beremiz

MQTT: allow publish and subscribe from user python code.

18 months ago, Edouard Tisserant
86fbb3991af6
Parents 803d4e64cc68
Children 3ef4b5b202fc
MQTT: allow publish and subscribe from user python code.
11 files changed, 402 insertions(+), 26 deletions(-)
  • +2 -1
    features.py
  • +1 -0
    mqtt/__init__.py
  • +2 -1
    mqtt/client.py
  • +84 -0
    mqtt/library.py
  • +2 -1
    mqtt/mqtt_client_gen.py
  • +54 -8
    mqtt/mqtt_template.c
  • +24 -0
    mqtt/pous.xml
  • +1 -1
    tests/projects/mqtt_client/beremiz.xml
  • +192 -14
    tests/projects/mqtt_client/plc.xml
  • +2 -0
    tests/projects/mqtt_client/py_ext_0@py_ext/baseconfnode.xml
  • +38 -0
    tests/projects/mqtt_client/py_ext_0@py_ext/pyfile.xml
    • --- a/features.py Thu Jan 09 09:46:43 2025 +0100
    +++ b/features.py Fri Dec 20 14:32:33 2024 +0100
    @@ -12,7 +12,8 @@
    ('Native', 'NativeLib.NativeLibrary', True),
    ('Python', 'py_ext.PythonLibrary', True),
    # FIXME ('Etherlab', 'etherlab.EthercatMaster.EtherlabLibrary', False),
    - ('SVGHMI', 'svghmi.SVGHMILibrary', 'svghmi')]
    + ('SVGHMI', 'svghmi.SVGHMILibrary', 'svghmi'),
    + ('MQTT', 'mqtt.MQTTLibrary', False)]
    catalog = [
    ('mqtt', _('MQTT client'), _('Map MQTT topics as located variables'), 'mqtt.MQTTClient'),
    --- a/mqtt/__init__.py Thu Jan 09 09:46:43 2025 +0100
    +++ b/mqtt/__init__.py Fri Dec 20 14:32:33 2024 +0100
    @@ -3,4 +3,5 @@
    from __future__ import absolute_import
    from .client import MQTTClient
    +from .library import MQTTLibrary
    --- a/mqtt/client.py Thu Jan 09 09:46:43 2025 +0100
    +++ b/mqtt/client.py Fri Dec 20 14:32:33 2024 +0100
    @@ -178,7 +178,8 @@
    #include "beremiz.h"
    """
    config = self.GetConfig()
    - c_code += self.modeldata.GenerateC(c_path, locstr, config, self.GetDataTypeInfos)
    + name = self.BaseParams.getName()
    + c_code += self.modeldata.GenerateC(name, c_path, locstr, config, self.GetDataTypeInfos)
    with open(c_path, 'w') as c_file:
    c_file.write(c_code)
    --- /dev/null Thu Jan 01 00:00:00 1970 +0000
    +++ b/mqtt/library.py Fri Dec 20 14:32:33 2024 +0100
    @@ -0,0 +1,84 @@
    +# mqtt/client.py
    +
    +from __future__ import absolute_import
    +
    +import os
    +
    +from POULibrary import POULibrary
    +import util.paths as paths
    +
    +mqtt_python_lib_code = """
    +def MQTT_publish(clientname, topic, payload, QoS = 1, Retained = False):
    + c_function_name = "__mqtt_python_publish_" + clientname
    + c_function = getattr(PLCBinary, c_function_name)
    + c_function.restype = ctypes.c_int # error or 0
    + c_function.argtypes = [
    + ctypes.c_char_p, # topic
    + ctypes.c_char_p, # data
    + ctypes.c_uint32, # datalen
    + ctypes.c_uint8, # QoS
    + ctypes.c_uint8, # Retained
    + ]
    + res = c_function(topic, payload, len(payload), QoS, Retained)
    + return res
    +
    +# C per client CallBack type for __mqtt_python_subscribe_{name}
    +c_cb_type = ctypes.CFUNCTYPE(ctypes.c_int, # return
    + ctypes.c_char_p, # topic
    + ctypes.POINTER(ctypes.c_char), # data
    + ctypes.c_uint32) # data length
    +
    +# CallBacks management
    +# - each call to MQTT_subscribe registers a callback
    +MQTT_subscribers_cbs = {}
    +
    +# - one callback registered to C side per client
    +MQTT_client_cbs = {}
    +
    +def per_client_cb_factory(client):
    + def per_client_cb(topic, dataptr, datalen):
    + payload = ctypes.string_at(dataptr, datalen)
    + subscriber = MQTT_subscribers_cbs[client].get(topic, None)
