Diff: ble/GattServer.h

Revision:

1131:692ddf04fc42

Parent:

1090:148d8b9b56a5

Child:

1135:22aada733dbd

--- a/ble/GattServer.h	Tue Jan 12 19:47:52 2016 +0000
+++ b/ble/GattServer.h	Wed Apr 06 19:13:46 2016 +0100
@@ -1,484 +1,417 @@
-/* mbed Microcontroller Library
- * Copyright (c) 2006-2013 ARM Limited
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef __GATT_SERVER_H__
-#define __GATT_SERVER_H__
-
-#include "Gap.h"
-#include "GattService.h"
-#include "GattAttribute.h"
-#include "GattServerEvents.h"
-#include "GattCallbackParamTypes.h"
-#include "CallChainOfFunctionPointersWithContext.h"
-
-class GattServer {
-public:
-    /* Event callback handlers. */
-    typedef FunctionPointerWithContext<unsigned> DataSentCallback_t;
-    typedef CallChainOfFunctionPointersWithContext<unsigned> DataSentCallbackChain_t;
-
-    typedef FunctionPointerWithContext<const GattWriteCallbackParams*> DataWrittenCallback_t;
-    typedef CallChainOfFunctionPointersWithContext<const GattWriteCallbackParams*> DataWrittenCallbackChain_t;
-
-    typedef FunctionPointerWithContext<const GattReadCallbackParams*> DataReadCallback_t;
-    typedef CallChainOfFunctionPointersWithContext<const GattReadCallbackParams *> DataReadCallbackChain_t;
-
-    typedef FunctionPointerWithContext<const GattServer *> GattServerShutdownCallback_t;
-    typedef CallChainOfFunctionPointersWithContext<const GattServer *> GattServerShutdownCallbackChain_t;
-
-    typedef FunctionPointerWithContext<GattAttribute::Handle_t> EventCallback_t;
-
-protected:
-    GattServer() :
-        serviceCount(0),
-        characteristicCount(0),
-        dataSentCallChain(),
-        dataWrittenCallChain(),
-        dataReadCallChain(),
-        updatesEnabledCallback(NULL),
-        updatesDisabledCallback(NULL),
-        confirmationReceivedCallback(NULL) {
-        /* empty */
-    }
-
-    /*
-     * The following functions are meant to be overridden in the platform-specific sub-class.
-     */
-public:
-
-    /**
-     * Add a service declaration to the local server ATT table. Also add the
-     * characteristics contained within.
-     */
-    virtual ble_error_t addService(GattService &service) {
-        /* Avoid compiler warnings about unused variables. */
-        (void)service;
-
-        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
-    }
-
-    /**
-     * Read the value of a characteristic from the local GATT server.
-     * @param[in]     attributeHandle
-     *                  Attribute handle for the value attribute of the characteristic.
-     * @param[out]    buffer
-     *                  A buffer to hold the value being read.
-     * @param[in/out] lengthP
-     *                  Length of the buffer being supplied. If the attribute
-     *                  value is longer than the size of the supplied buffer,
-     *                  this variable will hold upon return the total attribute value length
-     *                  (excluding offset). The application may use this
-     *                  information to allocate a suitable buffer size.
-     *
-     * @return BLE_ERROR_NONE if a value was read successfully into the buffer.
-     */
-    virtual ble_error_t read(GattAttribute::Handle_t attributeHandle, uint8_t buffer[], uint16_t *lengthP) {
-        /* Avoid compiler warnings about unused variables. */
-        (void)attributeHandle;
-        (void)buffer;
-        (void)lengthP;
-
-        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
-    }
-
-    /**
-     * Read the value of a characteristic from the local GATT server.
-     * @param[in]     connectionHandle
-     *                  Connection handle.
-     * @param[in]     attributeHandle
-     *                  Attribute handle for the value attribute of the characteristic.
-     * @param[out]    buffer
-     *                  A buffer to hold the value being read.
-     * @param[in/out] lengthP
-     *                  Length of the buffer being supplied. If the attribute
-     *                  value is longer than the size of the supplied buffer,
-     *                  this variable will hold upon return the total attribute value length
-     *                  (excluding offset). The application may use this
-     *                  information to allocate a suitable buffer size.
