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mirror of https://github.com/netbox-community/netbox.git synced 2024-05-10 07:54:54 +00:00
2023-02-27 15:38:21 -05:00

550 lines
17 KiB
Python

import datetime
import decimal
import json
import re
from decimal import Decimal
from itertools import count, groupby
import bleach
from django.contrib.contenttypes.models import ContentType
from django.core import serializers
from django.db.models import Count, OuterRef, Subquery
from django.db.models.functions import Coalesce
from django.http import QueryDict
from django.utils.html import escape
from django.utils import timezone
from django.utils.timezone import localtime
from jinja2.sandbox import SandboxedEnvironment
from mptt.models import MPTTModel
from dcim.choices import CableLengthUnitChoices, WeightUnitChoices
from extras.plugins import PluginConfig
from extras.utils import is_taggable
from netbox.config import get_config
from urllib.parse import urlencode
from utilities.constants import HTTP_REQUEST_META_SAFE_COPY
def title(value):
"""
Improved implementation of str.title(); retains all existing uppercase letters.
"""
return ' '.join([w[0].upper() + w[1:] for w in str(value).split()])
def get_viewname(model, action=None, rest_api=False):
"""
Return the view name for the given model and action, if valid.
:param model: The model or instance to which the view applies
:param action: A string indicating the desired action (if any); e.g. "add" or "list"
:param rest_api: A boolean indicating whether this is a REST API view
"""
is_plugin = isinstance(model._meta.app_config, PluginConfig)
app_label = model._meta.app_label
model_name = model._meta.model_name
if rest_api:
if is_plugin:
viewname = f'plugins-api:{app_label}-api:{model_name}'
else:
viewname = f'{app_label}-api:{model_name}'
# Append the action, if any
if action:
viewname = f'{viewname}-{action}'
else:
viewname = f'{app_label}:{model_name}'
# Prepend the plugins namespace if this is a plugin model
if is_plugin:
viewname = f'plugins:{viewname}'
# Append the action, if any
if action:
viewname = f'{viewname}_{action}'
return viewname
def csv_format(data):
"""
Encapsulate any data which contains a comma within double quotes.
"""
csv = []
for value in data:
# Represent None or False with empty string
if value is None or value is False:
csv.append('')
continue
# Convert dates to ISO format
if isinstance(value, (datetime.date, datetime.datetime)):
value = value.isoformat()
# Force conversion to string first so we can check for any commas
if not isinstance(value, str):
value = '{}'.format(value)
# Double-quote the value if it contains a comma or line break
if ',' in value or '\n' in value:
value = value.replace('"', '""') # Escape double-quotes
csv.append('"{}"'.format(value))
else:
csv.append('{}'.format(value))
return ','.join(csv)
def foreground_color(bg_color, dark='000000', light='ffffff'):
"""
Return the ideal foreground color (dark or light) for a given background color in hexadecimal RGB format.
:param dark: RBG color code for dark text
:param light: RBG color code for light text
"""
THRESHOLD = 150
bg_color = bg_color.strip('#')
r, g, b = [int(bg_color[c:c + 2], 16) for c in (0, 2, 4)]
if r * 0.299 + g * 0.587 + b * 0.114 > THRESHOLD:
return dark
else:
return light
def dynamic_import(name):
"""
Dynamically import a class from an absolute path string
"""
components = name.split('.')
mod = __import__(components[0])
for comp in components[1:]:
mod = getattr(mod, comp)
return mod
def count_related(model, field):
"""
Return a Subquery suitable for annotating a child object count.
"""
subquery = Subquery(
model.objects.filter(
**{field: OuterRef('pk')}
).order_by().values(
field
).annotate(
c=Count('*')
).values('c')
)
return Coalesce(subquery, 0)
def serialize_object(obj, resolve_tags=True, extra=None):
"""
Return a generic JSON representation of an object using Django's built-in serializer. (This is used for things like
change logging, not the REST API.) Optionally include a dictionary to supplement the object data. A list of keys
can be provided to exclude them from the returned dictionary. Private fields (prefaced with an underscore) are
implicitly excluded.
