Indesign API built-in events paragraph-style

Question

Does Indesign trigger any events when a paragraph style object does change? Or is there any built in javascript functionality that can observe an object? Object.obserce and Proxy are not working in CS6.

Answer 1

The documentation states that you can attach event listeners to DOM objects such as myParaStyle.addEventListener but I could never got something to work with those.

But you can use an idleEvent listener and look around at possible styles edits:

#targetengine "onAfterSelectionChanged"
var main  = function() {

var currDocId, stylesDB = {};


var onAfterParagraphStyleEdit  = function ( evt ) {
    var doc = evt.parent, docId;
    if ( !app.documents.length ) return;
    doc = app.activeDocument;
    docId = doc.id;

    if  ( !currDocId 
    ||
    currDocId!=docId ) {
        currDocId = docId;
        stylesDB = getStylesDB(doc);
        return;
    }

try {
    compareStyles ( doc, stylesDB ) ;
}
catch(err)  {
alert ( err.line+"//"+err.message );
}
}

var it = app.idleTasks.itemByName ("onAfterParagraphStyleEdit" );

if  ( !it.isValid ) {
    it  =app.idleTasks.add({name:"onAfterParagraphStyleEdit", sleep:100});
    it.addEventListener(IdleEvent.ON_IDLE, onAfterParagraphStyleEdit, false);
}
}
main(); 
var compareStyles = function ( doc, db ) {
var pss = doc.allParagraphStyles, ps, psId, psProps,
 n = pss.length, diffs = [];

 while ( n-- ) {
     ps = pss[n];
     psId = ps.id;
    if (  !db[psId] )  {
        db[psId] = ps.properties.toSource();
    }
    else {
        psProps = ps.properties.toSource();
        if ( db[psId] !=  psProps) {
            diffs.push ( ps.name +"["+ps.id+"]" );
            db[psId] = psProps;
        }
    }
}

diffs.length && alert("Those styles were modified…\r"+diffs.join("\r"
) );
}
var getStylesDB = function ( doc ) {
var db = {};
var pss = doc.allParagraphStyles, ps,
 n = pss.length;

while ( n-- ) {
    ps = pss[n];
    db[pss[n].id] = ps.properties.toSource();
}

return db;
}