Qt中简单使用Firebase

上一篇对Firebase进行了简要的介绍。

今天对Firebase进行简单的应用。在qt中，因为我不会Android和ios开发。

代码出自github:

https://github.com/clkasd/qt-firebaseapi

最主要的就是写一个类，Firebase.

直接代码：

firebase.h

#ifndef FIREBASE_H
#define FIREBASE_H

#include <QObject>
#include <QtNetwork/QNetworkAccessManager>
#include <QtNetwork/QNetworkReply>
#include <QtNetwork/QNetworkRequest>
#include <QUrl>
#include <QUrlQuery>
#include <QDebug>
#include <QtGlobal>
#include <datasnapshot.h>
class Firebase : public QObject
{
Q_OBJECT
public:
explicit Firebase(QObject *parent = 0);
Firebase(QString hostName,QString child);
Firebase(QString hostName);
void init();
void setValue(QString str);
void getValue();
void deleteValue();
void setToken(QString);
void listenEvents();
Firebase* child(QString childName);

signals:
void eventResponseReady(QString);
void eventDataChanged(DataSnapshot*);
public slots:
void replyFinished(QNetworkReply*);
void onReadyRead(QNetworkReply*);
void eventFinished();
void eventReadyRead();
private:
QString host;
QString firebaseToken="";
QNetworkAccessManager *manager;
QString currentNode;
QString latestNode;
QString buildPath(int);
QString createJson(QString);
void open(const QUrl &url);
QByteArray trimValue(const QByteArray &line) const;
};

#endif // FIREBASE_H

firebase.cc

#include "firebase.h"
#include <string.h>
#include <QIODevice>
#include <QBuffer>
#include <QJsonDocument>
#include <datasnapshot.h>
Firebase::Firebase(QObject *parent) :
QObject(parent)
{

}
void Firebase::init()
{
manager=new QNetworkAccessManager(this);
connect(manager,SIGNAL(finished(QNetworkReply*)),this,SLOT(replyFinished(QNetworkReply*)));
}
Firebase::Firebase(QString hostName)
{
host=hostName;
currentNode="";
init();
}
void Firebase::setToken(QString token)
{
firebaseToken=token;
}
Firebase::Firebase(QString hostName,QString child)
{
host=hostName
.append(child).append("/");
latestNode=child;
init();
}
Firebase* Firebase::child(QString childName)
{
Firebase *childNode=new Firebase(host,childName);
childNode->setToken(firebaseToken);
return childNode;
}
void Firebase::open(const QUrl &url)
{
QNetworkRequest request(url);
request.setRawHeader("Accept",
"text/event-stream");
QNetworkReply *_reply = manager->get(request);
connect(_reply, &QNetworkReply::readyRead, this, &Firebase::eventReadyRead);
connect(_reply, &QNetworkReply::finished, this, &Firebase::eventFinished);
}
void Firebase::eventFinished()
{
QNetworkReply *reply = qobject_cast<QNetworkReply*>(sender());
if (reply)
{
QUrl redirectUrl = reply->attribute(QNetworkRequest::RedirectionTargetAttribute).toUrl();
if (!redirectUrl.isEmpty())
{
reply->deleteLater();
open(redirectUrl);
return;
}
reply->deleteLater();
}
}
void Firebase::eventReadyRead()
{
QNetworkReply *reply = qobject_cast<QNetworkReply*>(sender());
if(reply)
{
QByteArray line=reply->readLine();
if(!line.isEmpty())
{
QByteArray eventName=trimValue(line);
line=reply->readAll();
if(eventName=="put")
{
DataSnapshot *dataSnapshot=new DataSnapshot(line);
emit eventDataChanged(dataSnapshot);
}
}
}
reply->readAll();
}
void Firebase::onReadyRead(QNetworkReply *reply)
{
/*qDebug()<<"incoming data";
qDebug()<<reply->readAll();*/
}
void Firebase::replyFinished(QNetworkReply *reply)
{
//qDebug()<<reply->readAll();
QString data=QString(reply->readAll());
emit eventResponseReady(data);
}
void Firebase::setValue(QString strVal)
{
//Json data creation
QNetworkRequest request(buildPath(1));
request.setHeader(QNetworkRequest::ContentTypeHeader,
"application/x-www-form-urlencoded");
QBuffer *buffer=new QBuffer();
buffer->open((QBuffer::ReadWrite));
buffer->write(createJson(strVal).toUtf8());
buffer->seek(0);
/*
* To be able to send "PATCH" request sendCustomRequest method is used.
* sendCustomRequest requires a QIOdevice so QBuffer is used.
* I had to seek 0 because it starts reading where it paused.
*/
manager->sendCustomRequest(request,"PATCH",buffer);
buffer->close();
}
void Firebase::getValue()
{
QNetworkRequest request(buildPath(0));
manager->get(request);
}
void Firebase::listenEvents()
{
open(buildPath(0));
}
void Firebase::deleteValue()
{
QNetworkRequest request(buildPath(0));
manager->deleteResource(request);
}
QString Firebase::createJson(QString str)
{
QString data=QString(QString("{").append("\"").append(latestNode).append("\"").append(":").append("\"").append(str).append("\"").append(QString("}")));
return data;
}
QString Firebase::buildPath(int mode)
{
QString destination="";
if(mode)
{
host.replace(QString("/").append(latestNode).append("/"),"");
destination
.append(host)
.append("/.json");
}
else
{
destination
.append(host)
.append(currentNode)
.append(".json");

}
if(!firebaseToken.isEmpty())
destination.append("?auth=").append(firebaseToken);

//根据你的实际情况，写destination
return destination;

}
QByteArray Firebase::trimValue(const QByteArray &line) const
{
QByteArray value;
int index = line.indexOf(':');
if (index > 0)
value = line.right(line.size() - index  - 1);
return value.trimmed();
}