Following on from my post QueryPropertyHistory Service with Row Control/Limiting, we incorporated this function in to a service which extends and adds the capability to specify Property names too, just like QueryNamedPropertyHistory.
We also created a similar service for QueryNamedPropertyHistoryRowLimited, below. This will need the additional input configuring for propetryNames, as per the default service QueryNamedPropertyHistory.
/* *** QueryNamedPropertyHistoryRowLimited *** */
//Does simple step-interpolation of a fixed number of points between startDate and endDate
//set default values for properties undefined
var ed = endDate;
var sd = startDate;
var mi = maxItems;
//if endDate is undefined, choose NOW as the endDate
if (ed == null) {
ed = new Date();
}
//if startDate is undefined or greater than the endDate, choose 24 hours ago as the startDate
if ((sd == null) || (sd > ed)) {
var dateValue = new Date();
sd = dateAddHours(dateValue, -24);
}
//if maxItems is null or undefined, set to 100 rows of data as default
if ((mi == null) || (mi == undefined)) {
mi = 100;
}
//calculate the time period between rows of data
var startUTC = Date.UTC(sd.getFullYear(), sd.getMonth(), sd.getUTCDate(), sd.getUTCHours(), sd.getUTCMinutes(), sd.getUTCSeconds());
var endUTC = Date.UTC(ed.getFullYear(), ed.getMonth(), ed.getUTCDate(), ed.getUTCHours(), ed.getUTCMinutes(), ed.getUTCSeconds());
var timeSlice = Math.round((endUTC -startUTC) / (mi - 1));
//setup the date for query on the first loop iteration
var loopDateUTC;
var count = 0;
//define the sort order, based on user selection
if(oldestFirst) {
loopDateUTC = startUTC;
} else {
loopDateUTC = endUTC;
}
//loop through for maxItems-1 iterations and get one row for the named properties each time
for (count=0; count < (mi); count++) {
var loopDate = new Date();
loopDate.setTime(loopDateUTC);
var params = {
oldestFirst: false /* BOOLEAN */,
maxItems: 1 /* NUMBER */,
endDate: loopDate /* DATETIME */,
propertyNames: propertyNames /* INFOTABLE */,
query: query /* QUERY */,
startDate: undefined /* DATETIME */
};
//if this is the first iteration, create the output table from the first result set
if (count == 0) {
//get one row of data to obtain the structure
var outputTable = me.QueryNamedPropertyHistory(params);
outputTable.RemoveAllRows(); //clear table rows for readding later
}
//get one row of data to add to our table
var propertyHistory = me.QueryNamedPropertyHistory(params);
var row = propertyHistory.getRow(0);
//set the datetime of the row to match the Query endDate
row.timestamp = loopDate; //because we know that timestamp will be our column name
outputTable.AddRow(row);
//prepare for next iteration
if(oldestFirst) {
loopDateUTC = loopDateUTC + (timeSlice);
} else {
loopDateUTC = loopDateUTC - (timeSlice);
}
}
var result = outputTable;
