pagelinks are supported, currently limited to 5 events

app/src/main/java/com/akdev/nofbeventscraper/FbEventScraper.java

@@ -1,28 +1,16 @@
 package com.akdev.nofbeventscraper;
 
-import android.content.SharedPreferences;
 import android.os.AsyncTask;
 
-import androidx.preference.PreferenceManager;
-
 import org.json.JSONException;
 import org.json.JSONObject;
 import org.jsoup.Jsoup;
 import org.jsoup.nodes.Document;
 
 import java.io.IOException;
-import java.lang.ref.WeakReference;
-import java.net.MalformedURLException;
-import java.net.URISyntaxException;
-import java.net.URL;
 import java.text.SimpleDateFormat;
 import java.util.Date;
-import java.util.List;
 import java.util.Locale;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-
-import static com.akdev.nofbeventscraper.FbEvent.createEventList;
 
 /**
  * This class can asynchronously scrape public facebook events
@@ -36,7 +24,7 @@ public class FbEventScraper extends AsyncTask<Void, Void, Void> {
     private FbEvent event;
 
     /**
-     * Constructor with WeakReference to the main activity, to update it's text fields.
+     * Constructor with reference to scraper to return results.
      *
      * @param scraper   Reference to FbScraper
      * @param input_url Input url to scrape from
@@ -162,6 +150,7 @@ public class FbEventScraper extends AsyncTask<Void, Void, Void> {
             Document document = Jsoup.connect(url).userAgent(user_agent).get();
 
             if (document == null) {
+                throw new IOException();
             }
             String json = document
                     .select("script[type = application/ld+json]")
@@ -209,7 +198,8 @@ public class FbEventScraper extends AsyncTask<Void, Void, Void> {
     }
 
     /**
-     * When scraping is finished, the scraper callback will receive the Event.
+     * When scraping is finished, the scraper callback will receive the event.
+     *
      * @param aVoid
      */
     protected void onPostExecute(Void aVoid) {

app/src/main/java/com/akdev/nofbeventscraper/FbPageScraper.java

@@ -0,0 +1,93 @@
+package com.akdev.nofbeventscraper;
+
+import android.os.AsyncTask;
+
+import org.jsoup.Jsoup;
+import org.jsoup.nodes.Document;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Pattern;
+
+/**
+ * This class can asynchronously scrape public facebook pages for event ids
+ * It returns a String list of event urls
+ */
+public class FbPageScraper extends AsyncTask<Void, Void, Void> {
+
+    private FbScraper scraper;
+    private int error;
+    private String url;
+    private List<String> event_links = new ArrayList<String>();
+
+    /**
+     * Constructor with reference to scraper to return results.
+     *
+     * @param scraper  Reference to FbScraper
+     * @param page_url Input url to scrape from
+     */
+    FbPageScraper(FbScraper scraper, String page_url) {
+
+        this.scraper = scraper;
+        this.url = page_url;
+        this.error = 0;
+    }
+
+    /**
+     * Started by execute().
+     * Gets the HTML doc from the input string and scrapes the event links from it.
+     *
+     * @param voids
+     * @return
+     */
+    @Override
+    protected Void doInBackground(Void... voids) {
+
+        try {
+            // use default android user agent
+            String user_agent = "Mozilla/5.0 (X11; Linux x86_64)";
+            Document document = Jsoup.connect(url).userAgent(user_agent).get();
+
+            if (document == null) {
+                throw new IOException();
+            }
+
+            String regex = "(/events/[0-9]*)(/\\?event_time_id=[0-9]*)?";
+
+            List<String> event_links_href = document
+                    .getElementsByAttributeValueMatching("href", Pattern.compile(regex))
+                    .eachAttr("href");
+
+            for (String link : event_links_href) {
+                this.event_links.add("https://www.facebook.com" + link);
+            }
+
+        } catch (IOException e) {
+            e.printStackTrace();
+            this.error = R.string.error_connection;
+        } catch (Exception e) {
+            e.printStackTrace();
+            this.error = R.string.error_unknown;
+        }
+
+        return null;
+    }
+
+    @Override
+    protected void onPreExecute() {
+        super.onPreExecute();
+    }
+
+    /**
+     * When scraping is finished, the scraper callback will receive the link list.
+     *
+     * @param aVoid
+     */
+    protected void onPostExecute(Void aVoid) {
+        super.onPostExecute(aVoid);
+
+        this.scraper.scrapePageResultCallback(this.event_links, this.error);
+    }
+}
+

