Extension:UploadWizard/CustomWikiTextLicenseFeature

This is a first draft of what we would like to see in a feature which fixes, "add custom license wikitext option". Be bold and edit this if we're getting it wrong.

Here is a first-draft mockup (constructed by directly manipulating the page in jQuery).



User stories
Note: user stories do not ever say how something is implemented, they just tell the story of what can be accomplished.
 * An experienced user is uploading a third-party image. She would like to use a license which we do not offer in the drop-down list. She is able to enter the wikitext that, when parsed, produces the license.
 * The user cannot intentionally or accidentally enter nonsense or a blank license

Validity
It would best nice to check if the wikitext So, if we are going to check wikitext correctness, we need to be ready to show errors in this interface.
 * parses (this can be done with an API call)
 * generates at least one template which is in Category:Licenses. (Is this possible?)

Correctness

 * The fact that this option exists should not make it easier to skip the licensing stage without at least entering something.
 * The interface should not attract confused or impatient people. We already have the FAL option and that seems to be a magnet for them.

Usability

 * Can we make this set a preference (or at least a cookie) so, if this custom wikitext is their favorite license, they don't have to keep snippets on hand?

Nongoals

 * Offering custom licenses for own-work images. We are still going to strongly urge people to use CC-BY-SA-3.0, or the other licenses currently in the "own-work" radio button section.

Thoughts and questions

 * Should we limit this feature to users who are autoconfirmed, or have some other user rights level that suggests they won't be confused by this, or won't abuse it?
 * A completely different idea: what if, instead of free wikitext, we autocompleted template names drawn from commons:Category:License tags and/or commons:Commons:Copyright tags ? It would be difficult to obtain the licenses in subcategories, but we can obtain them recursively and cache them for five minutes.