I have huge sets of numeric data.
this needs to be rendered as comma separated value.
For Ex.
123456.78 to be rendered as 123,457 using Ag-Grid.
Kindly help me on achieving this.
As per the cell rendering flow documentation (here), you can use the colDef.valueFormatter, like this:
var columnDefs = [
{headerName: "Number", field: "number"},
{headerName: "Formatted", field: "number", valueFormatter: currencyFormatter}
];
function currencyFormatter(params) {
return '£' + formatNumber(params.value);
}
function formatNumber(number) {
// this puts commas into the number eg 1000 goes to 1,000,
// i pulled this from stack overflow, i have no idea how it works
return Math.floor(number).toString().replace(/(\d)(?=(\d{3})+(?!\d))/g, "$1,");
}
You could also use a cellRenderer as other posts describe, but that's typically for more complex rendering, whereas the valueFormatter is specifically for this case. From the ag-grid documentation:
valueFormatter's are for text formatting.
cellRenderer's are for when you want to include HTML markup and
potentially functionality to the cell. So for example, if you want to
put punctuation into a value, use a valueFormatter, if you want to put
buttons or HTML links use a cellRenderer. It is possible to use a
combination of both, in which case the result of the valueFormatter
will be passed to the cellRenderer.
{
headerName: 'Salary', field: 'sal'
cellRenderer: this.CurrencyCellRenderer
}
private CurrencyCellRenderer(params:any) {
var usdFormate = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 4
});
return usdFormate.format(params.value);
}
Like these we can mention in Angular2 Typescript code.
You can do this by writing a "customcellRenderer", when you create a column definition provide a function to "cellRenderer " attribute and in renderer use number filter, something like this
var colDef = {
name: 'Col Name',
field' 'Col Field',
cellRenderer: function(params) {
var eCell = document.createElement('span');
var number;
if (!param.value || !isFinite(param.value)) {
number = '';
} else {
number = $filter('number')(param.value, 0);
}
eCell.innerHTML = number;
return eCell;
}
}
I'm trying to modify the TinyMCE 4 "link" plugin to allow users to select content from ListBox elements that are dynamically updated by AJAX requests.
I'm creating the ListBox elements in advance of editor.windowManager.open(), so they are initially rendered properly. I have an onselect handler that performs the AJAX request, and gets a response in JSON format.
What I need to do with the JSON response is to have it update another ListBox element, replacing the existing items with the new results.
I'm baffled, and the documentation is terribly unclear. I don't know if I should replace the entire control, or delete items and then add new ones. I don't know if I need to instantiate a new ListBox control, or render it to HTML, etc.
Basically, I have access to the original rendered ListBox (name: "module"} with
win.find('#module');
I have the new values from the AJAX request:
var data = tinymce.util.JSON.parse(text).data;
And I've tried creating a new Control configuration object, like
newCtrlconfig = {
type: 'listbox',
label: 'Class',
values: data
};
but I wouldn't know how to render it, much less have it replace the existing one.
I tried
var newList = tinymce.ui.Factory.create(newCtrlconfig);
and then
newList.renderHtml()
but even then, the rendered HTML did not contain any markup for the items. And examining these objects is just frustrating: there are "settings", "values", "_values", "items" all of which will happily store my values, but it isn't even clear which of them will work.
Since it's a ListBox and not a simple SELECT menu, I can't even easily use the DOM to manipulate the values.
Has anyone conquered the TinyMCE ListBox in 4.x?
I found this on the TinyMCE forum and I have confirmed that it works:
tinymce.PluginManager.add('myexample', function(editor, url) {
var self = this, button;
function getValues() {
return editor.settings.myKeyValueList;
}
// Add a button that opens a window
editor.addButton('myexample', {
type: 'listbox',
text: 'My Example',
values: getValues(),
onselect: function() {
//insert key
editor.insertContent(this.value());
//reset selected value
this.value(null);
},
onPostRender: function() {
//this is a hack to get button refrence.