"""
json_str = serializers.serialize('json', [obj])
data = json.loads(json_str)[0]['fields']
# Exclude any MPTTModel fields
if issubclass(obj.__class__, MPTTModel):
for field in ['level', 'lft', 'rght', 'tree_id']:
data.pop(field)
# Include custom_field_data as "custom_fields"
if hasattr(obj, 'custom_field_data'):
data['custom_fields'] = data.pop('custom_field_data')
# Resolve any assigned tags to their names. Check for tags cached on the instance;
# fall back to using the manager.
if resolve_tags and is_taggable(obj):
tags = getattr(obj, '_tags', None) or obj.tags.all()
data['tags'] = sorted([tag.name for tag in tags])
# Append any extra data
if extra is not None:
data.update(extra)
# Copy keys to list to avoid 'dictionary changed size during iteration' exception
for key in list(data):
# Private fields shouldn't be logged in the object change
if isinstance(key, str) and key.startswith('_'):
data.pop(key)
return data
def deserialize_object(model, fields, pk=None):
"""
Instantiate an object from the given model and field data. Functions as
the complement to serialize_object().
"""
content_type = ContentType.objects.get_for_model(model)
if 'custom_fields' in fields:
fields['custom_field_data'] = fields.pop('custom_fields')
data = {
'model': '.'.join(content_type.natural_key()),
'pk': pk,
'fields': fields,
}
instance = list(serializers.deserialize('python', [data]))[0]
return instance
def dict_to_filter_params(d, prefix=''):
"""
Translate a dictionary of attributes to a nested set of parameters suitable for QuerySet filtering. For example:
{
"name": "Foo",
"rack": {
"facility_id": "R101"
}
}
Becomes:
{
"name": "Foo",
"rack__facility_id": "R101"
}
And can be employed as filter parameters:
Device.objects.filter(**dict_to_filter(attrs_dict))
"""
params = {}
for key, val in d.items():
k = prefix + key
if isinstance(val, dict):
params.update(dict_to_filter_params(val, k + '__'))
else:
params[k] = val
return params
def normalize_querydict(querydict):
"""
Convert a QueryDict to a normal, mutable dictionary, preserving list values. For example,
QueryDict('foo=1&bar=2&bar=3&baz=')
becomes:
{'foo': '1', 'bar': ['2', '3'], 'baz': ''}
This function is necessary because QueryDict does not provide any built-in mechanism which preserves multiple
values.
"""
return {
k: v if len(v) > 1 else v[0] for k, v in querydict.lists()
}
def deepmerge(original, new):
"""
Deep merge two dictionaries (new into original) and return a new dict
"""
merged = dict(original)
for key, val in new.items():
if key in original and isinstance(original[key], dict) and val and isinstance(val, dict):
merged[key] = deepmerge(original[key], val)
else:
merged[key] = val
return merged
def drange(start, end, step=decimal.Decimal(1)):
"""
Decimal-compatible implementation of Python's range()
"""
start, end, step = decimal.Decimal(start), decimal.Decimal(end), decimal.Decimal(step)
if start < end:
while start < end:
yield start
start += step
else:
while start > end:
yield start
start += step
def to_meters(length, unit):
"""
Convert the given length to meters.
