added course number in download

.gitignore

@@ -45,3 +45,4 @@ jspm_packages
 
 # Yarn Integrity file
 .yarn-integrity
+.idea

README.md

@@ -7,7 +7,7 @@ npm install -g udemy-dl
 ```
 
 ### Version
-**0.0.15**
+**0.0.16**
 
 ### Usage
 
@@ -51,6 +51,7 @@ Options:
 
 
 ### Updates
+ - *(09/05/2018)* added course number in download.
  - *(02/05/2018)* bug fixes to for code changes in udemy.
  - *(02/05/2018)* Course materials are also downloaded now.
  - *(08/12/2017)* added option to select resolution.

lib/core.js

@@ -325,6 +325,7 @@ let check_course_status = function(course_id,cb){
  }
   var all_videos_list = [];
   var download_queue = [];
+  var video_number = 1;
 
   let get_data_links = function(course_id, lecture_start, lecture_end){
     // """Getting video links from api 2.0."""
@@ -619,6 +620,7 @@ let check_course_status = function(course_id,cb){
                 element.title  = json_source.title;
                 element.chapter  = item.chapter;
                 element.resolution = argv.resolution;
+                element.number = video_number++;
                 download_queue.push(element);
                 //console.log(element);
                 callback();

lib/download.js

@@ -56,7 +56,7 @@ function download(dataObj,callback) {
     var fileUrl = dataObj.data_url,
       base_path = argv.output ? files.getCurrentDirectoryBase() + path.sep + argv.output : files.getCurrentDirectoryBase(),
       //edited to get current file with its chapter number
-      title = sanitize(dataObj.title)+'.'+dataObj.extension,
+      title = dataObj.number+' - '+sanitize(dataObj.title)+'.'+dataObj.extension,
       apiPath = base_path + path.sep + sanitize(dataObj.chapter) + path.sep + title,
       total_size = 0,
       total_downloaded = 0,