cube-utils 0.1.6

Python functions for Cube projects using cube.py config file.

Cube Utils

Cube Utils is a Python library for parsing and extracting information from Cube query payloads. It provides utilities to extract cubes, members, filters, and URL parameters from query data structures. Additionally, it includes the complete Cube package functionality for configuration management and template context handling, making it compatible with both open-source Cube deployments and Cube Cloud.

Installation

You can install Cube Utils using pip:

pip install cube-utils

If you are using Cube, just add cube-utils to your requirements.txt file. e.g.

cube-utils

Usage

Here is an example of how to use the extract_cubes and extract_members functions from the cube_utils.query_parser module:

from cube_utils.query_parser import extract_cubes, extract_members

# Example payload
payload = {
    "dimensions": ["test_a.city", "test_a.country", "test_a.state"],
    "measures": ["test_b.count"],
    "filters": [
        {"values": ["US"], "member": "test_a.country", "operator": "equals"}
    ],
    "segments": ["test_d.us_segment"],
    "timeDimensions": [
        {
            "dimension": "test_c.time",
            "dateRange": ["2021-01-01", "2021-12-31"],
            "granularity": "month",
        }
    ],
}

# Extract cubes
cubes = extract_cubes(payload)
print(cubes)  # Output: ['test_a', 'test_b', 'test_c', 'test_d']

# Extract members
members = extract_members(payload)
print(members)  # Output: ['test_a.city', 'test_a.country', 'test_a.state', 'test_b.count', 'test_a.country', 'test_d.us_segment', 'test_c.time']

# Extract members from specific query keys only
dimensions_and_measures = extract_members(payload, query_keys=["dimensions", "measures"])
print(dimensions_and_measures)  # Output: ['test_a.city', 'test_a.country', 'test_a.state', 'test_b.count']

Filter Members and Values

You can extract filter members along with their values using the extract_filters_members_with_values function:

from cube_utils.query_parser import extract_filters_members_with_values

# Example payload with complex filters
payload = {
    "filters": [
        {"values": ["US", "CA"], "member": "test_a.country", "operator": "equals"},
        {
            "or": [
                {"values": ["New York"], "member": "test_a.city", "operator": "equals"},
                {"member": "test_a.state", "operator": "set"}
            ]
        }
    ],
    "segments": ["test_b.premium_users"]
}

# Extract filter members with their values
filter_members = extract_filters_members_with_values(payload)
print(filter_members)  
# Output: [('test_a.country', ['CA', 'US']), ('test_a.city', ['New York']), ('test_a.state', None), ('test_b.premium_users', None)]

URL Parameter Extraction

You can extract query parameters from a URL using the extract_url_params function from the cube_utils.url_parser module:

from cube_utils.url_parser import extract_url_params

url = "https://example.com/?foo=bar&baz=qux"
params = extract_url_params(url)
print(params)  # Output: {'foo': 'bar', 'baz': 'qux'}

Cube Package API

Cube Utils now includes the complete Cube package functionality, providing configuration management and template context handling capabilities.

Configuration Management

The config object allows you to set configuration options for your Cube deployment. You can import it directly from cube_utils:

from cube_utils import config

Direct Property Assignment

Set configuration properties directly:

config.base_path = '/cube-api'
config.api_secret = 'your-secret-key'
config.telemetry = False

Function-based Configuration

Assign functions to configuration properties:

config.context_to_app_id = lambda ctx: ctx['securityContext']['tenant_id']

# Or using a regular function
def get_app_id(context):
    return context['securityContext']['tenant_id']

config.context_to_app_id = get_app_id

Decorator-style Configuration

Use the @config decorator to configure properties:

# Using function name as property name
@config
def context_to_app_id(ctx):
    return ctx['securityContext']['tenant_id']

# Using custom property name
@config('context_to_app_id')
def app_id(ctx):
    return ctx['securityContext']['tenant_id']

Available Configuration Options

The configuration object supports numerous options including:

• API Settings: base_path, api_secret, telemetry
• Database: db_type, driver_factory
• Authentication: check_auth, check_sql_auth, context_to_app_id
• Caching: sql_cache, compiler_cache_size
• WebSockets: web_sockets, web_sockets_base_path
• Scheduled Refresh: scheduled_refresh_timer, scheduled_refresh_concurrency
• Advanced: query_rewrite, pre_aggregations_schema, orchestrator_options

Template Context Management

The TemplateContext class provides template variable, function, and filter management for Jinja templates:

from cube_utils import TemplateContext

template = TemplateContext()

Variable Registration

Register variables that can be used in Jinja templates:

template.add_variable('my_var', 123)
template.add_variable('api_version', '2.0')
template.add_variable('feature_flags', {'new_ui': True})

Function Registration

Register functions that can be called from templates:

# Method 1: Direct registration
def get_user_data():
    return {'name': 'John', 'role': 'admin'}

template.add_function('get_user_data', get_user_data)

# Method 2: Using decorator
@template.function
def get_current_time():
    from datetime import datetime
    return datetime.now().isoformat()

# Method 3: Using decorator with custom name
@template.function('get_status')
def check_system_status():
    return 'active'

Filter Registration

Register custom Jinja filters:

# Method 1: Direct registration
def wrap_in_quotes(value):
    return f'"{value}"'

template.add_filter('quote', wrap_in_quotes)

# Method 2: Using decorator
@template.filter
def uppercase(value):
    return str(value).upper()

# Method 3: Using decorator with custom name
@template.filter('currency')
def format_currency(value):
    return f'${value:.2f}'

Context Functions

Mark functions as context functions using the context_func decorator:

from cube_utils import context_func

@context_func
def my_context_function():
    return 'This is a context function'

Safe Strings

Create safe strings for template rendering:

from cube_utils import SafeString

safe_html = SafeString('<b>Bold text</b>')
print(safe_html.is_safe)  # True

Backward Compatibility

The settings object is provided as an alias to config for backward compatibility:

from cube_utils import settings

settings.base_path = '/api'  # Same as config.base_path = '/api'

Additional Utilities

File Repository

Access file repository functionality for reading configuration files:

from cube_utils import file_repository

# Read all supported files from a directory
files = file_repository('/path/to/cube/schema')
# Returns list of dictionaries with 'fileName' and 'content' keys
# Supports: .js, .yml, .yaml, .jinja, .py files

Exception Handling

Handle configuration and template-related errors:

from cube_utils import ConfigurationException, TemplateException

try:
    @config('unknown_property')
    def invalid_config():
        pass
except ConfigurationException as e:
    print(f"Configuration error: {e}")

try:
    template.add_function('test', 'not a function')
except TemplateException as e:
    print(f"Template error: {e}")

API Reference

Query Parsing Functions

Function	Description	Module
extract_cubes	Extract unique cube names from query payload	cube_utils.query_parser
extract_members	Extract all members from query payload	cube_utils.query_parser
extract_filters_members	Extract members from filters and segments only	cube_utils.query_parser
extract_filters_members_with_values	Extract filter members with their values	cube_utils.query_parser
extract_members_from_expression	Parse SQL expressions for member references	cube_utils.query_parser
extract_url_params	Extract URL query parameters	cube_utils.url_parser

Cube Package Classes

Class/Object	Description	Import
config	Global configuration object	from cube_utils import config
TemplateContext	Template management class	from cube_utils import TemplateContext
context_func	Context function decorator	from cube_utils import context_func
SafeString	Safe string class for templates	from cube_utils import SafeString
settings	Alias for config (backward compatibility)	from cube_utils import settings

Running Tests

To run the tests, use the following command:

python -m unittest discover tests

License

This project is licensed under the MIT License - see the LICENSE file for details.