---
name: "map_slippy_fetcher"
section: "3tcl"
platform: "linux"
package: "tcllib"
version: "2.0+dfsg-4"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/map_slippy_fetcher"
---

# map\_slippy\_fetcher(3tcl)

Accessing a server providing tiles for slippy-based maps

```

```

## NAME

map::slippy::fetcher - Accessing a server providing tiles for slippy-based maps

## SYNOPSIS

package require **Tcl 8.6 9**

package require **Tk 8.6**

package require **map::slippy**

package require **map::slippy::fetcher ?0.7?**

**::map::slippy::fetcher** *fetcherName* *levels* *url*

*fetcherName* **levels**

*fetcherName* **tileheight**

*fetcherName* **tilewidth**

*fetcherName* **get** *tile* *donecmd*

```

```

## DESCRIPTION

This package provides a class for accessing http servers providing tiles for slippy-based maps.

*BEWARE*, *Attention* Version *0.7* is *NOT backward compatible* with version 0.5 and earlier. This is due to switching this package's internals to the use of version 0.8 of **map::slippy**.

## API

- **::map::slippy::fetcher** *fetcherName* *levels* *url*

  Creates the fetcher *fetcherName* and configures it with the number of zoom *levels* supported by the tile server, and the *url* it is listening on for tile requests.

  The result of the command is *fetcherName*.

### METHODS

- *fetcherName* **levels**

  This method returns the number of zoom levels supported by the fetcher object, and the tile server it is accessing.

- *fetcherName* **tileheight**

  This method returns the height of tiles served, in pixels.

- *fetcherName* **tilewidth**

  This method returns the width of tiles served, in pixels.

- *fetcherName* **get** *tile* *donecmd*

  This is the main method of the fetcher, retrieving the image for the specified *tile*. The tile identifier is a list containing three elements, the zoom level, row, and column number of the tile, in this order.

  The command refix *donecmd* will be invoked when the fetcher either knows the image for the tile or that no image will forthcoming. It will be invoked with either 2 or 3 arguments, i.e.

  - \[1\]

    The string **set**, the *tile*, and the image.

  - \[2\]

    The string **unset**, and the *tile*.

-

  These two possibilities are used to either signal the image for the *tile*, or that the *tile* has no image defined for it.

## REFERENCES

- \[1\]

  *http://wiki.openstreetmap.org/wiki/Main\_Page*

## KEYWORDS

http, location, map, server, slippy, tile, url, zoom