I am trying to use Google Maps for Android, offline (always and forever).
Surprisingly, I can't find any question here that asks or solves this issue specifically.
When I use a new offline phone, both my app and Google Maps show a blank map (dah, no map loaded) and 'my' location blue dot is not shown. Well, actually, no marker is shown.
To Reproduce
Restore any Android phone to its factory settings
Enable location services (GPS, without connecting to the internet at any stage)
Open the Google Maps app
--> See that there is no 'my location' blue marker, although when you long click on the screen, the app shows its coordinates (meaning, GPS does work, but the map doesn't show it)
Technical Symptoms
Even when I load offline maps (.mbtiles format, custom ones, not Google's) they're still not shown (nor the markers). It's like Google put some code like this:
if (no internet) hideAllViews().
Note that once I connect the phone to the internet, our custom tiles do work, even if I later turn the phone offline.
I can interact with the map (long click to view the clicked location, for example, which shows that my GPS location indeed works), but that's about it (until I connect the phone to the internet, from which point I can turn it offline again but with everything surprisingly working).
Code Example - a simplified version
//build.gradle:
implementation 'com.google.android.gms:play-services-maps:17.0.0'
//MapActivity.kt
import com.google.android.gms.maps.GoogleMap
import com.google.android.gms.maps.MapView
import com.google.android.gms.maps.MapsInitializer
class MapActivity : AppCompatActivity {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.map_activity)
val mapFragment = supportFragmentManager.findFragmentByTag(MAP_FRAGMENT_TAG) as MapFragment?
?: MapFragment().also {
supportFragmentManager.beginTransaction().add(R.id.map, it, MAP_FRAGMENT_TAG).commit()
}
mapFragment.getMapAsync(::onMapReady)
mapFragment.retainInstance = true
}
private fun onMapReady(map: GoogleMap) {
map.isMyLocationEnabled = true
map.uiSettings.isMyLocationButtonEnabled = true
Log.d("GoogleMap", "Map should be ready and visible with my-location marker shown, if phone's GPS is enabled")
}
}
I hope someone here knows a trick or worked at Google and can shed some light on this.
Thank you!
As opposed to most similar questions, I do know how to make this work (internet...) but am asking specifically about a use case where a new phone can never be connected to the internet - not even one time for one second.
I am familiar with other offline maps services, but am trying to solve this with Google's maps, at least for now
It is not possible to load the API without connecting to the internet first since it was designed to be used online(As of now), so this is Working As Intended.
Please note that using Maps SDK for android requires an internet connection first to load because it checks the API key. Then you can use the Map offline for a certain period of time(there's no definite period of time for offline functionality that requires you to be online again)
But there are customers who are also interested in this functionality, so there is an ongoing entry for it in the Google Issue Tracker that was created since 2013 to let the API users be aware of this feature request.
You can view and star the feature request here:
https://issuetracker.google.com/35823181
Please note that the Issue Tracker entry above is the authoritative source for public information regarding the aforementioned feature requests, and all publicly-relevant updates will be posted there.
At work we are trying to use the optional campaign tracking UTM arguments when creating dynamic links through the firebase portal.
The dynamic links are working fine, and as far as I can tell from all the official documentation, just adding the UTM values in the final optional step when creating dynamic links should cause those values to be sent along with the dynamic_link_app_open event.
However, we are not seeing any attribution values when we look on the events OR conversions tabs for the dynamic_link_app_open event. We see that event is being sent but we just don't get the campaign attribution values so we have no idea what campaigns led to those events and conversions.
The documentation is really lacking on this particular feature and it's frustrating our marketing department which is ultimately ending up with the developers (i.e. me).
