### Install Appier Package (Bash)

Source: https://github.com/hivesolutions/appier/blob/master/CLAUDE.md

Provides commands to install the Appier package in development mode using pip and to install it from PyPI.

```Bash
pip install -e .

pip install appier
```

--------------------------------

### Install Dependencies and Run Tests (Bash)

Source: https://github.com/hivesolutions/appier/blob/master/CLAUDE.md

Installs project dependencies using pip and executes tests with pytest. It configures environment variables for testing specific adapters and HTTP backends.

```Bash
pip install -r requirements.txt
pip install -r extra.txt
pip install pytest netius
ADAPTER=tiny HTTPBIN=httpbin.bemisc.com pytest
```

--------------------------------

### Bash: Install and Run Appier

Source: https://github.com/hivesolutions/appier/blob/master/README.md

Commands to install the Appier framework using pip and run a Python application. This covers the basic setup and execution of an Appier web application.

```Bash
pip install appier
python hello.py
```

--------------------------------

### Appier Controller for Data Retrieval (Python)

Source: https://github.com/hivesolutions/appier/blob/master/CLAUDE.md

Illustrates how to create a controller in Appier that inherits from appier.Controller. This example defines a route to fetch user data using the previously defined User model.

```Python
class UserController(appier.Controller):
    @appier.route("/users", "GET")
    def list(self):
        return User.find()
```

--------------------------------

### Format Code with Black (Bash)

Source: https://github.com/hivesolutions/appier/blob/master/CLAUDE.md

Installs the Black code formatter and applies it to the entire project to ensure consistent code style.

```Bash
pip install black
black .
```

--------------------------------

### Starting an Appier App

Source: https://github.com/hivesolutions/appier/blob/master/doc/app.md

Provides the code to instantiate and run an Appier application. This is the standard method to launch the application's event loop and make it accessible.

```python
HelloApp().serve()

```

--------------------------------

### Basic Appier Application Structure (Python)

Source: https://github.com/hivesolutions/appier/blob/master/CLAUDE.md

Demonstrates the basic structure of an Appier application by defining a simple class that inherits from appier.App and includes a route for a 'Hello World' response.

```Python
import appier

class MyApp(appier.App):
    @appier.route("/", "GET")
    def hello(self):
        return "Hello World"
```

--------------------------------

### Appier Controller Example (Python)

Source: https://github.com/hivesolutions/appier/blob/master/doc/structure.md

Demonstrates a basic Appier controller. This 'CatController' defines a 'list' method that handles GET requests to '/cats'. It retrieves 'Cat' models, processes them, and renders a template.

```Python
import appier

import models

class CatController(appier.Controller):

    @appier.route("/cats", "GET")
    def list(self):
        cats = models.Cat.find()
        for cat in cats: cat.meow()
        return self.template(
            "cat/list.html.tpl",
            cats = cats
        )
```

--------------------------------

### Appier Configuration Example (JSON)

Source: https://github.com/hivesolutions/appier/blob/master/doc/structure.md

An example of an Appier configuration file named 'appier.json'. This JSON file contains settings that can be accessed during the application's runtime, such as a base URL.

```JSON
{
    "BASE_URL" : "http://www.hive.pt"
}
```

--------------------------------

### Install Appier with pip

Source: https://github.com/hivesolutions/appier/blob/master/README.rst

This command installs the Appier Python web framework using pip, the Python package installer. Ensure you have pip installed and configured correctly.

```shell
pip install appier
```

--------------------------------

### Appier App Example (Python)

Source: https://github.com/hivesolutions/appier/blob/master/doc/structure.md

Demonstrates the basic structure of an Appier application. It defines a simple 'Hello World' app with a root route that returns a string. The app is then instantiated and served.

```Python
import appier

class HelloApp(appier.App):

    @appier.route("/", "GET")
    def hello(self):
        return "Hello World"

HelloApp().serve()
```

--------------------------------

### Appier Handling Multiple HTTP Methods

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Demonstrates how a single handler method in Appier can be configured to respond to multiple HTTP methods for a given route. This example handles both GET and POST requests for '/cats/garfield'.

```Python
@appier.route("/cats/garfield", ("GET", "POST"))
def hello(self):
    return "hello from /cats/garfield"
```

