Load plugin depending on file extension

[ahenric]

Hi,

if I have multiple plugins for one interface, how can I distinguish between them? I basically want to load one plugin for the interface depending on the file extension of a file that is opened.

Must one basically get the instance (QPluginLoader, which loads a plugin), have each plugin have a function to return its name, if this does not match the file extension, unload the plugin and try the next one? Or is there a simpler way?

Thanks

[pmlit]

try that :
@switch (fileName.section('.', -1, -1))/* file extension /
{
case "abc" :// for "something.abc" files
/ load your file using QPluginLoader */
break;

case "xyz" :// for "plugin.xyz" files
    /* load your file the way you want */
break;

}
@

[lgeyer]

You can either

• load the plugin and determine the supported extension (as you suggested)
• encode the supported extension in the filename (eg. plugin_jpg.dll, plugin_bmp.dll)
• distribute and additional file which contains the supported extension (like QtCreators .pluginspec)

[lgeyer]

[quote author="pmlit" date="1340383889"]
@switch (fileName.section('.', -1, -1))/* file extension /
{
case "abc" :// for "something.abc" files
/ load your file using QPluginLoader */
break;

case "xyz" :// for "plugin.xyz" files
    /* load your file the way you want */
break;

}
@
[/quote]Be aware that a switch expression requires an integral type or a class type for which there is an unambiguous conversion to an integral type (or constexpr in C++11).

[pmlit]

[quote author="Lukas Geyer" date="1340389040"]Be aware that a switch expression requires an integral type or a class type for which there is an unambiguous conversion to an integral type (or constexpr in C++11).
[/quote]

I thought it was like switching a string because section() returns a QString.
If it do not work, you are maybe allowed to use if-else clauses, don't you ?

[lgeyer]

You cannot use a string (neither a std::string nor a QString) as switch expression. because it is not an intergal type. But you can of course, or better you will have to, use if ... else clauses.