//there may be a better way to do this
button = this;
},
});
self.refresh = function() {
//remove existing menu if it is already rendered
if(button.menu){
button.menu.remove();
button.menu = null;
}
button.settings.values = button.settings.menu = getValues();
};
});
Call following code block from ajax success method
//Set new values to myKeyValueList
tinyMCE.activeEditor.settings.myKeyValueList = [{text: 'newtext', value: 'newvalue'}];
//Call plugin method to reload the dropdown
tinyMCE.activeEditor.plugins.myexample.refresh();
The key here is that you need to do the following:
Get the 'button' reference by taking it from 'this' in the onPostRender method
Update the button.settings.values and button.settings.menu with the values you want
To update the existing list, call button.menu.remove() and button.menu = null
I tried the solution from TinyMCE forum, but I found it buggy. For example, when I tried to alter the first ListBox multiple times, only the first time took effect. Also first change to that box right after dialogue popped up didn't take any effect.
But to the solution:
Do not call button.menu.remove();
Also, the "hack" for getting button reference is quite unnecessary. Your job can be done simply using:
var button = win.find("#button")[0];
With these modification, my ListBoxes work just right.
Whole dialogue function:
function ShowDialog() {
var val;
win = editor.windowManager.open({
title: 'title',
body: {type: 'form',
items: [
{type: 'listbox',
name: 'categorybox',
text: 'pick one',
value: 0,
label: 'Section: ',
values: categories,
onselect: setValuebox(this.value())
},
{type: 'listbox',
name: 'valuebox',
text:'pick one',
value: '',
label: 'Page: ',
values: pagelist[0],
onselect: function(e) {
val = this.value();
}
}
]
},
onsubmit: function(e) {
//do whatever
}
});
var valbox = win.find("#valuebox")[0];
function setValuebox(i){
//feel free to call ajax
valbox.value(null);
valbox.menu = null;
valbox.settings.menu = pagelist[i];
// you can also set a value from pagelist[i]["values"][0]
}
}
categories and pagelist are JSONs generated from DB before TinyMCE load. pagelist[category] = data for ListBox for selected category. category=0 means all.
Hope I helped somebody, because I've been struggling this for hours.
It looks like the tinyMCE version that is included in wordpress 4.3 changed some things, and added a state object that caches the initial menu, so changing the menu is not enough anymore.
One will probably have to update the state object as well. Here is an example of updating the menu with data coming from an ajax request:
editor.addButton('shortcodes', {
icon: 'icon_shortcodes',
tooltip: 'Your tooltip',
type: 'menubutton',
onPostRender: function() {
var ctrl = this;
$.getJSON( ajaxurl , function( menu) {
// menu is the array containing your menu items
ctrl.state.data.menu = ctrl.settings.menu = menu;
});
}
});
As far as I can tell, these other approaches are broken in TinyMCE 4.9.
After spending most of the day tinkering to fix my own usage of these approaches, this is the working function I've found:
function updateListbox(win, data) { // win is a tinymce.ui.Window
listbox = win.find('#listbox'); // Substitute your listbox 'name'
formItem = listbox.parent();
listbox.remove();
formItem.append({
label: 'Dynamic Listbox',
type: 'listbox',
name: 'listbox',
values: data
});
}
A potentially simple issue with jQuery UI autocomplete is stumping me. My source is
var ac = [
{
label: "One Thing",
value: "One-Thing"
},
{
label: "Two Thing",
value: "Two-Thing"
},
]
I am invoking the widget with
$(function() {
$( "#search" ).autocomplete({
source: PK.getAutocompleteSource(),
focus: function( event, ui ) {
$("#search").val(ui.item.label);
return false;
},
select: function( event, ui ) {
$("#search").val(ui.item.label);
PK.render(ui.item.value);
}
});
});
All works fine. When I type in the #search input field, the matching label shows up in the dropdown, and when I select the correct search is performed. The widget even shows the label in the #search input field as I select different items in the dropdown using the arrow keys (or the mouse). Except, soon as I hit enter, the widget fills the #search input field with the value instead of the label. So the field shows One-Thing instead of One Thing.
How can I correct this? Surely what I am expecting is the more reasonable behavior, no?
if you want the label to be your value, just have the source be
var ac = ["One Thing", "Two Thing"]
alternatively, the select method of autocompletes default action is to put the value object (if specified) as the value of your input. you could also put event.preventDefault() in the select function and it will put the label as the value (as you have)
select: function( event, ui ) {
event.preventDefault();
$("#search").val(ui.item.label);
PK.render(ui.item.value);
}
If you want your label to be your value in the text box onFocus AND onSelect use this code:
select: function(event, ui) {
$('#hiddenid').val(ui.item.value);
event.preventDefault();
$("#search").val(ui.item.label); },
focus: function(event, ui) {
event.preventDefault();
$("#search").val(ui.item.label);}
I was missing the onFocus event (only setting the onSelect event). Thus, the value continued to show in the text input.