-     *
-     * @return BLE_ERROR_NONE if a value was read successfully into the buffer.
-     *
-     * @note This API is a version of the above, with an additional connection handle
-     *     parameter to allow fetches for connection-specific multivalued
-     *     attributes (such as the CCCDs).
-     */
-    virtual ble_error_t read(Gap::Handle_t connectionHandle, GattAttribute::Handle_t attributeHandle, uint8_t *buffer, uint16_t *lengthP) {
-        /* Avoid compiler warnings about unused variables. */
-        (void)connectionHandle;
-        (void)attributeHandle;
-        (void)buffer;
-        (void)lengthP;
-
-        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
-    }
-
-    /**
-     * Update the value of a characteristic on the local GATT server.
-     *
-     * @param[in] attributeHandle
-     *              Handle for the value attribute of the characteristic.
-     * @param[in] value
-     *              A pointer to a buffer holding the new value.
-     * @param[in] size
-     *              Size of the new value (in bytes).
-     * @param[in] localOnly
-     *              Should this update be kept on the local
-     *              GATT server regardless of the state of the
-     *              notify/indicate flag in the CCCD for this
-     *              Characteristic? If set to true, no notification
-     *              or indication is generated.
-     *
-     * @return BLE_ERROR_NONE if we have successfully set the value of the attribute.
-     */
-    virtual ble_error_t write(GattAttribute::Handle_t attributeHandle, const uint8_t *value, uint16_t size, bool localOnly = false) {
-        /* Avoid compiler warnings about unused variables. */
-        (void)attributeHandle;
-        (void)value;
-        (void)size;
-        (void)localOnly;
-
-        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
-    }
-
-    /**
-     * Update the value of a characteristic on the local GATT server. A version
-     * of the same as the above, with a connection handle parameter to allow updates
-     * for connection-specific multivalued attributes (such as the CCCDs).
-     *
-     * @param[in] connectionHandle
-     *              Connection handle.
-     * @param[in] attributeHandle
-     *              Handle for the value attribute of the characteristic.
-     * @param[in] value
-     *              A pointer to a buffer holding the new value.
-     * @param[in] size
-     *              Size of the new value (in bytes).
-     * @param[in] localOnly
-     *              Should this update be kept on the local
-     *              GattServer regardless of the state of the
-     *              notify/indicate flag in the CCCD for this
-     *              Characteristic? If set to true, no notification
-     *              or indication is generated.
-     *
-     * @return BLE_ERROR_NONE if we have successfully set the value of the attribute.
-     */
-    virtual ble_error_t write(Gap::Handle_t connectionHandle, GattAttribute::Handle_t attributeHandle, const uint8_t *value, uint16_t size, bool localOnly = false) {
-        /* Avoid compiler warnings about unused variables. */
-        (void)connectionHandle;
-        (void)attributeHandle;
-        (void)value;
-        (void)size;
-        (void)localOnly;
-
-        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
-    }
-
-    /**
-     * Determine the updates-enabled status (notification or indication) for the current connection from a characteristic's CCCD.
-     *
-     * @param       characteristic
-     *                The characteristic.
-     * @param[out]  enabledP
-     *                Upon return, *enabledP is true if updates are enabled, else false.
-     *
-     * @return BLE_ERROR_NONE if the connection and handle are found. False otherwise.
-     */
-    virtual ble_error_t areUpdatesEnabled(const GattCharacteristic &characteristic, bool *enabledP) {
-        /* Avoid compiler warnings about unused variables. */
-        (void)characteristic;
-        (void)enabledP;
-
-        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
-    }
-
-    /**
-     * Determine the connection-specific updates-enabled status (notification or indication) from a characteristic's CCCD.
-     *
-     * @param       connectionHandle
-     *                The connection handle.
-     * @param[out]  enabledP
-     *                Upon return, *enabledP is true if updates are enabled, else false.
-     *
-     * @param  characteristic
-     *           The characteristic.
-     *
-     * @return BLE_ERROR_NONE if the connection and handle are found. False otherwise.
