[IMP] survey_extra_fields : handle file question on page navigation

* Show a stored file (after navigating back) the same way as a freshly
  selected one: a "filename + Remove file" chip, input hidden until removal.
* Keep the stored file when a page is re-submitted without a new selection
  (instead of overwriting it with a skipped answer).
* "Remove file" now sends a sentinel to actually delete the stored file,
  so the removal persists across navigation.

survey_base/__init__.py

@@ -0,0 +1 @@
+from . import models

survey_base/__manifest__.py

@@ -0,0 +1,26 @@
+# Copyright 2016-2020 Akretion France (<https://www.akretion.com>)
+# @author: Alexis de Lattre <alexis.delattre@akretion.com>
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
+
+{
+    "name": "Survey base",
+    'summary': 'Add fields used by several survey addons',
+    'description': """
+Add fields used by several survey addons
+----------------------------------------------------
+* Add record reference in survey_question and survey.user_input.line
+* Add value_file in survey.user_input.line
+* Implementation of theses fields should be in another module
+
+""", 
+    "version": "18.0.1.0.0",
+    "license": "AGPL-3",
+    "author": "Elabore",
+    "website": "https://www.elabore.coop",
+    "category": "",
+    "depends": ["survey"],
+    "data": [        
+      
+    ],    
+    "installable": True,
+}

survey_base/i18n/fr.po

@@ -0,0 +1,54 @@
+# Translation of Odoo Server.
+# This file contains the translation of the following modules:
+# 	* survey_base
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: Odoo Server 16.0\n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2026-02-17 14:44+0000\n"
+"PO-Revision-Date: 2026-02-17 14:44+0000\n"
+"Last-Translator: \n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: \n"
+"Plural-Forms: \n"
+
+#. module: survey_base
+#: model:ir.model.fields,field_description:survey_base.field_survey_user_input_line__value_file
+msgid "File"
+msgstr "Fichier"
+
+#. module: survey_base
+#: model:ir.model.fields,field_description:survey_base.field_survey_user_input_line__value_file_fname
+msgid "File Name"
+msgstr "Nom du fichier"
+
+#. module: survey_base
+#: model:ir.model.fields,field_description:survey_base.field_survey_question_answer__record_reference
+#: model:ir.model.fields,field_description:survey_base.field_survey_user_input_line__record_reference
+msgid "Record"
+msgstr "Enregistrement"
+
+#. module: survey_base
+#: model:ir.model.fields,field_description:survey_base.field_survey_question_answer__record_reference_model
+#: model:ir.model.fields,field_description:survey_base.field_survey_user_input_line__record_reference_model
+msgid "Record Model"
+msgstr "Modèle de l'enregistrement"
+
+#. module: survey_base
+#: model:ir.model.fields,field_description:survey_base.field_survey_question_answer__smart_search
+#: model:ir.model.fields,field_description:survey_base.field_survey_user_input_line__smart_search
+msgid "Smart Search"
+msgstr "Recherche intelligente"
+
+#. module: survey_base
+#: model:ir.model,name:survey_base.model_survey_question_answer
+msgid "Survey Label"
+msgstr "Étiquette du sondage"
+
+#. module: survey_base
+#: model:ir.model,name:survey_base.model_survey_user_input_line
+msgid "Survey User Input Line"
+msgstr "Ligne d'entrée pour l'utilisateur du sondage"

survey_base/models/__init__.py

@@ -0,0 +1,2 @@
+from . import survey_question_answer
+from . import survey_user_input_line

survey_base/models/survey_question_answer.py

@@ -0,0 +1,19 @@
+
+import logging
+import textwrap
+import uuid
+
+from dateutil.relativedelta import relativedelta
+
+from odoo import api, fields, models, _
+from odoo.exceptions import ValidationError
+from odoo.tools import float_is_zero
+
+_logger = logging.getLogger(__name__)
+
+
+class SurveyQuestionAnswer(models.Model):
+    _inherit = 'survey.question.answer'
+
+    record_reference = fields.Many2oneReference(model_field="record_reference_model", string="Record")
+    record_reference_model = fields.Char("Record Model")

survey_base/models/survey_user_input_line.py

@@ -0,0 +1,46 @@
+
+import logging
+import textwrap
+import uuid
+
+from dateutil.relativedelta import relativedelta
+
+from odoo import api, fields, models, _
+from odoo.exceptions import ValidationError
+from odoo.tools import float_is_zero
+
+_logger = logging.getLogger(__name__)
+
+
+class SurveyUserInputLine(models.Model):
+    _inherit = 'survey.user_input.line'
+
+    #attachment fields
+    value_file = fields.Binary(string="File")
+    value_file_fname = fields.Char(string="File Name")
+
+    #record reference fields
+    record_reference = fields.Many2oneReference(model_field="record_reference_model", string="Record")
+    record_reference_model = fields.Char('Record Model')
+
+    """set record_reference when saving survey_user_input line
+    """
+    def set_record_reference_data(self, vals):
+        if vals.get('answer_type') == "suggestion" and 'suggested_answer_id' in vals:
+            #find model
+            answer = self.env['survey.question.answer'].browse(vals['suggested_answer_id'])
+            vals['record_reference_model'] = answer.record_reference_model
+            vals['record_reference'] = answer.record_reference
+
+    @api.model_create_multi
+    def create(self, vals_list):
+        for vals in vals_list:
+            self.set_record_reference_data(vals)
+        return super(SurveyUserInputLine, self).create(vals_list)
+
+
+    def write(self, vals):
+        self.set_record_reference_data(vals)
+        return super(SurveyUserInputLine, self).write(vals)
+    
+    

