geostyler-legend

geostyler-legend

A simple legend component for geostyler-style.

Installation

npm i geostyler-legend

Usage

In order to render a legend, you construct a legend renderer like this:

      const renderer = new LegendRenderer({
        maxColumnWidth: 300,
        maxColumnHeight: 300,
        overflow: 'auto',
        styles: [style],
        size: [600, 300],
        iconSize: [15, 15],
        legendItemTextSize: 14
      });
      renderer.render(someElement);

The styles property can contain a list of geostyler style objects that each correspond to one legend rendered.

There are currently three modes. If constructed as above, the renderer will render multiple columns if needed, with a maximum width and height as specified. The columns will break on any legend element.

If the overflow property is set to 'group', the columns will break on legend boundaries only, leaving the rest of the column empty if starting on a new legend.

If the maxColumnHeight property is not set, the renderer will render just one column with all the legends, thus ignoring the size parameter for the height.

The size and iconSize parameters refer to the legend overlay size and the legend icons size respectively.

The legendItemTextSize refers to the legend item's associated text font size. It's optional.

You can use this package to export your legend as image. To do that, if you don't know how many legend items you will have, you can define maxColumnWidth to 'fit-content'. This option permits to auto define the width of each column depending on its content. If this option is enabled, the first number in size array will be ignored.

Example :

      const renderer = new LegendRenderer({
        maxColumnWidth: 'fit-content',
        maxColumnHeight: 300,
        overflow: 'auto',
        styles: [style],
        size: [600, 300],
        iconSize: [15, 15],
        legendItemTextSize: 14
      });
      renderer.render(someElement);

Of course, you can use this option in html rendering context, too.

Development

If you want to contribute, you can build the project like this:

• git clone https://github.com/geostyler/geostyler-legend
• cd geostyler-legend
• npm i

and then

• npm run build

in order to get a production build.

Funding & financial sponsorship

Maintenance and further development of this code can be funded through the GeoStyler Open Collective. All contributions and expenses can transparently be reviewed by anyone; you see what we use the donated money for. Thank you for any financial support you give the GeoStyler project 💞