Making sap.m.StepInput accept empty values

How to use

1. Save the code below as a new JS-file wherever you keep your custom controls. Don't know where to put it? Create a subfolder in your app called control (next to view and controller) and refer to the UI5 walkthrough tutorial for further information.
2. Include it in your view as StepInputCustom (see tutorial for details).
3. Use StepInputCustom instead of sap.m.StepInput to enable empty values.

The Code

Replace your.namespace with the desired namespace - e.g. the namespace of your app if you lean on the walkthrough tutorial above.

The custom control overrides all methods, that sanitize values and adds a check for empty values to each of them. Non-empty values are simply passed on to the regular sap.m.StepInput, so there is no change in logic.

(function () {
	"use strict";
	
	/**
	 * A custom version of sap.m.StepInput, that can be empty.
	 */
	sap.m.StepInput.extend("your.namespace.StepInputCustom", { 
		renderer: {},
	
		_getDefaultValue : function (value, max, min) {
			if (value === "" || value === undefined || value === null) {
				return "";
			}
			return sap.m.StepInput.prototype._getDefaultValue.call(this, value, max, min);
		},
		
		_getFormatedValue : function (vValue) {
			if (vValue === "" || vValue === undefined || vValue === null) {
				return "";
			}
			return sap.m.StepInput.prototype._getFormatedValue.call(this, vValue);
		},
		
		setValue : function (oValue) {
			if (oValue === "" || oValue === undefined || oValue === null) {
				this._getInput().setValue("");
				this._disableButtons(0, this.getMax(), this.getMin());
				return this.setProperty("value", "", true);
			}
			return sap.m.StepInput.prototype.setValue.call(this, oValue);
		},
		
		validateProperty : function(sPropertyName, oValue) {
			if (sPropertyName === "value" && (oValue === null || oValue === "" || oValue === undefined)) {
				return "";
			}
			return sap.m.StepInput.prototype.validateProperty.call(this, sPropertyName, oValue);
		}
	});
})();