-     */
-    virtual ble_error_t areUpdatesEnabled(Gap::Handle_t connectionHandle, const GattCharacteristic &characteristic, bool *enabledP) {
-        /* Avoid compiler warnings about unused variables. */
-        (void)connectionHandle;
-        (void)characteristic;
-        (void)enabledP;
-
-        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
-    }
-
-    /**
-     * A virtual function to allow underlying stacks to indicate if they support
-     * onDataRead(). It should be overridden to return true as applicable.
-     */
-    virtual bool isOnDataReadAvailable() const {
-        return false; /* Requesting action from porters: override this API if this capability is supported. */
-    }
-
-    /*
-     * APIs with non-virtual implementations.
-     */
-public:
-    /**
-     * Add a callback for the GATT event DATA_SENT (which is triggered when
-     * updates are sent out by GATT in the form of notifications).
-     *
-     * @Note: It is possible to chain together multiple onDataSent callbacks
-     * (potentially from different modules of an application) to receive updates
-     * to characteristics.
-     *
-     * @Note: It is also possible to set up a callback into a member function of
-     * some object.
-     */
-    void onDataSent(const DataSentCallback_t& callback) {dataSentCallChain.add(callback);}
-    template <typename T>
-    void onDataSent(T *objPtr, void (T::*memberPtr)(unsigned count)) {
-        dataSentCallChain.add(objPtr, memberPtr);
-    }
-
-    /**
-     * @brief get the callback chain called when the event DATA_EVENT is triggered.
-     */
-    DataSentCallbackChain_t& onDataSent() {
-        return dataSentCallChain;
-    }
-
-    /**
-     * Set up a callback for when an attribute has its value updated by or at the
-     * connected peer. For a peripheral, this callback is triggered when the local
-     * GATT server has an attribute updated by a write command from the peer.
-     * For a central, this callback is triggered when a response is received for
-     * a write request.
-     *
-     * @Note: It is possible to chain together multiple onDataWritten callbacks
-     * (potentially from different modules of an application) to receive updates
-     * to characteristics. Many services, such as DFU and UART, add their own
-     * onDataWritten callbacks behind the scenes to trap interesting events.
-     *
-     * @Note: It is also possible to set up a callback into a member function of
-     * some object.
-     *
-     * @Note It is possible to unregister a callback using onDataWritten().detach(callback)
-     */
-    void onDataWritten(const DataWrittenCallback_t& callback) {dataWrittenCallChain.add(callback);}
-    template <typename T>
-    void onDataWritten(T *objPtr, void (T::*memberPtr)(const GattWriteCallbackParams *context)) {
-        dataWrittenCallChain.add(objPtr, memberPtr);
-    }
-
-    /**
-     * @brief provide access to the callchain of data written event callbacks
-     * It is possible to register callbacks using onDataWritten().add(callback);
-     * It is possible to unregister callbacks using onDataWritten().detach(callback)
-     * @return The data written event callbacks chain
-     */
-    DataWrittenCallbackChain_t& onDataWritten() {
-        return dataWrittenCallChain;
-    }
-
-    /**
-     * Setup a callback to be invoked on the peripheral when an attribute is
-     * being read by a remote client.
-     *
-     * @Note: This functionality may not be available on all underlying stacks.
-     * You could use GattCharacteristic::setReadAuthorizationCallback() as an
-     * alternative. Refer to isOnDataReadAvailable().
-     *
-     * @Note: It is possible to chain together multiple onDataRead callbacks
-     * (potentially from different modules of an application) to receive updates
-     * to characteristics. Services may add their own onDataRead callbacks
-     * behind the scenes to trap interesting events.
-     *
-     * @Note: It is also possible to set up a callback into a member function of
-     * some object.
-     *
-     * @Note It is possible to unregister a callback using onDataRead().detach(callback)
-     *
-     * @return BLE_ERROR_NOT_IMPLEMENTED if this functionality isn't available;
-     *         else BLE_ERROR_NONE.