    + if subscriber:
    + subscriber(topic, payload)
    + return 0
    + return 1
    + return per_client_cb
    +
    +def MQTT_subscribe(clientname, topic, cb, QoS = 1):
    + global MQTT_client_cbs, MQTT_subscribers_cbs
    + c_function_name = "__mqtt_python_subscribe_" + clientname
    + c_function = getattr(PLCBinary, c_function_name)
    + c_function.restype = ctypes.c_int # error or 0
    + c_function.argtypes = [
    + ctypes.c_char_p, # topic
    + ctypes.c_uint8] # QoS
    +
    + MQTT_subscribers_cbs.setdefault(clientname, {})[topic] = cb
    +
    + c_cb = MQTT_client_cbs.get(clientname, None)
    + if c_cb is None:
    + c_cb = c_cb_type(per_client_cb_factory(clientname))
    + MQTT_client_cbs[clientname] = c_cb
    + register_c_function = getattr(PLCBinary, "__mqtt_python_callback_setter_"+clientname )
    + register_c_function.argtypes = [c_cb_type]
    + register_c_function(c_cb)
    +
    + res = c_function(topic, QoS)
    + return res
    +
    +"""
    +
    +class MQTTLibrary(POULibrary):
    +
    + def GetLibraryPath(self):
    + return paths.AbsNeighbourFile(__file__, "pous.xml")
    +
    + def Generate_C(self, buildpath, varlist, IECCFLAGS):
    +
    + runtimefile_path = os.path.join(buildpath, "runtime_00_mqtt.py")
    + runtimefile = open(runtimefile_path, 'w')
    + runtimefile.write(mqtt_python_lib_code)
    + runtimefile.close()
    + return ((["mqtt"], [], False), "",
    + ("runtime_00_mqtt.py", open(runtimefile_path, "rb")))
    --- a/mqtt/mqtt_client_gen.py Thu Jan 09 09:46:43 2025 +0100
    +++ b/mqtt/mqtt_client_gen.py Fri Dec 20 14:32:33 2024 +0100
    @@ -356,7 +356,7 @@
    for row in data:
    writer.writerow([direction] + row)
    - def GenerateC(self, path, locstr, config, datatype_info_getter):
    + def GenerateC(self, name, path, locstr, config, datatype_info_getter):
    c_template_filepath = paths.AbsNeighbourFile(__file__, "mqtt_template.c")
    c_template_file = open(c_template_filepath , 'rb')
    c_template = c_template_file.read()
    @@ -365,6 +365,7 @@
    json_types = OD()
    formatdict = dict(
    + name = name,
    locstr = locstr,
    uri = config["URI"],
    clientID = config["clientID"],
    --- a/mqtt/mqtt_template.c Thu Jan 09 09:46:43 2025 +0100
    +++ b/mqtt/mqtt_template.c Fri Dec 20 14:32:33 2024 +0100
    @@ -260,8 +260,10 @@
    }}
    +typedef int(*callback_fptr_t)(char* topic, char* data, uint32_t datalen);
    +static callback_fptr_t __mqtt_python_callback_fptr_{name} = NULL;
    -int messageArrived(void *context, char *topicName, int topicLen, MQTTClient_message *message)
    +static int messageArrived(void *context, char *topicName, int topicLen, MQTTClient_message *message)
    {{
    int low = 0;
    int size = sizeof(topics) / sizeof(topics[0]);
    @@ -307,7 +309,15 @@
    high = mid - 1;
    }}
    // If we reach here, then the element was not present
    - LogWarning("MQTT unknown topic: %s\n", topicName);
    + if(__mqtt_python_callback_fptr_{name} &&
    + (*__mqtt_python_callback_fptr_{name})(topicName,
    + (char*)message->payload,
    + message->payloadlen) == 0){{
    + // Topic was handled in python
    + goto exit;
    + }} else {{
    + LogWarning("MQTT unknown topic: %s\n", topicName);
    + }}
    goto exit;
    found:
    @@ -357,19 +367,19 @@
    #ifdef USE_MQTT_5
    #define _SUBSCRIBE(Topic, QoS) \
    - MQTTResponse response = MQTTClient_subscribe5(client, #Topic, QoS, NULL, NULL); \
    + MQTTResponse response = MQTTClient_subscribe5(client, Topic, QoS, NULL, NULL); \
