Logging Interface Access

Thank you all for your advice.

Although I initially lacked some information, ultimately, I would like to calculate usage rates for each application from the log data. Therefore, I prefer to save the logs as records rather than text files. Additionally, since I need to calculate usage rates by organization, user information is also necessary.

Hence, I believe the approach Mike has already implemented is the closest to what I need.

I implemented the Web API as shown below. While it returns an image file as the response, it seems that neither a!startProcess, a!writeToDataStoreEntity, nor a!writeRecords functions are executing.

I implemented it using the GET method to return the image file. Is there anything else I should do?

a!localVariables(

  local!codea: 200,
  local!codeb: 200,
  local!codec: 200,

  local!a: a!writeToDataStoreEntity(
    dataStoreEntity: cons!XLOG_EVENT,
    valueToStore: 'type!{urn:com:appian:types:XLOG}XLOG_RT_EVENT'(
      timestamp: now(),
      appName: "Application Name",
      functionName: "Function Name",
      user: tostring(loggedInUser())
    ),
    onSuccess: a!save(local!codea, 201),
    onError: a!save(local!codea, 202)
  ),

  local!b: a!writeRecords(
    records: 'recordType!{}XLOG rtEvent'(
      'recordType!{}XLOG rtEvent.fields.{}timestamp': now(),
      'recordType!{}XLOG rtEvent.fields.{}appName': "Application Name RT",
      'recordType!{}XLOG rtEvent.fields.{}functionName': "Function Name RT",
      'recordType!{}XLOG rtEvent.fields.{}user': tostring(loggedInUser())
    ),
    onSuccess: a!save(local!codeb, 201),
    onError: a!save(local!codeb, 202)
  ),

  local!c: a!startProcess(
    processModel: cons!XLOG_pmTest,
    onSuccess: a!save(local!codec, 201),
    onError: a!save(local!codec, 202)
  ),

  local!d: a!richTextDisplayField(
    value: "code: " & local!codea & " " & local!codeb& " " & local!codec
  ),

  a!httpResponse(
    statusCode: local!codec,
    headers: {
      a!httpHeader(name: "Content-Type", value: "image/png"),
      a!httpHeader(name: "Cache-Control", value: "no-store, no-cache, must-revalidate, max-age=0"),
      a!httpHeader(name: "Pragma", value: "no-cache")
    },
    body: cons!XLOG_PNG
  )
)

NOTE:In this sample code, these local variables are only for debbuging.

Thank you all for your advice.

Although I initially lacked some information, ultimately, I would like to calculate usage rates for each application from the log data. Therefore, I prefer to save the logs as records rather than text files. Additionally, since I need to calculate usage rates by organization, user information is also necessary.

Hence, I believe the approach Mike has already implemented is the closest to what I need.

I implemented the Web API as shown below. While it returns an image file as the response, it seems that neither a!startProcess, a!writeToDataStoreEntity, nor a!writeRecords functions are executing.

I implemented it using the GET method to return the image file. Is there anything else I should do?

a!localVariables(

  local!codea: 200,
  local!codeb: 200,
  local!codec: 200,

  local!a: a!writeToDataStoreEntity(
    dataStoreEntity: cons!XLOG_EVENT,
    valueToStore: 'type!{urn:com:appian:types:XLOG}XLOG_RT_EVENT'(
      timestamp: now(),
      appName: "Application Name",
      functionName: "Function Name",
      user: tostring(loggedInUser())
    ),
    onSuccess: a!save(local!codea, 201),
    onError: a!save(local!codea, 202)
  ),

  local!b: a!writeRecords(
    records: 'recordType!{}XLOG rtEvent'(
      'recordType!{}XLOG rtEvent.fields.{}timestamp': now(),
      'recordType!{}XLOG rtEvent.fields.{}appName': "Application Name RT",
      'recordType!{}XLOG rtEvent.fields.{}functionName': "Function Name RT",
      'recordType!{}XLOG rtEvent.fields.{}user': tostring(loggedInUser())
    ),
    onSuccess: a!save(local!codeb, 201),
    onError: a!save(local!codeb, 202)
  ),

  local!c: a!startProcess(
    processModel: cons!XLOG_pmTest,
    onSuccess: a!save(local!codec, 201),
    onError: a!save(local!codec, 202)
  ),

  local!d: a!richTextDisplayField(
    value: "code: " & local!codea & " " & local!codeb& " " & local!codec
  ),

  a!httpResponse(
    statusCode: local!codec,
    headers: {
      a!httpHeader(name: "Content-Type", value: "image/png"),
      a!httpHeader(name: "Cache-Control", value: "no-store, no-cache, must-revalidate, max-age=0"),
      a!httpHeader(name: "Pragma", value: "no-cache")
    },
    body: cons!XLOG_PNG
  )
)

NOTE:In this sample code, these local variables are only for debbuging.

You web API structure as per this sample code doesnt seem right! the smart servcies should not be related to a local variable. 