I was still haveing a problem with arrow keys showing the values. So I actually found it better to assign both the value and label to the label, and then put the value on a 3rd property of the data. For example let's put it on id.
var ac = [
{
label: "One Thing",
value: "One Thing",
id: "One-Thing",
},
{
label: "Two Thing",
value: "Two Thing",
id: "Two-Thing"
},
]
Then when you use the select event, you can get id from ui:
select: function( event, ui ) {
PK.render(ui.item.id);
}
I want to create custom ExtJS form field components using other ExtJS components in it (e.g. TreePanel). How can I do it most easily?
I've read docs of Ext.form.field.Base but I don't want to define field body by fieldSubTpl. I just want to write code which creates ExtJS components and maybe some other code which gets and sets values.
Update: Summarized purposes are the followings:
This new component should fit in the
form GUI as a field. It should have
label and the same alignment (label,
anchor) of other fields without need
of further hacking.
Possibly, I have
to write some getValue, setValue
logic. I'd rather embed it into this component than making separated code which copies things into further hidden form fields that I also have to manage.
To extend #RobAgar 's answer, following a really simple Date Time field that I wrote for ExtJS 3 and it's quickport that I made for ExtJS 4. The important thing is the use of the Ext.form.field.Field mixin. This mixin provides a common interface for the logical behavior and state of form fields, including:
Getter and setter methods for field values
Events and methods for tracking value and validity changes
Methods for triggering validation
This can be used for combining multiple fields and let act them as one. For a total custom fieldtype I recommend to extend Ext.form.field.Base
Here is the example that I mentioned above. It should shoe how easy this can be done even for something like a date object where we need to format the data within the getter and setter.
Ext.define('QWA.form.field.DateTime', {
extend: 'Ext.form.FieldContainer',
mixins: {
field: 'Ext.form.field.Field'
},
alias: 'widget.datetimefield',
layout: 'hbox',
width: 200,
height: 22,
combineErrors: true,
msgTarget: 'side',
submitFormat: 'c',
dateCfg: null,
timeCfg: null,
initComponent: function () {
var me = this;
if (!me.dateCfg) me.dateCfg = {};
if (!me.timeCfg) me.timeCfg = {};
me.buildField();
me.callParent();
me.dateField = me.down('datefield')
me.timeField = me.down('timefield')
me.initField();
},
//#private
buildField: function () {
var me = this;
me.items = [
Ext.apply({
xtype: 'datefield',
submitValue: false,
format: 'd.m.Y',
width: 100,
flex: 2
}, me.dateCfg),
Ext.apply({
xtype: 'timefield',
submitValue: false,
format: 'H:i',
width: 80,
flex: 1
}, me.timeCfg)]
},
getValue: function () {
var me = this,
value,
date = me.dateField.getSubmitValue(),
dateFormat = me.dateField.format,
time = me.timeField.getSubmitValue(),
timeFormat = me.timeField.format;
if (date) {
if (time) {
value = Ext.Date.parse(date + ' ' + time, me.getFormat());
} else {
value = me.dateField.getValue();
}
}
return value;
},
setValue: function (value) {
var me = this;
me.dateField.setValue(value);
me.timeField.setValue(value);
},
getSubmitData: function () {
var me = this,
data = null;
if (!me.disabled && me.submitValue && !me.isFileUpload()) {
data = {},
value = me.getValue(),
data[me.getName()] = '' + value ? Ext.Date.format(value, me.submitFormat) : null;
}
return data;
},
getFormat: function () {
var me = this;
return (me.dateField.submitFormat || me.dateField.format) + " " + (me.timeField.submitFormat || me.timeField.format)
}
});
Now that's cool. The other day, I created a fiddle to answer another question before realizing I was off-topic. And here your are, finally bringing to my attention the question to my answer. Thanks!
So, here are the steps required in implementing a custom field from another component:
Creating the child component
Render the child component
Ensuring the child component is sized and resized correctly
Getting and setting value
Relaying events
Creating the child component
The first part, creating the component, is easy. There's nothing particular compared to creating a component for any other usage.
However, you must create the child in the parent field's initComponent method (and not at rendering time). This is because external code can legitimately expect that all dependent objects of a component are instantiated after initComponent (e.g. to add listeners to them).
