How to write text onto a mapbox vector tile - leaflet

I want to label stations on my map, and I would like to clusterize the stops at different zoom levels to filter them down. So as you zoom out all you get is the start and end, and then finally a single label start->end.
How do I render a text label on a vector tile ?
I could fetch the stations as a geojson and reload on zoom change if there's no easy way to do this with tiles.

Is there a reason you need to encode your data differently per-zoom-level in the tiles or are you mainly concerned with displaying data differently per-zoom-level? If the latter, I would recommend looking for an approach that focuses more on styling the vector tiles you already have rather than trying to generate those tiles in a more complex fashion. You could try using a zoom function to style your data. If you're using Mapbox Studio, you can also set zoom-specific style rules in the Studio UI, which is the route you'll probably want to go if you're using Leaflet (I see the Leaflet tag in your post but it's not entirely clear what your implementation looks like).
If the former, you may need to use a tool like Tippecanoe. This route will likely be a bit more complex, but gives you fine-grained control over how your vector tiles are generated. Keep in mind that once you've created your tiles using Tippecanoe, you'll still need to style them somehow.

Related

How to render Mapbox vector tiles only within a specific country's boundaries?

I'm working on rendering some vector tiles using Mapbox Gl JS. These tiles are within the US and Canada, but I need only those within US boundaries to be rendered.
My tileset has the following metadata: gsd, name, miles. There is no metadata that indicates the country itself.
Is there a way to render only the tiles within a specific boundary? I tried with queryRenderedFeatures, but I need a solution with the tiles within precise US boundaries.
I cannot add the tileset URL here because it's part of proprietary software.
There's no straightforward way of doing that, for the reasons you describe.
You can try something like generating a shape which is the inverse of the US (ie, the whole world with the US cut out of it) and overlaying it, to block out everything else. But it will cut off labels and look...not great.

possible to show road-path-smooth items at lower zoom levels

I'd like for my road-path-smooth elements to show at a lower zoom level than they currently are because my application is for the outdoors and these are more important elements. Is that possible? I can't seem to find out how to adjust this in studio.
If you're talking about displaying layers from the Mapbox Streets tileset, then no, it's probably not possible. The vector tiles are optimised for Mapbox's style (also, confusingly, called Mapbox Streets), and don't contain data that isn't already displayed.
Your need is a common one, but unfortunately the only way to solve it is to find a different set of vector tiles that meets your needs, or create one yourself.

Is it possible to add a watermark in MapBox vector tiles?

A client would like to add their URL as a brand/watermark within a MapBox tiled vector layer in MapBox Studio, so that the watermark appears wherever the tiled vector layer is displayed. (One possible use-case is to discourage competitors from stealing that tiled layer in their own maps.)
Is it possible to add a watermark to a tiled layer in MapBox, and ensure that it's visible at least once in every view?
I tried adding a duplicate copy of a polyline dataset as a Symbol Layer, and labelling it with the client's URL using the Text Field option. This works but has the side effect of preventing the labels from appearing on the original copy of the line layer.
It is not possible to add a single occurrence of a watermark to a map style in Studio in the way that the Mapbox watermark is displayed on a map, but there are alternative approaches to achieve what you are looking to do.
If the underlying goal is to prevent competitors from using a particular map style (and hence an underlying tiled layer), the best approach is to set scopes and URL restrictions on the Mapbox access tokens being used to access the map style in a public environment. You can find more useful information about token management and access tokens in general in the Mapbox documentation. This approach could be used in conjunction with adding a branded "watermark" on the client side -- for example, placing a fixed div in the corner of a web map loaded with GL JS. Although this watermark obviously isn't included in the style itself, setting a URL restriction on the access token used to load the map would prevent others from accessing the same map with that token on other domains.
You could also experiment with adding a low-opacity background-pattern to relevant layers in the map style itself. This property could be used to mimic a traditional watermarked effect, where a particular logo is placed on an image at multiple regular intervals.

Marker versus point feature?

When should one use a marker instead of a feature layer of points in Mapbox?
Points layers can be updated and styled dynamically using all the styling tools of Mapbox GL JS. Features in points layers can also be clicked, presenting a popup just like with a marker.
Given this, when would one want to use a marker?
As Andrew mentioned there are two sides two this:
Accessibility
Markers are implemented as DOM elements and thus can be included in the tab order and can be given accessibility attributes
Animation
As markers are DOM elements animating them is quite easy with a bit of CSS & JS. You can animate points on a circle layer too, but its much more of a hassle.
Small point count
The number of markers/points you can display at once is somewhat limited by what the DOM can manage. My suggestion is that, if you have more than 500 points to display, you should opt for a circle layer instead of markers (this is a very rough estimates and depends on other parameters as well, animation, point size etc.). Using a circle layer you will hit - depending on the hardware - a limit in the 10s of thounds of points.

Leafleftjs - OpenstreetMap : Bring road names on top of Overlay layers

I am new to OpenstreetMap and Leafletjs. I am trying to implement a map displaying journey time information on motorways (also called highways in some part of the world) by using different colors to show road congestion and the problem I'm facing is, once the map tiles are rendered, it comes with all information, like town/city names, road names etc.
On the basis of road information that I receive, I create road colorings in an overlay that sits on top of the tile layer. The problem is, once that happens, the road colorings cover the road names that appear on the tile layer. The problem can be seen in the image displayed below.
Is there a way, I could extract the road names so that I could put it in a layer above the road coloring layer so that road names appear on top of road colorings.
Thanks for any sort of help, Looking forward to some replies.
Thanks
In theory, you could create two sets of tiles: one with the road lines, another with the shields (labels). Render the shields tiles with a transparent background. Then hack Leaflet around to have a second tile layer above the overlay layer.
However... that's a whole bunch of hassle for a fairly simple problem. So: why not render the road numbers alongside the roads, rather than on top of them? That way, your overlay line won't obscure the numbers. Here's an example of a style that does this (disclaimer: my site!).
Assuming you're using Mapnik to render your tiles, you'll want to use TextSymbolizer rather than ShieldSymbolizer. Customising the style is (of course) much easier if you're using TileMill rather than pure Mapnik XML.
As you say, the roadnames (here ref icon symbolizers) are part of the OSM raster map tiles and can't changed easily.
So the easiest solution would be to switch to a mapstyle without labels.
Another idea would be to add more alpha to your cusom GPS track, so it get's more 'hollow' and fits better in the mapstyle. But the default OSM style isn't good for adding informations on top, as this basemap is already to detailed. Maybe it makes sense to use another one:
http://wiki.openstreetmap.org/wiki/Featured_tiles