    /* when using MQTT5 responce code is 1 for some reason even if no error */ \
    rc = response.reasonCode == 1 ? MQTTCLIENT_SUCCESS : response.reasonCode; \
    MQTTResponse_free(response);
    #else
    #define _SUBSCRIBE(Topic, QoS) \
    - rc = MQTTClient_subscribe(client, #Topic, QoS);
    + rc = MQTTClient_subscribe(client, Topic, QoS);
    #endif
    #define INIT_SUBSCRIPTION(Topic, QoS) \
    {{ \
    int rc; \
    - _SUBSCRIBE(Topic, QoS) \
    + _SUBSCRIBE(#Topic, QoS) \
    if (rc != MQTTCLIENT_SUCCESS) \
    {{ \
    LogError("MQTT client failed to subscribe to '%s', return code %d\n", #Topic, rc); \
    @@ -379,18 +389,18 @@
    #ifdef USE_MQTT_5
    #define _PUBLISH(Topic, QoS, cstring_size, cstring_ptr, Retained) \
    - MQTTResponse response = MQTTClient_publish5(client, #Topic, cstring_size, \
    + MQTTResponse response = MQTTClient_publish5(client, Topic, cstring_size, \
    cstring_ptr, QoS, Retained, NULL, NULL); \
    rc = response.reasonCode; \
    MQTTResponse_free(response);
    #else
    #define _PUBLISH(Topic, QoS, cstring_size, cstring_ptr, Retained) \
    - rc = MQTTClient_publish(client, #Topic, cstring_size, \
    + rc = MQTTClient_publish(client, Topic, cstring_size, \
    cstring_ptr, QoS, Retained, NULL);
    #endif
    #define PUBLISH_SIMPLE(Topic, QoS, C_type, c_loc_name, Retained) \
    - _PUBLISH(Topic, QoS, sizeof(C_type), &MQTT_##c_loc_name##_buf, Retained)
    + _PUBLISH(#Topic, QoS, sizeof(C_type), &MQTT_##c_loc_name##_buf, Retained)
    #define PUBLISH_JSON(Topic, QoS, C_type, c_loc_name, Retained) \
    int res = json_gen_##c_loc_name(&MQTT_##c_loc_name##_buf); \
    @@ -589,3 +599,39 @@
    }}
    }}
    +int __mqtt_python_publish_{name}(char* topic, char* data, uint32_t datalen, uint8_t QoS, uint8_t Retained)
    +{{
    + int rc = 0;
    +
    + if((rc = pthread_mutex_lock(&MQTT_thread_wakeup_mutex)) == 0){{
    + _PUBLISH(topic, QoS, datalen, data, Retained)
    + pthread_mutex_unlock(&MQTT_thread_wakeup_mutex);
    + if (rc != MQTTCLIENT_SUCCESS){{
    + LogError("MQTT python can't publish \"%s\", return code %d\n", topic, rc);
    + return rc;
    + }}
    + }} else {{
    + LogError("MQTT python can't obtain lock, return code %d\n", rc);
    + return rc;
    + }}
    + return 0;
    +}}
    +
    +
    +int __mqtt_python_subscribe_{name}(char* topic, uint8_t QoS)
    +{{
    + int rc;
    + _SUBSCRIBE(topic, QoS)
    + if (rc != MQTTCLIENT_SUCCESS)
    + {{
    + LogError("MQTT client failed to subscribe to '%s', return code %d\n", topic, rc);
    + return rc;
    + }}
    + return 0;
    +}}
    +
    +int __mqtt_python_callback_setter_{name}(callback_fptr_t cb)
    +{{
    + __mqtt_python_callback_fptr_{name} = cb;
    + return 0;
    +}}
    --- /dev/null Thu Jan 01 00:00:00 1970 +0000
    +++ b/mqtt/pous.xml Fri Dec 20 14:32:33 2024 +0100
    @@ -0,0 +1,24 @@
    +<?xml version='1.0' encoding='utf-8'?>
    +<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.plcopen.org/xml/tc6_0201" xmlns:xhtml="http://www.w3.org/1999/xhtml" xsi:schemaLocation="http://www.plcopen.org/xml/tc6_0201">
    + <fileHeader companyName="Beremiz" productName="Beremiz" productVersion="0.0" creationDateTime="2008-12-14T16:53:26"/>
    + <contentHeader name="Beremiz non-standard POUs library" modificationDateTime="2019-08-06T14:08:26">
    + <coordinateInfo>
    + <fbd>
    + <scaling x="0" y="0"/>
    + </fbd>
    + <ld>
    + <scaling x="0" y="0"/>
    + </ld>
    + <sfc>
    + <scaling x="0" y="0"/>
