Developer manual: Helper functions

Developer manual: Helper functions

Several helper functions are at your disposal so you don't have to reinvent the wheel every time you write something for MediacenterJS.

The following are an explanation of the "most usefull" helper functions available. These functions are all stored in the /lib/utils and /lib/handler folders. Be sure to examine them while writing your code.

Utilities /lib/utils

Ajax calls

Include:

var ajax_utils = require('/ajax-utils');

Utilize:

ajax_utils.xhrCall(apiUrl, function(response) { ... }); 

Parameters:

• URL for AJAX GET.
• Callback

Result:

Data served by call.

File retrieval

Include:

var file_utils = require('/file-utils');

Utilize:

file_utils.getLocalFiles(PATH, FILETYPES, function(err, files) { ... });

Parameters:

• PATH on disk
• Filetypes needed to be retrieved
• Callback

Result:

An object with arrays consisting of:

  'href': filePath, 'dir': rootdirectory, 'file': file.name 

Utilities /lib/handlers

Get configuration

Include:

var configuration_handler = require('/handlers/configuration-handler'),
var config = configuration_handler.initializeConfiguration();

Utilize:

config.xxxx

Parameters:

none

Result:

all configuration items as string. eg config.moviepath

App cache

The app cache helper consists of several small helpful functions for writing and getting data from and to the local disk like metadata, images etc.

Include:

var app_cache_handler = require('/handlers/app-cache-handler');

Utilize:

* app_cache_handler.ensureCacheDirExists(DIR, SUBFOLDER);
* app_cache_handler.getCacheDir(DIR, SUBFOLDER);
* app_cache_handler.getCachePath(DIR, SUBFOLDER, FILE);


 Get frontend friendly URL to cached file
 @param app 	   app cache dir
 @param subdir 	   subdir within app cache dir
 @param filename	   Name of file

* app_cache_handler.getFrontendCachePath(APP, SUBFOLDER, FILE);
* app_cache_handler.clearCache(APP, callback);


  Download images to cache dir
  @param app 	   app cache dir
  @param subdir 	   subdir within app cache dir
  @param url	   URL of image to be downloaded
  @param callback      The Callback (returns the contents as string)

* app_cache_handler.downloadDataToCache(APP,SUBFOLDER, URL callback);