Furthermore, you can be kind to yourself and create the child before calling the super method. If you create the child after the super method, you may get a call to your field's setValue method (see bellow) at a time when the child is not yet instantiated.
initComponent: function() {
this.childComponent = Ext.create(...);
this.callParent(arguments);
}
As you see, I am creating a single component, which is what you'll want in most case. But you can also want to go fancy and compose multiple child components. In this case, I think it would be clever to back to well known territories as quickly as possible: that is, create one container as the child component, and compose in it.
Rendering
Then comes the question of rendering. At first I considered using fieldSubTpl to render a container div, and have the child component render itself in it. However, we don't need the template features in that case, so we can as well bypass it completely using the getSubTplMarkup method.
I explored other components in Ext to see how they manage the rendering of child components. I found a good example in BoundList and its paging toolbar (see the code). So, in order to obtain the child component's markup, we can use Ext.DomHelper.generateMarkup in combination with the child's getRenderTree method.
So, here's the implementation of getSubTplMarkup for our field:
getSubTplMarkup: function() {
// generateMarkup will append to the passed empty array and return it
var buffer = Ext.DomHelper.generateMarkup(this.childComponent.getRenderTree(), []);
// but we want to return a single string
return buffer.join('');
}
Now, that's not enough. The code of BoundList learns us that there's another important part in component rendering: calling the finishRender() method of the child component. Fortunately, our custom field will have its own finishRenderChildren method called just when that needs to be done.
finishRenderChildren: function() {
this.callParent(arguments);
this.childComponent.finishRender();
}
Resizing
Now our child will be rendered in the right place, but it will not respect its parent field size. That is especially annoying in the case of a form field, because that means it won't honor the anchor layout.
That's very straightforward to fix, we just need to resize the child when the parent field is resized. From my experience, this is something that was greatly improved since Ext3. Here, we just need to not forget the extra space for the label:
onResize: function(w, h) {
this.callParent(arguments);
this.childComponent.setSize(w - this.getLabelWidth(), h);
}
Handling value
This part will, of course, depend on your child component(s), and the field you're creating. Moreover, from now on, it's just a matter of using your child components in a regular way, so I won't detail this part too much.
A minima, you also need to implement the getValue and setValue methods of your field. That will make the getFieldValues method of the form work, and that will be enough to load/update records from the form.
To handle validation, you must implement getErrors. To polish this aspect, you may want to add a handful of CSS rules to visually represent the invalid state of your field.
Then, if you want your field to be usable in a form that will be submitted as an actual form (as opposed to with an AJAX request), you'll need getSubmitValue to return a value that can be casted to a string without damage.
Apart from that, as far as I know, you don't have to worry about the concept or raw value introduced by Ext.form.field.Base since that's only used to handle the representation of the value in an actual input element. With our Ext component as input, we're way off that road!
Events
Your last job will be to implement the events for your fields. You will probably want to fire the three events of Ext.form.field.Field, that is change, dirtychange and validitychange.
Again, the implementation will be very specific to the child component you use and, to be honest, I haven't explored this aspect too much. So I'll let you wire this for yourself.
My preliminary conclusion though, is that Ext.form.field.Field offers to do all the heavy lifting for you, provided that (1) you call checkChange when needed, and (2) isEqual implementation is working with your field's value format.
Example: TODO list field
Finally, here's a complete code example, using a grid to represent a TODO list field.
You can see it live on jsFiddle, where I tries to show that the field behaves in an orderly manner.
Ext.define('My.form.field.TodoList', {
// Extend from Ext.form.field.Base for all the label related business
extend: 'Ext.form.field.Base'
,alias: 'widget.todolist'
// --- Child component creation ---
,initComponent: function() {
// Create the component
// This is better to do it here in initComponent, because it is a legitimate
// expectationfor external code that all dependant objects are created after
// initComponent (to add listeners, etc.)