--------------------------------

### Appier Template Example (Jinja2)

Source: https://github.com/hivesolutions/appier/blob/master/doc/structure.md

An example of a Jinja2 template used within an Appier project. It iterates over a list of 'cats' and displays their names in an HTML table.

```HTML
<table>
    {% for cat in cats %}
        <tr>
            <td>{{ cat.name }}</td>
        </tr>
    {% endfor %}
</table>
```

--------------------------------

### Appier Handling Longer URL Paths

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Shows how to define routes for more specific URL paths in Appier. This example maps a GET request to '/cats/garfield' to a handler method.

```Python
@appier.route("/cats/garfield", "GET")
def hello(self):
    return "hello from garfield"
```

--------------------------------

### Format Python Code with Black

Source: https://github.com/hivesolutions/appier/blob/master/AGENTS.md

This snippet demonstrates how to install and use the 'black' formatter to ensure consistent Python code style. It's a prerequisite for committing code.

```bash
pip install black
black .
```

--------------------------------

### Appier Model Definition (Python)

Source: https://github.com/hivesolutions/appier/blob/master/CLAUDE.md

Shows how to define a data model in Appier by creating a class that inherits from appier.Model and defining fields for attributes like 'name' and 'email'.

```Python
class User(appier.Model):
    name = appier.field()
    email = appier.field()
```

--------------------------------

### Python: Basic Hello World App

Source: https://github.com/hivesolutions/appier/blob/master/README.md

A simple 'Hello World' application using the Appier framework. This example demonstrates the basic structure of an Appier application, including defining a route and a handler function.

```Python
import appier

class HelloApp(appier.App):

    @appier.route("/", "GET")
    def hello(self):
        return "Hello World"

HelloApp().serve()
```

--------------------------------

### Run Full Test Suite with Pytest

Source: https://github.com/hivesolutions/appier/blob/master/AGENTS.md

This sequence of commands installs necessary dependencies and runs the project's test suite using 'pytest'. It includes setting an environment variable 'ADAPTER' and 'HTTPBIN'.

```bash
pip install -r requirements.txt
pip install -r extra.txt
pip install pytest netius
ADAPTER=tiny HTTPBIN=httpbin.bemisc.com pytest
```

--------------------------------

### Python: Async Hello World App

Source: https://github.com/hivesolutions/appier/blob/master/README.md

An asynchronous 'Hello World' application using Appier, compatible with Python 3.5+ and ASGI servers. This example showcases the use of `async` and `await` for non-blocking request handling.

```Python
import appier

class HelloApp(appier.App):

    @appier.route("/", "GET")
    async def hello(self):
        await self.send("Hello World")

HelloApp().serve()
```

--------------------------------

### Appier Basic Routing

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Demonstrates setting up a basic web application in Appier and handling requests to the root URL ('/'). It uses the @appier.route decorator to map the GET request to the hello method.

```Python
import appier

class HelloApp(appier.App):

    @appier.route("/", "GET")
    def hello(self):
        return "hello from /"

HelloApp().serve()
```

--------------------------------

### Basic Appier Web App

Source: https://github.com/hivesolutions/appier/blob/master/README.rst

This Python code demonstrates a minimal web application using the Appier framework. It defines a simple app that responds to GET requests at the root URL with 'Hello World'. The app is then served.

```Python
import appier

class HelloApp(appier.App):

    @appier.route("/", "GET")
    def hello(self):
        return "Hello World"

HelloApp().serve()
```

--------------------------------

### Generate Relative URL for Handler in Appier

Source: https://github.com/hivesolutions/appier/blob/master/doc/templates.md

Explains how to create a relative URL to a controller handler using the `url_for` method in Appier. This example links to the `list` handler in `CatController`.

```HTML
<a href="{{ url_for('cat.list') }}">List Cats</a>
```

--------------------------------

### Define Model Validations in Appier

Source: https://github.com/hivesolutions/appier/blob/master/doc/models.md

Demonstrates how to define validation rules for a model using the `validate` class method in Appier. It includes examples of `not_null`, `not_empty`, and `gte` validators.

```Python
class Cat(appier.Model):

    name = appier.field(
        type = unicode
    )

    age = appier.field(
        type = int
    )

    @classmethod
    def validate(cls):
        return super(Cat, cls).validate() + [
            appier.not_null("name"),
            appier.not_empty("name"),
            appier.gte("age", 5)
        ]
```