    + </sfc>
    + </coordinateInfo>
    + </contentHeader>
    + <types>
    + <dataTypes/>
    + <pous/>
    + </types>
    + <instances>
    + <configurations/>
    + </instances>
    +</project>
    --- a/tests/projects/mqtt_client/beremiz.xml Thu Jan 09 09:46:43 2025 +0100
    +++ b/tests/projects/mqtt_client/beremiz.xml Fri Dec 20 14:32:33 2024 +0100
    @@ -1,5 +1,5 @@
    <?xml version='1.0' encoding='utf-8'?>
    <BeremizRoot xmlns:xsd="http://www.w3.org/2001/XMLSchema" URI_location="PYRO://localhost:61131" Disable_Extensions="false">
    <TargetType/>
    - <Libraries Enable_Python_Library="false"/>
    + <Libraries Enable_Python_Library="true" Enable_MQTT_Library="true"/>
    </BeremizRoot>
    --- a/tests/projects/mqtt_client/plc.xml Thu Jan 09 09:46:43 2025 +0100
    +++ b/tests/projects/mqtt_client/plc.xml Fri Dec 20 14:32:33 2024 +0100
    @@ -1,7 +1,7 @@
    <?xml version='1.0' encoding='utf-8'?>
    <project xmlns:ns1="http://www.plcopen.org/xml/tc6_0201" xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www.plcopen.org/xml/tc6_0201">
    <fileHeader companyName="Beremiz" productName="Beremiz" productVersion="1" creationDateTime="2016-10-24T18:09:22"/>
    - <contentHeader name="First Steps" modificationDateTime="2024-07-25T16:55:27">
    + <contentHeader name="First Steps" modificationDateTime="2024-12-18T14:47:09">
    <coordinateInfo>
    <fbd>
    <scaling x="0" y="0"/>
    @@ -41,6 +41,18 @@
    </type>
    </variable>
    </localVars>
    + <localVars>
    + <variable name="python_eval0">
    + <type>
    + <derived name="python_eval"/>
    + </type>
    + </variable>
    + <variable name="python_eval1">
    + <type>
    + <derived name="python_eval"/>
    + </type>
    + </variable>
    + </localVars>
    </interface>
    <body>
    <FBD>
    @@ -52,7 +64,7 @@
    <expression>LocalVar0</expression>
    </inVariable>
    <inVariable localId="3" executionOrderId="0" height="27" width="82" negated="false">
    - <position x="126" y="224"/>
    + <position x="814" y="106"/>
    <connectionPointOut>
    <relPosition x="82" y="13"/>
    </connectionPointOut>
    @@ -224,11 +236,11 @@
    <variable formalParameter="IN0">
    <connectionPointIn>
    <relPosition x="0" y="50"/>
    - <connection refLocalId="12">
    + <connection refLocalId="3">
    <position x="956" y="103"/>
    - <position x="927" y="103"/>
    - <position x="927" y="115"/>
    - <position x="898" y="115"/>
    + <position x="926" y="103"/>
    + <position x="926" y="119"/>
    + <position x="896" y="119"/>
    </connection>
    </connectionPointIn>
    </variable>
    @@ -238,8 +250,8 @@
    <connection refLocalId="13">
    <position x="956" y="123"/>
    <position x="933" y="123"/>
    - <position x="933" y="171"/>
    - <position x="910" y="171"/>
    + <position x="933" y="159"/>
    + <position x="910" y="159"/>
    </connection>
    </connectionPointIn>
    </variable>
    @@ -253,20 +265,186 @@
    </variable>
    </outputVariables>
    </block>
    - <inVariable localId="12" executionOrderId="0" height="27" width="34" negated="false">
    - <position x="872" y="102"/>
    + <inVariable localId="13" executionOrderId="0" height="27" width="34" negated="false">
    + <position x="876" y="146"/>
    <connectionPointOut>
    <relPosition x="34" y="13"/>
    </connectionPointOut>
    <expression>666</expression>
    </inVariable>
    - <inVariable localId="13" executionOrderId="0" height="27" width="34" negated="false">
    - <position x="876" y="158"/>