app/src/main/java/com/akdev/nofbeventscraper/FbScraper.java

@@ -1,6 +1,7 @@
 package com.akdev.nofbeventscraper;
 
 import android.content.SharedPreferences;
+import android.os.AsyncTask;
 
 import androidx.preference.PreferenceManager;
 
@@ -8,6 +9,7 @@ import java.lang.ref.WeakReference;
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -17,8 +19,9 @@ import static com.akdev.nofbeventscraper.FbEvent.createEventList;
 public class FbScraper {
 
     protected List<FbEvent> events;
+    protected List<AsyncTask> tasks;
+    int remaining_events = 0;
     url_type_enum url_type = url_type_enum.EVENT;
-    private int error;
     private String input_url;
     private WeakReference<MainActivity> main; // no context leak with WeakReference
 
@@ -32,12 +35,31 @@ public class FbScraper {
         this.main = main;
         this.input_url = input_url;
         this.events = createEventList();
+        this.tasks = new ArrayList<>();
 
         run();
     }
 
     protected String getPageUrl(String url) throws URISyntaxException, MalformedURLException {
-        throw new URISyntaxException(url, "not implemented");
+
+        // check for url format
+        new URL(url).toURI();
+
+        String regex = "(facebook.com/)(pg/)?([^/?]*)";
+
+        Pattern pattern = Pattern.compile(regex);
+        Matcher matcher = pattern.matcher(url);
+
+        if (matcher.find()) {
+
+            String url_prefix = "https://mbasic.facebook.com/";
+            String url_suffix = "?v=events";
+
+            return url_prefix + matcher.group(3) + url_suffix;
+
+        } else {
+            throw new URISyntaxException(url, "Does not contain page.");
+        }
     }
 
     /**
@@ -81,6 +103,7 @@ public class FbScraper {
 
     void scrapeEvent(String event_url) {
         FbEventScraper scraper = new FbEventScraper(this, event_url);
+        tasks.add(scraper);
         scraper.execute();
     }
 
@@ -89,31 +112,55 @@ public class FbScraper {
         if (url_type == url_type_enum.EVENT) {
             if (event != null) {
                 main.get().addEvent(event);
-                main.get().input_helper(R.string.done, false);
+                main.get().input_helper(main.get().getString(R.string.done), false);
             } else {
-                main.get().input_helper(error, true);
+                main.get().input_helper(main.get().getString(error), true);
             }
+            killAllTasks();
+
         } else {
             main.get().addEvent(event);
+            remaining_events--;
+
+            if (remaining_events <= 0) {
+                main.get().input_helper(main.get().getString(R.string.done), false);
+                killAllTasks();
+            }
+        }
+    }
+
+    /**
+     * cancel vestigial async tasks
+     */
+    void killAllTasks() {
+        for (AsyncTask task : tasks) {
+            task.cancel(true);
+            task = null;
         }
     }
 
     void scrapePage(String page_url) {
-        /*
         FbPageScraper scraper = new FbPageScraper(this, page_url);
 
+        tasks.add(scraper);
         scraper.execute();
-         */
     }
 
-    protected void scrapePageResultCallback(String[] event_urls, int error) {
+    protected void scrapePageResultCallback(List<String> event_urls, int error) {
 
