Unlocking Background Layer with lots of other layers

Question

I've been looking at the similar questions, but no script has worked perfectly yet. I have a series of phoshop actions that I run on a regular basis. I have two version of each, one for if there's a locked background layer, and one for when its already been unlocked. Otherwise my actions error.
I'd like to simplify the process and have a script run that finds any locked layers (ie: background) and unlocks it, even if there are 15 other layers and even if I have another layer selected. It should also run without errors if there are no locked (background) layers to be found.
I don't know the first thing about writing my own scripts, so can somebody tell me what lines of code I'd need? Thank you Thank you!

Answer 1

function makeActiveByIndex( index, visible ){
    var desc = new ActionDescriptor();
    var ref = new ActionReference();
    ref.putIndex(charIDToTypeID( 'Lyr ' ), index )
    desc.putReference( charIDToTypeID( 'null' ), ref );
    desc.putBoolean( charIDToTypeID( 'MkVs' ), visible );
    executeAction( charIDToTypeID( 'slct' ), desc, DialogModes.NO );   
function getNumberOfLayers(){
    var ref = new ActionReference();
    ref.putProperty( charIDToTypeID( 'Prpr' ), charIDToTypeID( 'NmbL' ) );
    ref.putEnumerated( charIDToTypeID('Dcmn'), charIDToTypeID( 'Ordn' ), charIDToTypeID( 'Trgt' ) );
    return executeActionGet( ref ).getInteger( charIDToTypeID( 'NmbL' )) ;
function getProperty( psClass, psKey, index ){// integer:Class, integer:key
    var ref = new ActionReference();
    if( psKey != undefined ) ref.putProperty( charIDToTypeID( "Prpr" ), psKey );
    if(index != undefined ){
        ref.putIndex( psClass, index );
    }else{
        ref.putEnumerated( psClass , charIDToTypeID( "Ordn" ), charIDToTypeID( "Trgt" ) );
    try{
        var desc = executeActionGet(ref);
    }catch(e){ return; }// return on error
    if(desc.count == 0) return;// return undefined if property doesn't exists
    var dataType = desc.getType(psKey);
    switch(dataType){// not all types supported - returns undefined if not supported
        case DescValueType.INTEGERTYPE:
            return desc.getInteger(psKey);
            break;
        case DescValueType.ALIASTYPE:
            return desc.getPath(psKey);
            break;
        case DescValueType.BOOLEANTYPE:
            return desc.getBoolean(psKey);
            break;
        case DescValueType.BOOLEANTYPE:
            return desc.getBoolean(psKey);
            break;
        case DescValueType.UNITDOUBLE:
            return desc.getUnitDoubleValue(psKey);
            break;
        case DescValueType.STRINGTYPE:
            return desc.getString(psKey);
            break;
        case  DescValueType.OBJECTTYPE:
            return desc.getObjectValue(psKey);
            break;
        case  DescValueType.LISTTYPE:
            return desc.getList(psKey);
            break;
        case  DescValueType.ENUMERATEDTYPE:
            return desc.getEnumerationValue(psKey);
            break;
var doc = app.activeDocument;
var layerCount = getNumberOfLayers();
var invisibleLayers = [];
var loopStart = Number(!doc.layers[doc.layers.length-1].isBackgroundLayer);
for(var layerIndex = loopStart;layerIndex<=layerCount;layerIndex++){
    if(!getProperty( charIDToTypeID('Lyr '), stringIDToTypeID( 'visible' ), layerIndex )) invisibleLayers.push(layerIndex);
for(var hiddenIndex=0;hiddenIndex<invisibleLayers.length;hiddenIndex++){
    makeActiveByIndex( invisibleLayers[hiddenIndex], true);
    if(doc.activeLayer.allLocked) doc.activeLayer.allLocked = false;
    if(doc.activeLayer.pixelsLocked) doc.activeLayer.pixelsLocked = false;
    if(doc.activeLayer.positionLocked) doc.activeLayer.positionLocked = false;
    if(doc.activeLayer.transparentPixelsLocked) doc.activeLayer.transparentPixelsLocked = false;
    doc.activeLayer.visible =  false;