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Page Revision: 2010/10/12 14:57
Overview
In Jetfire a 'workflow' refers to a workflow object. A Jetfire 'workflow' is an instantiation of a '
Workflow Class'. Jetfire workflow classes have a number of unique
first class attributes such as persistence,
dynamic access modifiers, and
states. A workflow object at its heart is still a standard
OO object that describes data and operations (workflow class) that operate on the data.
Jetfire objects are either workflow objects or
Intrinsic Object s.
CLR vs Jetfire Object Model comparison
Unique features
In addition the Jetfire workflow objects have a number of feature not found in other languages.
- Workflow States
- Persistent
- Workflow objects are stored in a server nexus.
- Each workflow has a GUID supporting retrieval and tracking.
- Is automatically serialized to permanent storage.
- Upon start up workflow objects that reside in a fully cached workspace are automatically restored to client nexus.
- Workflow objects that are cached in 'partially' cached workspace are loaded on demand (when referenced) or when found as a result of a 'search' operation.
- Workflows can be made a 'Root Object' to prevent deletion by garbage collector.
- Integrated security
- Workflows can be assigned roles restricting which users have access to the workflow.
- Bound to source code
- Source code is compiled and dynamically linked to other source code.
- Code is represented as objects.
- Dynamic access modifiers
- Changes dynamically based on an optional 'access' or 'states' construct.
- The same workflow object can exist in multiple clients simultaneously.
- The server nexus is responsible for synchronizing updates.
Creating A Jetfire Workflow Object
A Jetfire object can be created programmatically by 2 techniques.
- Jetfire script using the 'new' operator.
- A workflow object can be created using the .net API.
Jetfire 'new' Operator
The new operator creates an instance of a workflow object. The new instance will be created in the same
workspace as the creating workflow object. If the new operator is executed by static code the new instance will be placed in the 'public' workspace by default.
namespace NewOperatorExample
{
public workflow Factory
{
// A method that creates a workflow object.
public MyFlow CreateMyFlow()
{
// the new operator creates a new instance
// of a MyFlow object;
return new MyFlow();
}
}
public workflow MyFlow
{
// Place methods, constructors and properties
// that define 'MyFlow' here.
}
}
Jetfire 'new' Operator 'root' Option
The '
root' option tells the 'Garbage Collector' not to collect the workflow even if the object has no references. This useful when container objects, such as
workspaces, are created programatically.
In order for the 'Garbage Collector' to collect 'root' objects they must be explicitly deleted.
namespace NewOperatorExample
{
public workflow Factory
{
// A method that creates a workflow object.
public workspace CreateWorkspace()
{
// the new operator creates a new instance
// of a workspace;
return new workspace() at root;
}
}
}
New Workflow Object using the Jetfire API