画面 Javascript API

Question

Can you explain the functions below:

1. viz = new tableau.Viz(containerDiv, url, options);

2.  function listenToMarksSelection() { viz.addEventListener(tableau.TableauEventName.MARKS_SELECTION, onMarksSelection); }

3. function onMarksSelection(marksEvent) { return marksEvent.getMarksAsync().then(reportSelectedMarks); }

4. function reportSelectedMarks(marks) {

   var html = "";

    for (var markIndex = 0; markIndex < marks.length; markIndex++) { var pairs = marks[markIndex].getPairs(); html += "<b>Mark " + markIndex + ":</b><ul>"; for (var pairIndex = 0; pairIndex < pairs.length; pairIndex++) { var pair = pairs[pairIndex]; html += "<li><b>Field Name:</b> " + pair.fieldName; html += "<br/><b>Value:</b> " + pair.formattedValue + "</li>"; } } }

Answer 1

2. This function just listen the selected mark

3. This one throw the selection in reportSelectedMarks

4. It take the marks and write it in an HTML file in a '<'li'>'. The fieldname would probably be a String and in the value it depend what you are workin with.

So basically these functions would be useful to dynamically print a selected mark on a graph or something like that and print a fielname and a value for that one.