GCM push notifications android

[ekkescorner]

@Schluchti great article - thx providing your experiences and sample app.

[Schluchti]

Second part is now done: https://gympulsr.com/blog/qt/2017/03/26/push-notification-android-qt.html

Hope I didn't miss anything (implemented the notifications a while ago and now tried to remember as much as I could ;-)). If something is missing, please let me know.

[ekkescorner]

@Schluchti cool - blog look great :)

probably next 2 weeks I'll test it.

just still optimizing all my apps for Qt 5.8

[Atr0n]

This post is deleted!

[Schluchti]

@Atr0n thanks! :)

You are refering to the android blog post, right? Have you enabled Gradle in the project settings? I haven't seen this errorin particular, but some similar packaging errors when using Ant. In my experience it sometimes also helps to delete the whole build folder to enforce a clean rebuild.

edit: are you sure that error is the acutal reason why it failed?

[Atr0n]

@Schluchti said in GCM push notifications android:

@Atr0n thanks! :)

You are refering to the android blog post, right? Have you enabled Gradle in the project settings? I haven't seen this errorin particular, but some similar packaging errors when using Ant. In my experience it sometimes also helps to delete the whole build folder to enforce a clean rebuild.

edit: are you sure that error is the acutal reason why it failed?

Hi @Schluchti,
I deleted my last post because after some investigations, I realiced Qt creator has a bug which makes impossible to use the last gradle version (or 3.3 in my case). QT-BUG
I will give it a try once qt creator 4.3 is out.
Anyway, thanks again for your blog. I hope you keep doing these amazing series.
Regards,

[Atr0n]

@Schluchti Finally I make it work. The python scripts need to be updated to make it works with python3 since apns2 it's only compatible with it at version 0.52. But everything works like a charm..
Thank you a lot.
PD: I can pull the python script modification to github if you want.

[Schluchti]

@Atr0n I am glad that it worked :) It would be great if you could create a pull request for it, many thanks!

[Atr0n]

@Schluchti Nice, thanks!
I have a final question for you: How do you stop notifications? For example, if the user log out.
I was thinking on moving MyGcmListenerService to the main Activity and start it from there. Then I can start and stop the service when I want. What do you think?
Regards,

[Schluchti]

@Atr0n I haven't done that, but I would probably try a different approach first. It's just a personal preference, but moving such a central component to a different place would be to risky for me. (I would be afraid to break something and miss messages in certain occasions).

Instead I would try to store the state (user logged in) somewhere and only show the notification when the user is logged in. One could do that either server-side (probably not that comfortable if the user logs in from different devices) or client-side. For example: You could store a boolean flag somewhere (e.q in SharedPreferences, so you can easily access it from the Java part) that saves the state (logged in/logged out). If you receive a new notification you first check if you are logged in. If you aren't, you discard the receive message.

But I am not an android expert...so please take that advice with a grain of salt ;-).

P.S: The disadvantage of that approach is, that you always receive messages although they aren't displayed. So if you are sending a lot of messages this could produce unnecessary load. Another thing is, that if you have a app, where users can explicitly disable push notifications, you are kind of screwing them over with that approach. (because messages are received anyhow) In that case I would probably go the way you described and look for ways to disable that feature completely (or even better: don't send notifications from the server in the first place)

[Atr0n]

@Schluchti Thanks again for your time!
Finally, I just want to share with you a piece of code that could help the people follow your tutorials. It's a notification sender using Qt code. I am not a Github guy, so I post it here in case you want to use it (or anyone else). Note that if you are using Windows, you need to install openssl 1.02 in your computer.

Edit: This is android only.

http.cpp

http::http(QObject *parent) : QObject(parent)
{
    m_manager = new QNetworkAccessManager(this);

    QUrl url("https://gcm-http.googleapis.com/gcm/send");
    QNetworkRequest request(url);
    request.setHeader(QNetworkRequest::ContentTypeHeader,"application/json");
    request.setRawHeader(QByteArray("Authorization"), QByteArray("key=your key here"));

    QByteArray data = "{\"data\" : { \"message\": \"Hello world\"}, \"to\" : \"your target here\" }";
    connect(m_manager,&QNetworkAccessManager::finished,this,&http::finished);
    m_manager->post(request,data);
    qDebug() << data;
}

void http::finished(QNetworkReply *reply)
{
    qDebug() << reply->error() << reply->errorString();
    m_mananger->deleteLater();
    m_manager = 0;
}

http.h

#ifndef HTTP_H
#define HTTP_H

#include <QObject>
#include <QNetworkAccessManager>
#include <QNetworkReply>

class http : public QObject
{
    Q_OBJECT
public:
    explicit http(QObject *parent = nullptr);

signals:

public slots:
    void finished(QNetworkReply *reply);

private:
    QNetworkAccessManager* m_manager;
};

#endif // HTTP_H