survey_extra_fields/__init__.py

@@ -0,0 +1,2 @@
+from . import controllers
+from . import models

survey_extra_fields/__manifest__.py

@@ -0,0 +1,33 @@
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
+
+{
+    "name": "Survey extra fields",
+    "summary": "Add extra question types to surveys",
+    "description": """
+Add extra question types to surveys:
+----------------------------------------------------
+* File upload question type
+  - Allows survey participants to upload a file as an answer
+  - Configurable maximum file size (in MB) per question (default: 10 MB, 0 = no limit)
+  - Configurable allowed file extensions per question (e.g. .pdf,.docx — empty = all types allowed)
+  - Client-side validation (size and extension) before form submission
+  - Server-side validation on save to enforce constraints
+""",
+    "version": "18.0.1.0.0",
+    "license": "AGPL-3",
+    "author": "Elabore",
+    "website": "https://www.elabore.coop",
+    "category": "",
+    "depends": ["base", "survey_base"],
+    "data": [
+        "views/survey_templates.xml",
+        "views/survey_user_views.xml",
+        "views/survey_question_views.xml",
+    ],
+    "assets": {
+        "survey.survey_assets": [
+            "/survey_extra_fields/static/src/js/survey_form.js",
+        ],
+    },
+    "installable": True,
+}

survey_extra_fields/controllers/__init__.py

@@ -0,0 +1 @@
+from . import main

survey_extra_fields/controllers/main.py

@@ -0,0 +1,61 @@
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
+
+from __future__ import annotations
+
+import base64
+from typing import TYPE_CHECKING, Any
+
+from odoo import http
+from odoo.http import request, content_disposition
+from odoo.addons.survey.controllers.main import Survey
+
+if TYPE_CHECKING:
+    from werkzeug.wrappers import Response
+
+
+class SurveyExtraFieldsController(Survey):
+
+    @http.route(
+        "/survey/file/<string:survey_token>/<string:answer_token>/<int:line_id>",
+        type="http",
+        auth="public",
+    )
+    def survey_file_download(
+            self,
+            survey_token: str,
+            answer_token: str,
+            line_id: int,
+            **kwargs: Any
+    ) -> Response:
+        survey = request.env["survey.survey"].sudo().search(
+            [("access_token", "=", survey_token)], limit=1
+        )
+        if not survey:
+            raise request.not_found()
+
+        answer = request.env["survey.user_input"].sudo().search(
+            [
+                ("survey_id", "=", survey.id),
+                ("access_token", "=", answer_token),
+            ],
+            limit=1,
+        )
+        if not answer:
+            raise request.not_found()
+
+        line = request.env["survey.user_input.line"].sudo().browse(line_id)
+        if not line.exists() or line.user_input_id != answer:
+            raise request.not_found()
+
+        if not line.value_file:
+            raise request.not_found()
+
+        file_content = base64.b64decode(line.value_file)
+        filename = line.value_file_fname or "file"
+        return request.make_response(
+            file_content,
+            headers=[
+                ("Content-Type", "application/octet-stream"),
+                ("Content-Disposition", content_disposition(filename)),
+            ],
+        )

