Collection of library function in the opencart by Rupak Nepali

These are the library name that we can get in the opencart
cache, captcha, cart, config, currency, customer, db, document, encryption, image, json, language, length, log, mail, pagination, request, response, session, tax, template, user, weight
How we can use the library:
$this->cache->function_name_available();
List of function name in the respective category:
Cache:
    $this->cache->get($key);
    $this->cache->set($key, $value):
    $this->cache->delete($key):

Captcha:
Captcha contains only two function and they are below:
getCode():
showImage():

Cart:
Functions that are in the cart library of opencart are:
$this->cart->getProducts():
add($product_id, $qty = 1, $options = array()):
update($key, $qty):
remove($key):
clear():
getWeight():
setMinQty():
getSubTotal():
getTaxes():
getTotal():
countProducts():
hasProducts():
hasStock():
hasShipping():
hasDownload():

config:
config consists of 5 functions and they are as follows:
get($key):
set($key, $value):
has($key):
load($filename):

currency:
set($currency):
format($number, $currency = '', $value = '', $format = TRUE):
convert($value, $from, $to):
getId():
getCode():
getValue($currency):
has($currency):

customer:
login($email, $password):
logout():
isLogged():
getId():
getFirstName():
getLastName():
getEmail():
getTelephone():
getFax():
getNewsletter():
getCustomerGroupId():
getAddressId():

db:
query($sql):
escape($value):
countAffected():
getLastId():

document:
setTitle($title):
getTitle():
setDescription($description):
getDescription():
setKeywords($keywords):
getKeywords():
setBase($base):
getBase():
setCharset($charset):
getCharset():
setLanguage($language):
getLanguage():
setDirection($direction):
getDirection():
addLink($href, $rel):
getLinks():
addStyle($href, $rel = 'stylesheet', $media = 'screen'):
getStyles():
addScript($script):
getScripts():
addBreadcrumb($text, $href, $separator = ' > '):
getBreadcrumbs():

encryption:
encrypt($value):
base64_encode()
decrypt($value):

image:
create($image):
save($file, $quality = 100):
resize($width = 0, $height = 0):
watermark($file, $position = 'bottomright'):
crop($top_x, $top_y, $bottom_x, $bottom_y):
rotate($degree, $color = 'FFFFFF'):
filter($filter):
text($text, $x = 0, $y = 0, $size = 5, $color = '000000'):
merge($file, $x = 0, $y = 0, $opacity = 100):
html2rgb($color):

Json:
encode($data):
decode($json, $assoc = FALSE):

Language:

get($key):
load($filename):

Length:
convert($value, $from, $to):
format($value, $unit, $decimal_point = '.', $thousand_point = ','):


log:
write($message):

Mail:
setTo($to):
setFrom($from):
addheader($header, $value):
setSender($sender):
setSubject($subject):
setText($text):
setHtml($html):
addAttachment($file, $filename = ''):
send():

Pagination:
render():

Request:
clean($data):

Response:
addHeader($header):
redirect($url):
setOutput($output, $level = 0):
compress($data, $level = 0):
output():

Session:
$this->session:

Tax:
setZone($country_id, $zone_id):
calculate($value, $tax_class_id, $calculate = TRUE):
getRate($tax_class_id):
getDescription($tax_class_id):
has($tax_class_id):

Template:
fetch($filename):

User:
login($username, $password):
logout():
hasPermission($key, $value):
isLogged():
getId():
getUserName():

Weight:
convert($value, $from, $to):
format($value, $unit, $decimal_point = '.', $thousand_point = ','):