I have developed a work around, but it's a hack:
When creating the dynamic link on the firebase portal, I put utm_source, utm_medium and utm_campaign query strings directly into the deep link like so (not our actual deep link for security reasons, but you get the idea):
https://www.example.com?utm_source=Test&utm_medium=Test&utm_campaign=Test
Then in the client, I have added code to rip these out of the resulting deep link after passing the dynamic link through the firebase dynamic links SDK. With these 3 bits of information I can send an app_open event to firebase analytics via the FirebaseAnalytics SDK like so:
FirebaseDynamicLinks.getInstance()
.getDynamicLink(getIntent())
.addOnSuccessListener(this, pendingDynamicLinkData -> {
if (pendingDynamicLinkData != null) {
Uri optionalDynamicDeepLink = pendingDynamicLinkData.getLink();
if (optionalDynamicDeepLink != null) {
List<String> utmSource = optionalDynamicDeepLink.getQueryParameters(UTM_SOURCE);
List<String> utmCampaign = optionalDynamicDeepLink.getQueryParameters(UTM_CAMPAIGN);
List<String> utmMedium = optionalDynamicDeepLink.getQueryParameters(UTM_MEDIUM);
if (!utmSource.isEmpty() && !utmCampaign.isEmpty() && !utmMedium.isEmpty()) {
String utmSourceParam = String.valueOf(utmSource);
String utmCampaignParam = String.valueOf(utmCampaign);
String utmMediumParam = String.valueOf(utmMedium);
Bundle params = new Bundle();
params.putString(FirebaseAnalytics.Param.SOURCE, utmSourceParam);
params.putString(FirebaseAnalytics.Param.CAMPAIGN, utmCampaignParam);
params.putString(FirebaseAnalytics.Param.MEDIUM, utmMediumParam);
FirebaseAnalytics.getInstance(this).logEvent(FirebaseAnalytics.Event.CAMPAIGN_DETAILS, params);
FirebaseAnalytics.getInstance(this).logEvent(FirebaseAnalytics.Event.APP_OPEN, params);
}
String dynamicDeepLink = optionalDynamicDeepLink.toString();
if (!handleDeepLink(dynamicDeepLink)) {
Generic.openLinkInCustomTabs(getApplicationContext(), deepLinkOptional);
}
} else {
if (!handleDeepLink(deepLinkOptional)) {
handleIntent(intent);
}
}
} else {
if (!handleDeepLink(deepLinkOptional)) {
handleIntent(intent);
}
}
}).addOnFailureListener(this, e -> {
if (!handleDeepLink(deepLinkOptional)) {
Generic.openLinkInCustomTabs(getApplicationContext(), deepLinkOptional);
}
});
Whilst this works, it begs the question; what is the point of the optional campaign tracking section when creating dynamic links? Presumably putting the utm_source, utm_medium and utm_campaign there is supposed to allow firebase to auto-magically populate the dynamic_link_app_open event with said campaign tracking data, but it doesn't.
For instance, here is how I've setup that optional final step:
I have then followed the dynamic link into the app several times as well as asking testers to do the same. I have waited over 36 hours (as I'm aware these events can take some time to propagate to the cloud) and we're seeing dynamic_link_app_open events build up, indicating an event is logged for our dynamic links, but when we drill into that event there is no UTM information collected.
Is this feature of firebase broken?
I can see this from official firebase documentation (https://firebase.google.com/docs/dynamic-links/analytics):
Which indicates that collection of UTM data from dynamic link clickthroughs is not supported on firebase, but is supported on google analytics. This isn't confusing at all (/sarcasm).
So presumably some of our data (i.e. the bit to do with campaign tracking) is collected/hosted by google analytics?
To add further confusion, the official documentation for firebase dynamic links states:
"If you mark Dynamic Link events as conversions, you can see how your Dynamic Links are performing on the Attribution page."
And then shows an image of the firebase portal UI which doesn't even match to reality:
I've searched and searched for an attribution tab on the firebase console but there isn't one... these docs are enough to drive a developer insane.
I reached out to Google, as the Issue still does not seem to be solved. Here is the answer:
"Currently, Firebase Dynamic Links UTM event tracking for iOS platforms is not supported due to the fingerprint matching mechanism for iOS platform limitation. As an action, I’ve linked this support ticket to our existing feature request to let our engineering team know of the increasing interest to have this utm_ tracking mechanism implemented for the iOS platform for FDL. I can’t share definite details or timeline for the release, but we are taking your interest moving forward to have this feature improvements. You can check our release notes for any updates."
I don't understand what "the fingerprint matching mechanism" exactly means. But I understand that it will take years until this Issue gets fixed.
I can understand your frustration, we are in the same problem for months now. I also think it should not be the way it works that you need to manually pick up the UTM Parameters. And I did find an older screenshot (from 2019) that showed that Dynamic Links SHOULD do this on their own:
[
This first part still works, but the Source/Medium/Campaign never make it into the Acquisition/Attribution reports. They DID do that in the past:
(example in screenshot is another Dynamic Link than in the first screenshot, sorry)
In talks with Google, it sounded as if they were indeed aware of this as a bug, but offered no specifics on whether or when this would be fixed.
