Odoo - Combine two fields heading in one2many

Question

I am working with odoo 10-e. I created custom module and in that module i want to show one2many records like this

----------------
| Long Cell    |
----------------
| 1    | 2     |
----------------

right now by default each column have its own heading which is actually string= value. I want to override default behavior.

Answer 1

First create the xml file which extends the ListView Template like this to add colspan feature in base list view template.

colspan.xml

<?xml version="1.0" encoding="UTF-8"?>
<templates id="template" xml:space="preserve">
<div t-extend="ListView">
     <t t-jquery="table" t-operation="replace">
        <table class="o_list_view table table-condensed table-striped">
        <t t-set="columns_count" t-value="visible_columns.length + (options.selectable ? 1 : 0) + (options.deletable ? 1 : 0)"/>
        <thead>
            <tr t-if="options.header">
                <t t-foreach="columns" t-as="column">
                    <th t-if="column.meta">
                        <t t-esc="column.string"/>
                    </th>
                </t>
                <th t-if="options.selectable" class="o_list_record_selector" width="1">
                    <div class="o_checkbox">
                        <input type="checkbox"/><span/>
                    </div>
                </th>
                <t t-set="col" t-value="0"/>
                <t t-foreach="columns" t-as="column">
                    <t t-if="col == 0">
                    <th t-if="!column.meta and column.invisible !== '1'" t-att-data-id="column.id"
                        t-attf-class="text-center #{((options.sortable and column.sortable and column.tag !== 'button') ? 'o_column_sortable' : '')}"
                            t-att-width="column.width()" t-att-colspan="column.colspan" >
                        <t t-set="col" t-value="column.colspan or 1"/>    
                        <t t-if="column.tag !== 'button'"><t t-raw="column.heading()"/></t>
                    </th>
                    </t>
                    <t t-if="col !== 0" t-set="col" t-value="col - 1"/>
                </t>
                <th t-if="options.deletable" class="o_list_record_delete"/>
            </tr>
        </thead>
        <tfoot>
            <tr>
                <td t-if="options.selectable"/>
                <td t-foreach="aggregate_columns" t-as="column" t-att-data-field="column.id" t-att-title="column.label">
                </td>
                <td t-if="options.deletable" class="o_list_record_delete"/>
            </tr>
        </tfoot>
    </table>
    </t>
</div>
</template>

Add in __manifest__.py

...
'qweb': [
        "static/src/xml/colspan.xml",
    ],
...

That's it.

You can use colspan in any field. in Listview.

Eg.

<tree>
    <field name="any_field" colspan="2"/>
</tree>

Try it.

I hope this will work for you.