Real Time Information Director User Documentation

RTID Metadata Language
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Director Metadata Is Implemented in Java
Director metadata is implemented in Java, a language that supports polymorphism. To
specify the attributes of a specific document type, you pass those attributes as parameters
to Java constructors.
To invoke a constructor, you use the Java new statement and provide the parameters
applicable to the object. For example, you define a circle in Java by typing “new Circle”
followed by the diameter; you define a rectangle by typing “new Rectangle” followed by
a length and width:
new Circle(16); // diameter = 16
new Rectangle(10, 8); // length = 10, width = 8
Metadata statements resemble these. (You’ll see some real examples soon.) You write
or modify the new statements that define the metadata.
But what of the logic that creates a Circle or a Rectangle from its parameters? The
behavior specific to a class is implemented in its other methods. In the case of Director
metadata, that implementation is transparent to you.
Director Metadata Is Easy to Write, in Most Cases
Writing metadata is not especially difficult. You don’t have to write procedural code,
such as if-then statements, loops, and switch statements. For the most part, you write new
statements. These statements are relatively concise, and there are models for you to
follow.
For convenience, you can use a Java Integrated Development Environment (IDE). A
Java IDE can show you when you have misspelled the name of a class, or when you have
mismatched braces or parentheses. It can prompt you with the parameters applicable to a
specific class and can complete the names of referenced objects for you.
Types of Document Definitions
You define metadata for the following types of documents:
• Insert documents. These documents originate in source systems and are loaded
into the data store.
• Update documents. These documents update existing records in the data store, so
they might contain only a subset of the fields defined for a corresponding insert
document.
• Query responses. These documents are returned to a client as the response to a
query. Query responses don’t have to correspond exactly to insert or update
documents. For example, a client might wish to receive partial information from
an order, or a document that contains information from multiple orders. (In fact,