Hi, 

To add the header and footer for each page, try with the following.

1- Create a custom layout and add header and footer to the custom layout.

<template id="report_custom_external_layout">
    <!-- Multicompany -->
    <t t-if="not o and doc">
        <t t-set="o" t-value="doc"/>
    </t>
    <t t-if="o and 'company_id' in o">
        <t t-set="company" t-value="o.company_id"></t>
    </t>
    <t t-if="not o or not 'company_id' in o">
        <t t-set="company" t-value="res_company"></t>
    </t>
    <div class="header">
        <div class="row">
            <img t-if="company.custom_report_header"
                 t-att-src="image_data_uri(company.custom_report_header)"
                 alt="Logo" width="100%"/> # optional
        </div>
    </div>
    <div class="footer o_standard_footer" style="position: relative;">
        <div style="width: 100%;">
            <img t-if="company.custom_report_footer"
                 t-att-src="image_data_uri(company.custom_report_footer)"
                 alt="Logo" width="100%"/> # optional
        </div>
    </div>
    <div class="article o_report_layout_standard"
         t-att-data-oe-model="o and o._name"
         t-att-data-oe-id="o and o.id"
         t-att-data-oe-lang="o and o.env.context.get('lang')">
        <t t-raw="0"/>
    </div>
</template>

2- While calling the template, add the custom layout.

<template id="report_template">
    <t t-call="web.html_container">
        <t t-call="module_name.report_custom_external_layout">
            #
            #
            # Table contents
            #
            #
            
        </t>
    </t>
</template>

This will result header and footer displaying on each page.

Hope it helps

To create a report in Odoo 17 with a fixed header and footer that appears on every page, you can leverage QWeb reports and CSS properties. Here's a step-by-step guide:

1. Design Your Report Template

The QWeb report is an XML-based template that defines how your report is rendered. To add fixed headers and footers:

Header and Footer in the Template

Use <header> and <footer> tags in your QWeb template to define content that repeats on every page.

Example:

xmlCopy code<?xml version="1.0" encoding="UTF-8"?>
<template id="report_invoice_document">
    <t t-call="web.html_container">
        <t t-foreach="docs" t-as="doc">
            <t t-call="web.external_layout">
                <div class="page">
                    <!-- Fixed Header -->
                    <header class="header">
                        <div>Invoice Report</div>
                        <div>Company: <t t-esc="doc.company_id.name" /></div>
                        <div>Date: <t t-esc="doc.date_invoice" /></div>
                    </header>

                    <!-- Main Content -->
                    <div class="content">
                        <h3>Invoice Details</h3>
                        <table>
                            <thead>
                                <tr>
                                    <th>Product</th>
                                    <th>Quantity</th>
                                    <th>Price</th>
                                    <th>Total</th>
                                </tr>
                            </thead>
                            <tbody>
                                <tr t-foreach="doc.invoice_line_ids" t-as="line">
                                    <td><t t-esc="line.product_id.name" /></td>
                                    <td><t t-esc="line.quantity" /></td>
                                    <td><t t-esc="line.price_unit" /></td>
                                    <td><t t-esc="line.price_subtotal" /></td>
                                </tr>
                            </tbody>
                        </table>
                    </div>

                    <!-- Fixed Footer -->
                    <footer class="footer">
                        <div>Page <span class="page-number"></span> of <span class="page-total"></span></div>
                        <div>Company Address: <t t-esc="doc.company_id.partner_id.contact_address" /></div>
                        <div>Thank you for your business!</div>
                    </footer>
                </div>
            </t>
        </t>
    </t>
</template>

2. Add CSS for Fixed Positioning

To ensure the header and footer remain fixed on every page, add the following CSS rules to your report styles:

xmlCopy code<?xml version="1.0" encoding="UTF-8"?>
<template id="report_styles" inherit_id="web.report_assets_common">
    <xpath expr="." position="inside">
        <style>
            /* Ensure the header is fixed at the top */
            .header {
                position: fixed;
                top: 0;
                left: 0;
                width: 100%;
                height: 50px; /* Adjust height as needed */
                background-color: #f5f5f5;
                text-align: center;
                border-bottom: 1px solid #ddd;
                padding: 10px;
            }

            /* Ensure the footer is fixed at the bottom */
            .footer {
                position: fixed;
                bottom: 0;
                left: 0;
                width: 100%;
                height: 50px; /* Adjust height as needed */
                background-color: #f5f5f5;
                text-align: center;
                border-top: 1px solid #ddd;
                padding: 10px;
            }

            /* Content area - Avoid overlap with header/footer */
            .content {
                margin-top: 60px; /* Adjust according to header height */
                margin-bottom: 60px; /* Adjust according to footer height */
            }

            /* Page break styling */
            .page {
                page-break-after: always;
            }
        </style>
    </xpath>
</template>

3. Link Your Stylesheet to the Report

Ensure your custom stylesheet is linked to the report. Add this to your report XML:

xmlCopy code<template id="report_invoice_document_action" inherit_id="account.report_invoice_document">
    <xpath expr="//t[@t-call='web.external_layout']" position="replace">
        <t t-call="your_module_name.report_invoice_document" />
    </xpath>
</template>

Replace your_module_name with the name of your module.

4. Adjust Pagination for PDF Rendering

Odoo uses wkhtmltopdf to render reports as PDFs. Ensure proper pagination and accurate display of headers/footers:

• Use the @media print CSS rule for print-specific adjustments.
• Ensure page-break-inside: avoid; is used for critical elements like tables.

Example:

cssCopy code@media print {
    .content table {
        page-break-inside: avoid;
    }
}

5. Enable Dynamic Page Numbers

For page numbers, add placeholders in your footer that wkhtmltopdf recognizes:

xmlCopy code<footer class="footer">
    <div>Page <span class="page-number"></span> of <span class="page-total"></span></div>
</footer>

Ensure wkhtmltopdf is updated to a compatible version (0.12.6 or higher) for the best results.

6. Test Your Report

• Go to Settings > Technical > Reports.
• Locate your report, ensure it is correctly linked, and print a preview.
• Adjust the layout if necessary.

Can I do these with a specific paper format say"A4 Portrait"?