Replace pipe "|" character in (backend) URLs

[nrenner]

The pipe "|" is not a valid URI character (taken from an old CycleStreets URI scheme without checking). It is used as a separator in lonlats and nogos URL parameters both for hash permalink and server request.

Candidates:

• slash "/"
  used in leaflet-hash #map=4/53.17/14.59, but as value (we use ",") not list separator
• semicolon ";"
  used by openstreetmap.org
• underscore "_"
• tilde "~"

see:

• handling url encoded parameters · abrensch/brouter#72
• Route URL comparison · Wiki

• RFC 3986 - Appendix A. Collected ABNF for URI

  URI           = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
  ...
  
  pchar         = unreserved / pct-encoded / sub-delims / ":" / "@"
  
  query         = *( pchar / "/" / "?" )
  fragment      = *( pchar / "/" / "?" )
  
  pct-encoded   = "%" HEXDIG HEXDIG
  
  unreserved    = ALPHA / DIGIT / "-" / "." / "_" / "~"
  reserved      = gen-delims / sub-delims
  gen-delims    = ":" / "/" / "?" / "#" / "[" / "]" / "@"
  sub-delims    = "!" / "$" / "&" / "'" / "(" / ")"
               / "*" / "+" / "," / ";" / "="

[ntruchsess]

since https://github.com/abrensch/brouter/commit/77ee79bdc3ae86b08ae96ee3f5702ce6d629239f brouter does apply standard URL-decoding to the whole query-string. So pipe-character might not be 'human readable' when being encoded, but such request is not for human eyes anyway. Being encoded does increase the payload by a few bytes though. In fact as the list of lon-lats is being used as a single query-parameter whose content is then tokenized into the array you shouldn't take any of the reserved delimiter-chars to separate lon-lat array members as most query-string building frameworks would apply url-encoding to these characters as well (because it's forbidden to use a not url-encoded reserved character within a query-parameter). My recommendation therefore is - as long you stick with get-request and long query-string - to leave it as it is and if you really want to change it take one of the 'unreserved' range. Otherwise I'd recommend you should e.g. use a post-request and put the payload e.g. json-encoded into the request body (where no such encoding-restrictions apply).

[ntruchsess]

BTW: have you seen my contribution to brouter, the support of open and closed polylines as nogo-areas? Currently one can use this using QMapshack. I'm working on a new Android-app with full support for it. Would be nice to see this in brouter-web as well.

[nrenner]

See #144 for polygon/line nogo support

[bagage]

I'd like brouter-web to replace the pipe | character with anything else. Apart of being non standard, it breaks URL recognition on various applications (eg. when you share a brouter link to a chat app, or email, or…).

In my opinion:

• / should not be used at it is usually used for app routing (eg. github.com/<user>/<repository>/issues. It does not make sense here.
• ~ sounds strange to me. It does not feel like a list items separator. Same for _
• ; would be the best candidate, but maybe , could do the trick too?

[nrenner]

; is also my favourite, , used to separate lon,lat - would like to keep distinguishing those two separators.

[nrenner]

Keeping this open to also adjust the server request just for consistency, but no rush, as the issues with | are fixed now.