README

What is Monolog Cascade?

Monolog Cascade is a Monolog extension that allows you to set up and configure multiple loggers and handlers from a single config file. This is a fork, with the intention of being fast and slim.

It's been inspired by the logging.config Python module.

Installation

Add monolog-cascade as a requirement in your composer.json file or run

$ composer require mattyg/monolog-cascade

Note: This fork of Monolog Cascade requires PHP 5.6 or higher.

Usage

<?php
use MattyG\MonologCascade\Cascade;

$config = json_decode(file_get_contents("/path/to/some/config.json"), true);
// Or if you prefer YAML
$config = yaml_parse_file("/path/to/some/config.yml");

// configure your loggers
Cascade::configure($config);

Then just use your logger as shown below

Cascade::getLogger('myApp')->info('Well, that works!');
Cascade::getLogger('myApp')->error('Maybe not...');

Configuring your loggers

This fork of Monolog Cascade only supports configuration passed as an array. This allows you to store your configuration in whatever format you desire, and avoids the runtime cost of checking which format you're using for configuration.

Configuration structure

Here is a sample JSON config file:

{
    "formatters": {
        "dashed": {
            "class": "Monolog\\Formatter\\LineFormatter",
            "format": "%datetime%-%channel%.%level_name% - %message%\n"
        }
    },
    "handlers": {
        "console": {
            "class": "Monolog\\Handler\\StreamHandler",
            "level": "DEBUG",
            "formatter": "dashed",
            "processors": "[memory_processor]",
            "stream": "php://stdout",
        },
        "info_file_handler": {
            "class": "Monolog\\Handler\\StreamHandler",
            "level": "INFO",
            "formatter": "dashed",
            "stream": "./example_info.log"
        }
    },
    "processors": {
        "web_processor": {
            "class": "Monolog\\Processor\\WebProcessor"
        },
        "memory_processor": {
            "class": "Monolog\\Processor\\MemoryUsageProcessor"
        }
    },
    "loggers": {
        "myLogger": {
            "handlers": ["console", "info_file_handler"],
            "processors": ["web_processor"]
        }
    }
}

More information on how the Cascade config parser loads and reads the parameters:

Only the loggers key is required. If formatters and/or handlers are ommitted, Monolog's default will be used. processors is optional and if ommitted, no processors will be used. (See the "Optional Keys" section further below).

Other keys are optional and would be interpreted as described below:

formatters - the array in which each key is the formatter identifier holds keys/values to configure your formatters. The only reserved key is class and it should contain the classname of the formatter you would like to use. Other parameters will be interpreted as constructor parameters for that class and passed in when the formatter object is instanced by the Cascade config loader.
If some parameters are not present in the constructor, they will be treated as extra parameters and Cascade will try to interpret them should they match any custom handler functions that are able to use them. (see Extra Parameters section below)

If class is not provided Cascade will default to Monolog\Formatter\LineFormatter
handlers - the array in which each key is the handler identifier holds keys/values to configure your handlers.
The following keys are reserved:
- class (optional): classname of the handler you would like to use
- formatter (optional): formatter identifier that you have defined
- processors (optional): array of processor identifiers that you have defined
Other parameters will be interpreted as constructor parameters for that Handler class and passed in when the handler object is instantiated by the Cascade config loader.
If some parameters are not present in the constructor, they will be interpreted as extra parameters and Cascade will try to interpret them should they match any custom handler functions that are able to use them. (see Extra Parameters section below)

If class is not provided Cascade will default to Monolog\Handler\StreamHandler
processors - the array in which each key is the processor identifier holds keys/values to configure your processors.
The following key is reserved:
- class (required): classname of the processor you would like to use
loggers - the array in which each key is the logger identifier may contain only a handlers key and/or a processors key. You can decide what handler(s) and/or processor(s) you would like your logger to use.

Note: If you would like to use objects as parameters for your handlers, you can pass a class name (using the class option) with the corresponding arguments just like you would configure your handler. Cascade recursively instantiates and loads those objects as it parses the config file. See this sample config file.

Optional keys

formatters, handlers and processors keys are optional. If ommitted Cascade will default to Monolog's default formatter and handler: Monolog\Formatter\LineFormatter and Monolog\Handler\StreamHandler to stderr. If processors is ommitted, your logger(s) won't use any.

Default parameters

If a constructor method provides default value(s) in their declaration, Cascade will look it up and identify those parameters as optional with their default values. It can therefore be ommitted in your config file.

Order of sections and params

Order of the sections within the config file has no impact as long as they are formatted properly.
Order of parameters does not matter either.

Extra parameters (other than constructor's)

You may want to have your Formatters and/or Handlers consume values other than via the constructor. Some methods may be called to do additional set up when configuring your loggers. Cascade interprets those extra params 3 different ways and will try do so in that order:

Instance method
Your Formatter or Handler has a defined method that takes a param as input. In that case you can write it as follow in your config file:
```
"formatters": {
    "spaced": {
        "class": "Monolog\\Formatter\\LineFormatter",
        "format": "%datetime% %channel%.%level_name%  %message%\n",
        "includeStacktraces": true
    }
}
```
In this example, the LineFormatter class has an includeStacktraces method that takes a boolean. This method will be called upon instantiation.

Public member
Your Formatter or Handler has a public member that can be set.

"formatters": {
    "spaced": {
        "class": "Monolog\\Formatter\\SomeFormatter",
        "somePublicMember": "some value"
    }
}

In this example, the public member will be set to the passed in value upon instantiation.

Custom handler function
See FormatterLoader::initExtraOptionsHandlers and HandlerLoader::initExtraOptionsHandlers. Those methods hold closures that can call instance methods if needed. The closure takes the instance and the parameter value as input.
```
self::$extraOptionHandlers = array(
    '\Monolog\Formatter\LineFormatter' => array(
        'includeStacktraces' => function ($instance, $include) {
            $instance->includeStacktraces($include);
        }
    )
);
```
You can add handlers at runtime if needed. (i.e. if you write your logger handler for instance)

Running Tests

Just run Phpunit:

$ phpunit tests/

Contributing

This extension is open source. Feel free to contribute and send a pull request!

Make sure your code follows the PSR-2 standards, is documented and has unit tests.

What's next?

add support for namespaced Loggers with message propagation (through handler inheritance) so children loggers log messages using parent's handlers
add more custom function handlers to cover all the possible options of the current Monolog Formatters and Handlers
~~add support for Processors (DONE)~~
~~add support for DB/Store and other handlers requiring injection into the constructor (issue #30) (DONE)~~
other suggestions?

mattyg / monolog-cascade

Maintainers

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