You can access values for composition-time markers and layer-time markers using the same methods. Access layer-time markers through the thisLayer.marker object; access composition-time markers through the thisComp.marker object.

For the purpose of expressions, markers are a special kind of Key object, so you can use methods such as nearestKey(time) to access markers, and markers also have time and index attributes. The index attribute is not the number (name) of the marker; it is the keyframe index number, representing the marker’s order in the time ruler.

Expressions have access to all of the values for a marker that you can set in the Composition Marker or Layer Marker dialog box. This expression on a text layer’s Source Text property displays the time, index, comment (name), chapter, URL, frame target, and cue point name for the layer marker nearest the current time, and whether the marker is for an event cue point:

  m = thisLayer.marker.nearestKey(time);  
  s = "time:" + timeToCurrentFormat(m.time) + "\r" +  
      "key index: " + m.index + "\r" +  
      "comment:" + m.comment + "\r" +  
      "chapter:" + m.chapter + "\r" +  
      "URL:" + m.url + "\r" +  
      "frame target: " + m.frameTarget + "\r" +  
      "cue point name: " + m.cuePointName + "\r" +  
      "Event cue point? " + m.eventCuePoint + "\r";  
  for (param in m.parameters){  
       s += "parameter: " + param + " value: " + m.parameters[param] + "\r";  
  } 
  s

comment

Return type: String.

Contents of Comment field in marker dialog box.

chapter

Return type: String.

Contents of Chapter field in marker dialog box.

url

Return type: String.

Contents of URL field in marker dialog box.

frameTarget

Return type: String.

Contents of Frame Target field in marker dialog box.

eventCuePoint

Return type: Boolean.

Setting for cue point type in marker dialog box. True for Event; false for Navigation.

cuePointName

Return type: String.

Contents of cue point Name field in marker dialog box.

parameters

Return type: associative array of String values.

Contents of Parameter Name and Parameter Value fields in marker dialog box.

For example, if you have a parameter named “background color”, then you can use the following expression to access its value at the nearest marker:

  thisComp.marker.nearestKey(time).parameters["background color"]