survey_extra_fields/i18n/fr.po

@@ -0,0 +1,129 @@
+# Translation of Odoo Server.
+# This file contains the translation of the following modules:
+# 	* survey_extra_fields
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: Odoo Server 18.0\n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2026-06-10 15:03+0000\n"
+"PO-Revision-Date: 2026-06-10 15:03+0000\n"
+"Last-Translator: \n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: \n"
+"Plural-Forms: \n"
+
+#. module: survey_extra_fields
+#: model_terms:ir.ui.view,arch_db:survey_extra_fields.survey_question_form_inh
+msgid ".pdf,.docx,.xlsx"
+msgstr ""
+
+#. module: survey_extra_fields
+#: model_terms:ir.ui.view,arch_db:survey_extra_fields.question_file
+msgid "<i class=\"fa fa-times me-1\"/>Remove file"
+msgstr "<i class=\"fa fa-times me-1\"/>Supprimer le fichier"
+
+#. module: survey_extra_fields
+#: model:ir.model.fields,field_description:survey_extra_fields.field_survey_question__allowed_extensions
+msgid "Allowed Extensions"
+msgstr "Extensions autorisées"
+
+#. module: survey_extra_fields
+#: model:ir.model.fields,field_description:survey_extra_fields.field_survey_user_input_line__answer_type
+msgid "Answer Type"
+msgstr "Type de réponse"
+
+#. module: survey_extra_fields
+#: model:ir.model.fields,help:survey_extra_fields.field_survey_question__allowed_extensions
+msgid ""
+"Comma-separated list of allowed extensions (e.g. .pdf,.docx). Leave empty to"
+" allow all types."
+msgstr ""
+"Liste d'extensions autorisées séparées par une virgule (e.g. .pdf,.docx). "
+"Laisser vide pour autoriser tous les types de fichier."
+
+#. module: survey_extra_fields
+#: model:ir.model.fields.selection,name:survey_extra_fields.selection__survey_question__question_type__file
+#: model:ir.model.fields.selection,name:survey_extra_fields.selection__survey_user_input_line__answer_type__file
+msgid "File"
+msgstr "Fichier"
+
+#. module: survey_extra_fields
+#: model:ir.model.fields,field_description:survey_extra_fields.field_survey_question__max_file_size
+#: model_terms:ir.ui.view,arch_db:survey_extra_fields.survey_question_form_inh
+msgid "Max File Size (MB)"
+msgstr "Taille maximale du fichier"
+
+#. module: survey_extra_fields
+#: model:ir.model.fields,help:survey_extra_fields.field_survey_question__max_file_size
+msgid "Maximum file size in MB. Leave 0 for no limit."
+msgstr ""
+"Taille maximale du fichier en MB. Laisser à 0 pour ne pas restreindre la "
+"taille. La valeur par défaut est 10 MB."
+
+#. module: survey_extra_fields
+#: model:ir.model.fields,field_description:survey_extra_fields.field_survey_question__question_type
+msgid "Question Type"
+msgstr "Type de question"
+
+#. module: survey_extra_fields
+#: model_terms:ir.ui.view,arch_db:survey_extra_fields.survey_page_print_inh_type_file
+msgid "Skipped"
+msgstr "Ignoré"
+
+#. module: survey_extra_fields
+#: model:ir.model,name:survey_extra_fields.model_survey_question
+msgid "Survey Question"
+msgstr "Question du sondage"
+
+#. module: survey_extra_fields
+#: model:ir.model,name:survey_extra_fields.model_survey_user_input
+msgid "Survey User Input"
+msgstr "Entrée utilisateur du sondage"
+
+#. module: survey_extra_fields
+#: model:ir.model,name:survey_extra_fields.model_survey_user_input_line
+msgid "Survey User Input Line"
+msgstr "Ligne d'entrée pour l'utilisateur du sondage"
+
+#. module: survey_extra_fields
+#. odoo-python
+#: code:addons/survey_extra_fields/models/survey_user_input.py:0
+msgid "The file '%(name)s' exceeds the maximum allowed size of %(size)s MB."
+msgstr ""
+"Le fichier '%(name)s' dépasse la taille maximale autorisée de %(size)s MB."
+
+#. module: survey_extra_fields
+#. odoo-python
+#: code:addons/survey_extra_fields/models/survey_user_input.py:0
+msgid "The file '%(name)s' is not allowed. Accepted formats: %(exts)s."
+msgstr ""
+"Le fichier '%(name)s' n'est pas autorisé. Les formats de fichier autorisés "
+"sont : %(exts)s."
+
+#. module: survey_extra_fields
+#. odoo-javascript
+#: code:addons/survey_extra_fields/static/src/js/survey_form.js:0
+msgid "The file exceeds the maximum allowed size of %s MB."
+msgstr "Le fichier dépasse la taille maximale autorisée de %s MB."
+
+#. module: survey_extra_fields
+#. odoo-python
+#: code:addons/survey_extra_fields/models/survey_user_input.py:0
+msgid "This answer cannot be overwritten."
+msgstr "Cette réponse ne peut pas être remplacée."
+
+#. module: survey_extra_fields
+#. odoo-javascript
+#: code:addons/survey_extra_fields/static/src/js/survey_form.js:0
+msgid "This file type is not allowed. Accepted formats: %s."
+msgstr ""
+"Le fichier n'est pas autorisé. Les formats de fichier autorisés sont : %s."
+
+#. module: survey_extra_fields
+#. odoo-javascript
+#: code:addons/survey_extra_fields/static/src/js/survey_form.js:0
+msgid "This question requires an answer."
+msgstr "Cette question requiert une réponse."

survey_extra_fields/models/__init__.py

@@ -0,0 +1,3 @@
+from . import survey_question
+from . import survey_user_input
+from . import survey_user_input_line

survey_extra_fields/models/survey_question.py

@@ -0,0 +1,20 @@
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
+
+from odoo import fields, models
+
+
+class SurveyQuestion(models.Model):
+    _inherit = "survey.question"
+
+    question_type = fields.Selection(
+        selection_add=[("file", "File")]
+    )
+    max_file_size = fields.Integer(
+        string="Max File Size (MB)",
+        default=10,
+        help="Maximum file size in MB. Leave 0 for no limit.",
+    )
+    allowed_extensions = fields.Char(
+        string="Allowed Extensions",
+        help="Comma-separated list of allowed extensions (e.g. .pdf,.docx). Leave empty to allow all types.",
+    )

