Doc: Improve plugin overview pages

* Rename "backend" to "plugin" for consistence
* Improve the connection snippets regarding error handling
* Add a hint to QCanBus::availableDevices()

Change-Id: I6fc24add5f9cb34e9ffad8b58f6134124f456cdd
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/src/serialbus/doc/src/passthrucan.qdoc b/src/serialbus/doc/src/passthrucan.qdoc
index 21e6283..eff2ef7 100644
--- a/src/serialbus/doc/src/passthrucan.qdoc
+++ b/src/serialbus/doc/src/passthrucan.qdoc
@@ -99,9 +99,13 @@
     signal:
 
     \code
-        connect(device, &QCanBusDevice::stateChanged,
-                this, &MyClass::canStateChanged);
-        device->connectDevice();
+        if (!device) {
+            // Error handling goes here
+        } else {
+            connect(device, &QCanBusDevice::stateChanged,
+                    this, &MyClass::canStateChanged);
+            device->connectDevice();
+        }
     \endcode
 
     \l {QCanBusDevice::}{state()} will return \l {QCanBusDevice::}{ConnectedState}