Add discardLanguage filter to RecordLoader.

- Clean up doc comments
- Add test
- Resolves #352

src/main/scala/io/archivesunleashed/package.scala

@@ -472,7 +472,7 @@ package object archivesunleashed {
         && DetectMimeTypeTika(r.getBinaryBytes).startsWith("image/"))
     }
 
-    /** Removes all data but selected mimeTypes specified in ArchiveRecord.
+    /** Removes all data but selected mimeTypes specified.
       *
       * @param mimeTypes a list of Mime Types
       */
@@ -488,15 +488,15 @@ package object archivesunleashed {
       rdd.filter(r => mimeTypes.contains(DetectMimeTypeTika(r.getBinaryBytes)))
     }
 
-    /** Removes all data that does not have selected status codes.
+    /** Removes all data that does not have selected HTTP status codes.
      *
      *  @param statusCodes a list of HTTP status codes
      */
     def keepHttpStatus(statusCodes: Set[String]): RDD[ArchiveRecord] = {
       rdd.filter(r => statusCodes.contains(r.getHttpStatus))
     }
 
-    /** Removes all data that does not have selected data.
+    /** Removes all data that does not have selected date.
       *
       * @param dates a list of dates
       * @param component the selected DateComponent enum value
@@ -513,7 +513,7 @@ package object archivesunleashed {
       rdd.filter(r => urls.contains(r.getUrl))
     }
 
-    /** Removes all data but selected url patterns.
+    /** Removes all data but selected URL patterns.
       *
       * @param urlREs a list of regular expressions
       */
@@ -555,47 +555,47 @@ package object archivesunleashed {
           }).exists(identity))
     }
 
-    /** Filters ArchiveRecord MimeTypes from RDDs.
+    /** Filters ArchiveRecord MimeTypes (web server).
       *
       * @param mimeTypes a list of Mime Types
       */
     def discardMimeTypes(mimeTypes: Set[String]): RDD[ArchiveRecord] = {
       rdd.filter(r => !mimeTypes.contains(r.getMimeType))
     }
 
-    /** Filters detected MimeTypes from RDDs.
+    /** Filters detected MimeTypes (Tika).
       *
       * @param mimeTypes a list of Mime Types
       */
     def discardMimeTypesTika(mimeTypes: Set[String]): RDD[ArchiveRecord] = {
       rdd.filter(r => !mimeTypes.contains(DetectMimeTypeTika(r.getBinaryBytes)))
     }
 
-    /** Filters detected dates from RDDs.
+    /** Filters detected dates.
       *
       * @param date a list of dates
       */
     def discardDate(date: String): RDD[ArchiveRecord] = {
       rdd.filter(r => r.getCrawlDate != date)
     }
 
-    /** Filters detected urls from RDDs.
+    /** Filters detected URLs.
       *
       * @param urls a list of urls
       */
     def discardUrls(urls: Set[String]): RDD[ArchiveRecord] = {
       rdd.filter(r => !urls.contains(r.getUrl))
     }
 
-    /** Filters detected status codes from RDDs.
+    /** Filters detected HTTP status codes.
       *
       * @param statusCodes a list of HTTP status codes
       */
     def discardHttpStatus(statusCodes: Set[String]): RDD[ArchiveRecord] = {
       rdd.filter(r => !statusCodes.contains(r.getHttpStatus))
     }
 
-    /** Filters detected url patterns from RDDs.
+    /** Filters detected URL patterns (regex).
      *
      *  @param urlREs a list of Regular expressions
      */
@@ -608,15 +608,15 @@ package object archivesunleashed {
           }).exists(identity))
     }
 
-    /** Filters detected domains (regex) from RDDs.
+    /** Filters detected domains (regex).
       *
       * @param urls a list of urls for the source domains
       */
     def discardDomains(urls: Set[String]): RDD[ArchiveRecord] = {
       rdd.filter(r => !urls.contains(r.getDomain))
     }
 
-    /** Filters detected content (regex) from RDDs.
+    /** Filters detected content (regex).
       *
       * @param contentREs a list of regular expressions
       */
@@ -628,5 +628,13 @@ package object archivesunleashed {
             case None => false
           }).exists(identity))
     }
+
+    /** Filters detected language.
+      *
+      * @param lang a set of ISO 639-2 codes
+      */
+    def discardLanguages(lang: Set[String]): RDD[ArchiveRecord] = {
+      rdd.filter(r => !lang.contains(DetectLanguage(RemoveHTML(r.getContentString))))
+    }
   }
 }

src/test/scala/io/archivesunleashed/RecordRDDTest.scala

@@ -117,6 +117,16 @@ class RecordRDDTest extends FunSuite with BeforeAndAfter {
     assert (r2.sameElements(r))
   }
 
+  test ("discard languages") {
+    val base2 = RecordLoader.loadArchives(arcPath, sc)
+      .keepValidPages()
+    val langs: Set[String] = Set("fr")
+    val r = Array("http://www.archive.org/", "http://www.archive.org/index.php")
+    val r2 = base2.discardLanguages(langs)
+      .map(r => r.getUrl).take(2)
+    assert (r2.sameElements(r))
+  }
+
   test ("check for keep content"){
     val expected = 1
     val base = RecordLoader.loadArchives(arcPath, sc)