Format of Reference Pages
In this User's Guide, all functions and
class methods have a reference page that describes their usage. To
understand how to implement a class method in your script, it helps
to understand the layout of the reference pages.
Syntax Section
The Syntax section of a reference page shows
how the method or function is called by your script, including the
arguments and return values. As an example, look at the
CImage:PolyFitImage method page:
Syntax
bSuccess = CImage:PolyFitImage( ct,
rt )
bSuccess =
CImage:PolyFitImage( ct, rt, bConserve )
bSuccess = CImage:PolyFitImage( ct, rt,
bConserve, CRect )
Here is how to understand what is written:
bSuccess is the returned value. the name
bSuccess is a dummy that should be
replaced by your own variable, should you want to use the value
returned by PolyFitImage. You
can omit the dummy value and = sign if you do not want to use the
returned value. In this case, bSuccess begins with the letter
"b" which indicates that the
return value is a boolean variable (true or false). Names are often prefixed with the letters
b, n, or s to
indicate that the returned value is a boolean, number, or string.
This protocol is not adhered to all the time, especially when the
type of value is either obvious or may actually be any of these
types.
CImage:
is the name of the class that owns the PolyFitImage method. When you call a
class member, like PolyFitImage, from your script you must prefix
it with the name of the actual class object and not the name of the
class. For example, if you created a CImage object like this:
I = CImage:new(),
then I is the instance of the
class object that must prefix the call to PolyFitImage. Putting it together, our
script would look like this: I:PolyFitImage. If a different
CImage exists and is named
I2, then you would call the
same member for the other instance using the syntax I2:PolyFitImage.
Within parentheses () are the parameters of the method. In
the example above, the first two parameters, ct and rt, are
required. The second two parameters are optional. If they are not
specified, then default values are used.
Often the parameter list contains a
reference to another class object, like the CRect in PolyFitImage. For a class object
reference like this, pass the name of an instance of the class. For
example, if you used R=NewRect(1,2,100,200) to create an
instance of a CRect,
then you would pass R as the
CRect argument.
In summary, your actual usage of this method might
look like any of the following:
bSuccess = I:PolyFitImage( 2, 3,
true, R )
bSuccess = I:PolyFitImage( 2, 3,
false )
bSuccess = I:PolyFitImage( 2, 3
)
I:PolyFitImage( 2, 3 )
Examples Section
This section is present on most of the description
pages. It usually gives a short description of how to implement the
method followed by a script. In the script, the line containing the
actual method of interest is highlighted. Comments are included in
green, like this -- this is a comment, as you would
see them in the Script Editor. For the PolyFitImage example, here is what is
meant by a script:
|
I = CImage:new()
|
|
|
I:Open( sPath )
|
|
|
I:PolyFitImage(7,4)
|
|
|
I:Display()
|
|
|
I:delete()
|
|
Related Topics Section
The Related Topics lists links to other
topics having related methods or a similar purpose, just as shown
below.
Related Topics