Test formulas.

src/cmdline.cc

@@ -485,6 +485,18 @@ static shared_ptr<Configuration> parseNormalCommandLine(Configuration *c, int ar
             i++;
             continue;
         }
+        if (!strncmp(argv[i], "--calculate_", 12))
+        {
+            // For example: --calculate_adjusted_kwh='total_kwh + 12345 kwh'
+            string extra_calculated_field = string(argv[i]+12);
+            if (extra_calculated_field == "") {
+                error("The calculated field command cannot be empty.\n");
+            }
+            debug("(cmdline) add calculated field %s\n", extra_calculated_field.c_str());
+            c->extra_calculated_fields.push_back(extra_calculated_field);
+            i++;
+            continue;
+        }
         if (!strncmp(argv[i], "--listenvs=", 11)) {
             c->list_shell_envs = true;
             c->list_meter = string(argv[i]+11);

src/config.cc

@@ -59,6 +59,7 @@ void parseMeterConfig(Configuration *c, vector<char> &buf, string file)
     vector<string> telegram_shells;
     vector<string> alarm_shells;
     vector<string> extra_constant_fields;
+    vector<string> extra_calculated_fields;
     vector<string> selected_fields;
 
     debug("(config) loading meter file %s\n", file.c_str());
@@ -152,6 +153,12 @@ void parseMeterConfig(Configuration *c, vector<char> &buf, string file)
             string keyvalue = p.first.substr(off)+"="+p.second;
             extra_constant_fields.push_back(keyvalue);
         }
+        else
+        if (startsWith(p.first, "calculate_"))
+        {
+            string keyvalue = p.first.substr(10)+"="+p.second;
+            extra_calculated_fields.push_back(keyvalue);
+        }
         else
             warning("Found invalid key \"%s\" in meter config file\n", p.first.c_str());
 
@@ -195,6 +202,7 @@ void parseMeterConfig(Configuration *c, vector<char> &buf, string file)
     }
     if (use) {
         mi.extra_constant_fields = extra_constant_fields;
+        mi.extra_calculated_fields = extra_calculated_fields;
         mi.shells = telegram_shells;
         mi.idsc = toIdsCommaSeparated(mi.ids);
         mi.selected_fields = selected_fields;

src/config.h

@@ -136,6 +136,7 @@ struct Configuration
     std::vector<std::string> selected_fields;
     std::vector<MeterInfo> meters;
     std::vector<std::string> extra_constant_fields; // Additional constant fields to always add to json.
+    std::vector<std::string> extra_calculated_fields; // Additional calculated fields to always add to json.
     // These extra constant fields can also be part of selected with selectfields.
     std::vector<SendBusContent> send_bus_content; // Telegrams used to wake up a meter for reading or mbus read-out requests.
     std::set<BusDeviceType> probe_for; // Which devices should be probed for? DEVICE_AUTO means all.

src/driver_em24.cc

@@ -133,13 +133,15 @@ namespace
             .set(DifVifKey("04FB82F53C"))
             );
 
+        /*
         addNumericFieldWithCalculator(
             "total_apparent_energy_consumption",
             "Calculated: the total apparent energy consumption.",
             PrintProperty::JSON | PrintProperty::FIELD | PrintProperty::IMPORTANT,
-            Quantity::Energy,
+            Quantity::Apparent_Energy,
             "total_energy_consumption_kwh + 99 kwh"
             );
+        */
     }
 }
 

src/main.cc

@@ -454,9 +454,10 @@ void setup_log_file(Configuration *config)
 
 void setup_meters(Configuration *config, MeterManager *manager)
 {
-    for (auto &m : config->meters)
+    for (MeterInfo &m : config->meters)
     {
         m.conversions = config->conversions;
+        m.extra_calculated_fields = config->extra_calculated_fields;
 
         if (m.usesPolling() || driverNeedsPolling(m.driver, m.driver_name))
         {

src/meters.cc

@@ -738,10 +738,12 @@ MeterCommonImplementation::MeterCommonImplementation(MeterInfo &mi,
     {
         hex2bin(mi.key, &meter_keys_.confidentiality_key);
     }
-    for (auto s : mi.shells) {
+    for (auto s : mi.shells)
+    {
         addShell(s);
     }
-    for (auto j : mi.extra_constant_fields) {
+    for (auto j : mi.extra_constant_fields)
+    {
         addExtraConstantField(j);
     }
 }
@@ -765,10 +767,12 @@ MeterCommonImplementation::MeterCommonImplementation(MeterInfo &mi,
     {
         hex2bin(mi.key, &meter_keys_.confidentiality_key);
     }
-    for (auto s : mi.shells) {
+    for (auto s : mi.shells)
+    {
         addShell(s);
     }
-    for (auto j : mi.extra_constant_fields) {
+    for (auto j : mi.extra_constant_fields)
+    {
         addExtraConstantField(j);
     }
 
@@ -794,6 +798,39 @@ void MeterCommonImplementation::addExtraConstantField(string ecf)
     extra_constant_fields_.push_back(ecf);
 }
 
