Global Model Not Accesible

user3349850 picture user3349850 · Oct 14, 2015 · Viewed 7.5k times · Source

I declared a model in Component.js of a UI5 application as below

init: function() {
  sap.ui.core.UIComponent.prototype.init.apply(this);
  var oModel1 = new sap.ui.model.json.JSONModel("model/mock.json");
  sap.ui.getCore().setModel(oModel1, "oModelForSales");
},

but was not able to access the model in any of the onInit methods inside controllers unless the model is set on view instead as below:

var oModel1 = new sap.ui.model.json.JSONModel("model/routes.json");
this.getView().setModel(oModel1);

The log for sap.ui.getCore().getModel("oModelForSales") in controllers onInit shows the model as undefined but I was able to fetch it in onBeforeRendering handler.

Why are core models, set in Component.js, not accessible in onInit?

Answer

Boghyon Hoffmann picture Boghyon Hoffmann · Feb 15, 2017

Avoid setting models on the Core directly if you're using Components. Components are meant to be independent and reusable parts and therefore will not inherit the Core models by default. Models should be set depending on your business case:

  • Models defined in the app descriptor (manifest.json) will be set on the Component. They are automatically propagated to its descendants. Given default model, the following returns true:

    this.getOwnerComponent().getModel() === this.getView().getModel() // returns: true
    

    Note: Calling this.getView().getModel(/*modelName*/) in onInit will still return undefined since the view doesn't know its parent at that moment yet (this.getView().getParent() returns null). Therefore, in onInit, call the getModel explicitly from the parent that owns the model:

    onInit: function() {
      const model = this.getOwnerComponent().getModel(/*modelName*/);
      // instead of this.getView().getModel
    },
    
  • Set models only on certain controls (e.g. View, Panel, etc.) if the data are not needed elsewhere.

  • Set models on the Core only if the app is not Component-based.

If Core models or any other model from upper hierarchy should still be propagated to the Component and its children, enable propagateModel when instantiating the ComponentContainer.

new ComponentContainer({
    //...,
    propagateModel: true
})

But again, this is not a good practice since Core models can be blindly overwritten by other apps on FLP as SAP recommends:

Do not use sap.ui.getCore() to register models.


About the Core model being undefined in onInit: This is not the case anymore as of version 1.34.0. The Core model can be accessed from anywhere in the controller. However, descendants of ComponentContainer are unaware of such models by default as explained above.