d3.csv操作数据切换列显示

Question

The data are read from a cvs.file

    "col1","col2"
    "row1col1","row1col2"

I would like to switch the column data in a force layout to select column 2 or column 1, but dynamically.

    node = nodeG.selectAll(".node")
            .data(data, function(d) {return d.column1;});//first option

    node = nodeG.selectAll(".node")
            .data(data, function(d) {return d.column2;});//second option

I tried to use a variable, for some reason it didn't work

    var data_variable = function(d) {return d.column1;}
                        || function(d) {return d.column2;} 
                        // pseudocode, data from input options

    node = nodeG.selectAll(".node")
            .data(data, data_variable);

Is this the correct approach or are the data better manipulated before display ?

Answer 1

It ended up to be a simple solution inside the main function:

var ls = d3.select("#selector").property("value");

if (ls === 'it' ){

  idValue = function(d) {
  return d.col1;
  };

  textValue = function(d) {
  return d.col1;
  };

 } else {

  idValue = function(d) {
  return d.col2;
  };

  textValue = function(d) {
  return d.col2;
  };

 };

I simply obtain the value from a drop down list and chose the returned functions conditionally