Basic Concepts

Iotellect SDK indoctrinates a generic approach to managing any type of data flowing inside the system, both raw data coming from devices and pre-processed data provided by different system facilities, such as alerts or trackers. This approach also applies to any of the pre-built vertical market solution, such as Iotellect Network Manager, Iotellect SCADA/HMI, Iotellect Access Control, and other.

Iotellect Architecture

Technically, Iotellect is a set of Java applications and components (libraries). Two primary Java applications that constitute the platform are:

  • Iotellect Server
  • Iotellect Client

Standalone software components embeddable into third-party software are:

Any code using other parts of the Iotellect SDK (e.g. Driver Development Kit, Plugin SDK, Widget Component SDK) runs either inside Iotellect Server JVM or inside Iotellect Client JVM.

The very formal description of Iotellect is available on Specification page.

Data Table Operations

  • The elementary unit of all data flowing inside the system is Data Table. Even simple scalar values (integers, strings, booleans) are represented by single-cell Data Tables for the sake of uniformity. The Java representation of Data Table is DataTable interface. Objects of classes implementing this interface can include zero or more DataRecord instances representing individual records.
  • Format of DataTable is represented by TableFormat class. It refers zero or more FieldFormat instances defining format of individual table fields.

Working via Contexts

  • Generally, all data should be accessed through different server contexts. Contexts are organized as a hierarchical context tree. The SDK includes Context interface for handling different context operations. Context instances may be retrieved from the ContextManager by their paths (full names). The Context interface also has a series of methods to access its parent and children.

Accessing Context Variables, Functions and Events

  • Every context provides access to its variables, functions and events. There are several methods to get their definitions: getVariableDefinition(), getVariableDefinitions(), getFuncitonDefinition(), getFuncitonDefinitions(), getEventDefinition(), getEventDefinitions(). Classes representing the definitions are VariableDefinition, FunctionDefinition and EventDefinition respectively.
  • Context interface provide a way to read/write values of variables: getVariable() and setVariable(). Value of every variable is an instance of DataTable (meaning an instance of a subtype of the DataTable type).
  • Context also provides a method for calling its functions: callFunction(). Both input and output of a function are instances of DataTable.
  • Events are handled by adding and removing event listeners using addEventListner() and removeEventListener() methods. Event listener must implement ContextEventListerner interface, but the real implementations will extend DefaultContextEventListener in most cases. Listeners working inside server plugins and drivers should pass an instance of UncheckedCallerController to the constructor of DefaultContextEventListener to ensure proper permissions.

getVariable() method returns an immutable DataTable that represents a variable value. This is valid even in the case of server-side code (plugins, drivers). To apply a new value to the context variable, clone the table first, then modify the cloned table and pass the latter to setVariable() method of the corresponding context.

Direct modifications of DataTable returned by getVariable() will produce an Immutable exception.

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