Patent Application
20060136935
The present invention relates to data processing by digital computer, and more particularly to a framework for managing software components.
Software applications are often structured into reusable software components. A software component is a group of software modules, or components, that can be combined with other software components to form a software application. Software components encapsulate functionality and allow an application developer of the software application to use the software component without having to understand its implementation.
In general, in one aspect, the invention provides methods and apparatus including computer program products implementing techniques for managing software components using a framework. The techniques provide a framework for executing embeddable reusable software components. The framework uses a framework state model and implements one or more interfaces. The framework state model includes multiple model states and multiple model state transitions, where each model state transition is a state transition from a model state to a model state. The techniques provide one or more embeddable reusable components, where each of the components implement a respective component state model that is a projection of the framework state model. Each component further implements one or more of the interfaces, and implements respective operations to perform state transitions supported by the component. The framework is operable to use the interfaces to cause components executing under the control of the framework to perform component operations, and to provide component state information to the framework. The interfaces define methods usable to determine a current state of a specified component, determine which state transitions are available state transitions for the current state for the specified component, and direct the specified component to perform a specified available state transition. The available state transitions are one or more of the allowable state transitions that are implemented by the selected component for the current state. The specified component implements the operations required to be performed in order to achieve the specified available state transition.
Advantageous implementations of the invention include one or more of the following features. The framework state model includes one or more mandatory model states and mandatory model state transitions that must be implemented by each component. The components have a hierarchical relationship. The component has one or more roles, where each component role specifies a subset of the interface that can be used by the framework to manage the component model state. The framework provides a component name service to identify the component implementing a specified component role. The component dynamically publishes at runtime all the available component model state transitions implemented for the current state. The available state transitions published by the component have one or more attributes including a description, an identifier, an icon, a tool-tip, and a position. The specified available state transition is selected by the framework based on user input directed to the specified component.
In another aspect, the invention provides methods and apparatus implementing techniques for receiving input at a framework identifying a component of one or more embeddable reusable software components, where the framework specifies a framework state model and implements one or more framework interfaces. The framework state model includes multiple model states and multiple model state transitions, where each model state transition is a state transition from a model state to a model state. The framework interfaces are operable to manage the components. Each component of the one or more embeddable reusable components implements respective components state model that is a projection of the framework state model. Each component implements one or more of the framework interfaces. The techniques further include determining the current state of the identified component using the framework interface, determining the available state transitions for the current state, and triggering one of the available state transitions based on input received by the framework. The available state transitions are one or more of the model state transitions for the current state that are implemented by the component. The operations required to perform the triggered state transitions are implemented by the component.
The invention can be implemented to realize one or more of the following advantages. The framework provides a predefined user interface for the management of reusable software components. Components implementing a projection of the framework state model and a subset of the framework interfaces can be managed with no knowledge at design time of functions provided by the component or the implementation of the component. Providing a predefined user interface for managing components facilitates the reuse of components in different applications and by different application developers. Components implementing a projection of the framework state mode can use and manage other components implementing a projection of the framework state model with no knowledge of their implementation. A customer receiving the components from a component developer can manage the components with no knowledge of the functions provided by the components or the implementation of the components. The customer can develop new components that implement a projection of the framework state model and manage them using the predefined user interface provided by the framework. One implementation of the invention provides all of the above advantages.
Details of one or more implementations of the invention are set forth in the accompanying drawings and in the description below. Further features, aspects, and advantages of the invention will become apparent from the description, the drawings, and the claims.
Like reference numbers and designations in the various drawings indicate like elements.
The set of component interfaces 125 includes one or more interface functions that are used by the framework to manage the component. The framework uses the component interfaces 125 to cause components to perform state transitions specified by the framework state model and to provide state information to the framework. The component interfaces 125 include interface functions to determine a current state of the component and interface functions to determine the available state transitions for the current state of the component. The available state transitions are the framework model state transitions that the component implements for the current state. The component interfaces 125 also include interface functions to direct the component to perform a specified state transition, where the specified state transition is one of the available state transitions for the current state. The component provides an implementation for all the state transitions in the component state model.
The “Present” state 210 of the framework state model is implemented using a state model 215 that includes five states—“Created” 220, “Edit” 225, “Display” 230, “Transient” 235, and “Background” 240. A component in the “Display” state cannot be modified. A component is in the “Transient” state 235 if it has been modified. A component is in the “Edit” state 225 if it has not been modified, but it can be modified. A component in the “Background” state 240 cannot be displayed or edited even though it has been loaded by the framework. The framework state model can specify mandatory model state transitions that must be implemented by each component state model. Table I is an example of the mandatory state transitions that must be implemented by each component state model.
A component can have one or more roles, where each role specifies a subset of the component interfaces that can be used by the framework to manage the component model state. For example, a component can have an edit role and a display role, where the edit role includes interface functions required to edit the component but the display role does not include these interface functions. The framework can provide a component name service for identifying a component that implements a specified role.
The framework can provide a visual interface for managing a component using the attributes associated with the state transitions of the component. For example, the component can provide a tool bar that visually displays information regarding the available state transitions for the current state of the component. For each available state transition, the toolbar can include a short description, an identifier, an icon and a tool-tip, and a position of the icon and tool-tip on the toolbar. The toolbar provided by the component can be used by the framework as part of a framework visual interface for managing the components. An embedding component can also provide a visual interface for managing embedded components using the attributes associated with the state transitions of the embedded component. For example, the embedding component can include an embedded component's toolbar as part of the embedding component's visual interface.
An embedding component manages embedded components using the component interfaces of the embedded components. If the implementation of a state transition for Component_A requires a corresponding state transition in Component_B, Component_A directs Component_B to perform the corresponding state transition using the Component_B framework interface. Similarly, Component_B directs Component_C to perform state transitions using the Component_C framework interface. For example, Component_A implements a Delete transition by deleting its own data from a database and triggering a Delete transition for Component_B. Component_B implements the Delete transition by deleting its own data from the database and triggering a Delete transition for Component_C, and Component_C implements the Delete transition by deleting its own data from the database.
The invention and all of the functional operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in this specification and structural equivalents thereof, or in combinations of them. The invention can be implemented as one or more computer program products, i.e., one or more computer programs tangibly embodied in an information carrier, e.g., in a machine-readable storage device or in a propagated signal, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. A computer program (also known as a program, software, software application, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file. A program can be stored in a portion of a file that holds other programs or data, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub-programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.
The processes and logic flows described in this specification, including the method steps of the invention, can be performed by one or more programmable processors executing one or more computer programs to perform functions of the invention by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus of the invention can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).
Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.
The invention has been described in terms of particular embodiments, but other embodiments can be implemented and are within the scope of the following claims. For example, the operations of the invention can be performed in a different order and still achieve desirable results. Other embodiments are within the scope of the following claims
