I need to pass the value of my two fields i.e date_from n date_to from my wizard to the report it calls/prints. Following is my code. This is working fine but only problem is i am not able to find how to print these two fields. Any help is appreciated.

class my_wizard_report(osv.osv_memory):

    _name = 'my.wizard.report'
##    _inherit = 'account.invoice'
    _description = 'Test Report'  

    _columns = {
        'date_from':fields.date('Date From',store=True),
        'date_to':fields.date('Date To',store=True),
        'invoice_ids':fields.many2many('account.invoice', string='Filter on invoices',help="Only selected invoices will be printed"),
    }

    _defaults = {
        'date_from': lambda *a: time.strftime('%Y-%m-%d'),
        'date_to': lambda *a: time.strftime('%Y-%m-%d'),
    }

    def print_report(self, cr, uid, ids, context=None):
        datas = {}
        if context is None:
            context = {}
        data = self.read(cr, uid, ids,['date_from', 'date_to', 'invoice_ids'], context=context)
        date_from = data[0]['date_from'] 
        date_to = data[0]['date_to']
        obj = self.pool.get('account.invoice')
        ids = obj.search(cr, uid, [('date_invoice','>=',date_from),('date_invoice','<=',date_to)])
        datas = {
                 'ids': ids,
                 'model': 'account.invoice',
                 'form': data
                }
        return {'type': 'ir.actions.report.xml', 'report_name': 'account.invoice.rnd5c3tV', 'datas': datas}





my_wizard_report()



<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>

<!-- cancel order  -->

        <record id="view_my_wiz_form" model="ir.ui.view">
            <field name="name">print.report.form</field>
            <field name="model">my.wizard.report</field>
            <field name="type">form</field>
            <field name="arch" type="xml">
                <form string="Print Report">
                    <group colspan="4" >
                        <field name="date_from" filter_domain="[('date_invoice','&gt;=',self)]" />
                        <field name="date_to" filter_domain="[('date_invoice','&lt;=',self)]"  />
                    </group>
                        <separator string="Print Only" colspan="4" />
                        <group colspan = "4">
                            <field name="invoice_ids" colspan="4" nolabel="1"/>
                        </group>
                    <group colspan="4" col="6">                     
                        <button  icon="gtk-ok" name="print_report" string="Print" type="object"/>
                   </group>
               </form>
            </field>
        </record>

        <record id="action_my_wiz_form" model="ir.actions.act_window">
            <field name="name">Print Report</field>
            <field name="res_model">my.wizard.report</field>
            <field name="view_type">form</field>
            <field name="view_mode">tree,form</field>
           <field name="view_id" ref="view_my_wiz_form"/>
           <field name="target">new</field>        
        </record>

        <act_window id="action_my_wiz_form_values"
            key2="client_action_multi" name="Print Report"
            res_model="my.wizard.report" src_model="add.penalty"
            view_mode="form" target="new" view_type="form"/>

    </data>
</openerp>

C:\fakepath\screen2.png

C:\fakepath\screen1.png

C:\fakepath\reports.png