From 6b06d315f307367efe13a50e6916d7c9293d7417 Mon Sep 17 00:00:00 2001
From: nauman-tintash <nauman@tintash.com>
Date: Thu, 15 Feb 2018 17:23:27 +0500
Subject: [PATCH 1/2] Added the feature to enable only selected file formats
 for selection as described in issue #40

---
 FileExplorer/FileExplorer/Configuration.swift   | 17 ++++++++++++++++-
 .../DirectoryContentViewModel.swift             |  6 ++++++
 .../FileExplorerViewController.swift            |  7 ++++++-
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/FileExplorer/FileExplorer/Configuration.swift b/FileExplorer/FileExplorer/Configuration.swift
index 4d94b07..f785759 100644
--- a/FileExplorer/FileExplorer/Configuration.swift
+++ b/FileExplorer/FileExplorer/Configuration.swift
@@ -41,11 +41,26 @@ struct ActionsConfiguration {
 struct FilteringConfiguration {
     var fileFilters: [Filter]
     var ignoredFileFilters: [Filter]
+    var selectableFileExtensions: [String]
 }
 
 extension FilteringConfiguration {
     init() {
-        self.init(fileFilters: [Filter](), ignoredFileFilters: [Filter]())
+        self.init(fileFilters: [Filter](), ignoredFileFilters: [Filter](), selectableFileExtensions: [String]())
+    }
+    
+    func isSelectableFileExtension(fileItem: Item<Any>) -> Bool{
+        var isSelectable = true
+        if selectableFileExtensions.count > 0 {
+            isSelectable = false
+            for selectableExtension in selectableFileExtensions {
+                if fileItem.extension == selectableExtension {
+                    isSelectable = true
+                    break
+                }
+            }
+        }
+        return isSelectable
     }
 }
 
diff --git a/FileExplorer/FileExplorer/DirectoryContentViewModel.swift b/FileExplorer/FileExplorer/DirectoryContentViewModel.swift
index 627d913..650b2c1 100644
--- a/FileExplorer/FileExplorer/DirectoryContentViewModel.swift
+++ b/FileExplorer/FileExplorer/DirectoryContentViewModel.swift
@@ -142,6 +142,12 @@ final class DirectoryContentViewModel {
                 return false
             } else if item.type == ItemType.file && !configuration.actionsConfiguration.canChooseFiles {
                 return false
+            } else if item.type == ItemType.file{
+                if configuration.filteringConfiguration.isSelectableFileExtension(fileItem: item) {
+                    return true && enabled
+                    } else {
+                    return false
+                }
             } else {
                 return true && enabled
             }
diff --git a/FileExplorer/FileExplorer/FileExplorerViewController.swift b/FileExplorer/FileExplorer/FileExplorerViewController.swift
index 13b3691..afa612b 100644
--- a/FileExplorer/FileExplorer/FileExplorerViewController.swift
+++ b/FileExplorer/FileExplorer/FileExplorerViewController.swift
@@ -73,6 +73,11 @@ public final class FileExplorerViewController: UIViewController {
     /// Results of multiple filters are combined and all of them aren't displayed by file explorer view controller. All files passing filters from `fileFilters` property are displayed if there are no filters in `ignoredFileFilters` array.
     public var ignoredFileFilters = [Filter]()
 
+    /// Filters that determine which files extensions can be selected by file explorer view controller.
+    ///
+    /// A list of String containing all the selectable file folmats. All files are displayed if `fileFilters` array is empty.
+    public var selectableFileExtensions = [String]()
+    
     /// The file explorer's delegate object.
     public weak var delegate: FileExplorerViewControllerDelegate?
 
@@ -118,7 +123,7 @@ public final class FileExplorerViewController: UIViewController {
                                                         canChooseFiles: canChooseFiles,
                                                         canChooseDirectories: canChooseDirectories,
                                                         allowsMultipleSelection: allowsMultipleSelection)
-        let filteringConfiguration = FilteringConfiguration(fileFilters: fileFilters, ignoredFileFilters: ignoredFileFilters)
+        let filteringConfiguration = FilteringConfiguration(fileFilters: fileFilters, ignoredFileFilters: ignoredFileFilters, selectableFileExtensions:selectableFileExtensions)
         let configuration = Configuration(actionsConfiguration: actionsConfiguration, filteringConfiguration: filteringConfiguration)
 
         if let item = Item<Any>.at(initialDirectoryURL, isDirectory: true) {

From fade6234044a5296db895157e96f20f82d870c58 Mon Sep 17 00:00:00 2001
From: nauman-tintash <nauman@tintash.com>
Date: Thu, 15 Feb 2018 17:27:52 +0500
Subject: [PATCH 2/2] Updated README with instructions to use the feature to
 enable only selected file formats for selection.

---
 README.md | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/README.md b/README.md
index 8b9ec43..e53a72e 100644
--- a/README.md
+++ b/README.md
@@ -161,6 +161,25 @@ public func fileExplorerViewController(_ controller: FileExplorerViewController,
 }
 ```
 
+### Deciding Which Files Extensions User can Choose
+
+Configure `FileExplorer` so that user is allowed to choose files of only specific file extensions:
+
+```Swift
+let fileExplorer = FileExplorerViewController()
+fileExplorer.canChooseFiles = true //specify whether user is allowed to choose files
+fileExplorer.canChooseDirectories = false //specify whether user is allowed to choose directories
+
+List the file extensions that can be choosen
+fileExplorer.selectableFileExtensions = ["png", "mp3"]
+
+fileExplorer.delegate = self
+
+self.present(fileExplorer, animated: true, completion: nil)
+```
+
+If no file extensions are specified as selectableFileExtensions, all file types are enabled by default.
+
 ### Deciding Whether User Can Delete Files and/or Directories
 
 Configure `FileExplorer` so that user is allowed to remove files and/or directories: