# css-class-names [](https://travis-ci.org/arturfsousa/css-class-names)
A python script for css class names conditional generation. Inspered by the node package [classnames](https://github.com/JedWatson/classnames).
## Why?
The node `classnames` package has been helping me a lot with `React/JSX` and general javascript front-end development. I really missed something similar to use when working with `django` and `jinja2` templates, so, I decided to create this package.
## Usage
You can add css class names by calling the function with arguments as:
* Strings
* Numbers: Floats or Integers (0 is allowed)
* Sequences: Lists or Tuples
* Dictionaries
```python
from css_class_names import class_names
class_names('header', 'is-visible') # 'header is-visible'
class_names(['is-visible', 'text-uppercase']) # 'is-visible text-uppercase'
class_names((100001000, 'clear')) # '100001000 clear'
class_names('header', {
'header--is-fixed': True,
'header--is-blue': False
})
# 'header header--is-fixed'
```
### Conditional dicts
Dictionaries can be used to concat class names conditionally using expressions:
```python
from css_class_names import class_names
errors = ['Some error']
class_names('alert', {
'alert-danger': errors,
'alert-success': not errors,
'small': True
})
# 'alert alert-danger'
class_names('client', {
'client-{}'.format(client.id): client,
'disable': not client.active()
})
# 'client client-989'
```
### Excludes falsy values
Falsy values (except 0) and not supported types will be ignored:
```python
from css_class_names import class_names
class_names([], '', False, {}, 0, object(), lambda x: x, None)
# '0'
```
### Strip and flatten
Strings are striped and sequences are recursively flattened:
```python
from css_class_names import class_names
class_names([' header ', [' green ', ' small ']])
# 'header green small'
```
### Dedupe
You can dedupe names with the `dedupe` argument:
```python
from css_class_names import class_names
class_names('cart', 'is-open', 'is-logged', {'is-logged': True}, dedupe=True)
# 'cart is-open is-logged'
```
### Prefix
You can add class name prefixes with the `prefix` argument. This is really usefull when you need a class namespace or using the [BEM](http://getbem.com/) methodology:
```python
from css_class_names import class_names
class_names('head', 'head--is-empty', {'head--is-large': True}, prefix='mysite-')
# 'mysite-head mysite-head--is-empty mysite-head--is-large'
```
## Development
After cloning the repository, create a virtualenv and use the `Makefile` commands to `setup` development requirements and run tests:
```bash
make setup
make lint
make test
make watch # run tests when code changes
make coverage
```
