[mkgmap-dev] Minor process-destination issue

Fri Dec 28 13:21:53 GMT 2012

> Am 22.11.2012 16:05, schrieb WanMil:
>>> Do we have a style-function for this?
>>>
>>> item( ${destination}, 1 ) -> Bonn
>>> item( ${destination}, 2 ) -> Rodenkirchen
>>
>> No we don't and it will not be so easy to implement that because the
>> functions do not have any parameters yet at the moment. So it's a big
>> change.
>>
>> But the style system has a regular expression substitution:
>> ${destination|subst:;=> }
>> So everything behind subst: (in this case ";") is replaced with the
>> string after the => (in this case " "). Maybe the ; must be escaped but
>> generally it should work.
>
> Hi,
> I'm now using these rules:
>
> # Set the routing direction
> highway=motorway & ref=* & destination=* { add display_name =
> '${ref|subst: =>}(${destination|subst:;=> |subst:/=> })' }
>
> highway=trunk    & ref=* & destination=* { add display_name =
> '${ref|subst: =>}(${destination|subst:;=> |subst:/=> })' }
>
> So chars '/' and ';' are replaced by space. Also I shorten the
> ref (A 1 -> A1) to save one character.
>
> Now, more than one destination city is displayed on my Nuvi Navi.
>
> Note that I removed the motorway_link and trunk_link. They have
> no highway-symbol-shield and so display_name is not working for them.
>
> Chris

Hi Chris,

thanks for the hints. I think I will use that in the mkgmap default 
style too.

Anyhow I am wondering about the exact meaning of the tag display_name. 
It's not documented and I found only a short piece of code 
(StyledConverter.java) handling that:

String refs = combineRefs(element);

// Insert display_name as first ref.
// This causes display_name to be displayed in routing
// directions, instead of only the ref.
String displayName = Label.squashSpaces(element.getTag("display_name"));

if (displayName != null) {
	// substitute '/' for ';' in display_name to avoid it
	// getting split below
	displayName = displayName.replace(";","/");
	if (refs == null)
		refs = displayName;
	else
		refs = displayName + ";" + refs;
}

The tag is not documented in the OSM wiki. Throughout europe it is used 
only 26 times, so I would not call it an official tag.

So in mkgmap it should be named mkgmap:display_name instead to document 
that it is an internal tag. Additionally it can be removed from the 
builtin-tag-list.

If noone opposes I will change that starting with introducing 
mkgmap:display_name (is there a better name?) but accepting display_name 
too (giving a warning on stderr). After a while display_name can be 
removed completely.

WanMil