survey_extra_fields/models/survey_user_input.py

@@ -0,0 +1,94 @@
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
+
+from __future__ import annotations
+
+import base64
+import json
+import os
+from typing import TYPE_CHECKING
+
+from odoo import _, models
+from odoo.exceptions import UserError, ValidationError
+
+if TYPE_CHECKING:
+    from odoo.addons.survey_extra_fields.models.survey_question import SurveyQuestion
+
+
+class SurveyUserInput(models.Model):
+    _inherit = "survey.user_input"
+
+    def _save_lines(
+        self,
+        question: SurveyQuestion,
+        answer: str | None,
+        comment: str | None = None,
+        overwrite_existing: bool = True,
+    ) -> None:
+        if question.question_type == "file":
+            old_answers = self.env["survey.user_input.line"].search([
+                ("user_input_id", "=", self.id),
+                ("question_id", "=", question.id),
+            ])
+            if old_answers and not overwrite_existing:
+                raise UserError(_("This answer cannot be overwritten."))
+            if not answer and any(line.value_file for line in old_answers):
+                # No new file was submitted: a file input cannot be pre-filled
+                # by the browser when navigating back to a previous page, so an
+                # empty answer here does not mean the user removed their file.
+                # Keep the previously uploaded file instead of overwriting it
+                # with a skipped answer.
+                return
+            vals = {
+                "user_input_id": self.id,
+                "question_id": question.id,
+                "skipped": False,
+                "answer_type": "file",
+            }
+            file_data = json.loads(answer) if answer else {}
+            if file_data.get("cleared"):
+                # The user explicitly removed the file: drop the stored data and
+                # mark the line as skipped.
+                vals.update(answer_type=None, skipped=True, value_file=False, value_file_fname=False)
+            elif file_data:
+                file_b64 = file_data.get("data", "")
+                file_name = file_data.get("name", "")
+                self._check_file_constraints(question, file_b64, file_name)
+                vals["value_file"] = file_b64
+                vals["value_file_fname"] = file_name
+            else:
+                vals.update(answer_type=None, skipped=True)
+            if old_answers:
+                old_answers.write(vals)
+            else:
+                self.env["survey.user_input.line"].create(vals)
+        else:
+            return super()._save_lines(
+                question, answer, comment=comment, overwrite_existing=overwrite_existing
+            )
+
+    def _check_file_constraints(
+            self,
+            question: SurveyQuestion,
+            file_b64: str,
+            file_name: str
+    ) -> None:
+        if question.max_file_size:
+            file_size = len(base64.b64decode(file_b64))
+            max_bytes = question.max_file_size * 1024 * 1024
+            if file_size > max_bytes:
+                raise ValidationError(
+                    _("The file '%(name)s' exceeds the maximum allowed size of %(size)s MB.",
+                      name=file_name, size=question.max_file_size)
+                )
+        if question.allowed_extensions:
+            allowed = [
+                allowed_extension.strip().lower()
+                for allowed_extension in question.allowed_extensions.split(",")
+                if allowed_extension.strip()
+            ]
+            file_extension = os.path.splitext(file_name)[1].lower()
+            if file_extension not in allowed:
+                raise ValidationError(
+                    _("The file '%(name)s' is not allowed. Accepted formats: %(exts)s.",
+                      name=file_name, exts=question.allowed_extensions)
+                )

survey_extra_fields/models/survey_user_input_line.py

@@ -0,0 +1,17 @@
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
+
+from odoo import fields, models
+
+
+class SurveyUserInputLine(models.Model):
+    _inherit = "survey.user_input.line"
+
+    answer_type = fields.Selection(
+        selection_add=[("file", "File")]
+    )
+
+    def _compute_display_name(self):
+        super()._compute_display_name()
+        for line in self:
+            if line.answer_type == "file" and line.value_file_fname:
+                line.display_name = line.value_file_fname

