Keep expressions intact when moving a control layer to another comp

[David Conklin]

Hey there,

This solution is not super straightforward, but also not that complicated. ESTK provides a handy little app.project.autoFixExpression(oldText, newText) command, that you can use to batch-fix expressions. This is the main thing you’re looking for.

The issue is, autoFixExpressions will only fix expressions that YOUR SCRIPT causes to break, not preexisting errors. So, in the script here’s what we do.

1. Make variables that have the names of the comps we need (the controller comp, the pre-comp, and the new comp).
2. Find these comps.
3. Copy controller from the controller (‘top’) comp, to the new comp.
4. Remove controller from top comp, thereby breaking the expression.
5. run .autoFixExpressions(topCompName, newCompName) to fix the expressions.

Here’s the script. Hope it helps!

(function fixExpressions(){
app.beginUndoGroup("Fix expressions.");

var proj = app.project

var topCompName = "Top Comp"; // comp where controller lives now.
var preCompName = "Pre-Comp"; // comp where expressions are (that break).
var newCompName = "Another Comp"; // comp you want the controller in.

// holders for comps.
var topComp,preComp,newComp;

// loop through project and get the comps.
for (var i = 1; i <= proj.numItems; ++i){
switch(proj.item(i).name){
case topCompName:
topComp = proj.item(i);
break;
case preCompName:
preComp = proj.item(i);
break;
case newCompName:
newComp = proj.item(i);
break;
default:
break;
}
}

// move controller
topComp.layer("Controller").copyToComp(newComp);

// delete from old comp.
topComp.layer("Controller").remove();

// fix expressions
proj.autoFixExpressions(topCompName,newCompName);

app.endUndoGroup();
})();

David Conklin
Motion Designer

[David Conklin]

Something I forgot to add, is that you’ll need to change line 31 and 34, ‘topComp.layer(“Controller”)’ to the name of your controller. If your control layer is just named ‘null’, you’d change them to ‘topComp.layer(“null”)’.

Best of luck!

David Conklin
Motion Designer

[Adira Kessler]

What there are expressions in multiple comps?

[Yoan Boisjoli]

I think you could do it with this script:

http://aescripts.com/pt_expressedit/

All you’d need to do is search and replace the old path to the new one.