Get path to property of a layer

[Xavier Gomez]

Shape layers and shape groups within them have a “Contents” property.
The shape layer’s content is not elided (see propertyGroup.elided attribute in the scripting guide) and has matchName “ADBE Roots Vector Group”.
A shape group’s content is elided (does not appear in GUI) and has matchName “ADBE Vectors Group”.

The parent of Ellipse 1 is not the “contents” of the shape but the contents of the group.
It might look a bit convoluted at start, but once you have understood these two differences it’s fine.

Xavier

[Xavier Gomez]

Sorry , in the before last line, i meant Ellipse Path 1 (which is in the content of the group), not Ellipse 1 (which is the group itself)

[Jakob Wagner]

I knew it, it was a trap!
Thank you Xavier. Now it makes better sense.

For other interested I ended up with this code, which works. (for now)

function testButtonClick()
{
var comp = app.project.activeItem;
var layers = comp.selectedLayers;
var layer = layers[0];
var selectedProperties = comp.selectedProperties;
var property = selectedProperties[0];

var propPath = getPropPath(property);
var prop = eval("layer.property"+getPropPath(property));
alert(prop.value)
}

function getPropPath(prop)
{
var layerRoot = false;
var propPath = "";

while(prop.parentProperty)
{
propPath = "('"+prop.name+"')"+propPath;
prop = prop.parentProperty;
}
return propPath;
}

[Xavier Gomez]

Be careful with “prop.name” as it is often not a reliable enough identifier.
Some properties in the same group can share the same name, as in indexed groups, or in effects (in later versions, some properties names of Adobe’s effects have been changed so that they don’t have the same name, but in earlier versions you could have several time the same property name in a given effect).

Xavier

[Jakob Wagner]

Alright. Thank you for the warning. I have changed this line:
propPath = “(‘”+prop.name+”‘)”+propPath;
to this line:
propPath = “(“+prop.propertyIndex+”)”+propPath;

And it works too. Is that better?

Can I ask you one last question? I’m using “prop.parentProperty” to detect if the property is a layer. A layer does not have a parent. Is there a better way of doing that? I tried instanceof, but I couldn’t get it to work.

[Xavier Gomez]

instanceof won’t work because not all layers have the same constructor (can’t remember the exact names, but i think text layers are instanceof TextLayer, shape layers of ShapeLayer, layers with source of AVLayer, etc, something like that, and they also have distinct matchNames).
while (prop.parentProperty) is completely fine.
You could also replace by : while (prop.propertyDepth>0) (that’s what i use, but it’s not better).

For the path itself, i think that for children of a named group, using propertyIndex or matchName makes no difference.
For children of an indexed group, it really depends on the usage of your script, because matchName can’t work (most of the time all children have the same matchName, so it can’t be a reliable identifier), and between the time you identify the property and the time you use the path, the user may have changed its position in the property stack, hence propertyIndex can also be unreliable.

Last tip: you should use try{}catch(){} around the eval, because the property may be gone/invalid.
You could also avoid the use of eval by saving the path as an array of identifiers, not a string, and looping over the array entries to recover the property. Then no need of try/catch.

Hope that helps.

Xavier.

[Jakob Wagner]

Hi Xavier

Thank you very much for taking the time. This is great info!

Have an awesome day,
Jakob