[8.0][html_text] Excerpt generator.

* [8.0][html_text] Excerpt generator.

This module adds a technical utility to allow the developer to get an excerpt from any HTML chunk.

You can choose the maximum amount of words or characters if you want.

See the README and inline docstrings for further details.

html_text/README.rst

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+.. image:: https://img.shields.io/badge/licence-AGPL--3-blue.svg
+   :target: http://www.gnu.org/licenses/agpl-3.0-standalone.html
+   :alt: License: AGPL-3
+
+====================
+Text from HTML field
+====================
+
+This module provides some technical features that allow to extract text from
+any chunk of HTML, without HTML tags or attributes. You can chose either:
+
+* To truncate the result by amount of words or characters.
+* To append an ellipsis (or any character(s)) at the end of the result.
+
+It can be used to easily generate excerpts.
+
+Usage
+=====
+
+This module just adds a technical utility, but nothing for the end user.
+
+If you are a developer and need this utility for your module, see these
+examples and read the docs inside the code.
+
+Python example::
+
+    @api.multi
+    def some_method(self):
+        # Get truncated text from an HTML field. It will 40 words and 100
+        # characters at most, and will have "..." appended at the end if it
+        # gets truncated.
+        truncated_text = self.env["ir.fields.converter"].text_from_html(
+            self.html_field, 40, 100, "...")
+
+QWeb example::
+
+    <t t-esc="env['ir.fields.converter'].text_from_html(doc.html_field)"/>
+
+.. image:: https://odoo-community.org/website/image/ir.attachment/5784_f2813bd/datas
+   :alt: Try me on Runbot
+   :target: https://runbot.odoo-community.org/runbot/149/8.0
+
+Known issues / Roadmap
+======================
+
+* An option could be added to try to respect the basic HTML tags inside the
+  excerpt (``<b>``, ``<i>``, ``<p>``, etc.).
+
+Bug Tracker
+===========
+
+Bugs are tracked on `GitHub Issues
+<https://github.com/OCA/server-tools/issues>`_. In case of trouble, please
+check there if your issue has already been reported. If you spotted it first,
+help us smashing it by providing a detailed and welcomed `feedback
+<https://github.com/OCA/
+server-tools/issues/new?body=module:%20
+html_text%0Aversion:%20
+8.0%0A%0A**Steps%20to%20reproduce**%0A-%20...%0A%0A**Current%20behavior**%0A%0A**Expected%20behavior**>`_.
+
+Credits
+=======
+
+Contributors
+------------
+
+* Jairo Llopis <yajo.sk8@gmail.com>
+
+Maintainer
+----------
+
+.. image:: https://odoo-community.org/logo.png
+   :alt: Odoo Community Association
+   :target: https://odoo-community.org
+
+This module is maintained by the OCA.
+
+OCA, or the Odoo Community Association, is a nonprofit organization whose
+mission is to support the collaborative development of Odoo features and
+promote its widespread use.
+
+To contribute to this module, please visit https://odoo-community.org.

html_text/__init__.py

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+# -*- coding: utf-8 -*-
+# © 2016 Grupo ESOC Ingeniería de Servicios, S.L.U. - Jairo Llopis
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+
+from . import models

html_text/__openerp__.py

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+# -*- coding: utf-8 -*-
+# © 2016 Grupo ESOC Ingeniería de Servicios, S.L.U. - Jairo Llopis
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+{
+    "name": "Text from HTML field",
+    "summary": "Generate excerpts from any HTML field",
+    "version": "8.0.1.0.0",
+    "category": "Tools",
+    "website": "https://grupoesoc.es",
+    "author": "Grupo ESOC Ingeniería de Servicios, "
+              "Odoo Community Association (OCA)",
+    "license": "AGPL-3",
+    "application": False,
+    "installable": True,
+    "external_dependencies": {
+        "python": [
+            "lxml.html",
+        ],
+    },
+    "depends": [
+        "base",
+    ],
+}

html_text/models/__init__.py

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+# -*- coding: utf-8 -*-
+# © 2016 Grupo ESOC Ingeniería de Servicios, S.L.U. - Jairo Llopis
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+
+from . import ir_fields_converter

