how to write data to a json file - php

Question

I have data that is coming from a form that should be submitted to a database. I need to know how I can write this same information I have submitted in my Ajax request to a file. I have a json writer attached to my store. Basically I just need to flush this data into a file. The database is on the server side, this would be a server side operation. How can I do this?
Here is the store
Ext.define('ClientInfo.store.LicenseStore', {
extend: 'Ext.data.Store',
requires: [
'ClientInfo.model.LicenseModel',
'Ext.data.proxy.Ajax',
'Ext.data.reader.Json',
'Ext.data.writer.Json'
],
constructor: function(cfg) {
var me = this;
cfg = cfg || {};
me.callParent([Ext.apply({
storeId: 'LicenseStore',
autoLoad: true,
autoSync: true,
model: 'ClientInfo.model.LicenseModel',
proxy: {
type: 'ajax',
extraParams: {
class: 'License',
method: 'get'
},
url: 'system/index.php',
reader: {
type: 'json',
rootProperty: 'topics'
},
writer: {
type: 'json',
writeAllFields: true,
encode: true,
rootProperty: 'topics'
}
}
}, cfg)]);
}
});
and here is current ajax request
var productstore = Ext.getStore('ProductStore');
var win = Ext.create ('Ext.window.Window' , {
title: 'License' ,
id: 'addLicenseWindow',
width: 500 ,
modal: true,
height: 300 ,
items: [
{
xtype: 'form',
bodyPadding: 10,
items: [
{
xtype: 'fieldset',
modelValidation: true,
title: 'Licence',
items: [
{
xtype: 'textfield',
anchor: '100%',
id: 'licensenumberTextField',
fieldLabel: 'Licence Number',
labelWidth: 140,
emptyText: 'Licence Number',
allowBlank: false,
blankText: 'This Field is required',
msgTarget: 'under',
},
{
xtype: 'datefield',
anchor: '100%',
id: 'startdateTextField',
fieldLabel: 'Start Date',
labelWidth: 140,
allowBlank: false,
blankText: 'This Field is required',
msgTarget: 'under'
},
{
xtype: 'datefield',
anchor: '100%',
id: 'enddateTextField',
fieldLabel: 'End Date',
labelWidth: 140,
allowBlank: false,
blankText: 'This Field is required',
msgTarget: 'under'
},
{
xtype: 'numberfield',
anchor: '100%',
id: 'durationTextField',
fieldLabel: 'Duration',
labelWidth: 140,
emptyText: 'Duration',
allowBlank: false,
blankText: 'This Field is required',
msgTarget: 'under'
},
{
xtype: 'datefield',
anchor: '100%',
id: 'expirydateTextField',
fieldLabel: 'Expiry Date',
labelWidth: 140,
allowBlank: false,
blankText: 'This Field is required',
msgTarget: 'under'
},
{
xtype: 'combobox',
fieldLabel: 'Product',
id: 'productidTextField',
valueField: 'product_id',
displayField: 'product_name',
store: productstore,
typeAhead: true,
queryMode: 'local',
minChars: 2,
renderTo: Ext.getBody()
},
{
xtype: 'combobox',
fieldLabel: 'Company',
id: 'companyidtf',
valueField: 'company_id',
displayField: 'name',
store: 'CompanyStore',
typeAhead: true,
queryMode: 'local',
minChars: 2,
renderTo: Ext.getBody()
}
]
}
],
dockedItems: [
{
xtype: 'toolbar',
dock: 'bottom',
items: [
{
xtype: 'button',
id: 'cancelLicenceBtn',
text: 'Cancel',
listeners: {
click: function(c){
Ext.getCmp('addLicenseWindow').close();
}
}
},
{
xtype: 'tbspacer',
flex: 1
},
{
xtype: 'button',
formBind: true,
id: 'saveLicenceBtn',
text: 'Save',
listeners: {
click: function(c){
Ext.Ajax.request({
url: 'system/index.php',
method: 'POST',
params: {
class: 'License',
method: 'add',
data: Ext.encode({
license_number: Ext.getCmp('licensenumberTextField').getValue(),
start_date: Ext.getCmp('startdateTextField').getValue(),
end_date: Ext.getCmp('enddateTextField').getValue(),
duration: Ext.getCmp('durationTextField').getValue(),
expiry_date: Ext.getCmp('expirydateTextField').getValue(),
product_id: Ext.getCmp('productidTextField').getValue(),
company_id: Ext.getCmp('companyidtf').getValue()
})
},
success: function( response ){
Ext.MessageBox.alert( 'Status', 'Record has been added.' );
Ext.getStore('LicenseStore').reload();
Ext.getStore('LicenseAllStore').reload();
Ext.getCmp( 'addLicenseWindow' ).close();
},
failure: function(){
Ext.MessageBox.alert( 'Status', 'Failed to add record.' );
}
});
}
}
}
]
}
]
}
]
});
win.show ();