Why should tags be space-delimited?_问答_开发者

I'm working on a Web application that uses tags like Stackoverflow tags. I've noticed that a lot of sites that use tags make them space-delimited, which disallows a tags like...

"favorite recipes"

Instead they enforce this...

"favorite-recipes" | "favorite_recipes" | "FavoriteRecipes"

If the tags were comma-deli开发者_JS百科mited, an item could have a set of tags like...

"cats, birds, favorite recipes, horses"

I have to decide on the policy for my app.

I guess I like the idea of space-delimited, but if my users aren't programmers they might be more comfortable with the familiar idea of commas denoting a list.

Why are comma-delimited tags unusual? Is there a major downside to them?

I think space delimited tags feel more like typing and you aren't syntactically bound to commas or pipes etc...

I also think that not allowing spaces in tags is kind of nice because you don't have to worry about turning them into URLs they are already ready to go.

Online tools like Delicious use space delimiting for tags, but other tools like Wordpress allow you to have spaces in tags so they require commas. If you do things this way, you will have to create similar tag "slugs" to make sure they work in a URL cleanly (i.e. my tag would be my-tag)

Remember, allowing too much freedom in your tag creation can result in some pretty crazy tags like "Things I like to do on a Saturday afternoon..." etc.

I think the idea is that a tag should be short and to the point.

If you go to type in "favorite recipes", when it doesn't work, you think to yourself "Oh, I should redo this." So you make "favorites" "recipes" instead.

If it was something you really needed, like "pork roast" then it makes sense to make it "pork-roast" but only after you've thought about really joining those works. Perhaps you shouldn't though - perhaps it should be "pork" "roast" so it shows up under searches for pork and searches for roast.

tl;dr It's for user experience and searching so they don't enter something that can't be easily searched for.

Yes, I also think that space-separated tags reduce complexity. And you can enter them faster, because you have the big space key to separate them. Maybe the brain is also less loaded, because it doesn't need to think about where to put a comma delimiter and where not.

I built an app with tags once, and used commas. The only down side to commas is that you have to do more thorough checking of empty tags. For instance in the example:

"George Bush, Bill Clinton, Barack Obama, "

If someone posts the tags with a comma at the end and there is a space it generally will get added to the database.

This is because if you simply check to delete once space you would turn Bill Clinton into BillClinton.

However you can make sure that the tag is at least a certain amount of characters to ensure there is not empty tags. This will not ensure that there is not three or four spaces in a row though.

Anther thing to note is that humans generally put spaces before words and after commas.

So in the example above there is a space after each comma and before each president. This space will be included in the database making the tag:

" Bill Clinton"

instead of

"Bill Clinton"

as the user probably attempted.

Once again you can eliminate both beginning and trailing spaces, but there is more server side code to implement in this case.

If you just use spaces then you can eliminate any unwanted characters like commas etc, and put the tags into an array using space characters to separate them.

I actually prefer tags that are comma or semi-colon delimited for two basic reasons:

It's more natural (user-centric not techie-centric)
It reduces redundancy, as the example noted "favorite-recipes" "favorite_recipes" "FavoriteRecipes"

And I'm afraid some of the other answers sort of make it sound as if web developers are (how shall I say this) less willing to do the work than, for instance, database developers - who've been addressing some of these same issues for years. (I've coded for web and client-server databases.)