How to make a program that supports plugins?

MTK358 · 08-18-2010, 12:18 PM

Using PyQt4, is it possible to make a program where you can separately write custom QWidget subclasses and let the user add/remove them to your main app?

Sergei Steshenko · 08-18-2010, 01:15 PM

Quote:

Originally Posted by MTK358

Using PyQt4, is it possible to make a program where you can separately write custom QWidget subclasses and let the user add/remove them to your main app?

I think the question is equivalent to the question about existence of dynamic compilation and linking in Python. I think that 'eval' and possibly 'import' are the positive answers.

MTK358 · 08-19-2010, 10:17 AM

Quote:

Originally Posted by Sergei Steshenko

I think the question is equivalent to the question about existence of dynamic compilation and linking in Python. I think that 'eval' and possibly 'import' are the positive answers.

How?

I can't find any good tutorials about this.

Sergei Steshenko · 08-19-2010, 10:36 AM

Quote:

Originally Posted by MTK358

How?

I can't find any good tutorials about this.

What "how" ? You take Python documentation and learn about 'import' and 'eval'.

As always, ask the first thing you do not understand in the official documentation.

MTK358 · 08-19-2010, 12:16 PM

I don't understand how they can be used to achieve my goal.

Sergei Steshenko · 08-19-2010, 12:25 PM

Quote:

Originally Posted by MTK358

I don't understand how they can be used to achieve my goal.

You can call 'import', 'eval' in from whatever place of executable Python code. The arguments to the function can (indirectly) be files containing code of the widgets you wish to link to your program - this is the answer to your "let the user add/remove them to your main app ?" question.

Obviously, you can write widgets in PyQt.

Sergei Steshenko · 08-19-2010, 12:35 PM

FWIW, entering

python eval

into Yahoo yields as the very first match

http://docs.python.org/library/functions.html
.

Find 'eval' in the page, read the description to the very end and show some useful curiosity in the context of the description, i.e. read about yet another function mentioned in the 'eval' description.

As before, you do not use WEB search and you do not read manuals.

Sergei Steshenko · 08-19-2010, 12:37 PM

And you know what, just read the whole http://docs.python.org/library/functions.html (i.e. in case of Perl I would say read the whole 'perldoc perlfunc') - just scrolling the page I've found yet another useful for the purpose functions - before 'eval'.