So I can only confirm that you are not alone with your problem...
2021 updated answer:
I guess the problem is fixed and now you can see the events of the dynamic link from the DebugView with all the params (as #Lukas Oldenburg said)
According to this answer:
UTM parameters that you choose in UI are parameters for mobile
tracking. If you want to pass UTM parameters to your "fallback"
website, you need to add them to the fallback address itself.
Background
Starting from API 25 of Android, apps can offer extra shortcuts in the launcher, by long clicking on them:
The problem
Thing is, all I've found is how your app can offer those shortcuts to the launcher, but I can't find out how the launcher gets the list of them.
Since it's a rather new API, and most users and developers don't even use it, I can't find much information about it, especially because I want to search of the "other side" of the API usage.
What I've tried
I tried reading the docs (here, for example). I don't see it being mentioned. Only the part of other apps is mentioned, but not of the receiver app (the launcher).
The questions
Given a package name of an app, how can I get a list of all of its "app shortcuts" using the new API?
Is it possible to use it in order to request to create a Pinned Shortcut out of one of them?
You need to make yourself the launcher app. After that you can query the packagemanager to get the shortcutinfo for a particular package:
fun getShortcutFromApp(packageName: String): List<Shortcut> {
val shortcutQuery = LauncherApps.ShortcutQuery()
shortcutQuery.setQueryFlags(FLAG_MATCH_DYNAMIC or FLAG_MATCH_MANIFEST or FLAG_MATCH_PINNED)
shortcutQuery.setPackage(packageName)
return try {
launcherApps.getShortcuts(shortcutQuery, Process.myUserHandle())
.map { Shortcut(it.id, it.`package`, it.shortLabel.toString(), it) }
} catch (e: SecurityException) {
Collections.emptyList()
}
}
A full implementation of this can be found here:
https://android.jlelse.eu/nhandling-shortcuts-when-building-an-android-launcher-5908d0bb50d2
Github link to project:
https://github.com/nongdenchet/Shortcuts
LauncherApps is a class provided by the Android framework:
https://developer.android.com/reference/android/content/pm/LauncherApps.html
"Class for retrieving a list of launchable activities for the current user and any associated managed profiles that are visible to the current user, which can be retrieved with getProfiles(). This is mainly for use by launchers. Apps can be queried for each user profile. Since the PackageManager will not deliver package broadcasts for other profiles, you can register for package changes here."
Great Question this was what i was looking for and I get one that might be useful
(Its all about Intent)
https://github.com/googlesamples/android-AppShortcuts
Note: If your app is static its simple to implement.
Updated:::
Here is a link that will show you the difference of dynamic or static shortcuts and its implementation if you like it please up vote.
https://www.novoda.com/blog/exploring-android-nougat-7-1-app-shortcuts/
I recently came across this app Purchase Apps, which is somehow able to retrieve apps I've paid for in google play after I signed in using my google account.
I'm trying to find out how it is being done as I want to build a similar app, but for the free apps which were downloaded.
However, I can't find which OAuth API Scope was used for retrieving that information, even after going through the entire list of APIs.
EDIT:
I'm putting a new bounty on this question, as suggested by a similar question I've asked about here, and because here and there I don't see a real answer about how to do it, and what can be done with it.
I'd like to refine the questions into multiple pieces:
What is the API that can be used to get information of purchased apps? Where can I read about it? Please show a full, working example of how to do it.
Can it do more ? Maybe perform search? Maybe show free apps that were installed? Maybe the time they were installed and uninstalled? And the categories of those apps?
Are there any special requirements for using this API ?
EDIT: I'm putting a max bounty on this, because no matter how much I've read and tried, I still failed to make a POC that can query the apps from the Play Store that the user has ever downloaded (name, package name, date installed and/or removed, icon URL, price...), including both paid and free apps.
If anyone finds a working sample, show how it's done, and also show how you've found about it (documentation or anything that has led you to the solution). I can't find it anywhere, and the current solutions here are too vague for me to start from.
Issue is resolved. The exploit has been closed.
