I think you can't?
If you're site has may be one language that is used most of the time or when it might only have 1 language then it could be useful to set the default language. I think it should select the language automatically if there's only 1 option.

Comments

hkirsman created an issue.

maestrojed’s picture

It would be a nice addition to set a default language for new content. Also, when editing existing code, ideally the select field would default to that language.

I tried to investigate. The codesnippet library seems to be powering that form and the select options,
/libraries/codesnippet/dialogs/codesnippet.js ~Line 45-53

setup: function( widget ) {
	if ( widget.ready && widget.data.lang )
		this.setValue( widget.data.lang );

	// The only way to have an empty select value in Firefox is
	// to set a negative selectedIndex.
	if ( CKEDITOR.env.gecko && ( !widget.data.lang || !widget.ready ) )
		this.getInputElement().$.selectedIndex = -1;
},

I am not sure what needs to be done or if the CKEditor plugin class can support this. Maybe some others will have some pointers?