I declared an onchange function for a one2many field. What I want is to get the current value of the that field at the moment of the onchange. I did this:

<field name="meetings" required="1" nolabel="1"
    on_change="onchange_meetings(meetings)">
    <tree string="Meetings">
        <field name="name" />
        <field name="begin_date" />
        <field name="end_date" />
    </tree>
</field>

I think it would be enough, but in the Python code, the variable meetings is giving me only the altered fields. For example, if I change only the begin_date, the variable meetings only returns the begin_date of one record and I can't get the rest of the records.

I need them because I want to know which is the earliest beginning date (comparing the begin_date of all the records) and the latest ending date (comparing the end_date of all the records). But to know that, I need to get all the current records of meetings, including even those which aren't stored in the database yet.

Can anyone help me, please?