[Qgis-developer] Proposal for plugin convention

[Martin Dobias]

On Tue, Mar 2, 2010 at 7:34 PM, Chris Crook <ccrook at linz.govt.nz> wrote:
> Hi
>
> Several of the plugins that Qgis can use put information into the project file.  For example plugin layers, renderers, and settings.  I think it might be a good idea to establish some conventions so that it is easy to determine what plugins are required to load a project, and to allow Qgis to provide meaningful error messages when the project is loaded in a Qgis instance that doesn't have the plugins loaded.
>
> [...]
>
> Does this sound like a good idea?  Or perhaps there is a better idea, or even conventions already in place that I have overlooked?

We've been talking about some conventions for plugins the last
hackfest few months ago as there's an increased need to make them
behave in an predictable way. However we haven't prepared any such
guidelines yet. Your suggestions make sense and I believe they should
be a part of the guidelines.

It would be good to investigate what modifications would have to be
done to make qgis handle these conventions well - e.g. the project bad
layer handler could be transformed to a more general "project errors"
handler and would inform the user about missing plugins, problem
severity (fatal / warning) and eventually allow automatically install
the missing plugins.

Probably we'll need to move the QgsPluginRegistry and some support
routines (including python plugins support) from qgis app to the core
library in order to allow QgsProject or other core classes inspect
what plugins are available and enabled.

Cheers
Martin