Question: Experts,

I need to declare an dynamic ID into a XML view in my extended Fiori app. I need this because I need to set an image src based on Item value.

Is there a way to do something like this?

```
<Image id="myImage{MyModelProperty}" />

```

Regards,
Andre

Answer: 
The calculated field will serve your requirement.

1.Set the flag in bootstrap configuration `data-sap-ui-xx-bindingSyntax="complex"`. Details is [here](https://openui5.hana.ondemand.com/#docs/guide/0c803921b1bf4b3a97a038fbd51ef542.html)

2.Define a formatter function in your controller js.

```js
imageFormatter : function(value) {
    var imageSrc = "myImage" + value;
    return imageSrc;
}

```

3.Declare the Image in the XML view as following

```js
<Image src="{path:'MyModelProperty',formatter:'.imageFormatter'}"/>

```

Hope it will solve your issue.
As far as I know IDs can not be built from model properties.
Why do you want to build the ID of the image instead of it's `src` property? 
If you want to make sure the uniqueness of image ID, then just let the framework to handle it. 

If you use the `src` property with model binding, changes of the underlying model property will take effect on the UI immediately. Just call the `setProperty("MyModelProperty", "new_image_postfix")` on your model instance.

Short example with a button and it's text binding:

```
<!DOCTYPE HTML>
<html>
  <head>
    <meta http-equiv="X-UA-Compatible" content="IE=edge"/>
    <meta http-equiv='Content-Type' content='text/html;charset=UTF-8'/>

    <script src="https://sapui5.hana.ondemand.com/resources/sap-ui-core.js"
            data-sap-ui-libs="sap.ui.commons"
            data-sap-ui-theme="sap_goldreflection">
    </script>
    <script type="text/javascript">
      var oModel = new sap.ui.model.json.JSONModel();
      oModel.setData({txt: "Sample"});
      sap.ui.getCore().setModel(oModel);
      var oButton = new sap.ui.commons.Button({id:"testBtn", text:"{/txt}", press:function(oEvent) { oModel.setProperty("/txt", "SampleUpdated") } });
      oButton.placeAt("content");
    </script>
  </head>
  <body class="sapUiBody" role="application">
    <div id="content"></div>
  </body>
</html>

```