// I will use this.grid for semantical access (value), and this.childComponent
// for generic issues (rendering)
this.grid = this.childComponent = Ext.create('Ext.grid.Panel', {
hideHeaders: true
,columns: [{dataIndex: 'value', flex: 1}]
,store: {
fields: ['value']
,data: []
}
,height: this.height || 150
,width: this.width || 150
,tbar: [{
text: 'Add'
,scope: this
,handler: function() {
var value = prompt("Value?");
if (value !== null) {
this.grid.getStore().add({value: value});
}
}
},{
text: "Remove"
,itemId: 'removeButton'
,disabled: true // initial state
,scope: this
,handler: function() {
var grid = this.grid,
selModel = grid.getSelectionModel(),
store = grid.getStore();
store.remove(selModel.getSelection());
}
}]
,listeners: {
scope: this
,selectionchange: function(selModel, selection) {
var removeButton = this.grid.down('#removeButton');
removeButton.setDisabled(Ext.isEmpty(selection));
}
}
});
// field events
this.grid.store.on({
scope: this
,datachanged: this.checkChange
});
this.callParent(arguments);
}
// --- Rendering ---
// Generates the child component markup and let Ext.form.field.Base handle the rest
,getSubTplMarkup: function() {
// generateMarkup will append to the passed empty array and return it
var buffer = Ext.DomHelper.generateMarkup(this.childComponent.getRenderTree(), []);
// but we want to return a single string
return buffer.join('');
}
// Regular containers implements this method to call finishRender for each of their
// child, and we need to do the same for the component to display smoothly
,finishRenderChildren: function() {
this.callParent(arguments);
this.childComponent.finishRender();
}
// --- Resizing ---
// This is important for layout notably
,onResize: function(w, h) {
this.callParent(arguments);
this.childComponent.setSize(w - this.getLabelWidth(), h);
}
// --- Value handling ---
// This part will be specific to your component of course
,setValue: function(values) {
var data = [];
if (values) {
Ext.each(values, function(value) {
data.push({value: value});
});
}
this.grid.getStore().loadData(data);
}
,getValue: function() {
var data = [];
this.grid.getStore().each(function(record) {
data.push(record.get('value'));
});
return data;
}
,getSubmitValue: function() {
return this.getValue().join(',');
}
});
Heh. After posting the bounty I found out that Ext.form.FieldContainer isn't just a field container, but a fully fledged component container, so there is a simple solution.
All you need to do is extend FieldContainer, overriding initComponent to add the child components, and implement setValue, getValue and the validation methods as appropriate for your value data type.
Here's an example with a grid whose value is a list of name/value pair objects:
Ext.define('MyApp.widget.MyGridField', {
extend: 'Ext.form.FieldContainer',
alias: 'widget.mygridfield',
layout: 'fit',
initComponent: function()
{
this.callParent(arguments);
this.valueGrid = Ext.widget({
xtype: 'grid',
store: Ext.create('Ext.data.JsonStore', {
fields: ['name', 'value'],
data: this.value
}),
columns: [
{
text: 'Name',
dataIndex: 'name',
flex: 3
},
{
text: 'Value',
dataIndex: 'value',
flex: 1
}
]
});
this.add(this.valueGrid);
},
setValue: function(value)
{
this.valueGrid.getStore().loadData(value);
},
getValue: function()
{
// left as an exercise for the reader :P
}
});
I've done this a few times. Here is the general process/pseudo-code I use:
Create an extension of field that provides the most useful re-use (typically Ext.form.TextField if you just want to get/set a string value)
In the afterrender of the field, hide the textfield, and create a wrapping element around this.el with this.wrap = this.resizeEl = this.positionEl = this.el.wrap()
Render any components to this.wrap (e.g. using renderTo: this.wrap in the config)
Override getValue and setValue to talk to the component(s) you rendered manually
You may need to do some manually sizing in a resize listener if your form's layout changes
Don't forget to cleanup any components you create in the beforeDestroy method!
I can't wait to switch our codebase to ExtJS 4, where these kinds of things are easy.
Good luck!
Since the question was asked rather vague - I only can provide the basic pattern for ExtJS v4.
Even if it's not too specific, it has the advance that it's rather universal like this:
Ext.define('app.view.form.field.CustomField', {
extend: 'Ext.form.field.Base',
requires: [
/* require further components */
],
/* custom configs & callbacks */
getValue: function(v){
/* override function getValue() */
},
setValue: function(v){
/* override function setValue() */
},
getSubTplData: [
/* most likely needs to be overridden */
],
initComponent: function(){
/* further code on event initComponent */
this.callParent(arguments);
}
});
The file /ext/src/form/field/Base.js provides the names of all configs and functions that can be overridden.