--------------------------------

### Python Appier Controller for Listing Cats

Source: https://github.com/hivesolutions/appier/blob/master/doc/controllers.md

Defines a GET route '/cats' in an Appier controller to list all cats. It retrieves cat entities from the data source, invokes a 'meow' method on each, and renders a 'cat/list.html.tpl' template with the cat data.

```Python
import appier

import models

class CatController(appier.Controller):

    @appier.route("/cats", "GET")
    def list(self):
        cats = models.Cat.find()
        for cat in cats: cat.meow()
        return self.template(
            "cat/list.html.tpl",
            cats = cats
        )
```

--------------------------------

### Appier Handling POST Requests

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Illustrates how to handle POST requests to a specific URL path using the @appier.route decorator in Appier. This example maps POST requests to '/cats/garfield'.

```Python
@appier.route("/cats/garfield", "POST")
def hello(self):
    return "hello from /cats/garfield"
```

--------------------------------

### Appier Capturing URL Parameters

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Explains how to capture dynamic parts of a URL path as parameters in Appier handler methods. The example uses '<name>' in the route to capture the name and pass it to the handler.

```Python
@appier.route("/cats/<name>", "GET")
def hello(self, name):
    return "hello from %s" % name
```

--------------------------------

### Delete a Cat Instance

Source: https://github.com/hivesolutions/appier/blob/master/doc/models.md

This Python code provides a simple example of how to delete a `Cat` instance from the database by calling the `delete()` method on the object.

```Python
cat.delete()
```

--------------------------------

### Appier Custom Exception Handler

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Illustrates how to define a custom handler for specific unhandled exceptions in Appier. This example catches `appier.NotFoundError` and returns a custom message.

```Python
@appier.exception_handler(appier.NotFoundError)
def not_found(self, error):
    return "The object you requested was not found"
```

--------------------------------

### Appier Handling Multiple URLs

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Shows how to associate multiple URL paths with a single handler method in Appier using multiple @appier.route decorators. This example maps both '/cats/garfield' and '/cats/felix' to the same handler.

```Python
@appier.route("/cats/garfield", "GET")
@appier.route("/cats/felix", "GET")
def hello(self):
    return "hello from garfield or felix (not sure which)"
```

--------------------------------

### Appier Retrieving URL/Form Parameters

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Shows how to retrieve parameters from the URL query string or form data in Appier using the `self.field()` method. This example retrieves a 'name' parameter.

```Python
@appier.route("/cats", ("GET", "POST"))
def hello(self):
    name = self.field("name")
    return "hello from %s" % name
```

--------------------------------

### Access Static Resource URL in Appier

Source: https://github.com/hivesolutions/appier/blob/master/doc/templates.md

Shows how to generate a URL for static resources (like images) using `url_for('static', ...)` in Appier. This example links to an image file located in the `static` directory.

```HTML
<img src="{{ url_for('static', filename = 'images/cats/felix.png') }}" />
```

--------------------------------

### Python Appier Controller for Redirecting Cat Show

Source: https://github.com/hivesolutions/appier/blob/master/doc/controllers.md

Defines a GET route '/cats/<int:id>' in an Appier controller that handles a specific cat's ID. Instead of returning data, it redirects the user to the 'animal.show' URL, passing the cat's ID.

```Python
@appier.route("/cats/<int:id>", "GET")
def show(self, id):
    return self.redirect(
        self.url_for("animal.show", id = id)
    )
```

--------------------------------

### Appier Model Definition (Python)

Source: https://github.com/hivesolutions/appier/blob/master/doc/structure.md

Illustrates how to define a data model in Appier. This example shows a 'Cat' model inheriting from 'appier.Model' with an 'id' field configured with specific properties like type, indexing, and auto-increment.

```Python
import appier

class Cat(appier.Model):

    id = appier.field(
        type = int,
        index = True,
        increment = True
    )
```

--------------------------------

### Generate Absolute URL in HTML

Source: https://github.com/hivesolutions/appier/blob/master/doc/email.md

Provides an HTML example demonstrating how to generate an absolute URL for a link using the `url_for` function with the `absolute=True` argument. This ensures the URL is prefixed with the `BASE_URL` configuration.

```HTML
<a href="{{ url_for('base.index', absolute = True) }}">The App</a>
```

--------------------------------

### Appier Type Casting URL Parameters

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Demonstrates Appier's ability to automatically cast captured URL parameters to specified types. This example casts the 'number' parameter to an integer.

```Python
@appier.route("/numbers/<int:number>", "GET")
def hello(self, number):
    return "this is number %d" % number
```