-        if (event_urls != null) {
+        if (event_urls.size() > 0) {
+            remaining_events = event_urls.size();
+            main.get().input_helper(main.get().getString(R.string.found_events, event_urls.size()), false);
             for (String event_url : event_urls) {
-                scrapeEvent(event_url);
+                try {
+                    String url = getEventUrl(event_url);
+                    scrapeEvent(url);
+                } catch (URISyntaxException | MalformedURLException e) {
+                    // ignore this event
+                }
             }
         } else if (url_type == url_type_enum.PAGE) {
-            main.get().input_helper(error, true);
+            main.get().input_helper(main.get().getString(error), true);
         }
     }
 
@@ -137,7 +184,7 @@ public class FbScraper {
 
         } catch (URISyntaxException | MalformedURLException e) {
             url_type = url_type_enum.INVALID;
-            main.get().input_helper(R.string.error_url, true);
+            main.get().input_helper(main.get().getString(R.string.error_url), true);
         }
     }
 

app/src/main/java/com/akdev/nofbeventscraper/MainActivity.java

@@ -12,7 +12,6 @@ import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 
-import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.view.menu.MenuBuilder;
 import androidx.appcompat.widget.Toolbar;
@@ -67,11 +66,11 @@ public class MainActivity extends AppCompatActivity {
     }
 
     /**
-     * Callback after clearing events from settings needed.
+     * Callback for Restoring data
      */
     @Override
-    public void onRestart() {
+    public void onResume() {
-        super.onRestart();
+        super.onResume();
 
         events.clear();
         events.addAll(getSavedEvents());
@@ -82,8 +81,8 @@ public class MainActivity extends AppCompatActivity {
      * Save events list to SharedPreferences as JSON
      */
     @Override
-    public void onSaveInstanceState(@NonNull Bundle state) {
+    public void onPause() {
-        super.onSaveInstanceState(state);
+        super.onPause();
 
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
         SharedPreferences.Editor prefs_edit = prefs.edit();
@@ -160,7 +159,7 @@ public class MainActivity extends AppCompatActivity {
                     startScraping();
                 } catch (Exception e) {
                     e.printStackTrace();
-                    input_helper(R.string.error_clipboard_empty, true);
+                    input_helper(getString(R.string.error_clipboard_empty), true);
                 }
             }
         });
@@ -171,9 +170,10 @@ public class MainActivity extends AppCompatActivity {
         View.OnClickListener listener = new View.OnClickListener() {
             @Override
             public void onClick(View view) {
-                input_helper(R.string.helper_add_link, true);
+                input_helper(getString(R.string.helper_add_link), true);
                 edit_text_uri_input.setText(null);
-                input_helper(R.string.helper_add_link, false);
+                scraper.killAllTasks();
+                input_helper(getString(R.string.helper_add_link), false);
             }
         };
         layout_uri_input.setErrorIconOnClickListener(listener);
@@ -225,9 +225,11 @@ public class MainActivity extends AppCompatActivity {
         scraper = new FbScraper(new WeakReference<>(this), url);
     }
 
-    public void input_helper(Integer resId, boolean error) {
+    public void input_helper(String str, boolean error) {
 
-        String str = (resId != null) ? getString(resId) : " ";
+        if (str == null) {
+            str = " ";
+        } // keep spacing
 
         if (error) {
             layout_uri_input.setError(str);

app/src/main/res/values-de/strings.xml

@@ -19,4 +19,5 @@
     <string name="preferences_event_setting">Veranstaltungsliste löschen</string>
     <string name="preferences_event_snackbar">"Veranstaltungen gelöscht "</string>
     <string name="done">Fertig</string>
+    <string name="found_events">%1$d Veranstaltungen gefunden</string>
 </resources>

app/src/main/res/values/strings.xml

@@ -31,5 +31,6 @@
     <string name="preferences_event_snackbar">Events list cleared</string>
     <string name="event_placeholder" translatable="false">Placeholder</string>
     <string name="done">Done</string>
+    <string name="found_events">Found %1$d events</string>
 
 </resources>