html_text/models/ir_fields_converter.py

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+# -*- coding: utf-8 -*-
+# © 2016 Grupo ESOC Ingeniería de Servicios, S.L.U. - Jairo Llopis
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+
+import logging
+from lxml import etree, html
+from openerp import api, models
+
+_logger = logging.getLogger(__name__)
+
+
+class IrFieldsConverter(models.Model):
+    _inherit = "ir.fields.converter"
+
+    @api.model
+    def text_from_html(self, html_content, max_words=None, max_chars=None,
+                       ellipsis=u"…", fail=False):
+        """Extract text from an HTML field in a generator.
+
+        :param str html_content:
+            HTML contents from where to extract the text.
+
+        :param int max_words:
+            Maximum amount of words allowed in the resulting string.
+
+        :param int max_chars:
+            Maximum amount of characters allowed in the resulting string. If
+            you apply this limit, beware that the last word could get cut in an
+            unexpected place.
+
+        :param str ellipsis:
+            Character(s) to be appended to the end of the resulting string if
+            it gets truncated after applying limits set in :param:`max_words`
+            or :param:`max_chars`. If you want nothing applied, just set an
+            empty string.
+
+        :param bool fail:
+            If ``True``, exceptions will be raised. Otherwise, an empty string
+            will be returned on failure.
+        """
+        # Parse HTML
+        try:
+            doc = html.fromstring(html_content)
+        except (etree.XMLSyntaxError, etree.ParserError):
+            if fail:
+                raise
+            else:
+                _logger.exception("Failure parsing this HTML:\n%s",
+                                  html_content)
+                return ""
+
+        # Get words
+        words = u"".join(doc.xpath("//text()")).split()
+
+        # Truncate words
+        suffix = max_words and len(words) > max_words
+        if max_words:
+            words = words[:max_words]
+
+        # Get text
+        text = u" ".join(words)
+
+        # Truncate text
+        suffix = suffix or max_chars and len(text) > max_chars
+        if max_chars:
+            text = text[:max_chars - (len(ellipsis) if suffix else 0)].strip()
+
+        # Append ellipsis if needed
+        if suffix:
+            text += ellipsis
+
+        return text

html_text/tests/__init__.py

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+# -*- coding: utf-8 -*-
+# © 2016 Grupo ESOC Ingeniería de Servicios, S.L.U. - Jairo Llopis
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+
+from . import test_extractor

html_text/tests/test_extractor.py

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+# -*- coding: utf-8 -*-
+# © 2016 Grupo ESOC Ingeniería de Servicios, S.L.U. - Jairo Llopis
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+
+from lxml import etree
+from openerp.tests.common import TransactionCase
+
+
+class ExtractorCase(TransactionCase):
+    def setUp(self):
+        super(ExtractorCase, self).setUp()
+
+        # Shortcut
+        self.text_from_html = self.env["ir.fields.converter"].text_from_html
+
+    def test_excerpts(self):
+        """Text gets correctly extracted."""
+        html = u"""
+            <html>
+                <body>
+                    <div class="this should not appear">
+                        <h1>I'm a title</h1>
+                        <p>I'm a paragraph</p>
+                        <small>¡Pues yo soy español!</small>
+                    </div>
+                </body>
+            </html>
+            """
+
+        self.assertEqual(
+            self.text_from_html(html),
+            u"I'm a title I'm a paragraph ¡Pues yo soy español!")
+        self.assertEqual(
+            self.text_from_html(html, 8),
+            u"I'm a title I'm a paragraph ¡Pues yo…")
+        self.assertEqual(
+            self.text_from_html(html, 8, 31),
+            u"I'm a title I'm a paragraph ¡P…")
+        self.assertEqual(
+            self.text_from_html(html, 7, ellipsis=""),
+            u"I'm a title I'm a paragraph ¡Pues")
+
+    def test_empty_html(self):
+        """Empty HTML handled correctly."""
+        self.assertEqual(self.text_from_html(""), "")
+        with self.assertRaises(etree.XMLSyntaxError):
+            self.text_from_html("", fail=True)
+
+    def test_bad_html(self):
+        """Bad HTML handled correctly."""
+        self.assertEqual(self.text_from_html("<<bad>"), "")
+        with self.assertRaises(etree.ParserError):
+            self.text_from_html("<<bad>", fail=True)