/**
* Copyright 2010-present Facebook.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.facebook;
import android.net.Uri;
import android.os.Bundle;
import bolts.AppLink;
import bolts.AppLinkResolver;
import bolts.Continuation;
import bolts.Task;
import com.facebook.model.GraphObject;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.*;
/**
* Provides an implementation for the {@link AppLinkResolver AppLinkResolver} interface that uses the Facebook App Link
* index to solve App Links, given a Url. It also provides an additional helper method that can resolve multiple App
* Links in a single call.
*/
public class FacebookAppLinkResolver implements AppLinkResolver {
private static final String APP_LINK_KEY = "app_links";
private static final String APP_LINK_ANDROID_TARGET_KEY = "android";
private static final String APP_LINK_WEB_TARGET_KEY = "web";
private static final String APP_LINK_TARGET_PACKAGE_KEY = "package";
private static final String APP_LINK_TARGET_CLASS_KEY = "class";
private static final String APP_LINK_TARGET_APP_NAME_KEY = "app_name";
private static final String APP_LINK_TARGET_URL_KEY = "url";
private static final String APP_LINK_TARGET_SHOULD_FALLBACK_KEY = "should_fallback";
private final HashMap<Uri, AppLink> cachedAppLinks = new HashMap<Uri, AppLink>();
/**
* Asynchronously resolves App Link data for the passed in Uri
*
* @param uri Uri to be resolved into an App Link
* @return A Task that, when successful, will return an AppLink for the passed in Uri. This may be null if no App
* Link data was found for this Uri.
* In the case of general server errors, the task will be completed with the corresponding error.
*/
public Task<AppLink> getAppLinkFromUrlInBackground(final Uri uri) {
ArrayList<Uri> uris = new ArrayList<Uri>();
uris.add(uri);
Task<Map<Uri, AppLink>> resolveTask = getAppLinkFromUrlsInBackground(uris);
return resolveTask.onSuccess(new Continuation<Map<Uri, AppLink>, AppLink>() {
@Override
public AppLink then(Task<Map<Uri, AppLink>> resolveUrisTask) throws Exception {
return resolveUrisTask.getResult().get(uri);
}
});
}
/**
* Asynchronously resolves App Link data for multiple Urls
*
* @param uris A list of Uri objects to resolve into App Links
* @return A Task that, when successful, will return a Map of Uri->AppLink for each Uri that was successfully
* resolved into an App Link. Uris that could not be resolved into App Links will not be present in the Map.
* In the case of general server errors, the task will be completed with the corresponding error.
*/
public Task<Map<Uri, AppLink>> getAppLinkFromUrlsInBackground(List<Uri> uris) {
final Map<Uri, AppLink> appLinkResults = new HashMap<Uri, AppLink>();
final HashSet<Uri> urisToRequest = new HashSet<Uri>();
StringBuilder graphRequestFields = new StringBuilder();
for (Uri uri : uris) {
AppLink appLink = null;
synchronized (cachedAppLinks) {
appLink = cachedAppLinks.get(uri);
}
if (appLink != null) {
appLinkResults.put(uri, appLink);
} else {
if (!urisToRequest.isEmpty()) {
graphRequestFields.append(',');
}
graphRequestFields.append(uri.toString());
urisToRequest.add(uri);
}
}
if (urisToRequest.isEmpty()) {
return Task.forResult(appLinkResults);
}
final Task<Map<Uri, AppLink>>.TaskCompletionSource taskCompletionSource = Task.create();
Bundle appLinkRequestParameters = new Bundle();
appLinkRequestParameters.putString("ids", graphRequestFields.toString());
appLinkRequestParameters.putString(
"fields",
String.format("%s.fields(%s,%s)", APP_LINK_KEY, APP_LINK_ANDROID_TARGET_KEY, APP_LINK_WEB_TARGET_KEY));
Request appLinkRequest = new Request(
null, /* Session */
