File size: 4,127 Bytes
4ff79c6 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 | # SPDX-FileCopyrightText: 2022-present deepset GmbH <info@deepset.ai>
#
# SPDX-License-Identifier: Apache-2.0
from typing import Any, List, Optional, Union
from jinja2 import Environment, nodes
from jinja2.ext import Extension
from haystack.lazy_imports import LazyImport
with LazyImport(message='Run "pip install arrow>=1.3.0"') as arrow_import:
import arrow
class Jinja2TimeExtension(Extension):
# Syntax for current date
tags = {"now"}
def __init__(self, environment: Environment): # pylint: disable=useless-parent-delegation
"""
Initializes the JinjaTimeExtension object.
:param environment: The Jinja2 environment to initialize the extension with.
It provides the context where the extension will operate.
"""
arrow_import.check()
super().__init__(environment)
@staticmethod
def _get_datetime(
timezone: str,
operator: Optional[str] = None,
offset: Optional[str] = None,
datetime_format: Optional[str] = None,
) -> str:
"""
Get the current datetime based on timezone, apply any offset if provided, and format the result.
:param timezone: The timezone string (e.g., 'UTC' or 'America/New_York') for which the current
time should be fetched.
:param operator: The operator ('+' or '-') to apply to the offset (used for adding/subtracting intervals).
Defaults to None if no offset is applied, otherwise default is '+'.
:param offset: The offset string in the format 'interval=value' (e.g., 'hours=2,days=1') specifying how much
to adjust the datetime. The intervals can be any valid interval accepted
by Arrow (e.g., hours, days, weeks, months). Defaults to None if no adjustment is needed.
:param datetime_format: The format string to use for formatting the output datetime.
Defaults to '%Y-%m-%d %H:%M:%S' if not provided.
"""
try:
dt = arrow.now(timezone)
except Exception as e:
raise ValueError(f"Invalid timezone {timezone}: {e}")
if offset and operator:
try:
# Parse the offset and apply it to the datetime object
replace_params = {
interval.strip(): float(operator + value.strip())
for param in offset.split(",")
for interval, value in [param.split("=")]
}
# Shift the datetime fields based on the parsed offset
dt = dt.shift(**replace_params)
except (ValueError, AttributeError) as e:
raise ValueError(f"Invalid offset or operator {offset}, {operator}: {e}")
# Use the provided format or fallback to the default one
datetime_format = datetime_format or "%Y-%m-%d %H:%M:%S"
return dt.strftime(datetime_format)
def parse(self, parser: Any) -> Union[nodes.Node, List[nodes.Node]]:
"""
Parse the template expression to determine how to handle the datetime formatting.
:param parser: The parser object that processes the template expressions and manages the syntax tree.
It's used to interpret the template's structure.
"""
lineno = next(parser.stream).lineno
node = parser.parse_expression()
# Check if a custom datetime format is provided after a comma
datetime_format = parser.parse_expression() if parser.stream.skip_if("comma") else nodes.Const(None)
# Default Add when no operator is provided
operator = "+" if isinstance(node, nodes.Add) else "-"
# Call the _get_datetime method with the appropriate operator and offset, if exist
call_method = self.call_method(
"_get_datetime",
[node.left, nodes.Const(operator), node.right, datetime_format]
if isinstance(node, (nodes.Add, nodes.Sub))
else [node, nodes.Const(None), nodes.Const(None), datetime_format],
lineno=lineno,
)
return nodes.Output([call_method], lineno=lineno)
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