Merge pull request #35 from scottmeschke/scottmeschke/source_persister_and_gson_parser_factories

Added factories for SourcePersisters and the various GsonParser imple…

README.md

@@ -23,8 +23,8 @@ Let's start by looking at what a fully configured store looks like, we will then
 ```java
 Store<Foo> Store = ParsingStoreBuilder.<BufferedSource, String>builder()
                .fetcher(this::ResponseAsSource)  //OkHttp responseBody.source()
-               .persister(new SourcePersister(new FileSystemImpl(context.getFilesDir())))
-               .parser(new GsonSourceParser<>(gson, Foo.class))
+               .persister(SourcePersisterFactory.create(context.getFilesDir())
+               .parser(GsonParserFactory.createSourceParser(gson, Foo.class))
                .open();
 	      
 ```
@@ -138,7 +138,7 @@ Our example can now be rewritten as:
 ```java
 Store<Article> Store = ParsingStoreBuilder.<BufferedSource, Article>builder()
                 .nonObservableFetcher(this::getResponse)
-                .parser(new GsonSourceParser<>(gson, Article.class))
+                .parser(GsonParserFactory.createSourceParser(gson, Article.class))
                 .open();
 ```
 
@@ -173,7 +173,7 @@ Now our data flow looks like:
                    return Observable.just(true);
                  }
                })
-               .parser(new GsonSourceParser<>(gson, String.class))
+               .parser(GsonParserFactory.createSourceParser(gson, String.class))
                .open();
 ```
 
@@ -192,8 +192,8 @@ We've found the fastest form of persistence is streaming network responses direc
 ```java
 Store<String> Store = ParsingStoreBuilder.<BufferedSource, String>builder()
                .nonObservableFetcher(this::ResponseAsSource)  //OkHttp responseBody.source()
-               .persister(new SourcePersister(new FileSystemImpl(context.getFilesDir())))
-               .parser(new GsonSourceParser<>(gson, String.class))
+               .persister(SourcePersisterFactory.create(context.getFilesDir()))
+               .parser(GsonParserFactory.createSourceParser(gson, String.class))
                .open();
 ```
 

app/src/main/java/com/nytimes/android/sample/activity/PersistingStoreActivity.java

@@ -8,12 +8,12 @@ import android.support.v7.widget.Toolbar;
 import android.widget.Toast;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
-import com.nytimes.android.external.fs.SourcePersister;
-import com.nytimes.android.external.fs.filesystem.FileSystemFactory;
+import com.nytimes.android.external.fs.SourcePersisterFactory;
+import com.nytimes.android.external.store.base.Persister;
 import com.nytimes.android.external.store.base.Store;
 import com.nytimes.android.external.store.base.impl.BarCode;
 import com.nytimes.android.external.store.base.impl.ParsingStoreBuilder;
-import com.nytimes.android.external.store.middleware.GsonSourceParser;
+import com.nytimes.android.external.store.middleware.GsonParserFactory;
 import com.nytimes.android.sample.BuildConfig;
 import com.nytimes.android.sample.R;
 import com.nytimes.android.sample.data.model.Children;
@@ -37,7 +37,7 @@ import static android.widget.Toast.makeText;
 
 public class PersistingStoreActivity extends AppCompatActivity {
 
-    private SourcePersister sourcePersister;
+    private Persister<BufferedSource> persister;
     private RecyclerView recyclerView;
     private PostAdapter postAdapter;
 
@@ -49,7 +49,7 @@ public class PersistingStoreActivity extends AppCompatActivity {
         setSupportActionBar((Toolbar) findViewById(R.id.toolbar));
 
         try {
-            sourcePersister = persister();
+            persister = newPersister();
         } catch (IOException exception) {
             throw new RuntimeException(exception);
         }
@@ -91,13 +91,13 @@ public class PersistingStoreActivity extends AppCompatActivity {
     private Store<RedditData> provideRedditStore() {
         return ParsingStoreBuilder.<BufferedSource,RedditData>builder()
                 .fetcher(this::fetcher)
-                .persister(sourcePersister)
-                .parser(new GsonSourceParser<>(provideGson(),RedditData.class))
+                .persister(persister)
+                .parser(GsonParserFactory.createSourceParser(provideGson(),RedditData.class))
                 .open();
     }
 
-    private SourcePersister persister() throws IOException {
-        return new SourcePersister(FileSystemFactory.create(getApplicationContext().getCacheDir()));
