InDesign JSX User Script to Adjust Table Widths Relative to Frame Width

adjustTableWidths.jsx

// Inspiration:
// https://forums.adobe.com/message/2524327
// http://www.indiscripts.com/post/2009/10/work-around-the-width-height-gap

var myDoc = app.activeDocument;

function getWidth(/*PageItem*/obj, /*bool*/visible)
// return the [width,height] of <obj>
// according to its (geometric|visible)Bounds
{
var boundsProperty = ((visible)?'visible':'geometric')+'Bounds';
var b = obj[boundsProperty];
// width=right-left
return b[3]-b[1];
}

function adjustTableWidths(relWidths) {
	for(var T=0; T < myDoc.textFrames.length; T++){
		var frameWidth = getWidth(myDoc.textFrames[T], true);
		
		for(var i=0; i < myDoc.textFrames[T].tables.length; i++){
			if(myDoc.textFrames[T].tables[i].columns.length == relWidths.length) {
				for(var j=0; j < relWidths.length; j++){
					var colWidth = frameWidth * (relWidths[j] / 100);
					myDoc.textFrames[T].tables[i].columns[j].width = colWidth;
				}
			}
		}
	}
}

adjustTableWidths([50,50]);

adjustTableWidths([26,44,20]);

alert("Table widths updated successfully!");