    + <block localId="14" typeName="python_eval" instanceName="python_eval0" executionOrderId="0" height="60" width="98">
    + <position x="849" y="235"/>
    + <inputVariables>
    + <variable formalParameter="TRIG">
    + <connectionPointIn>
    + <relPosition x="0" y="30"/>
    + <connection refLocalId="8" formalParameter="OUT">
    + <position x="849" y="265"/>
    + <position x="782" y="265"/>
    + <position x="782" y="199"/>
    + <position x="794" y="199"/>
    + <position x="794" y="95"/>
    + <position x="784" y="95"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + <variable formalParameter="CODE">
    + <connectionPointIn>
    + <relPosition x="0" y="50"/>
    + <connection refLocalId="16">
    + <position x="849" y="285"/>
    + <position x="797" y="285"/>
    + <position x="797" y="291"/>
    + <position x="745" y="291"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + </inputVariables>
    + <inOutVariables/>
    + <outputVariables>
    + <variable formalParameter="ACK">
    + <connectionPointOut>
    + <relPosition x="98" y="30"/>
    + </connectionPointOut>
    + </variable>
    + <variable formalParameter="RESULT">
    + <connectionPointOut>
    + <relPosition x="98" y="50"/>
    + </connectionPointOut>
    + </variable>
    + </outputVariables>
    + </block>
    + <inVariable localId="15" executionOrderId="0" height="27" width="354" negated="false">
    + <position x="1384" y="186"/>
    + <connectionPointOut>
    + <relPosition x="354" y="13"/>
    + </connectionPointOut>
    + <expression>'sys.stdout.write("MQTT PYTHON TEST OK\n")'</expression>
    + </inVariable>
    + <inVariable localId="16" executionOrderId="0" height="27" width="218" negated="false">
    + <position x="527" y="278"/>
    <connectionPointOut>
    - <relPosition x="34" y="13"/>
    + <relPosition x="218" y="13"/>
    </connectionPointOut>
    - <expression>666</expression>
    + <expression>'publish_example("mhooo")'</expression>
    </inVariable>
    + <block localId="12" typeName="python_eval" instanceName="python_eval1" executionOrderId="0" height="60" width="98">
    + <position x="1803" y="146"/>
    + <inputVariables>
    + <variable formalParameter="TRIG">
    + <connectionPointIn>
    + <relPosition x="0" y="30"/>
    + <connection refLocalId="19" formalParameter="OUT">
    + <position x="1803" y="176"/>
    + <position x="1472" y="176"/>
    + <position x="1472" y="173"/>
    + <position x="1302" y="173"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + <variable formalParameter="CODE">
    + <connectionPointIn>
    + <relPosition x="0" y="50"/>
    + <connection refLocalId="15">
    + <position x="1803" y="196"/>
    + <position x="1748" y="196"/>
    + <position x="1748" y="199"/>
    + <position x="1738" y="199"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + </inputVariables>
    + <inOutVariables/>
    + <outputVariables>
    + <variable formalParameter="ACK">
    + <connectionPointOut>
    + <relPosition x="98" y="30"/>
    + </connectionPointOut>
    + </variable>
    + <variable formalParameter="RESULT">
    + <connectionPointOut>
    + <relPosition x="98" y="50"/>
    + </connectionPointOut>
    + </variable>
    + </outputVariables>
    + </block>
    + <block localId="17" typeName="EQ" executionOrderId="0" height="60" width="63">
    + <position x="1144" y="204"/>
    + <inputVariables>
    + <variable formalParameter="IN1">
    + <connectionPointIn>
    + <relPosition x="0" y="30"/>
    + <connection refLocalId="18">
