Hi,

First, create a new form view for your model where you do all customization needed.

After that use "fields_view_get" for the purchase_inquiry_ids model to return this custom view when your context has "default_purchase_order_id" as a key.

@api.model
def fields_view_get(self, view_id=None, view_type=False, toolbar=False, submenu=False):
     if view_type == 'form' and self.env.context.get('default_purchase_order_id'):
         view_id = "the_custom_view_id"
     return super(YourClass, self).fields_view_get(view_id=view_id, view_type=view_type, toolbar=toolbar, submenu=submenu)

Best regards.

I tried to simplify the code by inherit the default view of the 'purchase_inquiry' and pass an attribute to a specific field but it lead me up to a blind alley.

I was obligated to follow the long way.

I write the view from scratch and there I customize what I need :

<notebook>
    <page string="purchase_inquiry_ids">       
<!-- 	                            	<field name="purchase_inquiry_ids" context="{'default_purchase_order_id': active_id}" options="{'always_reload': True}"/> --> 
    	<field name="purchase_inquiry_ids" context="{'default_purchase_order_id': active_id}">
    		<form string="Demande d'offre Form">
		                	<header>
							    <button string="Set to draft" type="object" name="draft_progressbar" attrs="{'invisible': [('state', '=', 'draft')]}"/>
							    <button string="Sent" type="object" name="sent_progressbar" attrs="{'invisible': [('state','=','sent')]}"/>
							    <button string="Received" type="object" name="received_progressbar" attrs="{'invisible': [('state','=','received')]}"/>						    
							    <button string="Accepted" type="object" name="accepted_progressbar" class="oe_highlight" attrs="{'invisible': [('state','=','accepted')]}"/>
							    <button string="Refused" type="object" name="refused_progressbar" class="oe_highlight" attrs="{'invisible': [('state','=','refused')]}"/>
							    <button string="Create Command" type="object" name="create_command" class="oe_highlight" attrs="{'invisible': [('state','!=','accepted')]}"/>
							    <field name="state" widget="statusbar" statusbar_visible="draft, sent, received, accepted, refused"/>
							</header>
		                    <sheet>
		                        <group>
		                            <field name="name"/>
	                                <field name="purchase_order_id" readonly="1"/>
	                            	<field name="provider_id"/>
	                            	<field name="date_inquiry"/>
	                            	<field name="datefinal_inquiry"/>
		                        </group>
		                        <group col="6">
	                                <field name="product" placeholder="Product Name"/>
	                                <field name="qte" placeholder="Nbr Emballage"/>
	                                <field name="qte_total_unity" placeholder="Qte Totale"/>
		                        </group>
		                    	<notebook>
			                    	<page string="Informations">
			                    		<group>
			                    			<field name="price"/>
			                    		</group>
			                    	</page>
			                    	<page string="Description">
			                    		<label for="description" string="Description"/>
			                    		<field name="description"/>
			                    	</page>
			                    </notebook>
		                    </sheet>
		                </form>
    	</field>
    </page>
</notebook>

You can give readonly="1" for a one2many field

just add

<field name="purchase_inquiry_ids" readonly="1" context="{'default_purchase_order_id': active_id}"/>