survey_extra_fields/static/src/js/survey_form.js

@@ -0,0 +1,232 @@
+/** @odoo-module **/
+
+import publicWidget from "@web/legacy/js/public/public_widget";
+import { _t } from "@web/core/l10n/translation";
+import { rpc } from "@web/core/network/rpc";
+
+publicWidget.registry.SurveyFormWidget.include({
+    /**
+     * @override
+     * Bind delegated listeners on the form root so they keep working after each
+     * page is re-rendered (the inner content is replaced on navigation, but the
+     * root element persists). They let the user clear a selected file before
+     * submitting the form.
+     */
+    start: function () {
+        return this._super.apply(this, arguments).then(() => {
+            this.$el.on(
+                "change.surveyExtraFile",
+                'input[data-question-type="file"]',
+                this._onFileInputChange.bind(this)
+            );
+            this.$el.on(
+                "click.surveyExtraFile",
+                ".o_survey_file_clear",
+                this._onFileClearClick.bind(this)
+            );
+        });
+    },
+
+    /**
+     * On selection, show the file "chip" (filename + remove button) and hide the
+     * raw input, so a freshly selected file looks exactly like an already stored
+     * one (rendered server-side when navigating back).
+     */
+    _onFileInputChange: function (ev) {
+        const input = ev.currentTarget;
+        const container = input.closest(".o_survey_comment_container");
+        if (!container || !(input.files && input.files.length > 0)) {
+            return;
+        }
+        const chip = container.querySelector(".o_survey_file_selected");
+        const nameEl = container.querySelector(".o_survey_file_name");
+        if (nameEl) {
+            nameEl.textContent = input.files[0].name;
+        }
+        if (chip) {
+            chip.classList.remove("d-none");
+        }
+        delete input.dataset.fileCleared;
+        input.classList.add("d-none");
+    },
+
+    /**
+     * Discard the current file: hide the chip and bring back the input so the
+     * user can pick a new one. A file already stored server-side is only really
+     * replaced once a new file is submitted (see _save_lines).
+     */
+    _onFileClearClick: function (ev) {
+        ev.preventDefault();
+        const container = ev.currentTarget.closest(".o_survey_comment_container");
+        if (!container) {
+            return;
+        }
+        const input = container.querySelector('input[data-question-type="file"]');
+        const chip = container.querySelector(".o_survey_file_selected");
+        if (input) {
+            input.value = "";
+            // Flag the explicit removal so the submit tells the server to drop
+            // any previously stored file (instead of preserving it).
+            input.dataset.fileCleared = "1";
+            input.classList.remove("d-none");
+        }
+        if (chip) {
+            chip.classList.add("d-none");
+        }
+    },
+
+    _readFileAsDataURL: function (file) {
+        return new Promise(function (resolve, reject) {
+            const reader = new FileReader();
+            reader.onload = function (e) {
+                resolve(e.target.result);
+            };
+            reader.onerror = function () {
+                reject(reader.error);
+            };
+            reader.readAsDataURL(file);
+        });
+    },
+
+    /**
+     * @override
+     * The base implementation builds the submit params synchronously and fires
+     * the RPC immediately. File inputs need to be read asynchronously (FileReader),
+     * so when the current page contains file answers we replicate the submit flow
+     * here, injecting the base64 file payload before submitting.
+     */
+    _submitForm: async function (options) {
+        const fileInputs = this.el.querySelectorAll('input[data-question-type="file"]');
+        // A file action is either a new selection or an explicit removal of a
+        // previously stored file (which must be communicated to the server).
+        const hasFileAction = Array.from(fileInputs).some(
+            (input) => (input.files && input.files.length > 0) || input.dataset.fileCleared
+        );
+
+        if (!hasFileAction || this.options.isStartScreen) {
+            return this._super(options);
+        }
+
+        const params = {};
+        if (options.previousPageId) {
+            params.previous_page_id = options.previousPageId;
+        }
+        if (options.nextSkipped) {
+            params.next_skipped_page_or_question = true;
+        }
+
+        const $form = this.$("form");
+        const formData = new FormData($form[0]);
+
+        if (!options.skipValidation && !this._validateForm($form, formData)) {
+            return;
+        }
+
+        this._prepareSubmitValues(formData, params);
+
+        // Read all selected files as base64 and add them to the submit params.
+        // Explicitly cleared inputs (no new file) send a "cleared" sentinel so
+        // the server removes the previously stored file.
+        const filePromises = [];
+        for (const input of fileInputs) {
+            if (input.files && input.files.length > 0) {
+                const file = input.files[0];
+                const name = input.name;
+                filePromises.push(
+                    this._readFileAsDataURL(file).then((dataURL) => {
+                        params[name] = JSON.stringify({
+                            data: dataURL.split(",")[1],
+                            name: file.name,
+                        });
+                    })
+                );
+            } else if (input.dataset.fileCleared) {
+                params[input.name] = JSON.stringify({ cleared: true });
+            }
+        }
+
+        // Prevent user from submitting more times using enter key.
+        this.preventEnterSubmit = true;
+        if (this.options.sessionInProgress) {
+            this.fadeInOutDelay = 400;
+            this.readonly = true;
+        }
+
+        await Promise.all(filePromises);
+
+        const submitPromise = rpc(
+            `/survey/submit/${this.options.surveyToken}/${this.options.answerToken}`,
+            params
+        );
+        this._nextScreen(submitPromise, options);
+    },
+
+    /**
+     * @override
+     * Add client-side validation (required, max size, allowed extensions) for
+     * file questions, which the base implementation does not know about.
+     */
+    _validateForm: function ($form, formData) {
+        const result = this._super.apply(this, arguments);
+        const errors = {};
+        const inactiveQuestionIds = this.options.sessionInProgress
+            ? []
+            : this._getInactiveConditionalQuestionIds();
+
+        $form.find('input[data-question-type="file"]').each(function () {
+            const $questionWrapper = $(this).closest(".js_question-wrapper");
+            const questionId = $questionWrapper.attr("id");
+            if (inactiveQuestionIds.includes(parseInt(questionId))) {
+                return;
+            }
+            const questionRequired = $questionWrapper.data("required");
+            const constrErrorMsg =
+                $questionWrapper.data("constrErrorMsg") ||
+                _t("This question requires an answer.");
+            if (questionRequired && !(this.files && this.files.length > 0)) {
+                // A file may already be stored server-side (e.g. uploaded then
+                // navigating back): the chip is visible even though the input is
+                // empty. Treat that as a valid answer.
+                const container = this.closest(".o_survey_comment_container");
+                const chip = container && container.querySelector(".o_survey_file_selected");
+                const hasExistingFile = chip && !chip.classList.contains("d-none");
+                if (!hasExistingFile) {
+                    errors[questionId] = constrErrorMsg;
+                }
+                return;
+            }
+            if (this.files && this.files.length > 0) {
+                const file = this.files[0];
+                const maxSizeMB = parseInt($(this).data("maxFileSize"));
+                if (maxSizeMB && file.size > maxSizeMB * 1024 * 1024) {
+                    errors[questionId] = _t(
+                        "The file exceeds the maximum allowed size of %s MB.",
+                        maxSizeMB
+                    );
+                    return;
+                }
+                const allowedExtensions = $(this).data("allowedExtensions");
+                if (allowedExtensions) {
+                    const allowed = allowedExtensions
+                        .split(",")
+                        .map((e) => e.trim().toLowerCase());
+                    const ext = "." + file.name.split(".").pop().toLowerCase();
+                    if (!allowed.includes(ext)) {
+                        errors[questionId] = _t(
+                            "This file type is not allowed. Accepted formats: %s.",
+                            allowedExtensions
+                        );
+                    }
+                }
+            }
+        });
+
+        if (Object.keys(errors).length > 0) {
+            this._showErrors(errors);
+            return false;
+        }
+        return result;
+    },
+});
+
+export default publicWidget.registry.SurveyFormWidget;

