Forum OpenACS Q&A: XOTcl Question

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1: XOTcl Question
Posted by Richard Hamilton on 03/11/11 11:53 PM
I am trying to work through some XOTcl code to understand it and I want to be able to refer to the code for the various methods so that I can see how things go together.

In the following code:

TableWidget t1 -volatile -columns ....etc.....

I can see that TableWidget inherits the volatile method from ::xotcl::Object, and I note that all methods with a 'c' superscript seem to be NOT displayed in the api browser. Does the 'c' mean that the method is inherited from a superclass? If so where are the method declarations kept (since ::xotcl::Object seems to be the top of the hierarchy in the API browser)?

https://openacs.org/xotcl/show-object?show%5fmethods=1&show%5fsource=0&object=%3a%3aTableWidget

So I cannot find the code for methods such as 'volatile'.

Also, why is there a hyphen when '-volatile' and 'column' are used? They look like parameters but are listed as methods.

I will continue to work through the tutorial and I apologise if the answers to these questions are in front of me.

Regards
Richard

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2: Re: XOTcl Question (response to 1)
Posted by Gustaf Neumann on 03/12/11 09:29 AM
The "C" stands for "implemented in C". The C implemented methods (and other predefined methods of XOTcl) are documented in the language reference (http://media.wu.ac.at/doc/langRef-xotcl.html). To see the source-code, you would have to study the implementation of XOTcl.

Concerning the dashes ('-'): One can invoke every defined method during object creation by prefixing the method name with the dash...

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3: Re: XOTcl Question (response to 2)
Posted by Richard Hamilton on 03/13/11 03:52 PM
Thank you Gustaf, that was a great help. I had decided to go through the tutorial before reading the language reference. Perhaps I should do it the other way around! 😊

R.

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4: Re: XOTcl Question (response to 3)
Posted by Gustaf Neumann on 03/14/11 12:05 PM
The reference manual is for the documentation of the predefined methods. Note that there is as well the XOTcl Tutorial http://media.wu.ac.at/doc/tutorial.html that might serve better for starters...