Accessing Type Members

LINQ Reporting Engine enables you to access the following public (static and instance) members of accessible types (see “Working with Types” for more information) in template expressions:

• Fields
• Methods
• Constructors

Note – To access a static member of a type in a template expression, the type must be set known for the engine (see “Setting up Known External Types” for more information).

A function type member can be used in a template expression only if the following additional requirements are met:

• The function member returns a value.
• The function member does not take generic type arguments.

The engine supports the following features when dealing with function members:

• Overload resolution according to C# Language Specification 5.0
• Using of parameters taking a variable number of arguments

In addition to C# Language features, the engine provides the following extra features to simplify type member access:

• Accessing members of an object without specifying the object’s identifier (see “Using Contextual Object Member Access” for more information)
• Accessing missing members of an object (see “Accessing Missing Members of Data Objects” for more information)

---

FAQ

1. Q: How can I access a static field or method of a Java class inside a LINQ Reporting Engine template?
   A: First register the class as a known external type using engine.getKnownTypes().add(ClassName.class). Then you can reference the static member directly in the template, e.g., <<ClassName.StaticField>> or <<ClassName.StaticMethod(arg)>>.

2. Q: Are instance methods of objects passed to the template callable from the template expression?
   A: Yes. If an object is supplied to the engine as a data source, you can invoke its public instance methods directly, such as <<objectInstance.InstanceMethod()>>. The method must be public and return a value.

3. Q: Can I create a new object inside a template using a constructor?
   A: Constructors are supported as long as they are public, have no generic type arguments, and return a value (the new instance). Use the syntax <<new ClassName(arg1, arg2)>> after the type has been added to the known types list.

4. Q: What restrictions apply to methods used as function members in template expressions?
   A: The method must return a value and cannot have generic type parameters. Overload resolution follows the C# Language Specification 5.0 rules, and methods that accept a variable number of arguments (params) are also supported.

5. Q: Why does the engine report “type must be known” when I try to use a static member?
   A: The engine only allows static members of types that have been explicitly added to the known external types collection. Add the type with engine.getKnownTypes().add(YourClass.class) before processing the template.