+    private Persister<BufferedSource> newPersister() throws IOException {
+        return SourcePersisterFactory.create(getApplicationContext().getCacheDir());
     }
 
     private Observable<BufferedSource> fetcher(BarCode barCode) {

filesystem/src/main/java/com/nytimes/android/external/fs/SourcePersisterFactory.java

@@ -0,0 +1,26 @@
+package com.nytimes.android.external.fs;
+
+import com.nytimes.android.external.fs.filesystem.FileSystemFactory;
+import com.nytimes.android.external.store.base.Persister;
+
+import java.io.File;
+import java.io.IOException;
+
+import okio.BufferedSource;
+
+/**
+ * Factory for {@link SourcePersister}
+ */
+
+public class SourcePersisterFactory {
+
+    /**
+     * Returns a new {@link BufferedSource} persister with the provided file as the root of the
+     * persistence {@link com.nytimes.android.external.fs.filesystem.FileSystem}.
+     * @throws IOException
+     */
+    public static Persister<BufferedSource> create(File root) throws IOException {
+        if (root == null) throw new IllegalArgumentException("root file cannot be null.");
+        return new SourcePersister(FileSystemFactory.create(root));
+    }
+}

middleware/src/main/java/com/nytimes/android/external/store/middleware/GsonParserFactory.java

@@ -0,0 +1,72 @@
+package com.nytimes.android.external.store.middleware;
+
+import com.google.gson.Gson;
+import com.nytimes.android.external.store.base.Parser;
+
+import java.io.Reader;
+
+import okio.BufferedSource;
+
+/**
+ * Factory which returns various Gson {@link Parser} implementations.
+ */
+public class GsonParserFactory {
+
+    /**
+     * Returns a new Parser which parses from {@link Reader} to the specified type, using
+     * the provided {@link Gson} instance.
+     */
+    public static <T> Parser<Reader, T> createReaderParser(Gson gson, Class<T> parsedClass) {
+        if (gson == null) throw new IllegalArgumentException("gson cannot be null.");
+        if (parsedClass == null) throw new IllegalArgumentException("parsedClass cannot be null.");
+        return new GsonReaderParser<>(gson, parsedClass);
+    }
+
+    /**
+     * Returns a new Parser which parses from {@link Reader} to the specified type, using
+     * a new default configured {@link Gson} instance.
+     */
+    public static <T> Parser<Reader, T> createReaderParser(Class<T> parsedClass) {
+        if (parsedClass == null) throw new IllegalArgumentException("parsedClass cannot be null.");
+        return new GsonReaderParser<>(new Gson(), parsedClass);
+    }
+
+    /**
+     * Returns a new Parser which parses from {@link BufferedSource} to the specified type, using
+     * the provided {@link Gson} instance.
+     */
+    public static <T> Parser<BufferedSource, T> createSourceParser(Gson gson, Class<T> parsedClass) {
+        if (gson == null) throw new IllegalArgumentException("gson cannot be null.");
+        if (parsedClass == null) throw new IllegalArgumentException("parsedClass cannot be null.");
+        return new GsonSourceParser<>(gson, parsedClass);
+    }
+
+    /**
+     * Returns a new Parser which parses from {@link Reader} to the specified type, using
+     * a new default configured {@link Gson} instance.
+     */
+    public static <T> Parser<BufferedSource, T> createSourceParser(Class<T> parsedClass) {
+        if (parsedClass == null) throw new IllegalArgumentException("parsedClass cannot be null.");
+        return new GsonSourceParser<>(new Gson(), parsedClass);
+    }
+
+    /**
+     * Returns a new Parser which parses from a String to the specified type, using
+     * the provided {@link Gson} instance.
+     */
+    public static <T> Parser<String, T> createStringParser(Gson gson, Class<T> parsedClass) {
+        if (gson == null) throw new IllegalArgumentException("gson cannot be null.");
+        if (parsedClass == null) throw new IllegalArgumentException("parsedClass cannot be null.");
+        return new GsonStringParser<>(gson, parsedClass);
+    }
+
+    /**
+     * Returns a new Parser which parses from a String to the specified type, using
+     * a new default {@link Gson} instance.
+     */
+    public static <T> Parser<String, T> createStringParser(Class<T> parsedClass) {
+        if (parsedClass == null) throw new IllegalArgumentException("parsedClass cannot be null.");
+        return new GsonStringParser<>(new Gson(), parsedClass);
+    }
+
+}