Creating a photoshop action to save a batch of images as patterns

If you want also to export the last pattern defined (as I needed), then this is how it should be done:

var patternName = 'PatternName';
var patternPath = 'somePath/' + patternName + '.pat';
definePattern(patternName);
var lastPatternIndex = getPatternIndexByName(patternName);
exportPattern(lastPatternIndex, patternPath);
function definePattern(patternName) {
   var dialogMode = DialogModes.NO;
   var desc1 = new ActionDescriptor();
   var ref1 = new ActionReference();
   ref1.putClass(cTID('Ptrn'));
   desc1.putReference(cTID('null'), ref1);
   var ref2 = new ActionReference();
   ref2.putProperty(cTID('Prpr'), sTID("selection"));
   ref2.putEnumerated(cTID('Dcmn'), cTID('Ordn'), cTID('Trgt'));
   desc1.putReference(cTID('Usng'), ref2);
   desc1.putString(cTID('Nm '), patternName);
   executeAction(cTID('Mk '), desc1, dialogMode);
}
function exportPattern(patternIndex, patternPath) {
   var idsetd = charIDToTypeID( "setd" );
   var desc74 = new ActionDescriptor();
   var idnull = charIDToTypeID( "null" );
   desc74.putPath( idnull, new File( patternPath ) );
   var idT = charIDToTypeID( "T " );
   var list10 = new ActionList();
   var ref31 = new ActionReference();
   var idPtrn = charIDToTypeID( "Ptrn" );
   ref31.putIndex( idPtrn, patternIndex );
   list10.putReference( ref31 );
   desc74.putList( idT, list10 );
   executeAction( idsetd, desc74, DialogModes.NO );
}     
function getPatternIndexByName(match) {
    try {
        var r = new ActionReference();
        r.putProperty(charIDToTypeID("Prpr"), stringIDToTypeID("presetManager"));
        r.putEnumerated(charIDToTypeID("capp"), charIDToTypeID("Ordn"), charIDToTypeID("Trgt"));
        var list = executeActionGet(r).getList(stringIDToTypeID("presetManager"));
        for (var i = 0; i < list.count; i++) {
            if (list.getObjectType(i) == charIDToTypeID("PttR")) {
                var list2 = list.getObjectValue(i).getList(stringIDToTypeID("name"));
                for (var x = 0; x < list2.count; x++) {
                    var name = list2.getString(x);
                    if (name.indexOf(match) >= 0) return x + 1;
                }
                break;
            }
        }
        return -1;
    }
    catch (e) {
        alert(e);
        return -1;
    }
}

You might want to move this thread to the general photoshop forum if tou want an action.  However your not going to be able to do create the action you want for when you record menu Edit>Define Pattern the "Pattern Name Dialog" will pop up and whatever is used in it will be recorded into the action.

Also Photoshop Scripting DOM does not have a interface for creating and nameing patterns.  However you should bne ale to write a script to do what you want using code generated with Photoshop Scriptlistner Plug-in and modifying the hard coded name to a variable you set with somthing like the active document name.

Before defining the patern you may be able to see if the name is all ready use for a pattern name so you can add something to the name to avoid duplicateing name.

ScriptListner Code difine pattern

// =======================================================

var idMk = charIDToTypeID( "Mk  " );

    var desc14 = new ActionDescriptor();

    var idnull = charIDToTypeID( "null" );

        var ref12 = new ActionReference();

        var idPtrn = charIDToTypeID( "Ptrn" );

        ref12.putClass( idPtrn );

    desc14.putReference( idnull, ref12 );

    var idUsng = charIDToTypeID( "Usng" );

        var ref13 = new ActionReference();

        var idPrpr = charIDToTypeID( "Prpr" );

        var idfsel = charIDToTypeID( "fsel" );

        ref13.putProperty( idPrpr, idfsel );

        var idDcmn = charIDToTypeID( "Dcmn" );

        var idOrdn = charIDToTypeID( "Ordn" );

        var idTrgt = charIDToTypeID( "Trgt" );

        ref13.putEnumerated( idDcmn, idOrdn, idTrgt );

    desc14.putReference( idUsng, ref13 );

    var idNm = charIDToTypeID( "Nm  " );

    desc14.putString( idNm, "Pattern 5" );      <------ change "Pattern 5" to be a variable

executeAction( idMk, desc14, DialogModes.NO );