"""
try:
if length < 0:
raise ValueError("Length must be a positive number")
except TypeError:
raise TypeError(f"Invalid value '{length}' for length (must be a number)")
valid_units = CableLengthUnitChoices.values()
if unit not in valid_units:
raise ValueError(f"Unknown unit {unit}. Must be one of the following: {', '.join(valid_units)}")
if unit == CableLengthUnitChoices.UNIT_KILOMETER:
return length * 1000
if unit == CableLengthUnitChoices.UNIT_METER:
return length
if unit == CableLengthUnitChoices.UNIT_CENTIMETER:
return length / 100
if unit == CableLengthUnitChoices.UNIT_MILE:
return length * Decimal(1609.344)
if unit == CableLengthUnitChoices.UNIT_FOOT:
return length * Decimal(0.3048)
if unit == CableLengthUnitChoices.UNIT_INCH:
return length * Decimal(0.3048) * 12
raise ValueError(f"Unknown unit {unit}. Must be 'km', 'm', 'cm', 'mi', 'ft', or 'in'.")
def to_grams(weight, unit):
"""
Convert the given weight to kilograms.
"""
try:
if weight < 0:
raise ValueError("Weight must be a positive number")
except TypeError:
raise TypeError(f"Invalid value '{weight}' for weight (must be a number)")
valid_units = WeightUnitChoices.values()
if unit not in valid_units:
raise ValueError(f"Unknown unit {unit}. Must be one of the following: {', '.join(valid_units)}")
if unit == WeightUnitChoices.UNIT_KILOGRAM:
return weight * 1000
if unit == WeightUnitChoices.UNIT_GRAM:
return weight
if unit == WeightUnitChoices.UNIT_POUND:
return weight * Decimal(453.592)
if unit == WeightUnitChoices.UNIT_OUNCE:
return weight * Decimal(28.3495)
raise ValueError(f"Unknown unit {unit}. Must be 'kg', 'g', 'lb', 'oz'.")
def render_jinja2(template_code, context):
"""
Render a Jinja2 template with the provided context. Return the rendered content.
"""
environment = SandboxedEnvironment()
environment.filters.update(get_config().JINJA2_FILTERS)
return environment.from_string(source=template_code).render(**context)
def prepare_cloned_fields(instance):
"""
Generate a QueryDict comprising attributes from an object's clone() method.
"""
# Generate the clone attributes from the instance
if not hasattr(instance, 'clone'):
return QueryDict(mutable=True)
attrs = instance.clone()
# Prepare querydict parameters
params = []
for key, value in attrs.items():
if type(value) in (list, tuple):
params.extend([(key, v) for v in value])
elif value not in (False, None):
params.append((key, value))
else:
params.append((key, ''))
# Return a QueryDict with the parameters
return QueryDict(urlencode(params), mutable=True)
def shallow_compare_dict(source_dict, destination_dict, exclude=tuple()):
"""
Return a new dictionary of the different keys. The values of `destination_dict` are returned. Only the equality of
the first layer of keys/values is checked. `exclude` is a list or tuple of keys to be ignored.
"""
difference = {}
for key, value in destination_dict.items():
if key in exclude:
continue
if source_dict.get(key) != value:
difference[key] = value
return difference
def flatten_dict(d, prefix='', separator='.'):
"""
Flatten netsted dictionaries into a single level by joining key names with a separator.
:param d: The dictionary to be flattened
:param prefix: Initial prefix (if any)
:param separator: The character to use when concatenating key names
"""
ret = {}
for k, v in d.items():
key = separator.join([prefix, k]) if prefix else k
if type(v) is dict:
ret.update(flatten_dict(v, prefix=key, separator=separator))
else:
ret[key] = v
return ret
def array_to_ranges(array):
"""
Convert an arbitrary array of integers to a list of consecutive values. Nonconsecutive values are returned as
single-item tuples. For example:
[0, 1, 2, 10, 14, 15, 16] => [(0, 2), (10,), (14, 16)]"
"""
group = (
list(x) for _, x in groupby(sorted(array), lambda x, c=count(): next(c) - x)
)
return [
(g[0], g[-1])[:len(g)] for g in group
]
def array_to_string(array):
"""
Generate an efficient, human-friendly string from a set of integers. Intended for use with ArrayField.