survey_extra_fields/tests/__init__.py

@@ -0,0 +1 @@
+from . import test_survey_file

survey_extra_fields/tests/test_survey_file.py

@@ -0,0 +1,297 @@
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
+
+import base64
+import json
+from unittest.mock import patch, MagicMock
+
+from werkzeug.exceptions import NotFound
+from werkzeug.wrappers import Response
+
+from odoo.addons.survey.tests import common
+
+
+class TestSurveyFileCommon(common.TestSurveyCommon):
+    def setUp(self):
+        super().setUp()
+        self.file_content = b"Hello, this is a test file."
+        self.file_b64 = base64.b64encode(self.file_content).decode()
+        self.file_name = "test_document.pdf"
+
+        self.question_file = self._add_question(
+            self.page_0,
+            "Upload your document",
+            "file",
+            constr_mandatory=False,
+            survey_id=self.survey.id,
+        )
+        self.question_file_required = self._add_question(
+            self.page_0,
+            "Upload your required document",
+            "file",
+            constr_mandatory=True,
+            survey_id=self.survey.id,
+        )
+
+    def _create_answer_with_file(self):
+        answer = self._add_answer(self.survey, False, email="test@example.com")
+        line = self.env["survey.user_input.line"].create({
+            "user_input_id": answer.id,
+            "question_id": self.question_file.id,
+            "answer_type": "file",
+            "skipped": False,
+            "value_file": self.file_b64,
+            "value_file_fname": self.file_name,
+        })
+        return answer, line
+
+
+class TestSurveyFileSaveLines(TestSurveyFileCommon):
+    """Test the _save_lines method for file question type."""
+
+    def test_save_file_answer(self):
+        """Submitting a file stores base64 data and filename."""
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        file_json = json.dumps({"data": self.file_b64, "name": self.file_name})
+
+        answer._save_lines(self.question_file, file_json)
+
+        line = answer.user_input_line_ids.filtered(
+            lambda l: l.question_id == self.question_file
+        )
+        self.assertEqual(len(line), 1)
+        self.assertEqual(line.answer_type, "file")
+        self.assertFalse(line.skipped)
+        self.assertEqual(line.value_file, self.file_b64.encode())
+        self.assertEqual(line.value_file_fname, self.file_name)
+
+    def test_save_file_skipped(self):
+        """Submitting empty answer marks the line as skipped."""
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+
+        answer._save_lines(self.question_file, "")
+
+        line = answer.user_input_line_ids.filtered(
+            lambda l: l.question_id == self.question_file
+        )
+        self.assertEqual(len(line), 1)
+        self.assertTrue(line.skipped)
+        self.assertFalse(line.answer_type)
+
+    def test_save_file_update_existing(self):
+        """Submitting a new file updates the existing answer line."""
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        file_json_1 = json.dumps({"data": self.file_b64, "name": "first.pdf"})
+        answer._save_lines(self.question_file, file_json_1)
+
+        new_b64 = base64.b64encode(b"Updated content").decode()
+        file_json_2 = json.dumps({"data": new_b64, "name": "second.pdf"})
+        answer._save_lines(self.question_file, file_json_2)
+
+        lines = answer.user_input_line_ids.filtered(
+            lambda l: l.question_id == self.question_file
+        )
+        self.assertEqual(len(lines), 1, "Should update, not create a second line")
+        self.assertEqual(lines.value_file, new_b64.encode())
+        self.assertEqual(lines.value_file_fname, "second.pdf")
+
+    def test_save_file_then_empty_keeps_file(self):
+        """Submitting empty after a file keeps it (file inputs cannot be
+        pre-filled when navigating back, so an empty answer must not erase it)."""
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        file_json = json.dumps({"data": self.file_b64, "name": self.file_name})
+        answer._save_lines(self.question_file, file_json)
+
+        answer._save_lines(self.question_file, "")
+
+        line = answer.user_input_line_ids.filtered(
+            lambda l: l.question_id == self.question_file
+        )
+        self.assertEqual(len(line), 1)
+        self.assertFalse(line.skipped)
+        self.assertEqual(line.value_file, self.file_b64.encode())
+        self.assertEqual(line.value_file_fname, self.file_name)
+
+    def test_save_file_explicitly_cleared(self):
+        """Submitting the 'cleared' sentinel after a file removes it."""
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        file_json = json.dumps({"data": self.file_b64, "name": self.file_name})
+        answer._save_lines(self.question_file, file_json)
+
+        answer._save_lines(self.question_file, json.dumps({"cleared": True}))
+
+        line = answer.user_input_line_ids.filtered(
+            lambda l: l.question_id == self.question_file
+        )
+        self.assertEqual(len(line), 1)
+        self.assertTrue(line.skipped)
+        self.assertFalse(line.value_file)
+        self.assertFalse(line.value_file_fname)
+
+
+class TestSurveyFileConstraints(TestSurveyFileCommon):
+    """Test _check_file_constraints validation logic."""
+
+    def test_no_constraints(self):
+        """No max_file_size and no allowed_extensions: any file passes."""
+        self.question_file.write({"max_file_size": 0, "allowed_extensions": False})
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        file_json = json.dumps({"data": self.file_b64, "name": "anything.exe"})
+        answer._save_lines(self.question_file, file_json)
+        line = answer.user_input_line_ids.filtered(
+            lambda l: l.question_id == self.question_file
+        )
+        self.assertFalse(line.skipped)
+
+    def test_file_within_size_limit(self):
+        """File smaller than max_file_size passes."""
+        self.question_file.write({"max_file_size": 10})
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        file_json = json.dumps({"data": self.file_b64, "name": self.file_name})