-     */
-    ble_error_t onDataRead(const DataReadCallback_t& callback) {
-        if (!isOnDataReadAvailable()) {
-            return BLE_ERROR_NOT_IMPLEMENTED;
-        }
-
-        dataReadCallChain.add(callback);
-        return BLE_ERROR_NONE;
-    }
-    template <typename T>
-    ble_error_t onDataRead(T *objPtr, void (T::*memberPtr)(const GattReadCallbackParams *context)) {
-        if (!isOnDataReadAvailable()) {
-            return BLE_ERROR_NOT_IMPLEMENTED;
-        }
-
-        dataReadCallChain.add(objPtr, memberPtr);
-        return BLE_ERROR_NONE;
-    }
-
-    /**
-     * @brief provide access to the callchain of data read event callbacks
-     * It is possible to register callbacks using onDataRead().add(callback);
-     * It is possible to unregister callbacks using onDataRead().detach(callback)
-     * @return The data read event callbacks chain
-     */
-    DataReadCallbackChain_t& onDataRead() {
-        return dataReadCallChain;
-    }
-
-    /**
-     * Setup a callback to be invoked to notify the user application that the
-     * GattServer instance is about to shutdown (possibly as a result of a call
-     * to BLE::shutdown()).
-     *
-     * @Note: It is possible to chain together multiple onShutdown callbacks
-     * (potentially from different modules of an application) to be notified
-     * before the GattServer is shutdown.
-     *
-     * @Note: It is also possible to set up a callback into a member function of
-     * some object.
-     *
-     * @Note It is possible to unregister a callback using onShutdown().detach(callback)
-     */
-    void onShutdown(const GattServerShutdownCallback_t& callback) {
-        shutdownCallChain.add(callback);
-    }
-    template <typename T>
-    void onShutdown(T *objPtr, void (T::*memberPtr)(void)) {
-        shutdownCallChain.add(objPtr, memberPtr);
-    }
-
-    /**
-     * @brief provide access to the callchain of shutdown event callbacks
-     * It is possible to register callbacks using onShutdown().add(callback);
-     * It is possible to unregister callbacks using onShutdown().detach(callback)
-     * @return The shutdown event callbacks chain
-     */
-    GattServerShutdownCallbackChain_t& onShutdown() {
-        return shutdownCallChain;
-    }
-
-    /**
-     * Set up a callback for when notifications or indications are enabled for a
-     * characteristic on the local GATT server.
-     */
-    void onUpdatesEnabled(EventCallback_t callback) {updatesEnabledCallback = callback;}
-
-    /**
-     * Set up a callback for when notifications or indications are disabled for a
-     * characteristic on the local GATT server.
-     */
-    void onUpdatesDisabled(EventCallback_t callback) {updatesDisabledCallback = callback;}
-
-    /**
-     * Set up a callback for when the GATT server receives a response for an
-     * indication event sent previously.
-     */
-    void onConfirmationReceived(EventCallback_t callback) {confirmationReceivedCallback = callback;}
-
-    /* Entry points for the underlying stack to report events back to the user. */
-protected:
-    void handleDataWrittenEvent(const GattWriteCallbackParams *params) {
-        dataWrittenCallChain.call(params);
-    }
-
-    void handleDataReadEvent(const GattReadCallbackParams *params) {
-        dataReadCallChain.call(params);
-    }
-
-    void handleEvent(GattServerEvents::gattEvent_e type, GattAttribute::Handle_t attributeHandle) {
-        switch (type) {
-            case GattServerEvents::GATT_EVENT_UPDATES_ENABLED:
-                if (updatesEnabledCallback) {
-                    updatesEnabledCallback(attributeHandle);
-                }
-                break;
-            case GattServerEvents::GATT_EVENT_UPDATES_DISABLED:
-                if (updatesDisabledCallback) {
-                    updatesDisabledCallback(attributeHandle);
-                }
-                break;
-            case GattServerEvents::GATT_EVENT_CONFIRMATION_RECEIVED:
-                if (confirmationReceivedCallback) {
-                    confirmationReceivedCallback(attributeHandle);
-                }
-                break;
-            default:
-                break;
-        }
-    }
-
-    void handleDataSentEvent(unsigned count) {
-        dataSentCallChain.call(count);
-    }
-
-public:
-    /**
-     * Notify all registered onShutdown callbacks that the GattServer is
-     * about to be shutdown and clear all GattServer state of the
-     * associated object.
