Backport Jinja filters from v4 branch

Signed-off-by: Philippe Ombredanne <[email protected]>

Author: pombredanne

src/attributecode/attrib.py

@@ -32,6 +32,7 @@
 import attributecode
 from attributecode import ERROR
 from attributecode import Error
+from attributecode.attrib_util import get_template
 from attributecode.licenses import COMMON_LICENSES
 from attributecode.model import parse_license_expression
 from attributecode.util import add_unc
@@ -46,7 +47,7 @@ def generate(abouts, template_string=None, vartext_dict=None):
     syntax_error = check_template(template_string)
     if syntax_error:
         return 'Template validation error at line: %r: %r' % (syntax_error)
-    template = jinja2.Template(template_string)
+    template = get_template(template_string)
 
     try:
         captured_license = []
@@ -119,13 +120,14 @@ def generate(abouts, template_string=None, vartext_dict=None):
     return rendered
 
 
+
 def check_template(template_string):
     """
     Check the syntax of a template. Return an error tuple (line number,
     message) if the template is invalid or None if it is valid.
     """
     try:
-        jinja2.Template(template_string)
+        get_template(template_string)
     except (jinja2.TemplateSyntaxError, jinja2.TemplateAssertionError) as e:
         return e.lineno, e.message
 

src/attributecode/attrib_util.py

@@ -0,0 +1,119 @@
+#!/usr/bin/env python
+# -*- coding: utf8 -*-
+
+# ============================================================================
+#  Copyright (c) 2018 nexB Inc. http://www.nexb.com/ - All rights reserved.
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#      http://www.apache.org/licenses/LICENSE-2.0
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+# ============================================================================
+
+from __future__ import absolute_import
+from __future__ import print_function
+from __future__ import unicode_literals
+
+from jinja2 import Environment
+from jinja2.filters import environmentfilter
+from jinja2.filters import make_attrgetter
+from jinja2.filters import ignore_case
+from jinja2.filters import FilterArgumentError
+
+
+"""
+Extra JINJA2 custom filters and other template utilities.
+"""
+
+
+def get_template(template_text):
+    """
+    Return a template built from a text string.
+    Register custom templates as needed.
+    """
+    env = Environment(autoescape=True)
+    # register our custom filters
+    env.filters.update(dict(
+        unique_together=unique_together,
+        multi_sort=multi_sort))
+    return env.from_string(template_text)
+
+
+@environmentfilter
+def multi_sort(environment, value, reverse=False, case_sensitive=False,
+               attributes=None):
+    """
+    Sort an iterable using an "attributes" list of attribute names available on
+    each iterable item. Sort ascending unless reverse is "true". Ignore the case
+    of strings unless "case_sensitive" is "true".
+
+    .. sourcecode:: jinja
+
+        {% for item in iterable|multi_sort(attributes=['date', 'name']) %}
+            ...
+        {% endfor %}
+    """
+    if not attributes:
+        raise FilterArgumentError(
+            'The multi_sort filter requires a list of attributes as argument, '
+            'such as in: '
+            "for item in iterable|multi_sort(attributes=['date', 'name'])")
+
+    # build a list of attribute getters, one for each attribute
+    do_ignore_case = ignore_case if not case_sensitive else None
+    attribute_getters = []
+    for attribute in attributes:
+        ag = make_attrgetter(environment, attribute, postprocess=do_ignore_case)
+        attribute_getters.append(ag)
+
+    # build a key function that has runs all attribute getters
+    def key(v):
+        return [a(v) for a in attribute_getters]
+
+    return sorted(value, key=key, reverse=reverse)
+
+
+@environmentfilter
+def unique_together(environment, value, case_sensitive=False, attributes=None):
+    """
+    Return a list of unique items from an iterable. Unicity is checked when
+    considering together all the values of an "attributes" list of attribute
+    names available on each iterable item.. The items order is preserved. Ignore
+    the case of strings unless "case_sensitive" is "true".
+    .. sourcecode:: jinja
+
+        {% for item in iterable|unique_together(attributes=['date', 'name']) %}
+            ...
+        {% endfor %}
+
+    """
+    if not attributes:
+        raise FilterArgumentError(
+            'The unique_together filter requires a list of attributes as argument, '
+            'such as in: '
+            "{% for item in iterable|unique_together(attributes=['date', 'name']) %} ")
+
+    # build a list of attribute getters, one for each attribute
+    do_ignore_case = ignore_case if not case_sensitive else None
+    attribute_getters = []
+    for attribute in attributes:
+        ag = make_attrgetter(environment, attribute, postprocess=do_ignore_case)
+        attribute_getters.append(ag)
+
+    # build a unique_key function that has runs all attribute getters
+    # and returns a hashable tuple
+    def unique_key(v):
+        return tuple(repr(a(v)) for a in attribute_getters)
+
+    unique = []
+    seen = set()
+    for item in value:
+        key = unique_key(item)
+        if key not in seen:
+            seen.add(key)
+            unique.append(item)
+    return unique