We will be closing this bug due to being logged in a Preview version of Android. If the issue is still relevant and reproducible in the latest public release (Android Q), please capture a bugreport and log the bug in https://source.android.com/setup/contribute/report-bugs. If a reply is not received within the next 14 days, this issue will be closed. Thank you for your understanding.
Latest update:
This is a bug and Google will address it in the next update.
We've deferred this issue for consideration in a future release. Thank
you for your time to make Android better
This answer has turned into a conglomeration of ideas and been edited to include information from discussion in the comments.
The androidmarket api, would be a customised api written by the developer. It's not available to the public.
To address your concerns in the comments. The developer would have utilised the current apis available through Android Developer and Google to create a project that manages all of these.
As for accessing Full Account Access, I'm not sure exactly how these developers have achieved this.
I'd recommend using the AccountManager, which is part of android.accounts, has access to credentials and a method getUserData. The account manager has access to passwords and is capable of creating and deleting accounts. This, possibly used with Content Provider
See Udinic/SyncAdapter Authentication.
To reply to your comment:
This blog should help you to get started. Write your own Android Authenticator.
How these apps actually work, I cannot tell you. They may also have different implementations (unless they're a collaborative effort behind the scenes, they most certainly will be different).
One guess. Firstly use GoogleSignInAccount with com.google.android.gms.auth.api.signin.
There a definition for scope, to determine the extent of the permissions the app is granted.
Using requestScopes(), the
public static final String PROFILE
.../ It lets your web app access over-the-air Android app installs.
For example:
GoogleSignInOptions gso =
new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
.requestEmail().
.requestScopes(new Scope("https://www.googleapis.com/auth/contacts.readonly"))
.build();
If full access can be gained a list of all apps used by the account holder can be found and compared to what's on the device.
Package Manager will retrieve a list of all apps currently installed on the device.
PackageInfo provides the details about the app.
INSTALL_REASON_USER will also filter out apps that have been actively installed by the user.
You might want to look at com.google.firebase.appindexing and Log User Actions. Different actions can be tracked.
The users account history is found at https://myactivity.google.com/myactivity.
A helpful link is the OAuth 2.0 Playground.
This github repo node-google-play, using node, is current and will call Google Play APIs. As did the archive that was used as an "unofficial" api, android-market-api, to query the market place.
App 1
The app claims to use the following permissions:
Version 2.1.8 can access:
$ In-app purchases
Other
receive data from Internet
view network connections
full network access
use accounts on the device
prevent device from sleeping
read Google service configuration
Noteworthy, the app doesn't set any permissions when there was a basic, install. I was unable to use any of the features, as I have no paid apps. So for the initial search - there were no permissions needed, which would indicate the app didn't have access to my account.
I checked the permissions - there were none set. So the only thing required was to accept the pop up, as displayed in your question.
App 2
The other app you refer to that does the same thing is more upfront about what is being accessed.
My Paid Apps
SECURITY/PRIVACY NOTICE
The first time you run this app, it will ask for full permission to your Google account. This is unfortunately
the only way to access the required information. No personal
information is stored, no information about your apps is shared with
the developer of this app, nor shared with any third parties.
Everything is kept on your phone only.
I've gone into detail over these apps in this blog post, which was for a university capstone project (no monetary gain). I'm inclined to think this is an exploit in the API and not status by design by Google, as there are no API calls to fetch purchases of apps other than the developer's own app. I hypothesize it's a zero day exploit, in which case there's no legitimate way to access this information.
In case of one of these applications (My Paid Apps), after checking the network traffic it is pretty obvious that it does use the Store's Account page to retrieve the list of paid applications.
Now, the mechanism it uses is the same mechanism that Google Chrome currently, and Pokemon GO supposedly at a point in time used.
In a nutshell, steps to do so are as follow:
Login:
What the mentioned program do for the first step is to log the user in and get access to the user's access token. To do so, it uses the android.accounts.AccountManager.getAuthToken() method. (See more: AccountManager)
However, as for the token scope, oauth2:https://www.google.com/accounts/OAuthLogin is requested.
It might be important to note that based on the OAth2 documentation from Google, this scope is not valid; however, it seems like a valid scope for Google OAuth v1.
Converting the newly retrieved access token to a ubertoken:
Now, what actually ubertoken supposed to do, is unknown and there is no official documentation about it. However, it was seen in the wild to be used by chrome browser to login users.
This is done by requesting the https://accounts.google.com/OAuthLogin?source=ChromiumBrowser&issueuberauth=1 page.