-     *
-     * This function is meant to be overridden in the platform-specific
-     * sub-class. Nevertheless, the sub-class is only expected to reset its
-     * state and not the data held in GattServer members. This shall be achieved
-     * by a call to GattServer::reset() from the sub-class' reset()
-     * implementation.
-     *
-     * @return BLE_ERROR_NONE on success.
-     */
-    virtual ble_error_t reset(void) {
-        /* Notify that the instance is about to shutdown */
-        shutdownCallChain.call(this);
-        shutdownCallChain.clear();
-
-        serviceCount = 0;
-        characteristicCount = 0;
-
-        dataSentCallChain.clear();
-        dataWrittenCallChain.clear();
-        dataReadCallChain.clear();
-        updatesEnabledCallback       = NULL;
-        updatesDisabledCallback      = NULL;
-        confirmationReceivedCallback = NULL;
-
-        return BLE_ERROR_NONE;
-    }
-
-protected:
-    uint8_t serviceCount;
-    uint8_t characteristicCount;
-
-private:
-    DataSentCallbackChain_t           dataSentCallChain;
-    DataWrittenCallbackChain_t        dataWrittenCallChain;
-    DataReadCallbackChain_t           dataReadCallChain;
-    GattServerShutdownCallbackChain_t shutdownCallChain;
-    EventCallback_t                   updatesEnabledCallback;
-    EventCallback_t                   updatesDisabledCallback;
-    EventCallback_t                   confirmationReceivedCallback;
-
-private:
-    /* Disallow copy and assignment. */
-    GattServer(const GattServer &);
-    GattServer& operator=(const GattServer &);
-};
-
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __GATT_SERVER_H__
+#define __GATT_SERVER_H__
+
+#include "Gap.h"
+#include "GattService.h"
+#include "GattAttribute.h"
+#include "GattServerEvents.h"
+#include "GattCallbackParamTypes.h"
+#include "CallChainOfFunctionPointersWithContext.h"
+
+class GattServer {
+public:
+
+    /* Event callback handlers. */
+    typedef FunctionPointerWithContext<unsigned> DataSentCallback_t;
+    typedef CallChainOfFunctionPointersWithContext<unsigned> DataSentCallbackChain_t;
+
+    typedef FunctionPointerWithContext<const GattWriteCallbackParams*> DataWrittenCallback_t;
+    typedef CallChainOfFunctionPointersWithContext<const GattWriteCallbackParams*> DataWrittenCallbackChain_t;    
+
+    typedef FunctionPointerWithContext<const GattReadCallbackParams*> DataReadCallback_t;
+    typedef CallChainOfFunctionPointersWithContext<const GattReadCallbackParams *> DataReadCallbackChain_t;
+
+    typedef FunctionPointerWithContext<GattAttribute::Handle_t> EventCallback_t;
+
+protected:
+    GattServer() :
+        serviceCount(0),
+        characteristicCount(0),
+        dataSentCallChain(),
+        dataWrittenCallChain(),
+        dataReadCallChain(),
+        updatesEnabledCallback(NULL),
+        updatesDisabledCallback(NULL),
+        confirmationReceivedCallback(NULL) {
+        /* empty */
+    }
+
+    /*
+     * The following functions are meant to be overridden in the platform-specific sub-class.
+     */
+public:
+
+    /**
+     * Add a service declaration to the local server ATT table. Also add the
+     * characteristics contained within.
+     */
+    virtual ble_error_t addService(GattService &service) {
+        /* Avoid compiler warnings about unused variables. */
+        (void)service;
+
+        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
+    }
+
+    /**
+     * Read the value of a characteristic from the local GATT server.
+     * @param[in]     attributeHandle
+     *                  Attribute handle for the value attribute of the characteristic.
+     * @param[out]    buffer
+     *                  A buffer to hold the value being read.
+     * @param[in/out] lengthP
+     *                  Length of the buffer being supplied. If the attribute
+     *                  value is longer than the size of the supplied buffer,
+     *                  this variable will hold upon return the total attribute value length
+     *                  (excluding offset). The application may use this
+     *                  information to allocate a suitable buffer size.
+     *
+     * @return BLE_ERROR_NONE if a value was read successfully into the buffer.