Following the documentation at http://docs.sencha.com/ext-js/4-0/#/api/Ext.form.field.Base
This code will create a reusable TypeAhead/Autocomplete style field for selecting a language.
var langs = Ext.create( 'Ext.data.store', {
fields: [ 'label', 'code' ],
data: [
{ code: 'eng', label: 'English' },
{ code: 'ger', label: 'German' },
{ code: 'chi', label: 'Chinese' },
{ code: 'ukr', label: 'Ukranian' },
{ code: 'rus', label: 'Russian' }
]
} );
Ext.define( 'Ext.form.LangSelector', {
extend: 'Ext.form.field.ComboBox',
alias: 'widget.LangSelector',
allowBlank: false,
hideTrigger: true,
width: 225,
displayField: 'label',
valueField: 'code',
forceSelection: true,
minChars: 1,
store: langs
} );
You can use the field in a form simply by setting the xtype to the widget name:
{
xtype: 'LangSelector'
fieldLabel: 'Language',
name: 'lang'
}
Many of the answers either use the Mixin Ext.form.field.Field or just extends on some already made class that suits their needs - which is fine.
But I do not recommend fully overwriting the setValue method, that is IMO really bad form!
A lot more happens than just setting and getting the value, and if you fully overwrite it - well you will for instance mess up the dirty state, processing of rawValue etc..
Two options here I guess, one is to callParent(arguments) inside the method you declare to keep things streamlined, or to at the end when you are done apply the inherited method from where ever you got it (mixin or extend).
But do not just overwrite it with no regards for what that already made method does behind the scenes.
Also remember that if you use other field types in your new class - then do set the isFormField property to false - otherwise your getValues method on the form will take those values and run with em!
Another solution could be this tree-field implementation.
It behaves just like a normal form field:
https://github.com/wencywww/Ext.ux.form.field.Tree
Here is an example of a custom panel that extends an Ext Panel. You can extend any component, check the docs for the fields, methods and events you can play with.
Ext.ns('yournamespace');
yournamespace.MyPanel = function(config) {
yournamespace.MyPanel.superclass.constructor.call(this, config);
}
Ext.extend(yournamespace.MyPanel, Ext.Panel, {
myGlobalVariable : undefined,
constructor : function(config) {
yournamespace.MyPanel.superclass.constructor.apply(this, config);
},
initComponent : function() {
this.comboBox = new Ext.form.ComboBox({
fieldLabel: "MyCombo",
store: someStore,
displayField:'My Label',
typeAhead: true,
mode: 'local',
forceSelection: true,
triggerAction: 'all',
emptyText:'',
selectOnFocus:true,
tabIndex: 1,
width: 200
});
// configure the grid
Ext.apply(this, {
listeners: {
'activate': function(p) {
p.doLayout();
},
single:true
},
xtype:"form",
border: false,
layout:"absolute",
labelAlign:"top",
bodyStyle:"padding: 15px",
width: 350,
height: 75,
items:[{
xtype:"panel",
layout:"form",
x:"10",
y:"10",
labelAlign:"top",
border:false,
items:[this.comboBox]
},
{
xtype:"panel",
layout:"form",
x:"230",
y:"26",
labelAlign:"top",
border:false,
items:[{
xtype:'button',
handler: this.someAction.createDelegate(this),
text: 'Some Action'
}]
}]
}); // eo apply
yournamespace.MyPanel.superclass.initComponent.apply(this, arguments);
this.comboBox.on('select', function(combo, record, index) {
this.myGlobalVariable = record.get("something");
}, this);
}, // eo function initComponent
someAction : function() {
//do something
},
getMyGlobalVariable : function() {
return this.myGlobalVariable;
}
}); // eo extend
Ext.reg('mypanel', yournamespace.MyPanel);
Could you describe the UI requirements that you have a bit more? Are you sure that you even need to do build an entire field to support the TreePanel? Why not set the value of a hidden field (see the "hidden" xtype in the API) from a click handler on a normal tree panel?
To answer your question more fully, you can find many tutorials on how to extend ExtJS components. You do this by leveraging the Ext.override() or Ext.Extend() methods.
But my feeling is that you may be over-complicating your design. You can achieve what you need to do by setting a value to this hidden field. If you have complex data, you can set the value as some XML or JSON string.
EDIT Here's a few tutorials. I highly recommend going with the KISS rule when it comes to your UI design. Keep It Simple Stupid!
Extending components using panels