--------------------------------

### Appier Custom Error Handler (404)

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Shows how to define a custom handler for specific HTTP error codes in Appier. This example provides a custom response for a 404 Not Found error.

```Python
@appier.error_handler(404)
def not_found_code(self, error):
    return "404 - The page you requested was not found"
```

--------------------------------

### Managing User Tokens in Session

Source: https://github.com/hivesolutions/appier/blob/master/doc/access_control.md

These Python examples show how to manage user access tokens within the session object. Tokens are added to `self.session["tokens"]` upon login and removed upon logout.

```Python
self.session["tokens"] = ["base"]
# To log out:
del self.session["tokens"]
```

```Python
self.session["tokens"] = ["base", "admin"]
```

```Python
self.session["tokens"] = ["*"]
```

--------------------------------

### Basic Appier App Structure

Source: https://github.com/hivesolutions/appier/blob/master/doc/app.md

Demonstrates the fundamental structure of an Appier application. It shows how to define a simple 'Hello World' route using the @appier.route decorator and how to create a class that inherits from appier.App.

```python
import appier

class HelloApp(appier.App):

    @appier.route("/", "GET")
    def hello(self):
        return "Hello World"

```

--------------------------------

### Configuring Appier App Initialization

Source: https://github.com/hivesolutions/appier/blob/master/doc/app.md

Illustrates how to configure an Appier application by defining its __init__ method. This allows for setting application-specific parameters like the application name during instantiation.

```python
class HelloApp(appier.App):

    def __init__(self, *args, **kwargs):
        appier.App.__init__(
            self,
            name = "app_name",
            *args, **kwargs
        )

```

--------------------------------

### Python - Advanced Cat Retrieval

Source: https://github.com/hivesolutions/appier/blob/master/doc/models.md

Demonstrates retrieving cats that are not named 'Garfield' using the '$ne' operator with get, count, and find methods.

```Python
not_garfield = Cat.get(name = {"$ne" : "Garfield"})
number_not_garfields = Cat.count(name = {"$ne" : "Garfield"})
number_garfields = Cat.find(name = {"$ne" : "Garfield"})
```

--------------------------------

### Bash: Run Async App with Uvicorn

Source: https://github.com/hivesolutions/appier/blob/master/README.md

Instructions to run an asynchronous Appier application using the Uvicorn server. This requires setting the SERVER environment variable to 'uvicorn' before executing the Python script.

```Bash
SERVER=uvicorn python hello.py
```

--------------------------------

### Render Basic Template in Appier

Source: https://github.com/hivesolutions/appier/blob/master/doc/templates.md

Demonstrates how to render a Jinja2 template using the `template` method in an Appier controller. The `list` handler in `CatController` renders 'cat/list.html.tpl'.

```Python
import appier

class CatController(appier.Controller):

    @appier.route("/cats", "GET")
    def list(self):
        return self.template(
            "cat/list.html.tpl"
        )
```

--------------------------------

### Access Reserved Session Variable in Jinja2

Source: https://github.com/hivesolutions/appier/blob/master/doc/templates.md

Shows how to access reserved variables injected into Jinja2 templates by Appier. This example displays the logged-in user's email from the `session` object.

```HTML
<p>Logged in as {{ session.email }}</p>
```

--------------------------------

### Listen to Post Create Persistence Event

Source: https://github.com/hivesolutions/appier/blob/master/doc/events.md

This Python code demonstrates how to listen to the 'post_create' persistence event for a `Cat` model using `bind_g`. The `handle_cat_post_create` method is executed after a new `Cat` instance has been successfully created and saved.

```python
@classmethod
def setup(cls):
    super(MeowTracker, cls).setup()
    cat.Cat.bind_g("post_create", cls.handle_cat_post_create)

@classmethod
def handle_cat_post_create(cls, ctx):
    print("Cat '%s' was born" % ctx.name)
```

--------------------------------

### Get Current Location URL in Appier

Source: https://github.com/hivesolutions/appier/blob/master/doc/templates.md

Demonstrates how to retrieve the current relative or absolute URL path using the `location` variable within `url_for` in Appier. This is useful for creating self-referential links.

```HTML
<a href="{{ url_for('location', absolute = True) }}">Loop Link</a>
```