+     */
+    virtual ble_error_t read(GattAttribute::Handle_t attributeHandle, uint8_t buffer[], uint16_t *lengthP) {
+        /* Avoid compiler warnings about unused variables. */
+        (void)attributeHandle;
+        (void)buffer;
+        (void)lengthP;
+
+        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
+    }
+
+    /**
+     * Read the value of a characteristic from the local GATT server.
+     * @param[in]     connectionHandle
+     *                  Connection handle.
+     * @param[in]     attributeHandle
+     *                  Attribute handle for the value attribute of the characteristic.
+     * @param[out]    buffer
+     *                  A buffer to hold the value being read.
+     * @param[in/out] lengthP
+     *                  Length of the buffer being supplied. If the attribute
+     *                  value is longer than the size of the supplied buffer,
+     *                  this variable will hold upon return the total attribute value length
+     *                  (excluding offset). The application may use this
+     *                  information to allocate a suitable buffer size.
+     *
+     * @return BLE_ERROR_NONE if a value was read successfully into the buffer.
+     *
+     * @note This API is a version of the above, with an additional connection handle
+     *     parameter to allow fetches for connection-specific multivalued
+     *     attributes (such as the CCCDs).
+     */
+    virtual ble_error_t read(Gap::Handle_t connectionHandle, GattAttribute::Handle_t attributeHandle, uint8_t *buffer, uint16_t *lengthP) {
+        /* Avoid compiler warnings about unused variables. */
+        (void)connectionHandle;
+        (void)attributeHandle;
+        (void)buffer;
+        (void)lengthP;
+
+        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
+    }
+
+    /**
+     * Update the value of a characteristic on the local GATT server.
+     *
+     * @param[in] attributeHandle
+     *              Handle for the value attribute of the characteristic.
+     * @param[in] value
+     *              A pointer to a buffer holding the new value.
+     * @param[in] size
+     *              Size of the new value (in bytes).
+     * @param[in] localOnly
+     *              Should this update be kept on the local
+     *              GATT server regardless of the state of the
+     *              notify/indicate flag in the CCCD for this
+     *              Characteristic? If set to true, no notification
+     *              or indication is generated.
+     *
+     * @return BLE_ERROR_NONE if we have successfully set the value of the attribute.
+     */
+    virtual ble_error_t write(GattAttribute::Handle_t attributeHandle, const uint8_t *value, uint16_t size, bool localOnly = false) {
+        /* Avoid compiler warnings about unused variables. */
+        (void)attributeHandle;
+        (void)value;
+        (void)size;
+        (void)localOnly;
+
+        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
+    }
+
+    /**
+     * Update the value of a characteristic on the local GATT server. A version
+     * of the same as the above, with a connection handle parameter to allow updates
+     * for connection-specific multivalued attributes (such as the CCCDs).
+     *
+     * @param[in] connectionHandle
+     *              Connection handle.
+     * @param[in] attributeHandle
+     *              Handle for the value attribute of the characteristic.
+     * @param[in] value
+     *              A pointer to a buffer holding the new value.
+     * @param[in] size
+     *              Size of the new value (in bytes).
+     * @param[in] localOnly
+     *              Should this update be kept on the local
+     *              GattServer regardless of the state of the
+     *              notify/indicate flag in the CCCD for this
+     *              Characteristic? If set to true, no notification
+     *              or indication is generated.
+     *
+     * @return BLE_ERROR_NONE if we have successfully set the value of the attribute.
+     */
+    virtual ble_error_t write(Gap::Handle_t connectionHandle, GattAttribute::Handle_t attributeHandle, const uint8_t *value, uint16_t size, bool localOnly = false) {
+        /* Avoid compiler warnings about unused variables. */
+        (void)connectionHandle;
+        (void)attributeHandle;
+        (void)value;
+        (void)size;
+        (void)localOnly;
+
+        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
+    }
+
+    /**
+     * Determine the updates-enabled status (notification or indication) for the current connection from a characteristic's CCCD.
+     *
+     * @param       characteristic
+     *                The characteristic.
+     * @param[out]  enabledP
+     *                Upon return, *enabledP is true if updates are enabled, else false.
+     *
+     * @return BLE_ERROR_NONE if the connection and handle are found. False otherwise.
