A moderator just converted my accepted answer to a comment. Why was my accepted answer converted to a comment?
Screenshot of the question:
I have edited my answer, but now I am not able to flag it as undeleted. Why?
If a question can be answered by just a link then it's most likely symptomatic of a low quality question with little research beforehand. Stack Overflow should not become just a collection of links and awarding reputation from what's basically just a Google search seems a little perverse.
In the general case there's always scope to elaborate on a link, even a link to an API. A synopsis of the API in question for example, or a summary of the problems it solves (and can't solve) in relation to the question. If there's not enough meat to the question to make that possible then it's a bad question.
As the moderator that converted it to a comment, here's what happened:
The flag for "not an answer" was applied to your "answer", not the question, not other answers (at least, not that I've seen in the flag queue as of yet). At the time, I was looking specifically at your answer (in addition to the rest of the post).
As others have commented (and I believe they are correct and I used this exact reasoning when approaching this situation), upvotes and accepted "answers" don't validate posts which really aren't answers.
The points about whether or not a question is a real question have merit, and it will be looked at. However, moderators are encouraged on Stack Overflow (and some of the higher volume sites) to not hunt for content, but work primarily off the flag queue, so it's not guaranteed whether or not the question will be looked at in this light (although it more than likely will be now since you brought it's attention to meta, which pretty much has the effect of flagging the entire post in an indirect way).
With that in mind, even if the post is closed, it doesn't in any way validate that what you provided was nothing more than two links, and not an answer.
Was it helpful to the poster? Yes.
Was it an answer that contributed to the overall quality of the site and by extension, the Internet (as per the mission statement of Stack Exchange)? Absolutely not.
I think you'll also see by many of the comments that they agree.
In those cases, it's more often than not an indicator that the information should be placed in a comment, which is exactly what was done.
Also, it should be noted that your current edit is truly questionable, in the sense that it's nothing more than a copy-and-paste of the manual. We prefer to have users put some effort into providing an answer and discourage copy-paste answers.
Generally, people frown on link-only answers for the reasons others have better described here. Many of these get flagged as not being real answers, and some get deleted or converted to comments.
Your answers were better than the typical ones I see (which often just consist of something like "check this link I think it help u"), and the whole point is to link to the FMDB framework, but they could have been fleshed out a little bit. If nothing else, this would help someone in the future to find replacement links to the project, should the ones you provided go dead.
I'd suggest re-posting an answer worded something like the following:
This gives a little more context on what FMDB is, why they might want to use it, and where they could find out more about it.
To be honest, though, I'd vote for the other answer there because Core Data really is the way to go for storing data on iOS, and can save a tremendous amount of code over raw SQLite. However, Gus just updated his FMDB to a 2.0 version, and it can be useful for certain applications.
I think we need to start being more circumspect in removing link-only answers. Sure, if the question is
But this question was asking for an API. The answer provided an API. I'm guessing it was a good api, since it got 3 upvotes. It was very nice of the other answerer to provide a link to another api, and also give some commentary on how to use it, but I don't think that should be a requirement.
If I ask a question looking for an api to run dynamic queries in linq, and someone gives me a link to the dynamic linq api, then golden— +1 and accept. My question is now answered. I don't expect him to also give me commentary on how to use it. It's my job to learn the tool, and if I get stuck, I'll ask a new question.