decojs/Source/deco/spa/viewModelFactory.js

Scalable frontend architecture

define([], function() {
  return {
    getViewModelFromAttributes: function(target){
      var viewModelName = target.getAttribute("data-viewmodel");
      var model = target.getAttribute("data-model");

      return {
        target: target,
        viewModelName: viewModelName,
        model: model
      };
    },
    
    getParentViewModelElement: function(element, maxAncestor){
      while(element = element.parentNode){
        if(element === maxAncestor) return null;
        if(element.hasAttribute("data-viewmodel")) return element;
      }
      return null;
    },
    
    loadViewModel: function(data){
      return new Promise(function(resolve, reject){
        require([data.viewModelName], resolve, reject);
      }).then(function(ViewModel){
        return {
          viewModelName: data.viewModelName,
          ViewModel: ViewModel,
          model: data.model,
          target: data.target
        }
      }, function(error){
        throw new Error("Could not load the following modules:\n"+error.requireModules.join("\n"));
      });
    },

    createViewModel: function(data, subscribe, params) {
      var model = (data.model && (data.model.charAt(0) == '{' || data.model.charAt(0) == '['))
        ? JSON.parse(data.model)
        : params;
      var whenContext = subscribe();
      var viewModel = new data.ViewModel(model, whenContext);
      viewModel['@SymbolDecoWhenContext'] = whenContext;
      return {
        viewModelName: data.viewModelName,
        viewModel: viewModel,
        target: data.target
      }
    }
  }
});