public async Task <City> GetCityData(string elementWebId)
{
string url = baseUrl + "streamsets/" + elementWebId + "/value";
string response = await DownloadWebData(url);
PIListObject elementData = JsonConvert.DeserializeObject <PIListObject>(response);
return(new City(elementData));
}
private async Task <Cities> GetCitiesDataNoBatch()
{
//Exercise 1
//First HTTP request against PI Web API to get the WebId of the AF database Weather
//Generate the url for making the first HTTP request
string url = baseUrl + @"assetdatabases?path=\\pisrv01\Weather";
//Retrieve the string response from URL
string response = await DownloadWebData(url);
//JsonConvert.DeserializeObject from JSON.NET converts the JSON string into a PIObject.
PIObject dbData = JsonConvert.DeserializeObject <PIObject>(response);
//Second HTTP request against PI Web API to get the WebId from all attributes "Wikipedia Thumbnail Url" (one per each city).
//HINT: https://pisrv01.pischool.int/piwebapi/help/controllers/element/actions/findelementattributes
url = baseUrl + "assetdatabases/" + dbData.WebId + "/elementattributes?attributeNameFilter=*Wikipedia%20Thumbnail%20Url*";
response = await DownloadWebData(url);
PIListObject imageAttributes = JsonConvert.DeserializeObject <PIListObject>(response);
//Third HTTP request against PI Web API to get the current values from all attributes "Wikipedia Thumbnail Url" using the WebId retrieved from the previous call.
//Get the WebIds from the PIListObject
List <string> webIds = imageAttributes.GetItemsWebIds();
//Using the GetValuesAdHoc method from StreamSet Controller
//HINT: https://pisrv01.pischool.int/piwebapi/help/controllers/streamset/actions/getvaluesadhoc
url = baseUrl + "streamsets/value?";
foreach (string webId in webIds)
{
url = url + string.Format("webId={0}&", webId);
}
url = url.Substring(0, url.Length - 1);
response = await DownloadWebData(url);
PIListObject imagesValues = JsonConvert.DeserializeObject <PIListObject>(response);
//Using both PIListObjects as inputs, the Cities object is created.
Cities cities = new Cities(imageAttributes, imagesValues);
return(cities);
}
private async Task <Cities> GetCitiesDataWithBatch()
{
//Exercise 5
//Please refer to the following page for more information about Batch: https://pisrv01.pischool.int/piwebapi/help/controllers/batch/actions/execute
Dictionary <string, PIBatchRequest> globalBatch = new Dictionary <string, PIBatchRequest>();
//First internal request gets the WebId of the AF database Weather
PIBatchRequest batchGetDbWebId = new PIBatchRequest()
{
Method = "GET",
Resource = baseUrl + @"assetdatabases?path=\\pisrv01\Weather"
};
//Second internal request gets the WebId from all attributes "Wikipedia Thumbnail Url" (one per each city)
//using the WebId returned from the first internal request
PIBatchRequest batchGetElementsWebIds = new PIBatchRequest()
{
Method = "GET",
Resource = baseUrl + "assetdatabases/{0}/elementattributes?attributeNameFilter=*Wikipedia%20Thumbnail%20Url*",
Parameters = new List <string>()
{
"$.1.Content.WebId"
},
ParentIds = new List <string>()
{
"1"
}
};
//Third internal request gets the current values from all attributes "Wikipedia Thumbnail Url"
//using the WebIds returned from the second internal request
PIBatchRequest batchGetAttributesValues = new PIBatchRequest()
{
Method = "GET",
RequestTemplate = new PIRequestTemplate()
{
Resource = baseUrl + "streams/{0}/value"
},
Parameters = new List <string>()
{
"$.2.Content.Items[*].WebId"
},
ParentIds = new List <string>()
{
"2"
}
};
//Add all internal requests to the dictionary and create a JSON response for the body of the HTTP request
globalBatch.Add("1", batchGetDbWebId);
globalBatch.Add("2", batchGetElementsWebIds);
globalBatch.Add("3", batchGetAttributesValues);
string json = JsonConvert.SerializeObject(globalBatch);
//It is important to define that the format of the body message is JSON
HttpContent httpContent = new StringContent(json, Encoding.UTF8, "application/json");
string url = baseUrl + "/batch";
//Start to make the HTTP request and wait for the response
string response = await PostWebData(url, httpContent);
//Deserialize the response to have access to the responses of each internal request
Dictionary <string, PIBatchResponse> batchData = JsonConvert.DeserializeObject <Dictionary <string, PIBatchResponse> >(response);
//Convert the string responses to PIListObject and PIValue[]
PIListObject imageAttributes = JsonConvert.DeserializeObject <PIListObject>(batchData["2"].Content.ToString());
JArray items = (JArray)(batchData["3"].Content["Items"]);
PIValue[] piValues = new PIValue[items.Count];
for (int i = 0; i < items.Count; i++)
{
piValues[i] = JsonConvert.DeserializeObject <PIValue>(items[i]["Content"].ToString());
}
//Using both PIListObjects as inputs, the Cities object is created.
Cities cities = new Cities(imageAttributes, piValues);
return(cities);
}