+     */
+    virtual ble_error_t areUpdatesEnabled(const GattCharacteristic &characteristic, bool *enabledP) {
+        /* Avoid compiler warnings about unused variables. */
+        (void)characteristic;
+        (void)enabledP;
+
+        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
+    }
+
+    /**
+     * Determine the connection-specific updates-enabled status (notification or indication) from a characteristic's CCCD.
+     *
+     * @param       connectionHandle
+     *                The connection handle.
+     * @param[out]  enabledP
+     *                Upon return, *enabledP is true if updates are enabled, else false.
+     *
+     * @param  characteristic
+     *           The characteristic.
+     *
+     * @return BLE_ERROR_NONE if the connection and handle are found. False otherwise.
+     */
+    virtual ble_error_t areUpdatesEnabled(Gap::Handle_t connectionHandle, const GattCharacteristic &characteristic, bool *enabledP) {
+        /* Avoid compiler warnings about unused variables. */
+        (void)connectionHandle;
+        (void)characteristic;
+        (void)enabledP;
+
+        return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porters: override this API if this capability is supported. */
+    }
+
+    /**
+     * A virtual function to allow underlying stacks to indicate if they support
+     * onDataRead(). It should be overridden to return true as applicable.
+     */
+    virtual bool isOnDataReadAvailable() const {
+        return false; /* Requesting action from porters: override this API if this capability is supported. */
+    }
+
+    /*
+     * APIs with non-virtual implementations.
+     */
+public:
+    /**
+     * Add a callback for the GATT event DATA_SENT (which is triggered when
+     * updates are sent out by GATT in the form of notifications).
+     *
+     * @Note: It is possible to chain together multiple onDataSent callbacks
+     * (potentially from different modules of an application) to receive updates
+     * to characteristics.
+     *
+     * @Note: It is also possible to set up a callback into a member function of
+     * some object.
+     */
+    void onDataSent(const DataSentCallback_t& callback) {dataSentCallChain.add(callback);}
+    template <typename T>
+    void onDataSent(T *objPtr, void (T::*memberPtr)(unsigned count)) {
+        dataSentCallChain.add(objPtr, memberPtr);
+    }
+
+    /**
+     * @brief get the callback chain called when the event DATA_EVENT is triggered. 
+     */
+    DataSentCallbackChain_t& onDataSent() { 
+        return dataSentCallChain;
+    }
+
+    /**
+     * Set up a callback for when an attribute has its value updated by or at the
+     * connected peer. For a peripheral, this callback is triggered when the local
+     * GATT server has an attribute updated by a write command from the peer.
+     * For a central, this callback is triggered when a response is received for
+     * a write request.
+     *
+     * @Note: It is possible to chain together multiple onDataWritten callbacks
+     * (potentially from different modules of an application) to receive updates
+     * to characteristics. Many services, such as DFU and UART, add their own
+     * onDataWritten callbacks behind the scenes to trap interesting events.
+     *
+     * @Note: It is also possible to set up a callback into a member function of
+     * some object.
+     * 
+     * @Note It is possible to unregister a callback using onDataWritten().detach(callback)
+     */
+    void onDataWritten(const DataWrittenCallback_t& callback) {dataWrittenCallChain.add(callback);}
+    template <typename T>
+    void onDataWritten(T *objPtr, void (T::*memberPtr)(const GattWriteCallbackParams *context)) {
+        dataWrittenCallChain.add(objPtr, memberPtr);
+    }
+
+    /**
+     * @brief provide access to the callchain of data written event callbacks
+     * It is possible to register callbacks using onDataWritten().add(callback);
+     * It is possible to unregister callbacks using onDataWritten().detach(callback) 
+     * @return The data written event callbacks chain
+     */    
+    DataWrittenCallbackChain_t& onDataWritten() {
+        return dataWrittenCallChain;
+    }
+
+    /**
+     * Setup a callback to be invoked on the peripheral when an attribute is
+     * being read by a remote client.
+     *
+     * @Note: This functionality may not be available on all underlying stacks.
+     * You could use GattCharacteristic::setReadAuthorizationCallback() as an
+     * alternative. Refer to isOnDataReadAvailable().
