How to create dependent cell dropdownown / selection In GWT celltable 2.3?
I am using gwt2.3 celltable.
My cell table will have multiple columns of multiple columns.
ex. Name and Address Columns Are Dependent The Name and Address columns contain my custom select cells.
In column Name: 1 cell contains jon, tom, steve
when the Name cell contains jon then I want to set US and UK in the address cell
if user change cell of cells then i want to set India and China to address cell
if user changes Name cell for steve then I want to set japana and bhutan in address cell
I want to change dependent data from address cell when cell selection changes.
How can I achieve this goal? Any sample code or pointers for this?
Thanks in advance.
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This is a solution for GWT 2.5, but it should probably work in 2.3. I find it best to change your RecordInfo when the selection in the first column changes. You can do it similarly to this in your CustomSelectionCell:
@Override
public void onBrowserEvent(Context context, Element parent, C value, NativeEvent event, ValueUpdater<C> valueUpdater) {
super.onBrowserEvent(context, parent, value, event, valueUpdater);
if (BrowserEvents.CHANGE.equals(event.getType())) {
Xxxxx newValue = getSelectedValueXxxxx();
valueUpdater.update(newValue);
}
}
Then when you use your cell, add a fieldUpdater like this, which will update the RecordInfo with the new value and ask you to redraw the line:
column.setFieldUpdater(new FieldUpdater<.....>() {
....
recordInfo.setXxxxx(newValue);
cellTable.redrawRow(index);
....
});
This will render another CustomSelectionCell, there you can check if the RecordInfo value has changed and update the seletion values as needed. Example:
@Override
public void render(Context context, C value, SafeHtmlBuilder sb) {
if (!value.getXxxxx().equals(this.lastValue)) {
this.items = loadItemsForValueXxxx(value.getXxxxx());
}
.... // Your usual render.
}
Be careful when you change items to set the item to the default.
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Or you can do something like create a custom cell that has methods that you can call on the getValue of that particular column
say
final DynamicSelectionCell selection = new DynamicSelectionCell("...");
Column<GraphFilterCondition, String> operandColumn=new Column<GraphFilterCondition, String>(selection) {
@Override
public String getValue(FilterCondition object) {
if(object.getWhereCol()!=null){
((DynamicSelectionCell)this.getCell()).addOptions(new String[]{">","<",">="});
}
if(object.getWhereCondition()!=null){
return object.getWhereCondition().getGuiName();
}
return "";
}
};
This should work I think.
Also check this other question
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This is my implementation of DynamicSelectionCell.
DynamicSelectionCell allows you to display different options for different rows in the same GWT.
Use one DynamicSelectionCell object and use the addOption method to add options for each row. The parameters are saved on the card with a key line number.
For each row $ i in the table, the parameters stored in the Map for the key $ i are displayed.
Works with DataGrid, CellTable.
CODE
public class DynamicSelectionCell extends AbstractInputCell<String, String> {
public TreeMap<Integer, List<String>> optionsMap = new TreeMap<Integer, List<String>>();
interface Template extends SafeHtmlTemplates {
@Template("<option value=\"{0}\">{0}</option>")
SafeHtml deselected(String option);
@Template("<option value=\"{0}\" selected=\"selected\">{0}</option>")
SafeHtml selected(String option);
}
private static Template template;
private TreeMap<Integer, HashMap<String, Integer>> indexForOption = new TreeMap<Integer, HashMap<String, Integer>>();
/**
* Construct a new {@link SelectionCell} with the specified options.
*
* @param options the options in the cell
*/
public DynamicSelectionCell() {
super("change");
if (template == null) {
template = GWT.create(Template.class);
}
}
public void addOption(List<String> newOps, int key){
optionsMap.put(key, newOps);
HashMap<String, Integer> localIndexForOption = new HashMap<String, Integer>();
indexForOption.put(ind, localIndexForOption);
refreshIndexes();
}
public void removeOption(int index){
optionsMap.remove(index);
refreshIndexes();
}
private void refreshIndexes(){
int ind=0;
for (List<String> options : optionsMap.values()){
HashMap<String, Integer> localIndexForOption = new HashMap<String, Integer>();
indexForOption.put(ind, localIndexForOption);
int index = 0;
for (String option : options) {
localIndexForOption.put(option, index++);
}
ind++;
}
}
@Override
public void onBrowserEvent(Context context, Element parent, String value,
NativeEvent event, ValueUpdater<String> valueUpdater) {
super.onBrowserEvent(context, parent, value, event, valueUpdater);
String type = event.getType();
if ("change".equals(type)) {
Object key = context.getKey();
SelectElement select = parent.getFirstChild().cast();
String newValue = optionsMap.get(context.getIndex()).get(select.getSelectedIndex());
setViewData(key, newValue);
finishEditing(parent, newValue, key, valueUpdater);
if (valueUpdater != null) {
valueUpdater.update(newValue);
}
}
}
@Override
public void render(Context context, String value, SafeHtmlBuilder sb) {
// Get the view data.