Converting ubertoken to website session:
Later on, using the newly created ubertoken it is possible to get a website session using the https://accounts.google.com/MergeSession API endpoint. After this step, the application is essentially capable of loading all personal pages that you can open using your browser while logged in; except some special pages including Payment settings.
Retrieving the list of paid applications:
Requesting and parsing the https://play.google.com/store/account page.
Following is the application's traffic as captured by 'Packet Capture':
As it is clearly visible in the picture, the end result is identical to what I get when I normally open the store's account page on my PC with Chrome Desktop:
Side note:
It seems none of these endpoints are documented as they are primarily used by Google's own programs and should be considered internal. Therefore I strongly recommend not using them in any program or code that you expect to run for a long time or in a production environment.
Also, there is bad news here for you too, it seems that the Google Play's account page only lists paid applications or special free apps (more especially OEM apps). I will try to find some time and dig deeper into the other application.
Interesting articles:
Pokemon tokens
Exploiting Google Chrome's OAuth2 Tokens
If you have root access, You can access /data/data/com.android.vending/databases/library.db
OnePlus3T:/data/data/com.android.vending/databases
-rw-rw---- 1 u0_a2 u0_a2 229376 2018-12-26 18:01 library.db
This database has all information, which app you have downloaded, which apps you have purchased, and even in which app you have done IAP.
Check ownership table, It has all information.
ownership (account STRING, library_id STRING, backend INTEGER, doc_id STRING, doc_type INTEGER, offer_type INTEGER, document_hash INTEGER, subs_valid_until_time INTEGER, app_certificate_hash STRING, app_refund_pre_delivery_endtime_ms INTEGER, app_refund_post_delivery_window_ms INTEGER, subs_auto_renewing INTEGER, subs_initiation_time INTEGER, subs_trial_until_time INTEGER, inapp_purchase_data STRING, inapp_signature STRING, preordered INTEGER, owned_via_license INTEGER, shared_by_me INTEGER, sharer_gaia_id TEXT, shareability INTEGER, purchase_time INTEGER, PRIMARY KEY (account, library_id, backend, doc_id, doc_type, offer_type))
Dealing with unofficial Google APIs is incredibly complicated territory. It's going to be possible to get this to work, but that's all I'll say. Proceed at your own risk.
The first thing you're going to need to do is get a Google Play auth token. This can be done several ways, but here's how they do it in Purchased Apps:
public static String getAuthToken(Activity activity, String userEmail) {
AccountManager accountManager = AccountManager.get(activity);
Account userAccount = new Account(userEmail, "com.google");
Bundle options = new Bundle();
options.putBoolean("suppressProgressScreen", true);
String token;
try {
Bundle result = accountManager
.getAuthToken(userAccount, "androidmarket", options, activity, null, null)
.getResult();
token = result.getString("authtoken");
} catch (OperationCanceledException e) {
Log.d(TAG, "Login canceled by user");
return null;
} catch (IOException | AuthenticatorException e) {
Log.e(TAG, "Login failed", e);
return null;
}
return token;
}
A few things to note here:
The above code must be run asynchronously. I recommend RxJava, but an AsyncTask will work.
You must supply a email for the account you want to use. I'll leave the details up to you but this is fairly easy using AccountManager.
After you have an auth token, you can now access any Google Play Store endpoint. The main one used by Purchased Apps is https://android.clients.google.com/fdfe/purchaseHistory. Another one you might be interested in is https://android.clients.google.com/fdfe/details?doc=(package name) (from APKfetch code). Here's a page with some more and some analysis. If you make a request to these APIs, you'll need to supply several headers:
Authorization - "GoogleLogin auth=(your auth token)"
User-Agent - "Android-Finsky/6.4.12.C-all%20%5B0%5D%202744941 (api=3,versionCode=80641200,sdk=" + VERSION.SDK_INT + ",isWideScreen=0)";
X-DFE-Device-Id - your device's Google Services Framework ID, obtained from AdvertisingIdClient.
X-DFE-Client-Id - "am-android-google"
Accept-Language - The device's language code, eg "en".
Now, you need to parse the response. Here's where things get tricky. These APIs returns a message encoded as a Protobuf, so it's essentially just binary data unless you have a schema (which of course, only Google has). One way to go about this in theory is to decompile the Google Play Store app and reuse their generated protobuf models with a tool like JADX.
