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javauser-interfacesmartgwt

smartgwt add blank row in ComboBoxItem or allow user to set blank value

I am trying to add blank row with null value in ComboBoxItem of smartgwt which is already bind to data source coming from database.

I have tried changes in service layer, controller layer and database too, but that was not recommended by my senior.

All I need to do changes on UI layer only.

Solution

  • Take a look at the Special Values ComboBox SmartGWT showcase demo. I think it does what you want.

    Here is an extract taken from that demo's code (although I recommend you to look at it and study the code to see what's best in your case):

    LinkedHashMap<String,String> hashMap = new LinkedHashMap<String,String>();  
hashMap.put("**EmptyValue**", "None");  
hashMap.put("-1", "Not Applicable");  

ComboBoxItem comboBoxItem = new ComboBoxItem();  
comboBoxItem.setName("filteredCombo");  
comboBoxItem.setTitle("Choose an item (ComboBox)");  
comboBoxItem.setAddUnknownValues(false);  
comboBoxItem.setOptionDataSource(ItemSupplyXmlDS.getInstance());  
comboBoxItem.setDisplayField("itemName");  
comboBoxItem.setValueField("itemID");  
comboBoxItem.setPickListWidth(300);  
comboBoxItem.setPickListFields(skuField, itemNameField);  
comboBoxItem.setSpecialValues(hashMap);  
comboBoxItem.setSeparateSpecialValues(true);