Option for omitting a filename

[jczaplew]

Adds the option noFilename to the main tilestrata configuration parameters to allow for the {z}/{x}/{y}.{extension} request format.

While this is a global setting, I can also see arguments for having it be a route-specific parameter.

To use it, simply pass {noFilename: true} when initializing the the tileserver, and pass the file extension in place of the filename (.route('png')) .

Let me know what you think!

[codecov-io]

Codecov Report

Merging #21 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #21      +/-   ##
==========================================
+ Coverage   97.51%   97.52%   +<.01%     
==========================================
  Files           8        8              
  Lines         685      686       +1     
==========================================
+ Hits          668      669       +1     
  Misses         17       17

Impacted Files	Coverage Δ
lib/TileRequest.js	100% <100%> (ø)	⬆️

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[brianreavis]

Thanks for taking a stab at this @jczaplew! One concern is that as this is now it'll cause certain problems downstream in plugins that currently expect filename to be indicative of the mime type. The tilestrata-disk plugin is what comes to mind: https://github.com/naturalatlas/tilestrata-disk/blob/master/lib/cache.js#L101

The quick fix is to make req.filename have a dot in front (.png vs png).

Instead of a noFilename option, what do you think about making it configurable per route like you hinted about with some sort of convention like a leading * (that we could note in the readme):

.route('*.png')

Once we get this worked out, I'd love to get this in! I have a feeling it'll make quite a few people happy.

[jczaplew]

Sounds good @brianreavis! Makes a lot of sense.

Another oddity that I'm not sure is a concern or not is that this approach will result in caches like tilestrata-disk saving the tiles as /{z}/{x}/{y}/*.{extension}, when ideally they would be saved as /{z}/{x}/{y}.{extension} instead. It certainly works and I don't see many drawbacks besides a lack of elegance. Perhaps it is something that can be optionally changed on the caches themselves.

[jczaplew]

@brianreavis - is there anything else you would like changed on this pull?

[brianreavis]

Oops, sorry – fell off my radar. Thanks for the nudge! Going to merge this as it is and make some subtle changes to address some of the questions you bring up. Might be easier to do it than try to articulate :)

Really appreciate the work on this!

[brianreavis]

Alright, this is now out in 2.1.0. Thanks for tackling the bulk of this @jczaplew! To sum up the adjustments in e002a71:

• Made resolution suffixes parse fine. e.g. route('*@2x.png')
• Exposed hasFilename on TileRequest
• Made the filename convention "t" + extension for these sorts of requests. This way we don't end up with filenames with asterisks and it's totally backwards-compatible with everything. I thought about just stripping the * off, but leaving people with dotfiles (that some OS's hide by default) didn't seem like a great idea either.
  • Although it is a little funky, I think it's fine if the convention is clear and we expose hasFilename to make it transparent.
• More tests / documentation

Just as a footnote, if you want a cache layout that matches the urls for whatever reason, something like this (ish) would work:

var dest = req.z + '/' + req.x + '/' + req.y;
if (req.hasFilename) {
   dest += '/' + req.filename;
} else {
   dest += req.filename.substring(1);
}

[jczaplew]

Awesome! Thanks a ton @brianreavis!