Objects, Events and Platform Functions

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Each platform provides the following types of custom language constructs:

Objects

These provide a way to access the various facilities and subsystems of the host platform. For example, in a platform which supports networking, we would have a socket object that handles TCP/IP communication.

Each object has properties, methods and events:

A property of an object allows you to read or change an internal variable for this object. For example, a serial port object may have a baudrate property. Change the value of this property, and the actual physical baudrate changes. There are also read-only properties which only provide information.

 

 

ser.baudrate = 3 ' set the baudrate

x = ser.numofports ' find out how many serial ports the device has.

 

 

A method of an object is a way to make the object perform a certain action. It is basically a procedure. It can optionally take arguments or return values. Our ser object could have getdata and setdata methods, for instance.

 

 

s = ser.getdata(50) ' gets up to 50 bytes of data into variable s.

ser.setdata(s) ' prepares up to 50 bytes of data for sending.

ser.send ' no arguments, returns nothing. Sends data.

 

 

An event of an object is something that 'happens' to this object in reality. When TiOS registers an event, an event handler for it is automatically called, if it exists in your source code. Event handlers are simply subs with no arguments.

 

 

sub on ser_data_arrival

' ... do something! ... <-- will be called when data arrives into the serial port.

end sub

 

Platform Functions

Many functions commonly available in other BASIC versions are implemented in Tibbo Basic on the platform level and not on the "pure" language level; these include also seemingly universal functions, such as string processing, or various date and time functions. This is done so because not every platform would actually need these functions, universal as they may seem. Some platforms may have very limited resources, and not every platform needs to know what the time is, or how to parse strings.