ckanext-versioned-tiledmap

A CKAN extension with a map view for versioned-datastore backed resources.

Overview

A CKAN plugin with a map view for versioned-datastore backed resources allowing for map visualizations of large resources with millions of data points.

This repository is a fork* of ckanext-map.

*you can't fork repositories within the same organisation, so this repository is a duplicate of ckanext-map.

Installation

Path variables used below:

• $INSTALL_FOLDER (i.e. where CKAN is installed), e.g. /usr/lib/ckan/default
• $CONFIG_FILE, e.g. /etc/ckan/default/development.ini

Pre-install setup

This extension depends on the following projects, which must be installed first:

• versioned-datastore-tile-server

Installing from PyPI

pip install ckanext-versioned-tiledmap

Installing from source

1. Clone the repository into the src folder:

   cd $INSTALL_FOLDER/src
   git clone https://github.com/NaturalHistoryMuseum/ckanext-versioned-tiledmap.git

2. Activate the virtual env:

   . $INSTALL_FOLDER/bin/activate

3. Install via pip:

   pip install $INSTALL_FOLDER/src/ckanext-versioned-tiledmap

Installing in editable mode

Installing from a pyproject.toml in editable mode (i.e. pip install -e) requires setuptools>=64; however, CKAN 2.9 requires setuptools==44.1.0. See our CKAN fork for a version of v2.9 that uses an updated setuptools if this functionality is something you need.

Post-install setup

1. Add 'versioned_tiledmap' to the list of plugins in your $CONFIG_FILE:

   ckan.plugins = ... versioned_tiledmap

2. Install lessc globally:

   npm install -g "less@~4.1"

3. Add latitude and longitude fields for the resources you want to use this view for.

Configuration

These are the options that can be specified in your .ini config file.

Name	Description	Default
versioned_tilemap.tile_layer.url	The URL to use for the base world tiles	https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png
versioned_tilemap.tile_layer.attribution	The attribution text to show for this layer (can be HTML)	Base tiles provided by OpenStreetMap. <a href="openstreetmap.org/copyright">View copyright information</a>
versioned_tilemap.tile_layer.opacity	The opacity for the tile layer	0.8
versioned_tilemap.zoom_bounds.min	Minimum zoom level for initial display of the resource's data	3
versioned_tilemap.zoom_bounds.max	Maximum zoom level for initial display of the resource's data	18
versioned_tilemap.style.plot.point_radius	The integer radius of the rendered points (including the border)	4
versioned_tilemap.style.plot.point_colour	The hex value to render the points in	#ee0000
versioned_tilemap.style.plot.border_width	The integer border width of the rendered points	1
versioned_tilemap.style.plot.border_colour	The hex value to render the borders of the points in	#ffffff
versioned_tilemap.style.plot.grid_resolution	The integer size of the cells in the grid that each tile is split into for the UTFGrid. The default of 4 produces a 64x64 grid within each tile	4
versioned_tilemap.style.gridded.cold_colour	The hex value to be used to render the points with the lowest counts	#f4f11a
versioned_tilemap.style.gridded.hot_colour	The hex value to be used to render the points with the highest counts	#f02323
versioned_tilemap.style.gridded.range_size	This many colours will be used to render the points dependant on their counts	12
versioned_tilemap.style.gridded.resize_factor	A resize value to use when smoothing the tile. This value will be used to scale the tile and then down (with anti-aliasing) to produce a smoother output. Increasing this value will negatively impact performance	4
versioned_tilemap.style.gridded.grid_resolution	The integer size of the cells in the grid that each tile is split into. The default of 8 produces a 32x32 grid within each tile and therefore matches the default grid.json setting too	8
versioned_tilemap.style.heatmap.point_radius	The integer radius of the rendered points (including the border)	8
versioned_tilemap.style.heatmap.cold_colour	The hex value to be used to render the points with the lowest counts	#0000ee
versioned_tilemap.style.heatmap.hot_colour	The hex value to be used to render the points with the highest counts	#ee0000
versioned_tilemap.style.heatmap.intensity	The decimal intensity (between 0 and 1) to render the tile with	0.5
versioned_tilemap.info_template	The name of the template to use when a point is clicked	point_detail
versioned_tilemap.quick_info_template	The name of the template to use when a point is hovered over	point_detail_hover

Usage

After enabling this extension in the list of plugins, the Map view should become available for resources with latitude and longitude values.

Testing

There is a Docker compose configuration available in this repository to make it easier to run tests. The ckan image uses the Dockerfile in the docker/ folder.

To run the tests against ckan 2.9.x on Python3:

1. Build the required images:

   docker compose build

2. Then run the tests. The root of the repository is mounted into the ckan container as a volume by the Docker compose configuration, so you should only need to rebuild the ckan image if you change the extension's dependencies.

   docker compose run ckan