Unfortunately, I've tried this and it doesn't really work. Protobuf model classes are just too complex for a standard decompiler. What you can use is a tool called PBTK. You'll ideally want to run this on the Google Play Store 6.1.12 APK, since that's the last version before they started using ProGuard. Do note that this program has two errors in its script that need to be fixed before running it: changing 'extracto' to 'extractor' in gui.py and removing the assertion statement on line 500 of jar_extract.py.
Now, that should output all of the response classes as .proto files. Create a folder under src/main called proto and drag the entire generated 'com' directory to it. You can delete everything that's not under com/google/android/finsky/protos. Follow instructions online to setup Gradle with the Protobuf Lite plugin.
When you want to parse a response, you can use the ResponseWrapper class, since they all appear to be contained under that.
That's about as far as I can take you. There's a good chance I got some part of this wrong; JADX is your best friend here, because the best way to figure out what an app is doing is by looking at its code. Hope this helps and happy developing!
you can get the package name of all installed apps on device and then get the information of every installed package that you find in the device from google play without any need to get to user account. there is some third party or unofficial apis to get google play apps details as json by getting the app package name. for example: https://42matters.com/
then use the received information for every package to find free ones.
i have two resources for you to consider, but first, in a word, no. there is no api from GOOGLE to let you do what you want, as these metrics arent stored in the phone, they are on the google play store servors, and google has no OFFICIAL api for the play store. you can however glean some info from these two sites:
https://www.quora.com/Is-there-an-API-for-the-Google-Play-Storeenter link description here
https://android.stackexchange.com/questions/162146/how-to-see-all-the-apps-i-have-downloaded-from-google-play-store
and this is enough to see how to accomplish this.
first, a list of what apps have been downloaded by an account is only referencable by the account. and this can be done through the play store. since your app will be installed on that users phone, this dosnt matter... you're in.
second, you will need a 3rd party API built for the GOOGLE PLAY STORE, there are some out there, check the first link.
using the api of your choice, you will send a get request, to the play store, and in return you should receive in most cases a json object to deserialize.
deserialize the object, and you will have your list. which list you get will depend on the endpoint you use, but that should be explained by/in the API itself.
good luck!
I want to open Google Maps in Navigation mode from a mobile web link. This seems easy enough for iOS devices using https://developers.google.com/maps/documentation/ios/urlscheme
Is there an equivalent for Android? All I could find was this: https://developer.android.com/guide/appendix/g-app-intents.html
But that doesn't allow you to specify "transitmode" and the other parameters needed to get directions as far as I can tell.
Actually, a slight modification of the methods described in the iOS Doc would work here too (I tested it before putting it here albeit, in a native app and not a web link).
The parameters necessary for this to work are pretty much the same as with the ones listed in the iOS documentation:
From the iOS Docs:
Parameters:
saddr: Sets the starting point for directions searches. This can be a
latitude,longitude or a query formatted address. If it is a query
string that returns more than one result, the first result will be
selected. If the value is left blank, then the user’s current
location will be used.
daddr: Sets the end point for directions searches. Has the same
format and behavior as saddr.
directionsmode: Method of transportation. Can be set to:
driving, transit, or walking.
They are actually, pretty much the same. They are however, no where to be found in the documents. Also, while the first 2 parameters work the usual way here, the last parameter directionsmode does not work as is. A workaround is however, listed below.
That being said, a simple URL can be constructed that can then be passed as an Uri to an Intent that will then handle the application to be launched (Google Maps if installed and/or list of browsers to choose from)
String mapURL = http://maps.google.com/maps?saddr=-33.9417, 150.9473&daddr=-33.92050, 151.04287&dirflg=d
Intent intent = new Intent(android.content.Intent.ACTION_VIEW, Uri.parse(mapURL));
startActivity(intent);
A few variations for the Transit Mode:
&dirflg=d = for Driving directions (this is the default mode. leaving it out is the same as putting it in explicityly).
&dirflg=w = for Walking directions
&dirflg=r = for Public transit.
&dirflg=b = for Biking directions.
That being said, at the time of running these test (I admit I was curious enough to test a little further after seeing this question ;-) ), the modes listed in the Travel Modes section don't seem work!
A little proof of sorts:
Note: Credit for the initial discovery of the options