slicy.sketchplugin

var artboards = [[doc currentPage] artboards];
var sketchDoc = undefined;
var assetsFolder = undefined;
var layerNames = [];
var uniqueNames = [];
layers = doc.currentPage().layers();
var nameCount = 0;

function exportWithOptions(layer,path,extension,scale){
  scaleValue = scale && scale.length ? scale[0].match(/\d/)[0] : 1;
  if(scale && scale[0].match(/\+/)){
    var export_data = [{
      "format": extension.replace(".",""),
      "scale": 1,
      "suffix": ""
    },{
      "format": extension.replace(".",""),
      "scale": scaleValue,
      "suffix": ""
    }];
  }
  else{
    var export_data = [{
      "format": extension.replace(".",""),
      "scale": scaleValue,
      "suffix": ""
    }];
  }
  var export_options = [layer exportOptions];
  var export_sizes = [export_options sizes];

  // Clear all exportable sizes
  while([export_sizes count] > 0) {
    [[export_sizes firstObject] remove]
  }
  for (var s = 0; s < export_data.length; s++) {
    var size_data = export_data[s]
    var size = [[layer exportOptions] addExportSize]
    [size setFormat:size_data.format]
    [size setScale:size_data.scale]
    [size setName:size_data.suffix]
  }
  // This is just a hack to force the updating of the UI to see the new sizes in the inspector
  [[doc currentPage] deselectAllLayers]
  [layer select:true byExpandingSelection:true]

  var rect = [layer rectByAccountingForStyleSize:[[layer absoluteRect] rect]];
  log(rect)
  var slices = [MSSliceMaker slicesFromExportableLayer:layer inRect:rect];
  eachArray(slices,function(slice,i){
    var layerName = path;
    layerName += export_data[i].scale > 1 ? "@"+export_data[i].scale : "";
    layerName += extension;
    [doc saveArtboardOrSlice: slice toFile: layerName];
  })
}
function eachArray(list,callback){
  for(var i=0, l = [list count]; i<l; i++){
    callback(list.objectAtIndex(i),i);
  }
}
function eachLayer(layers,func){
  if([layers firstObject].class() === MSArtboardGroup){
    eachArray(layers,function(art){
      var layers = art.children()
      eachArray(layers,func)
    });
  }
  else{
    eachArray(layers,func)
  }
}

function main(){
  if(sketch.doc.fileURL()){
    sketchDoc = sketch.doc.fileURL().path();
    assetsFolder = sketchDoc.replace(".sketch","") + ".assets/";
  }
  else{
    [doc showMessage:"Save your work before exporting"]
    return 0;
  }
  //Delete folder
  [[NSFileManager defaultManager] removeItemAtPath:assetsFolder error:nil];

  //Create unique names
  eachLayer(layers,function(layer){
    var match = 0;
    var layerName = layer.name();
    var isExportable = layerName.match(/\..+$/);
    if(isExportable){
      layerName = layer.name().replace(/\..+$/,"");
      layerName = layerName.replace(" ","-");
      layerName = layerName.toLowerCase();
      layerNames.forEach(function(existingName){
        if(layerName === existingName){
          match += 1;
        }
      })
      layerNames.push(layerName);
      match > 0 ? uniqueNames.push(layerName+"-"+match) :  uniqueNames.push(layerName);
    }
  })

  eachLayer(layers,function(layer){
    var layerName = layer.name();
    var options = layerName.match(/\..+$/);
    if(options){
      var extension = options[0].match(/\.\w+/)[0];
      var scale = options[0].match(/[\+\-@].+/);
      if(layer.isVisible() === 1){
        var path = assetsFolder + uniqueNames[nameCount];
        exportWithOptions(layer, path, extension, scale)
      }
      nameCount++;
    }
  });
  var doneMessage = "Exported " + layerNames.length + " elements";
  [doc showMessage:doneMessage ]
}

main()