    + <position x="1144" y="234"/>
    + <position x="1114" y="234"/>
    + <position x="1114" y="235"/>
    + <position x="1104" y="235"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + <variable formalParameter="IN2">
    + <connectionPointIn>
    + <relPosition x="0" y="50"/>
    + <connection refLocalId="14" formalParameter="RESULT">
    + <position x="1144" y="254"/>
    + <position x="1063" y="254"/>
    + <position x="1063" y="285"/>
    + <position x="947" y="285"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + </inputVariables>
    + <inOutVariables/>
    + <outputVariables>
    + <variable formalParameter="OUT">
    + <connectionPointOut>
    + <relPosition x="63" y="30"/>
    + </connectionPointOut>
    + </variable>
    + </outputVariables>
    + </block>
    + <inVariable localId="18" executionOrderId="0" height="27" width="95" negated="false">
    + <position x="1009" y="222"/>
    + <connectionPointOut>
    + <relPosition x="95" y="13"/>
    + </connectionPointOut>
    + <expression>'mhooo'</expression>
    + </inVariable>
    + <block localId="19" typeName="AND" executionOrderId="0" height="60" width="63">
    + <position x="1239" y="143"/>
    + <inputVariables>
    + <variable formalParameter="IN1">
    + <connectionPointIn>
    + <relPosition x="0" y="30"/>
    + <connection refLocalId="14" formalParameter="ACK">
    + <position x="1239" y="173"/>
    + <position x="990" y="173"/>
    + <position x="990" y="265"/>
    + <position x="947" y="265"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + <variable formalParameter="IN2">
    + <connectionPointIn>
    + <relPosition x="0" y="50"/>
    + <connection refLocalId="17" formalParameter="OUT">
    + <position x="1239" y="193"/>
    + <position x="1223" y="193"/>
    + <position x="1223" y="234"/>
    + <position x="1207" y="234"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + </inputVariables>
    + <inOutVariables/>
    + <outputVariables>
    + <variable formalParameter="OUT">
    + <connectionPointOut>
    + <relPosition x="63" y="30"/>
    + </connectionPointOut>
    + </variable>
    + </outputVariables>
    + </block>
    </FBD>
    </body>
    </pou>
    --- /dev/null Thu Jan 01 00:00:00 1970 +0000
    +++ b/tests/projects/mqtt_client/py_ext_0@py_ext/baseconfnode.xml Fri Dec 20 14:32:33 2024 +0100
    @@ -0,0 +1,2 @@
    +<?xml version='1.0' encoding='utf-8'?>
    +<BaseParams xmlns:xsd="http://www.w3.org/2001/XMLSchema" IEC_Channel="1" Name="py_ext_0"/>
    --- /dev/null Thu Jan 01 00:00:00 1970 +0000
    +++ b/tests/projects/mqtt_client/py_ext_0@py_ext/pyfile.xml Fri Dec 20 14:32:33 2024 +0100
    @@ -0,0 +1,38 @@
    +<?xml version='1.0' encoding='utf-8'?>
    +<PyFile xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    + <variables/>
    + <globals>
    + <xhtml:p><![CDATA[
    +import sys
    +last_payload = None
    +
    +def topic_callback(topic, payload):
    + global last_payload
    + last_payload = payload
    +
    +# called from PLC
    +def publish_example(data):
    + global last_payload
    + MQTT_publish("mqtt_0", "py_test", data)
    + return last_payload
    +
    +]]></xhtml:p>
    + </globals>
    + <init>
    + <xhtml:p><![CDATA[
    +]]></xhtml:p>
    + </init>
    + <cleanup>
    + <xhtml:p><![CDATA[
    +]]></xhtml:p>
    + </cleanup>
    + <start>
    + <xhtml:p><![CDATA[
    +MQTT_subscribe("mqtt_0", "py_test", topic_callback)
    +]]></xhtml:p>
    + </start>
    + <stop>
    + <xhtml:p><![CDATA[
    +]]></xhtml:p>
    + </stop>
    +</PyFile>