java - How to create a checkbox (i dont want entire column) in a grid (GXT 3) -

i trying add checkbox(i dont want checkbox column) in grid (gxt 3.0), while getting values model(vo/dto) if got null value want add checkbox instead of null.

any idea?

thanks in advance

you should oveeride datareader http://dev.sencha.com/deploy/gxt-3.0.0/javadoc/gxt/com/sencha/gxt/data/shared/loader/class-use/datareader.html

assuming have got grid checkcolumnconfig.

checkcolumnconfig checkcolumnconfig = new checkcolumnconfig ("myproperty" + prop.getid(), "myproperty"                 + prop.getid(), 40); 

the associated loader should :

rpcproxy<beanmodel> proxy = new rpcproxy<beanmodel>() {         @override         protected void load(object loadconfig, asynccallback<beanmodel> callback) {             //call rpc service         }     };     final listloader<baselistloadresult<beanmodel>> loader = new baselistloader<baselistloadresult<beanmodel>>(         proxy, new customgridbeanmodelreader());     loader.load(); 

now implements logic in datereader :

public class customgridbeanmodelreader implements datareader<list<beanmodel>> {  /** reader. */ private beanmodelreader reader = new beanmodelreader();  /**  * checks if factory each bean.  *   * @return true, if factory each bean  */ public boolean isfactoryforeachbean() {     return reader.isfactoryforeachbean(); }  /* (non-javadoc)  * @see com.extjs.gxt.ui.client.data.datareader#read(java.lang.object, java.lang.object)  */ public list<beanmodel> read(object loadconfig, object data) {     listloadresult<modeldata> models = reader.read(loadconfig, data);     list<modeldata> modelsdata = models.getdata();     iterator<modeldata> itmodels = modelsdata.iterator();     list<beanmodel> newmodelsdata = new arraylist<beanmodel>();     while (itmodels.hasnext()) {         beanmodel model = (beanmodel) itmodels.next();         mybean mybean = model.getbean();         //add logic         if ((mybean.getmyproperty() == null){             model.set("myproperty" + mybean.getid(), true);         }         //add more logic         //...         newmodelsdata.add(model);     }     return newmodelsdata; }  /**  * sets factory each bean.  *   * @param factoryforeachbean new factory each bean  */ public void setfactoryforeachbean(boolean factoryforeachbean) {     reader.setfactoryforeachbean(factoryforeachbean); } 

}