+        answer._save_lines(self.question_file, file_json)
+        line = answer.user_input_line_ids.filtered(
+            lambda l: l.question_id == self.question_file
+        )
+        self.assertFalse(line.skipped)
+
+    def test_file_exceeds_size_limit(self):
+        """File larger than max_file_size raises ValidationError."""
+        self.question_file.write({"max_file_size": 1})
+        large_content = b"x" * (1 * 1024 * 1024 + 1)
+        large_b64 = base64.b64encode(large_content).decode()
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        file_json = json.dumps({"data": large_b64, "name": self.file_name})
+        with self.assertRaises(Exception):
+            answer._save_lines(self.question_file, file_json)
+
+    def test_allowed_extension_passes(self):
+        """File with an allowed extension passes."""
+        self.question_file.write({"allowed_extensions": ".pdf,.docx"})
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        file_json = json.dumps({"data": self.file_b64, "name": "report.docx"})
+        answer._save_lines(self.question_file, file_json)
+        line = answer.user_input_line_ids.filtered(
+            lambda l: l.question_id == self.question_file
+        )
+        self.assertFalse(line.skipped)
+
+    def test_disallowed_extension_raises(self):
+        """File with a disallowed extension raises ValidationError."""
+        self.question_file.write({"allowed_extensions": ".pdf,.docx"})
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        file_json = json.dumps({"data": self.file_b64, "name": "script.exe"})
+        with self.assertRaises(Exception):
+            answer._save_lines(self.question_file, file_json)
+
+    def test_both_constraints_valid(self):
+        """File respecting both size and extension constraints passes."""
+        self.question_file.write({"max_file_size": 10, "allowed_extensions": ".pdf"})
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        file_json = json.dumps({"data": self.file_b64, "name": self.file_name})
+        answer._save_lines(self.question_file, file_json)
+        line = answer.user_input_line_ids.filtered(
+            lambda l: l.question_id == self.question_file
+        )
+        self.assertFalse(line.skipped)
+
+
+class TestSurveyFileDisplayName(TestSurveyFileCommon):
+    """Test the display_name computation for file answer lines."""
+
+    def test_display_name_filename(self):
+        answer = self._add_answer(self.survey, self.survey_manager.partner_id)
+        line = self.env["survey.user_input.line"].create({
+            "user_input_id": answer.id,
+            "question_id": self.question_file.id,
+            "answer_type": "file",
+            "skipped": False,
+            "value_file": self.file_b64,
+            "value_file_fname": "my_filename.pdf",
+        })
+        self.assertEqual(line.display_name, "my_filename.pdf")
+
+
+class TestSurveyFileDownloadController(TestSurveyFileCommon):
+    """Test the file download controller logic with mocked request."""
+
+    def _call_download(self, survey_token, answer_token, line_id):
+        """Call the controller method with a mocked request context."""
+        from odoo.addons.survey_extra_fields.controllers.main import (
+            SurveyExtraFieldsController,
+        )
+
+        mock_request = MagicMock()
+        mock_request.env = self.env
+        mock_request.not_found.return_value = NotFound()
+        mock_request.make_response.side_effect = (
+            lambda content, headers=None: Response(content, headers=headers)
+        )
+
+        controller = SurveyExtraFieldsController()
+        with patch(
+            "odoo.addons.survey_extra_fields.controllers.main.request",
+            mock_request,
+        ):
+            try:
+                return controller.survey_file_download(
+                    survey_token, answer_token, line_id
+                )
+            except NotFound:
+                return NotFound()
+
+    def test_download_valid(self):
+        """Valid tokens return the file content."""
+        answer, line = self._create_answer_with_file()
+
+        response = self._call_download(
+            self.survey.access_token, answer.access_token, line.id
+        )
+
+        self.assertIsInstance(response, Response)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.data, self.file_content)
+
+    def test_download_invalid_survey_token(self):
+        """Invalid survey token returns not_found."""
+        answer, line = self._create_answer_with_file()
+
+        response = self._call_download(
+            "invalid-token", answer.access_token, line.id
+        )
+
+        self.assertIsInstance(response, NotFound)
+
+    def test_download_invalid_answer_token(self):
+        """Invalid answer token returns not_found."""
+        answer, line = self._create_answer_with_file()
+
+        response = self._call_download(
+            self.survey.access_token, "invalid-token", line.id
+        )
+
+        self.assertIsInstance(response, NotFound)
+
+    def test_download_line_not_belonging_to_answer(self):
+        """Accessing a line from another answer returns not_found."""
+        answer, line = self._create_answer_with_file()
+        other_answer = self._add_answer(self.survey, False, email="other@example.com")
+
+        response = self._call_download(
+            self.survey.access_token, other_answer.access_token, line.id
+        )
+
+        self.assertIsInstance(response, NotFound)
+
+    def test_download_no_file(self):
+        """Accessing a line without file data returns not_found."""
+        answer = self._add_answer(self.survey, False, email="test@example.com")
+        line = self.env["survey.user_input.line"].create({
+            "user_input_id": answer.id,
+            "question_id": self.question_file.id,
+            "skipped": True,
+        })
+
+        response = self._call_download(
+            self.survey.access_token, answer.access_token, line.id
+        )
+
+        self.assertIsInstance(response, NotFound)

