Web cartography helpers

ul-br to bbox

javascript:(function () {
  var ul, br, validCoords = /^[+-]?\d+(\.\d+)?,[+-]?\d+(\.\d+)?$/;
    
  do {
    if (!(ul = window.prompt('Type in the value for UL (upper left) as lng, lat. Example: 58, 58'))) {
      return;
    }
    if (!ul.replace(/ /g, '').match(validCoords)) {
      console.log('Invalid format for UL, please type again');
      ul = undefined;
    }
  } while(!ul);
  
  do {
    if (!(br = window.prompt('Type in the value for BR (bottom right) as lng, lat: Example: 45, 45'))) {
      return;
    }
    if (!br.replace(/ /g, '').match(validCoords)) {
      console.log('Invalid format for BR, please type again');
      br = undefined;
    }
  } while(!br);
        
  ul = ul.split(',');
  br = br.split(',');
    
  var bbox = '['+ul[0]+', '+br[1]+', '+br[0]+', '+ul[1]+']';
  console.log('bbox: ' + bbox);
  alert('Here is the bbox, it is also printed out in the console: ' + bbox);
})();