--------------------------------

### Configure TinyDB Settings

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Sets up the configuration for TinyDB, a lightweight document-oriented database. It includes options for the database file path (TINY_PATH) and the storage engine (TINY_STORAGE).

```Python
import os

TINY_PATH = os.environ.get('TINY_PATH', 'db.json')
TINY_STORAGE = os.environ.get('TINY_STORAGE', 'json')
```

--------------------------------

### Configure File Session Persistence (Python)

Source: https://github.com/hivesolutions/appier/blob/master/doc/sessions.md

Demonstrates how to configure the Appier application to use FileSession for persisting session data. This involves passing the session_c keyword argument during app initialization.

```Python
import appier

class HelloApp(appier.App):

    def __init__(self):
        appier.App.__init__(
            self,
            session_c = appier.session.FileSession
        )

HelloApp().serve()
```

--------------------------------

### Appier Server Configuration

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Defines the server environment for the Appier application. Includes settings for the server type, host address, port, and backlog for pending connections.

```Python
SERVER = "legacy"  # Options: legacy, netius, waitress, tornado, cherrypi
HOST = "127.0.0.1"  # Address to bind the server to
PORT = 8080  # Port for the server to listen on
BACKLOG = socket.SOMAXCONN  # Max pending connections
```

--------------------------------

### Appier HTTP Client Configuration

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Sets up the HTTP client used for making external requests. Includes options for the client type, connection reuse, and request timeout.

```Python
HTTP_CLIENT = "netius"  # Options: legacy, netius, requests
HTTP_REUSE = True  # Reuse HTTP client connections
HTTP_TIMEOUT = 60  # Timeout in seconds for HTTP requests
```

--------------------------------

### Running an Appier App (Shell)

Source: https://github.com/hivesolutions/appier/blob/master/doc/structure.md

Shows the command to execute a Python script that serves an Appier application. This is typically run from the project's root directory.

```Shell
python hello.py
```

--------------------------------

### Appier Configuration via Environment Variable

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Demonstrates how to override configuration settings defined in a file by using environment variables. This is useful for managing different configurations across various deployment environments.

```bash
LEVEL=WARNING python hello.py
```

--------------------------------

### Send Email with Default Configuration (Python)

Source: https://github.com/hivesolutions/appier/blob/master/doc/email.md

Demonstrates sending an email using the `email` method with default configuration settings. The template, subject, sender, and receivers are specified.

```Python
self.email(
    "template.html.tpl",
    subject = "Test email",
    sender = "Sender Name <sender@email.com>",
    subject = "Test email",
    sender = "sender@email.com",
    receivers = ["receiver@email.com"]
)
```

--------------------------------

### Enable Database Query Debugging

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Controls the display of extra debug information related to database queries. When SHOW_QUERIES is set to True, detailed query information will be logged.

```Python
import os

SHOW_QUERIES = os.environ.get('SHOW_QUERIES', 'False').lower() == 'true'
```

--------------------------------

### Create Cat Instance with Automatic Form Data Mapping

Source: https://github.com/hivesolutions/appier/blob/master/doc/models.md

This Python snippet shows how to create a new `Cat` instance using `Cat.new()`, which facilitates automatic mapping of form data to model attributes. It also demonstrates how to apply form data to an existing `cat` object using the `apply()` method.

```Python
cat = Cat.new()
cat.save()

# Applying form data to an existing cat
cat.apply()
```

--------------------------------

### Appier Parameter Default Values and Casting

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Illustrates how to specify default values and custom casting functions when retrieving parameters using `self.field()` in Appier. This example retrieves an integer 'number' with a default of 5.

```Python
@appier.route("/numbers", ("GET", "POST"))
def hello(self):
    number = self.field("number", 5, cast = int)
    return "this is number %d" % number
```

--------------------------------

### Configure Email Settings

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Sets up email functionality using SMTP. Requires connection details like URL, host, port, username, password, and TLS settings. Optionally, a HELO host and email locale can be specified.

```python
SMTP_URL = "smtps://username:password@host.com:25"
SMTP_HOST = "host.com"
SMTP_PORT = 25
SMTP_USER = "username"
SMTP_PASSWORD = "password"
SMTP_STARTTLS = True
SMTP_HELO_HOST = "client.com"
EMAIL_LOCALE = "en_US"
```

--------------------------------

### Appier Application Settings

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Provides application-specific settings such as the base URL for resolving relative URLs, a secret key for cryptographic operations, and a list of parts for dynamic loading.

```Python
BASE_URL = "http://localhost:8080"  # Base URL for absolute URL generation
SECRET = None  # Secret key for cryptographic operations
PARTS = []  # List of Appier Parts to load dynamically
```

