management example: restoration area (modern Javascript)

This example demostrates the use of modern Javascript for manipulating input data.

The script mimicks restoration efforts, i.e. planting of trees in given years of specific stands.
The code reads a CSV file (scripts/mgmtData.csv) and creates a data structure in memory. The table is structured as an iLand initialization file, and includes and additional column 'year'.

The code looks every year if work needs to be done, and then splits the data for each stand and executes some operation.

/* Load a tabular data set into a JS Object.
   Each row is stored as an object with name-value pairs in an array.
   Example:
   inifile = loadFromFile("init/test.csv"); 
   var elem = inifile[0].stand_id; // access via row number
   elem = inifile.find(row => row.stand_id == 2); // search for certain element by value
   elem = inifile.filter(row => row.stand_id > 10); // get a subset of elements
*/

function loadFromFile(filename) {
	var res = [];
	// load CSV File
	var csv = Factory.newCSVFile(Globals.path(filename));
	// convert each row to an object with column names as property names
	for (var r=0;r<csv.rowCount;++r) {
		var obj = {};
		for (var c=0;c<csv.colCount;++c) {
			obj[csv.columnName(c)] = csv.jsValue(r,c);
		}
		res.push(obj);
	}
	return res;
}

// convert to CSV
// https://stackoverflow.com/questions/11257062/converting-json-object-to-csv-format-in-javascript
function convertToCSV(arr) {
  const array = [Object.keys(arr[0])].concat(arr)

  return array.map(it => {
    return Object.values(it).toString()
  }).join('\n')
}

// load a CSV file that looks like this:
// ID,year,species,count,dbh_from,dbh_to,hd,age
// 1,258,pigl,1700,5.1,5.1,78.44,10
// ...
// (ID: stand-id, year: year of management)
var init_file = loadFromFile("scripts/mgmtData.csv");

function runManagement(year) {
	// look for all lines with the current year
	let elems = init_file.filter(x => x.year == year);
	if (elems.length == 0)
		return; // nothing to do this year
	
	// get a unique list of stands that are to be processed this year
	let stand_ids = [ ...new Set(elems.map( x => x.ID)) ];
	stand_ids = Array.from(stand_ids); // convert to array
	
	// loop over all stands 
	for (i in stand_ids) {
		console.log("Stand: " + stand_ids[i] );
		let single_init = elems.filter(x => x.ID == stand_ids[i]);
		let mgmt_str = convertToCSV(single_init);
		
		console.log("Mgmt content: \n" + mgmt_str);
		
		// Globals.addTreesOnMap(x, mgmt_str)
		// do other things here....
	}
}