+void MeterCommonImplementation::addExtraCalculatedField(string ecf)
+{
+    verbose("(meter) Adding calculated field: %s\n", ecf.c_str());
+
+    vector<string> parts = splitString(ecf, '=');
+
+    if (parts.size() != 2)
+    {
+        warning("Invalid formula for calculated field. %s\n", ecf.c_str());
+        return;
+    }
+
+    string vname;
+    Unit unit;
+
+    bool ok = extractUnit(parts[0], &vname, &unit);
+    if (!ok)
+    {
+        warning("Could not extract a valid unit from calculated field name %s\n", parts[0].c_str());
+        return;
+    }
+
+    Quantity quantity = toQuantity(unit);
+
+    addNumericFieldWithCalculator(
+        vname,
+        "Calculated: "+ecf,
+        PrintProperty::JSON | PrintProperty::FIELD,
+        quantity,
+        parts[1]
+        );
+}
+
 vector<string> &MeterCommonImplementation::shellCmdlines()
 {
     return shell_cmdlines_;
@@ -965,6 +1002,15 @@ void MeterCommonImplementation::addNumericFieldWithCalculator(string vname,
 {
     Formula *f = newFormula();
     bool ok = f->parse(this, formula);
+    if (!ok)
+    {
+        string err = f->errors();
+        warning("Warning! Ignoring calculated field %s because parse failed:\n%s",
+                vname.c_str(),
+                err.c_str());
+        delete f;
+        return;
+    }
     assert(ok);
 
     field_infos_.push_back(
@@ -2417,6 +2463,10 @@ shared_ptr<Meter> createMeter(MeterInfo *mi)
     {
         shared_ptr<Meter> newm = di->construct(*mi);
         newm->addConversions(mi->conversions);
+        for (string &j : mi->extra_calculated_fields)
+        {
+            newm->addExtraCalculatedField(j);
+        }
         newm->setPollInterval(mi->poll_interval);
         if (mi->selected_fields.size() > 0)
         {

src/meters.h

@@ -159,6 +159,7 @@ struct MeterInfo
     int bps {};     // For mbus communication you need to know the baud rate.
     vector<string> shells;
     vector<string> extra_constant_fields; // Additional static fields that are added to each message.
+    vector<string> extra_calculated_fields; // Additional field calculated using formulas.
     vector<Unit> conversions; // Additional units desired in json.
     vector<string> selected_fields; // Usually set to the default fields, but can be override in meter config.
 
@@ -172,7 +173,7 @@ struct MeterInfo
     string str();
     DriverName driverName();
 
-    MeterInfo(string b, string n, MeterDriver d, string e, vector<string> i, string k, LinkModeSet lms, int baud, vector<string> &s, vector<string> &j)
+    MeterInfo(string b, string n, MeterDriver d, string e, vector<string> i, string k, LinkModeSet lms, int baud, vector<string> &s, vector<string> &j, vector<string> &calcfs)
     {
         bus = b;
         name = n;
@@ -183,6 +184,7 @@ struct MeterInfo
         key = k;
         shells = s;
         extra_constant_fields = j;
+        extra_calculated_fields = calcfs;
         link_modes = lms;
         bps = baud;
     }
@@ -197,6 +199,7 @@ struct MeterInfo
         key = "";
         shells.clear();
         extra_constant_fields.clear();
+        extra_calculated_fields.clear();
         link_modes.clear();
         bps = 0;
     }
@@ -471,6 +474,7 @@ struct Meter
     virtual MeterKeys *meterKeys() = 0;
 
     virtual void addConversions(std::vector<Unit> cs) = 0;
+    virtual void addExtraCalculatedField(std::string ecf) = 0;
     virtual vector<Unit>& conversions() = 0;
     virtual void addShell(std::string cmdline) = 0;
     virtual vector<string> &shellCmdlines() = 0;

src/meters_common_implementation.h

@@ -67,6 +67,7 @@ struct MeterCommonImplementation : public virtual Meter
     void setPollInterval(time_t interval);
     time_t pollInterval();
     bool usesPolling();
+    void addExtraCalculatedField(std::string ef);
 
     void onUpdate(function<void(Telegram*,Meter*)> cb);
     int numUpdates();

test.sh

@@ -84,6 +84,9 @@ if [ "$?" != "0" ]; then RC="1"; fi
 tests/test_conversions.sh $PROG
 if [ "$?" != "0" ]; then RC="1"; fi
 
+tests/test_formulas.sh $PROG
+if [ "$?" != "0" ]; then RC="1"; fi
+
 tests/test_fields.sh $PROG
 if [ "$?" != "0" ]; then RC="1"; fi
 

tests/test_formulas.sh

@@ -0,0 +1,34 @@
+#!/bin/sh
+
+PROG="$1"
+
+rm -rf testoutput
+mkdir -p testoutput
+TEST=testoutput
+
+TESTNAME="Test formulas"
+TESTRESULT="ERROR"
+
+$PROG --format=json \
+      --calculate_sumtemp_c='external_temperature_c+flow_temperature_c' \
+      --calculate_addtemp_c='external_temperature_c + 1100 c' \
+      23442D2C998734761B168D2087D19EAD217F1779EDA86AB6_710008190000081900007F13 \
+      MyTapWater multical21 76348799 "" \
+      > $TEST/test_output.txt
+
+cat > $TEST/test_expected.txt <<EOF
+{"media":"cold water","meter":"multical21","name":"MyTapWater","id":"76348799","status":"DRY","total_m3":6.408,"target_m3":6.408,"flow_temperature_c":127,"external_temperature_c":19,"current_status":"DRY","time_dry":"22-31 days","time_reversed":"","time_leaking":"","time_bursting":"","sumtemp_c":146,"addtemp_c":1119,"timestamp":"1111-11-11T11:11:11Z"}
+EOF
+
+if [ "$?" = "0" ]
+then
+    cat $TEST/test_output.txt | sed 's/"timestamp":"....-..-..T..:..:..Z"/"timestamp":"1111-11-11T11:11:11Z"/' > $TEST/test_responses.txt
+    diff $TEST/test_expected.txt $TEST/test_responses.txt
+    if [ "$?" = "0" ]
+    then
+        echo "OK: $TESTNAME"
+        TESTRESULT="OK"
+    fi
+fi
+
+if [ "$TESTRESULT" = "ERROR" ]; then echo ERROR: $TESTNAME;  exit 1; fi