--------------------------------

### Appier Configuration File

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Defines application settings using a JSON file, typically named `appier.json`. This file serves as a central point for variables that dictate the app's platform and behavior.

```json
{
    "LEVEL": "INFO"
}
```

--------------------------------

### Retrieve Appier Configuration Value with Default

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Illustrates how to provide a default value when retrieving configuration settings using `appier.conf()`. This ensures the application can still function even if a specific setting is not provided.

```python
level = appier.conf("LEVEL", "INFO")
```

--------------------------------

### Create and Save a New Cat Instance

Source: https://github.com/hivesolutions/appier/blob/master/doc/models.md

This Python code illustrates the process of creating a new `Cat` object, setting its `name` attribute, and persisting it to the database using the `save()` method. The `id` attribute is automatically managed due to the `increment` flag in the model definition.

```Python
cat = Cat()
cat.name = "Garfield"
cat.save()
```

--------------------------------

### Listen to Global Cat Event

Source: https://github.com/hivesolutions/appier/blob/master/doc/events.md

This Python code shows how to set up a global listener for the 'cat_meowed' event using `bind_g`. The `MeowTracker` model's `handle_cat_mehowed` class method will be invoked whenever a `Cat` triggers this event.

```python
import cat

class MeowTracker(appier.Model):

    @classmethod
    def setup(cls):
        super(MeowTracker, cls).setup()
        cat.Cat.bind_g("cat_meowed", cls.handle_cat_mehowed)

    @classmethod
    def handle_cat_mehowed(cls, ctx):
        print("Cat '%s' mehowed" % ctx.name)
```

--------------------------------

### Enable File Logging via Environment Variable

Source: https://github.com/hivesolutions/appier/blob/master/doc/logging.md

Enables logging to a file by setting the FILE_LOG environment variable to 1 before executing the Python script.

```Bash
FILE_LOG=1 python hello.py
```

--------------------------------

### Send Email with Explicit Configuration (Python)

Source: https://github.com/hivesolutions/appier/blob/master/doc/email.md

Shows how to send an email by providing SMTP configuration parameters directly to the `email` method, overriding global settings. This includes host, port, username, password, and TLS settings.

```Python
self.email(
    "template.html.tpl",
    subject = "Test email",
    sender = "Sender Name <sender@hive.pt>",
    receivers = ["receiver@hive.pt"],
    host = "hostname.com",
    port = 25,
    username = "username",
    password = "password"
    stls = True
)
```

--------------------------------

### Configure MongoDB Connection

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Sets up the connection to a MongoDB database using environment variables. It supports different URL formats like MONGOHQ_URL, MONGOLAB_URI, and MONGO_URL. The MONGO_DB variable specifies the default database name.

```Python
import os

MONGO_URL = os.environ.get('MONGOHQ_URL') or os.environ.get('MONGOLAB_URI') or os.environ.get('MONGO_URL') or 'mongodb://localhost'
MONGO_DB = os.environ.get('MONGO_DB', None)
```

--------------------------------

### Configure Preferences Settings

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Specifies the preferences manager and its storage location. Similar to cache, it supports various backends like file, memory, or Redis. For file-based preferences, a file path is needed for storage.

```python
PREFERENCES = "file"
PREFERENCES_PATH = "/etc/appier/prefs.db"
```

--------------------------------

### Appier Host Rewriting Configuration

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Configures host rewriting rules for incoming requests. If FORCE_HOST is set and the request host does not match, a rewrite will occur.

```Python
FORCE_HOST = None  # Rewrite request if host header does not match this value
```

--------------------------------

### Referencing Static Files in Templates (HTML)

Source: https://github.com/hivesolutions/appier/blob/master/doc/structure.md

Shows how to reference a JavaScript file located in the 'static/js/' directory from an HTML template using Appier's 'url_for' function.

```HTML
<script type="text/javascript" src="{{ url_for('static', filename = 'js/main.js') }}"></script>
```

--------------------------------

### Configure Redis Connection

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Configures the connection to a Redis server using environment variables. It supports REDISTOGO_URL and REDIS_URL for connection strings and REDIS_POOL to enable connection pooling.

```Python
import os

REDIS_URL = os.environ.get('REDISTOGO_URL') or os.environ.get('REDIS_URL') or 'redis://localhost'
REDIS_POOL = os.environ.get('REDIS_POOL', 'True').lower() == 'true'
```

