Sanitize zoom sequence value

src/js/timeline/Timeline.js

@@ -426,6 +426,9 @@ class Timeline {
  // Set TimeNav Height
  this.options.timenav_height = this._calculateTimeNavHeight(this.options.timenav_height);
 
+ // Sanitize zoom sequence
+ this.options.zoom_sequence = this._sanitizeZoomSequence(this.options.zoom_sequence);
+
  // Create TimeNav
  this._timenav = new TimeNav(this._el.timenav, this.config, this.options, this.language);
  this._timenav.on('loaded', this._onTimeNavLoaded, this);
@@ -724,6 +727,51 @@ class Timeline {
  return height;
  }
 
+ /**
+ * Sanitize value of zoom sequence.
+ * Should be an array with numeric values or respective string or
+ * undefined if not set by author
+ * @param {number[]|string} [zoomSequence] - Values intended as possible zoom levels
+ * @returns {number[]} Sanitized array of possible zoom levels.
+ */
+ _sanitizeZoomSequence(zoomSequence) {
+ // Ensure string contains proper number array representation
+ if (typeof zoomSequence === 'string') {
+ // Forgive spaces in URL fragment
+ zoomSequence = decodeURI(zoomSequence).replace(/\s/g, '');
+
+ const validRegExp = /^\[([0-9]*[.])?[0-9]+(,([0-9]*[.])?[0-9]+)*\]$/;
+ if (!validRegExp.test(zoomSequence)) {
+ return Timeline.DEFAULT_ZOOM_SEQUENCE; // Not valid string representation of array with numbers
+ }
+
+ zoomSequence = zoomSequence
+ .substring(1, zoomSequence.length - 1)
+ .split(',');
+ }
+
+ if (!Array.isArray(zoomSequence)) {
+ return Timeline.DEFAULT_ZOOM_SEQUENCE; // Nothing that we can work with
+ }
+
+ // Remove invalid values and sort in ascending order
+ zoomSequence = zoomSequence.reduce((valid, value) => {
+ const numberValue = Number.parseFloat(value);
+ if (
+ Number.isNaN(numberValue) ||
+ numberValue < 0 || // Zoom factor must be greater than zero
+ valid.includes(numberValue) // Duplicate
+ ) {
+ return valid;
+ }
+
+ return [...valid, numberValue];
+ }, []);
+ zoomSequence.sort((a, b) => a - b);
+
+ return zoomSequence;
+ }
+
  _validateOptions() {
  // assumes that this.options and this.config have been set.
  var INTEGER_PROPERTIES = ['timenav_height', 'timenav_height_min', 'marker_height_min', 'marker_width_min', 'marker_padding', 'start_at_slide', 'slide_padding_lr'];
@@ -1023,6 +1071,9 @@ class Timeline {
 
 }
 
+/** @const {number[]} DEFAULT_ZOOM_SEQUENCE Array of Fibonacci numbers for TimeNav zoom levels */
+Timeline.DEFAULT_ZOOM_SEQUENCE = [0.5, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89];
+
 classMixin(Timeline, I18NMixins, Events)
 
 export { Timeline }