Collect Files - Script

Search Footage composition in active item; Within Footage composition, search the number of items that exist within (the number of items may vary); Collect all these items to use in the Script. Then; Sum the time duration of all the items that are within the Footage composition. And apply this calculated time, in time duration of the active composition.

var currentlyOpenComp = app.project.activeItem;
if(currentlyOpenComp instanceof CompItem){     //1. This verifies that the current active item is a comp
     var allMyLayers = currentlyOpenComp.selectedLayers;     //2. Grabs selected layers
     var allMyLayersLength = allMyLayers.length;
     var timeDurationValue = 0;     //Generic variable to collect time to
     var checkTheseLayerDurations, checkTheseLayerDurationsLength;     //Variables for later
     for(var i=0; i<allMyLayersLength; i++){     //Loop through selected layers
          if(allMyLayers instanceof AVLayer && allMyLayers.source instanceof CompItem){     //Verify that layer is AVLayer and then check it's source to make sure it's a CompItem

               checkTheseLayerDurations = allMyLayers.source.layers;     //Grabs the layers inside the comp

               checkTheseLayerDurationsLength = checkTheseLayerDurations.length;
               for(var d=1; d<=checkTheseLayerDurationsLength; d++){     //Loop through layers to grab time durations
                    timeDurationValue += checkTheseLayerDurations.source.duration;     //Assumes each layer is an AVLayer that has a source, and grabs it's duration and adds it to the previous time total
               }
               allMyLayers.source.duration = timeDurationValue;     //Sets the comp duration to the final duration total.

          }
     }
}