For example:
[0, 1, 2, 10, 14, 15, 16] => "0-2, 10, 14-16"
"""
ret = []
ranges = array_to_ranges(array)
for value in ranges:
if len(value) == 1:
ret.append(str(value[0]))
else:
ret.append(f'{value[0]}-{value[1]}')
return ', '.join(ret)
def content_type_name(ct, include_app=True):
"""
Return a human-friendly ContentType name (e.g. "DCIM > Site").
"""
try:
meta = ct.model_class()._meta
app_label = title(meta.app_config.verbose_name)
model_name = title(meta.verbose_name)
if include_app:
return f'{app_label} > {model_name}'
return model_name
except AttributeError:
# Model no longer exists
return f'{ct.app_label} > {ct.model}'
def content_type_identifier(ct):
"""
Return a "raw" ContentType identifier string suitable for bulk import/export (e.g. "dcim.site").
"""
return f'{ct.app_label}.{ct.model}'
#
# Fake request object
#
class NetBoxFakeRequest:
"""
A fake request object which is explicitly defined at the module level so it is able to be pickled. It simply
takes what is passed to it as kwargs on init and sets them as instance variables.
"""
def __init__(self, _dict):
self.__dict__ = _dict
def copy_safe_request(request):
"""
Copy selected attributes from a request object into a new fake request object. This is needed in places where
thread safe pickling of the useful request data is needed.
"""
meta = {
k: request.META[k]
for k in HTTP_REQUEST_META_SAFE_COPY
if k in request.META and isinstance(request.META[k], str)
}
return NetBoxFakeRequest({
'META': meta,
'COOKIES': request.COOKIES,
'POST': request.POST,
'GET': request.GET,
'FILES': request.FILES,
'user': request.user,
'path': request.path,
'id': getattr(request, 'id', None), # UUID assigned by middleware
})
def clean_html(html, schemes):
"""
Sanitizes HTML based on a whitelist of allowed tags and attributes.
Also takes a list of allowed URI schemes.
"""
ALLOWED_TAGS = [
"div", "pre", "code", "blockquote", "del",
"hr", "h1", "h2", "h3", "h4", "h5", "h6",
"ul", "ol", "li", "p", "br",
"strong", "em", "a", "b", "i", "img",
"table", "thead", "tbody", "tr", "th", "td",
"dl", "dt", "dd",
]
ALLOWED_ATTRIBUTES = {
"div": ['class'],
"h1": ["id"], "h2": ["id"], "h3": ["id"], "h4": ["id"], "h5": ["id"], "h6": ["id"],
"a": ["href", "title"],
"img": ["src", "title", "alt"],
}
return bleach.clean(
html,
tags=ALLOWED_TAGS,
attributes=ALLOWED_ATTRIBUTES,
protocols=schemes
)
def highlight_string(value, highlight, trim_pre=None, trim_post=None, trim_placeholder='...'):
"""
Highlight a string within a string and optionally trim the pre/post portions of the original string.
Args:
value: The body of text being searched against
highlight: The string of compiled regex pattern to highlight in `value`
trim_pre: Maximum length of pre-highlight text to include
trim_post: Maximum length of post-highlight text to include
trim_placeholder: String value to swap in for trimmed pre/post text
"""
# Split value on highlight string
try:
if type(highlight) is re.Pattern:
pre, match, post = highlight.split(value, maxsplit=1)
else:
highlight = re.escape(highlight)
pre, match, post = re.split(fr'({highlight})', value, maxsplit=1, flags=re.IGNORECASE)
except ValueError as e:
# Match not found
return escape(value)
# Trim pre/post sections to length
if trim_pre and len(pre) > trim_pre:
pre = trim_placeholder + pre[-trim_pre:]
if trim_post and len(post) > trim_post:
post = post[:trim_post] + trim_placeholder
return f'{escape(pre)}<mark>{escape(match)}</mark>{escape(post)}'
def local_now():
"""
Return the current date & time in the system timezone.
"""
return localtime(timezone.now())