Object key = context.getKey();
String viewData = getViewData(key);
if (viewData != null && viewData.equals(value)) {
clearViewData(key);
viewData = null;
}
int selectedIndex = getSelectedIndex(viewData == null ? value : viewData, context.getIndex());
sb.appendHtmlConstant("<select tabindex=\"-1\">");
int index = 0;
try{
for (String option : optionsMap.get(context.getIndex())) {
if (index++ == selectedIndex) {
sb.append(template.selected(option));
} else {
sb.append(template.deselected(option));
}
}
}catch(Exception e){
System.out.println("error");
}
sb.appendHtmlConstant("</select>");
}
private int getSelectedIndex(String value, int ind) {
Integer index = indexForOption.get(ind).get(value);
if (index == null) {
return -1;
}
return index.intValue();
}
}
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Varun Tulsian's answer is very good, but the code is incomplete.
DynamicSelectionCell stores the parameters of each row in the map. When a cell is updated or displayed on its own, it matches the row index from your context to the corresponding list of rows in your map.
For posterity, see the simplified and updated version below:
public class DynamicSelectionCell extends AbstractInputCell<String, String> {
interface Template extends SafeHtmlTemplates {
@Template("<option value=\"{0}\">{0}</option>")
SafeHtml deselected(String option);
@Template("<option value=\"{0}\" selected=\"selected\">{0}</option>")
SafeHtml selected(String option);
}
private static Template template;
/**
* key: rowIndex
* value: List of options to show for this row
*/
public TreeMap<Integer, List<String>> optionsMap = new TreeMap<Integer, List<String>>();
/**
* Construct a new {@link SelectionCell} with the specified options.
*
*/
public DynamicSelectionCell() {
super("change");
if (template == null) {
template = GWT.create(Template.class);
}
}
public void addOptions(List<String> newOps, int rowIndex) {
optionsMap.put(rowIndex, newOps);
}
public void removeOptions(int rowIndex) {
optionsMap.remove(rowIndex);
}
@Override
public void onBrowserEvent(Context context, Element parent, String value,
NativeEvent event, ValueUpdater<String> valueUpdater) {
super.onBrowserEvent(context, parent, value, event, valueUpdater);
String type = event.getType();
if ("change".equals(type)) {
Object key = context.getKey();
SelectElement select = parent.getFirstChild().cast();
String newValue = optionsMap.get(context.getIndex()).get(select.getSelectedIndex());
setViewData(key, newValue);
finishEditing(parent, newValue, key, valueUpdater);
if (valueUpdater != null) {
valueUpdater.update(newValue);
}
}
}
@Override
public void render(Context context, String value, SafeHtmlBuilder sb) {
// Get the view data.
Object key = context.getKey();
String viewData = getViewData(key);
if (viewData != null && viewData.equals(value)) {
clearViewData(key);
viewData = null;
}
int selectedIndex = getSelectedIndex(viewData == null ? value : viewData, context.getIndex());
sb.appendHtmlConstant("<select tabindex=\"-1\">");
int index = 0;
try {
for (String option : optionsMap.get(context.getIndex())) {
if (index++ == selectedIndex) {
sb.append(template.selected(option));
} else {
sb.append(template.deselected(option));
}
}
} catch (Exception e) {
System.out.println("error");
}
sb.appendHtmlConstant("</select>");
}
private int getSelectedIndex(String value, int rowIndex) {
if (optionsMap.get(rowIndex) == null) {
return -1;
}
return optionsMap.get(rowIndex).indexOf(value);
}
}
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