# *Prop* class reference
See also:
* ArduinoProps sketch
* PropData class reference
* PropAction class reference
*Prop* (see `Prop.h`) is an interface (base class) implemented by 3 classes:
* ***BridgeProp*** for Yun board and Yun shield
* ***EthernetProp*** for Ethernet shield
* ***WifiProp*** for WiFiNINA boards
## Constructors
* `BridgeProp(const char*, const char*, const char*, const char*, const int)`
* `EthernetProp(const char*, const char*, const char*, const char*, const int)`
* `WifiProp(const char*, const char*, const char*, const char*, const int)`
Each constructor implement the ***Prop*** interface:
* `Props(const char* client_id, const char* in_box, const char* out_box, const char* broker, const int port)`
```csharp
BridgeProp prop(u8"Arduino Blink", // as MQTT client id, should be unique per client for given broker
u8"Room/My room/Props/Arduino Blink/inbox",
u8"Room/My room/Props/Arduino Blink/outbox",
"192.168.1.53", // your MQTT server IP address
1883); // your MQTT server port;
```
## Interface
The *Prop* class interface is consistent with the Prop class of the PyProps library for Raspberry boards.
* `virtual void begin(void(*)(String) = NULL) = 0`
- the pure virtual `begin()` sets the network client
* `void addData(PropData*)`
- registers a PropData instance to be treated by `sendAllData()` and `sendDataChanges()` methods
* `void loop()`
- is the method to be called in the sketch *loop()*
* `void resetIntervals(const int changes, const int silent)`
* `void resetMcu()`
- restarts the sketch (like the reset button)
* `void sendAllData()`
- sends the `DATA` message for all registered data
* `void sendDataChanges()`
- sends the `DATA` message for all registered data that value has changed since last call
* `void sendData(String variables)`
- send the `data` string in a `DATA` message
* `void sendDone(String action)`
- send the `action` string in a `DONE` message
* `void sendMesg(String message)`
- send the `message` string in a `MESG` message to the *outbox*
* `void sendMesg(String topic, char* message)`
- send the `message` string in a `MESG` message to the `topic` parameter
* `void sendOmit(String action)`
- send the `action` string in a `OMIT` message
* `void sendOver(String challenge)`
- send the `challenge` string in a `OVER` message
* `void sendProg(String program)`
- send the `program` string in a `PROG` message
* `void sendRequ(String request)`
- send the `request` string in a `REQU` message to the *outbox*
* `void sendRequ(String topic, char*)`
- send the `request` string in a `REQU` message to the `topic` parameter
For `send----()` methods see *Application protocol for escape room 2.0 prop*
## Author
**Faure Systems** (Oct 18th, 2019)
* company: FAURE SYSTEMS SAS
* mail: *dev at faure dot systems*
* github: fauresystems
* web: Faure Systems