pythondjangosvgpostgisgeodjango

How to represent SVG polygon in HTML using deffinition coming from POSTGIS ST_AsSVG function

In my django app I have postgis database. I tried to get a polygon as a SVG, so I could represent that polygon in HTML using the SVG standard.

I use the following query: SELECT ST_AsSVG(geom) from country_limit cl where cl.id=3;

And It returned the following result:

M -85.941653 -12.285635 L -85.941653 -12.291673 -85.927577 -12.291673 -85.927577 -12.285635 Z

But when I try to represent that result inside an SVG, in HTML, It does not display the polygon. Here is my code.

 <svg height="210" width="400">
   
    <path d="M -85.941653 -12.285635 L -85.941653 -12.291673 -85.927577 -12.291673 -85.927577 -12.285635 Z" />

 </svg>

How can I use the result from postgis ST_AsSVG to represent a geometry as SVG in HTML

Solution

  • Your shape is

    1. very very very small
    2. outside the usual drawing area since it has negative co-ordinates

    Both of these issues can be solved by using an appropriate viewBox.

    <svg height="210" width="400" viewBox="-85.942 -12.292 0.05 0.05">
   
    <path d="M -85.941653 -12.285635 L -85.941653 -12.291673 -85.927577 -12.291673 -85.927577 -12.285635 Z" />

 </svg>