--------------------------------

### Listen to Instance-Specific Cat Event

Source: https://github.com/hivesolutions/appier/blob/master/doc/events.md

This Python snippet illustrates how to listen to an event ('cat_meowed') on a specific instance of the `MeowTracker` model using the `bind` method. The `handle_cat_mehowed` method within the instance will be called when the event occurs.

```python
class MeowTracker(appier.Model):

    def listen(self):
        self.bind("cat_meowed", self.handle_cat_mehowed)

    def handle_cat_mehowed(self, ctx):
        print("Cat '%s' mehowed" % ctx.name)
```

--------------------------------

### Debug Configuration

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Enables extended file path inclusion in traceback lines and specifies whether to use the Git engine for traceback debugging.

```Python
EXTENDED_PATH = True
EXTENDED_GIT = False
```

--------------------------------

### Bus Configuration

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Configures the bus manager for creating federated environments and orchestration using an event-driven approach. It also defines a global name for diffusion scopes.

```Python
BUS = "memory"  # or "redis"
BUS_NAME = "global"
```

--------------------------------

### Retrieve Appier Configuration Value

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Shows how to access configuration values within the application logic using the `appier.conf()` function. This allows dynamic adjustment of application behavior based on external settings.

```python
level = appier.conf("LEVEL")
```

--------------------------------

### Configure Logging Settings

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Manages application logging verbosity and output. Supports file, stream, memory, and remote syslog logging. Custom logging formats and extra debug information can be enabled.

```python
LEVEL = "INFO"
FILE_LOG = True
STREAM_LOG = True
MEMORY_LOG = True
SYSLOG_HOST = "syslog.server.com"
SYSLOG_PORT = 514
SYSLOG_PROTO = "udp"
LOGGING = ["complex"]
LOGGING_EXTRA = True
LOGGING_FORMAT = "%(asctime)s - %(levelname)s - %(message)s"
```

--------------------------------

### Session Management Configuration

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Defines the session manager to be used, supporting file, memory, or Redis-based sessions. It also allows specifying a custom file path for session storage.

```Python
SESSION = "file"  # or "memory", "redis", "client"
SESSION_FILE_PATH = "/path/to/sessions"
```

--------------------------------

### Access Compressed Static Resource URL in Appier

Source: https://github.com/hivesolutions/appier/blob/master/doc/templates.md

Illustrates how to request a compressed version of a static resource in Appier by adding the `compress = True` argument to `url_for`. This can optimize bandwidth usage.

```HTML
<img src="{{ url_for('static', filename = 'images/cats/felix.png', compress = True) }}" />
```

--------------------------------

### Appier Accessing Uploaded Files

Source: https://github.com/hivesolutions/appier/blob/master/doc/requests.md

Demonstrates how to access uploaded files in Appier when handling 'multipart/form-data' POST requests. It shows how to retrieve a file object using `self.field()` and access its properties.

```Python
@appier.route("/file", "POST")
def hello(self):
    file = self.field("form_file_name")
    return "you uploaded a file of type %s named %s" % (file.mime, file.name)
```

--------------------------------

### Add Runtime Validations in Appier

Source: https://github.com/hivesolutions/appier/blob/master/doc/models.md

Illustrates how to add and execute custom validation methods at runtime for specific entities in Appier. This is useful for validations that are not applicable to all instances of a model.

```Python
@classmethod
def validate_password_strength(cls):
    return [
        appier.string_gt("_password", 5)
    ]
```

```Python
account.validate_extra("password_strength")
account.save()
```

--------------------------------

### Send Email with Plain Text Template (Python)

Source: https://github.com/hivesolutions/appier/blob/master/doc/email.md

Illustrates sending an email with a separate template for the plain text version. The `plain_template` argument is used to specify the file for the plain text content.

```Python
self.email(
    "template.html.tpl",
    plain_template = "plain_template.txt.tpl",
    subject = "Test email",
    sender = "Sender Name <sender@hive.pt>",
    receivers = ["receiver@hive.pt"]
)
```

--------------------------------

### Render Template with Data in Appier

Source: https://github.com/hivesolutions/appier/blob/master/doc/templates.md

Shows how to pass data from a controller to a Jinja2 template in Appier. The `models.Cat.find()` result is passed as the `cats` variable to 'cat/list.html.tpl'.

```Python
cats = models.Cat.find()
return self.template(
    "cat/list.html.tpl",
    cats = cats
)
```