+     *
+     * @Note: It is possible to chain together multiple onDataRead callbacks
+     * (potentially from different modules of an application) to receive updates
+     * to characteristics. Services may add their own onDataRead callbacks
+     * behind the scenes to trap interesting events.
+     *
+     * @Note: It is also possible to set up a callback into a member function of
+     * some object.
+     *
+     * @Note It is possible to unregister a callback using onDataRead().detach(callback)
+     *
+     * @return BLE_ERROR_NOT_IMPLEMENTED if this functionality isn't available;
+     *         else BLE_ERROR_NONE.
+     */
+    ble_error_t onDataRead(const DataReadCallback_t& callback) {
+        if (!isOnDataReadAvailable()) {
+            return BLE_ERROR_NOT_IMPLEMENTED;
+        }
+
+        dataReadCallChain.add(callback);
+        return BLE_ERROR_NONE;
+    }
+    template <typename T>
+    ble_error_t onDataRead(T *objPtr, void (T::*memberPtr)(const GattReadCallbackParams *context)) {
+        if (!isOnDataReadAvailable()) {
+            return BLE_ERROR_NOT_IMPLEMENTED;
+        }
+
+        dataReadCallChain.add(objPtr, memberPtr);
+        return BLE_ERROR_NONE;
+    }
+
+    /**
+     * @brief provide access to the callchain of data read event callbacks
+     * It is possible to register callbacks using onDataRead().add(callback);
+     * It is possible to unregister callbacks using onDataRead().detach(callback) 
+     * @return The data read event callbacks chain
+     */
+    DataReadCallbackChain_t& onDataRead() {
+        return dataReadCallChain;
+    }
+
+    /**
+     * Set up a callback for when notifications or indications are enabled for a
+     * characteristic on the local GATT server.
+     */
+    void onUpdatesEnabled(EventCallback_t callback) {updatesEnabledCallback = callback;}
+
+    /**
+     * Set up a callback for when notifications or indications are disabled for a
+     * characteristic on the local GATT server.
+     */
+    void onUpdatesDisabled(EventCallback_t callback) {updatesDisabledCallback = callback;}
+
+    /**
+     * Set up a callback for when the GATT server receives a response for an
+     * indication event sent previously.
+     */
+    void onConfirmationReceived(EventCallback_t callback) {confirmationReceivedCallback = callback;}
+
+    /* Entry points for the underlying stack to report events back to the user. */
+protected:
+    void handleDataWrittenEvent(const GattWriteCallbackParams *params) {
+        dataWrittenCallChain.call(params);
+    }
+
+    void handleDataReadEvent(const GattReadCallbackParams *params) {
+        dataReadCallChain.call(params);
+    }
+
+    void handleEvent(GattServerEvents::gattEvent_e type, GattAttribute::Handle_t attributeHandle) {
+        switch (type) {
+            case GattServerEvents::GATT_EVENT_UPDATES_ENABLED:
+                if (updatesEnabledCallback) {
+                    updatesEnabledCallback(attributeHandle);
+                }
+                break;
+            case GattServerEvents::GATT_EVENT_UPDATES_DISABLED:
+                if (updatesDisabledCallback) {
+                    updatesDisabledCallback(attributeHandle);
+                }
+                break;
+            case GattServerEvents::GATT_EVENT_CONFIRMATION_RECEIVED:
+                if (confirmationReceivedCallback) {
+                    confirmationReceivedCallback(attributeHandle);
+                }
+                break;
+            default:
+                break;
+        }
+    }
+
+    void handleDataSentEvent(unsigned count) {
+        dataSentCallChain.call(count);
+    }
+
+protected:
+    uint8_t serviceCount;
+    uint8_t characteristicCount;
+
+private:
+    DataSentCallbackChain_t    dataSentCallChain;
+    DataWrittenCallbackChain_t dataWrittenCallChain;
+    DataReadCallbackChain_t    dataReadCallChain;
+    EventCallback_t            updatesEnabledCallback;
+    EventCallback_t            updatesDisabledCallback;
+    EventCallback_t            confirmationReceivedCallback;
+
+private:
+    /* Disallow copy and assignment. */
+    GattServer(const GattServer &);
+    GattServer& operator=(const GattServer &);
+};
+
 #endif // ifndef __GATT_SERVER_H__
\ No newline at end of file