Please check the documentation for steps/considerations. In you use case you can create a web API that has a!startProcess() in it. Whatever you are trying to accomplish in a!writeRecord() and a!writeToDataStoreEntity() should be moved inside the process. 

The https Response configuration would also come within the onSuccess or onError of a!startProcess() configuration.

"Usage Rate" ... isn't this about users actually doing something vs. just staring at a page? User activity in Appian is closely tied to starting processes. When writing records, you can also write record events which then should correlate with "user activity".

Dear Stephan,

I generally agree with your opinion.
However, we are building a portal site for users and are considering displaying various information for them on the top page.
Since there are quite a few users for whom simply viewing the portal site is sufficient, we would like to also track who has accessed the portal site.

Dear Harsha,

Thank you for your advice.

I reviewed the documentation again, modified my code and confirmed that a!startProcess() and a!writeRecord can be executed.

However, as mentioned in my initial post,
(1) Create a Web API on Appian that returns an image as the response and simultaneously saves a log.
(2) Place an image on the target interface and set the endpoint of the Web API created in (1) as the image source.
(3) As a result, when the interface is opened, the Web API in (1) is called, and the log is recorded.

Since we intend to implement this behavior, the Web API must be implemented with the GET method.

As a result, we encountered the error:
"Smart Services cannot be executed in Web APIs that have a method of 'GET'."

and cannot proceed further.

Is there any way to work around this?

It is my understanding that portal users do not 'log in' to Appian, and therefore loggedInUser() will return the service account that is called from the portal rather than the person accessing the portal. You can probably add some metadata (headers, path, query param, etc) to your API call to get some sort of user info.

Hi Keizo,

It is not a hard requirement to write records from a Process Model. For APIs that are intended to be called frequently, it is better in practice to call a!writeRecords() from the API object itself to remove the overhead and latency of starting a process.

Keep in mind that, if enabled in the record types, you can write multiple related records at once if they are sync'ed records and have a relationship defined. For me, this has worked for 99% of my use cases. For the other 1%, I did something like the following: 

a!writeRecords(
    records: {Record A and its embedded related records}
    onSuccess: a!writeRecords(
        records: {Record not related to record A}
        onSuccess: a!httpResponse()
        onError: a!httpResponse()
    ),
    onError: a!httpResponse()
)

This isn't really how to structure what I was suggesting.  My setup has 5 main layers - it could potentially be condensed some, but the layer structure defined here gives you levels of abstraction that will increase potential reusability and reduce rework efforts should you decide to change the way something works in the future.

1. On your interface, call an expression rule in a Local Variable definition, passing in the person's username, and relevant details about where they're viewing from.
2. In the expression rule, call an Integration you set up, and map the results.  It doesn't need to do anything as complex as returning an "image file", it could simply return a timestamp or boolean value.  My suggestion would be simply having it return a "last updated" timestamp (to be stored in the aforementioned Local Variable).
3. In the integration, call the Web API you set up, passing in the details sent in from the Expression Rule.  Tie it to a Connected System pointing at your own environment and with a Service Account that has permissions to launch the process model used in the Web API.
4. in the Web API, configure as a POST method and call the designated Process Model using a!startProcess(), passing in the same relevant details having been passed down.
5. In the process model, you can do your DB write / update, passing back values to the caller indicating that it ran successfully (such as a "last updated" timestamp value).  If you decide to look up an existing row for the user in question (such as grouping rows by day, so as not to clutter the table with a row for every single refresh), it will be trivially easy, for instance, to pre-query any relevant row for the user per location/day, and if one exists, update that row, and otherwise, create a new one.  Or just write a new row every time, that part is up to you.

Thanks Jesse.

I understood that. But the error "Smart Services cannot be executed in Web APIs that have a method of 'GET'." is still remaining...

I'm sorry for causing confusion. The "Portal Site" I mentioned is not the Appian Portal, but a portal site in the usual sense, meaning the entry point for users.

Web APIs using 'GET' method cannot call any smart services as per Appian Design. So for intended functionality use the 'POST' method in web API and setup an Integration that calls your web API from target interface. As soon as interface loads, the Integration (executed on load against a local variable) will call the API. API will execute the smart service and record log with a success response for integration. When setting up a!httpResponse for web API in response body you can send back the image as well.

a!httpResponse(
  statusCode: 200,
  headers: {
    a!httpHeader(name: "content-type", value: "application/json")
  },
  body: a!iconIndicator("STATUS_WARN")
)

However as earlier discussed in this thread that to log the interface load activity you don't necessarily need to follow what ChatGPT suggested. 

The web API can write to db and respond back with a successful message. That web API can be called using an integration in the interface. So on load the integration->web API->write records will execute. On Error of API execution, response can be a user friendly message asking them to re-load the interface.

Is there any reason for image to be involved in the response and showing it on interface if you just want to log the interface load activity?