--------------------------------

### Supervisor Configuration

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Sets the interval in seconds for peer checking and controls the timeout for peer health check operations.

```Python
SUPERVISOR_INTERVAL = 60.0
```

--------------------------------

### Generate Absolute URL for Handler in Appier

Source: https://github.com/hivesolutions/appier/blob/master/doc/templates.md

Demonstrates how to generate an absolute URL for a handler in Appier by setting `absolute = True` in the `url_for` method. This prefixes the URL with `BASE_URL` from configuration.

```HTML
<a href="{{ url_for('cat.list', absolute = True) }}">List Cats</a>
```

--------------------------------

### Configure Cache Settings

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Defines the cache manager and its storage path. Supports different cache backends like file, memory, or Redis. For file-based caching, a specific directory path is required.

```python
CACHE = "file"
CACHE_PATH = "/var/cache/appier"
```

--------------------------------

### Define Cat Model with Fields and Configuration

Source: https://github.com/hivesolutions/appier/blob/master/doc/models.md

This Python snippet demonstrates how to define a `Cat` model inheriting from `appier.Model`. It showcases the use of `appier.field` to declare attributes like `id` and `name`, specifying their types (`int`, `unicode`) and configurations such as `index` and `increment`.

```Python
class Cat(appier.Model):

    id = appier.field(
        type = int,
        index = True,
        increment = True
    )

    name = appier.field(
        type = unicode,
        index = True
    )
```

--------------------------------

### Python - Cat Model URL Resolution

Source: https://github.com/hivesolutions/appier/blob/master/doc/models.md

Shows how to define a get_show_url method within the Cat model to resolve a route URL using the owner's url_for method.

```Python
class Cat(appier.Model):

    id = appier.field(
        type = int,
        index = True,
        increment = True
    )

    def get_show_url(self):
        url = self.owner.url_for("cats.show", id = self.id)
        return url
```

--------------------------------

### Appier SSL/TLS Configuration

Source: https://github.com/hivesolutions/appier/blob/master/doc/configuration.md

Configures SSL/TLS encryption for the Appier application. Requires paths to key and certificate files when SSL is enabled, and can force SSL for all requests.

```Python
SSL = False  # Enable or disable SSL
KEY_FILE = None  # Path to SSL key file (required if SSL is True)
CER_FILE = None  # Path to SSL certificate file (required if SSL is True)
FORCE_SSL = False  # Force all requests to use HTTPS
```

--------------------------------

### Configure Logging Level via Environment Variable

Source: https://github.com/hivesolutions/appier/blob/master/doc/logging.md

Sets the logging level for an application by exporting the LEVEL environment variable before running the script. Only messages at or above the specified level will be logged.

```Bash
LEVEL=ERROR python hello.py
```

--------------------------------

### Log Output with ERROR Level

Source: https://github.com/hivesolutions/appier/blob/master/doc/logging.md

Demonstrates the output when an application is run with the logging level set to ERROR. Only error and critical messages are displayed.

```Bash
error message
critical message
```

--------------------------------

### Loop Through Data in Jinja2 Template

Source: https://github.com/hivesolutions/appier/blob/master/doc/templates.md

Illustrates how to iterate over a list of objects (`cats`) within a Jinja2 template. Each `cat` object's `name` attribute is displayed in a table row.

```HTML
<table>
    {% for cat in cats %}
        <tr>
            <td>{{ cat.name }}</td>
        </tr>
    {% endfor %}
</table>
```

--------------------------------

### Log Info Messages in Python

Source: https://github.com/hivesolutions/appier/blob/master/doc/logging.md

Logs an informational message using the logger object within an Appier application. This is a basic logging operation.

```Python
self.logger.info("information message")
```

--------------------------------

### Display Session Email in Template (HTML)

Source: https://github.com/hivesolutions/appier/blob/master/doc/sessions.md

Illustrates how to access and display a session variable, specifically 'email', within an HTML template using Appier's templating syntax.

```HTML
<p>Logged in as {{ session.email }}</p>
```

--------------------------------

### Log Warning Messages in Python

Source: https://github.com/hivesolutions/appier/blob/master/doc/logging.md

Logs a warning message using the logger object. This is useful for indicating potential issues that do not stop the application's execution.

```Python
self.logger.warn("warning message")
```