survey_extra_fields/views/survey_question_views.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+
+    <record id="survey_question_form_inh" model="ir.ui.view">
+        <field name="name">survey.question.form.inherit.extra_fields</field>
+        <field name="model">survey.question</field>
+        <field name="inherit_id" ref="survey.survey_question_form"/>
+        <field name="arch" type="xml">
+            <xpath expr="//page[@name='options']//field[@name='matrix_subtype']" position="before">
+                <field name="max_file_size"
+                    invisible="question_type != 'file'"
+                    string="Max File Size (MB)"/>
+                <field name="allowed_extensions"
+                    invisible="question_type != 'file'"
+                    placeholder=".pdf,.docx,.xlsx"/>
+            </xpath>
+        </field>
+    </record>
+
+</odoo>

survey_extra_fields/views/survey_templates.xml

@@ -0,0 +1,81 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+
+    <!-- Extend question_container (form view during survey filling) -->
+    <template
+        id="question_container_inh_type_file"
+        inherit_id="survey.question_container"
+    >
+        <xpath expr="//t[@t-call='survey.question_matrix']" position="after">
+            <t t-if="question.question_type == 'file'">
+                <t t-call="survey_extra_fields.question_file"/>
+            </t>
+        </xpath>
+    </template>
+
+    <template id="question_file" name="Question: File">
+        <div class="o_survey_comment_container p-0">
+            <t t-set="existing_fname" t-value="answer_lines and answer_lines[0].value_file_fname"/>
+            <t t-if="survey_form_readonly">
+                <p t-if="existing_fname" class="mb-1">
+                    <i class="fa fa-paperclip me-1"/><t t-out="answer_lines[0].value_file_fname"/>
+                </p>
+            </t>
+            <t t-else="">
+                <!-- Uploaded file display, shown both for a fresh selection and when a
+                     file was already stored server-side (e.g. navigating back). The raw
+                     file input is hidden until the user clicks "Remove file". -->
+                <span t-attf-class="o_survey_file_selected d-inline-flex align-items-center #{'' if existing_fname else 'd-none'}">
+                    <i class="fa fa-paperclip me-1"/>
+                    <span class="o_survey_file_name"><t t-out="existing_fname or ''"/></span>
+                    <button type="button" class="btn btn-link btn-sm text-danger o_survey_file_clear ms-2 py-0">
+                        <i class="fa fa-times me-1"/>Remove file
+                    </button>
+                </span>
+                <input
+                    type="file"
+                    t-attf-class="o_survey_question_file #{'d-none' if existing_fname else ''}"
+                    t-att-name="question.id"
+                    t-att-data-question-type="question.question_type"
+                    t-att-accept="question.allowed_extensions or None"
+                    t-att-data-max-file-size="question.max_file_size or None"
+                    t-att-data-allowed-extensions="question.allowed_extensions or None"
+                />
+            </t>
+        </div>
+    </template>
+
+    <!-- Extend print/review page to show file answers -->
+    <template
+        id="survey_page_print_inh_type_file"
+        inherit_id="survey.survey_page_print"
+    >
+        <xpath expr="//div[hasclass('o_survey_question_error')]" position="before">
+            <t t-if="question.question_type == 'file'">
+                <t t-if="answer_lines">
+                    <t t-set="answer_line" t-value="answer_lines[0]"/>
+                    <t t-if="answer_line.skipped">
+                        <div class="row g-0">
+                            <div class="col-12 col-md-6 col-lg-4 rounded ps-4 o_survey_question_skipped">
+                                <input type="text"
+                                    class="form-control fst-italic o_survey_question_file bg-transparent rounded-0 p-0"
+                                    value="Skipped"/>
+                            </div>
+                        </div>
+                    </t>
+                    <t t-elif="answer_line.value_file_fname">
+                        <div class="row g-0">
+                            <div class="col-12 col-md-6 col-lg-4">
+                                <a t-attf-href="/survey/file/#{survey.access_token}/#{answer.access_token}/#{answer_line.id}"
+                                   target="_blank">
+                                    <i class="fa fa-download me-1"/><t t-out="answer_line.value_file_fname"/>
+                                </a>
+                            </div>
+                        </div>
+                    </t>
+                </t>
+            </t>
+        </xpath>
+    </template>
+
+</odoo>

survey_extra_fields/views/survey_user_views.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+
+    <record id="survey_user_input_line_view_form_inh" model="ir.ui.view">
+        <field name="name">survey.user_input.line.view.form.inherit.extra_fields</field>
+        <field name="model">survey.user_input.line</field>
+        <field name="inherit_id" ref="survey.survey_user_input_line_view_form"/>
+        <field name="arch" type="xml">
+            <xpath expr="//field[@name='suggested_answer_id']" position="after">
+                <field name="value_file" filename="value_file_fname" colspan="2"
+                    invisible="answer_type != 'file'"/>
+                <field name="value_file_fname" invisible="1"/>
+            </xpath>
+        </field>
+    </record>
+
+</odoo>