"", /* Graph path */
appLinkRequestParameters, /* Query parameters */
null, /* HttpMethod */
new Request.Callback() { /* Callback */
@Override
public void onCompleted(Response response) {
FacebookRequestError error = response.getError();
if (error != null) {
taskCompletionSource.setError(error.getException());
return;
}
GraphObject responseObject = response.getGraphObject();
JSONObject responseJson = responseObject != null ? responseObject.getInnerJSONObject() : null;
if (responseJson == null) {
taskCompletionSource.setResult(appLinkResults);
return;
}
for (Uri uri : urisToRequest) {
String uriString = uri.toString();
if (!responseJson.has(uriString)) {
continue;
}
JSONObject urlData = null;
try {
urlData = responseJson.getJSONObject(uri.toString());
JSONObject appLinkData = urlData.getJSONObject(APP_LINK_KEY);
JSONArray rawTargets = appLinkData.getJSONArray(APP_LINK_ANDROID_TARGET_KEY);
int targetsCount = rawTargets.length();
List<AppLink.Target> targets = new ArrayList<AppLink.Target>(targetsCount);
for (int i = 0; i < targetsCount; i++) {
AppLink.Target target = getAndroidTargetFromJson(rawTargets.getJSONObject(i));
if (target != null) {
targets.add(target);
}
}
Uri webFallbackUrl = getWebFallbackUriFromJson(uri, appLinkData);
AppLink appLink = new AppLink(uri, targets, webFallbackUrl);
appLinkResults.put(uri, appLink);
synchronized (cachedAppLinks) {
cachedAppLinks.put(uri, appLink);
}
} catch (JSONException e) {
// The data for this uri was missing or badly formed.
continue;
}
}
taskCompletionSource.setResult(appLinkResults);
}
});
appLinkRequest.executeAsync();
return taskCompletionSource.getTask();
}
private static AppLink.Target getAndroidTargetFromJson(JSONObject targetJson) {
String packageName = tryGetStringFromJson(targetJson, APP_LINK_TARGET_PACKAGE_KEY, null);
if (packageName == null) {
// Package name is mandatory for each Android target
return null;
}
String className = tryGetStringFromJson(targetJson, APP_LINK_TARGET_CLASS_KEY, null);
String appName = tryGetStringFromJson(targetJson, APP_LINK_TARGET_APP_NAME_KEY, null);
String targetUrlString = tryGetStringFromJson(targetJson, APP_LINK_TARGET_URL_KEY, null);
Uri targetUri = null;
if (targetUrlString != null) {
targetUri = Uri.parse(targetUrlString);
}
return new AppLink.Target(packageName, className, targetUri, appName);
}
private static Uri getWebFallbackUriFromJson(Uri sourceUrl, JSONObject urlData) {
// Try and get a web target. This is best effort. Any failures results in null being returned.
try {
JSONObject webTarget = urlData.getJSONObject(APP_LINK_WEB_TARGET_KEY);
boolean shouldFallback = tryGetBooleanFromJson(webTarget, APP_LINK_TARGET_SHOULD_FALLBACK_KEY, true);
if (!shouldFallback) {
// Don't use a fallback url
return null;
}
String webTargetUrlString = tryGetStringFromJson(webTarget, APP_LINK_TARGET_URL_KEY, null);
Uri webUri = null;
if (webTargetUrlString != null) {
webUri = Uri.parse(webTargetUrlString);
}
// If we weren't able to parse a url from the web target, use the source url
return webUri != null ? webUri: sourceUrl;
} catch (JSONException e) {
// If we were missing a web target, just use the source as the web url
return sourceUrl;
}
}
private static String tryGetStringFromJson(JSONObject json, String propertyName, String defaultValue) {
try {
return json.getString(propertyName);
} catch(JSONException e) {
return defaultValue;
}
}
private static boolean tryGetBooleanFromJson(JSONObject json, String propertyName, boolean defaultValue) {
try {
return json.getBoolean(propertyName);
} catch (JSONException e) {
return defaultValue;
}
}
}