handler payload() to get key's and values.

[fooballs]

Hello!

im folowing the get_Document Example on Firestore, but i can't get the key & values for the fbdo.payload() to move to other var's.

I really apreciated of you could give an example how handle the information im geeting.

Example.
String documentPath = "info/countries";
String mask = "Singapore";

    Serial.println("------------------------------------");
    Serial.println("Get a document...");

    if (Firebase.Firestore.getDocument(&fbdo, FIREBASE_PROJECT_ID, "", documentPath.c_str(), mask.c_str()))
    {
        Serial.println("PASSED");
        Serial.println("------------------------------------");
        Serial.println(fbdo.payload());
        Serial.println("------------------------------------");
        Serial.println();
    }

Regards.

[mobizt]

The payload is string of JSON. It need to pass to JSON parser e.g. FirebaseJson to get the value you want.

The JSON structure of payload returned from Fitestore can be complex which based on your database structure.

To parse payload with FirebaseJson class.

    if (Firebase.Firestore.getDocument(&fbdo, FIREBASE_PROJECT_ID, "", documentPath.c_str(), mask.c_str()))
    {
        Serial.println("PASSED");
        Serial.println("------------------------------------");

        FirebaseJson json;

        json.setJsonData(fbdo.payload());

        FirebaseJsonData data;

        json.get(data, "fields/Singapore/mapValue/fields/time_zone/integerValue");
        if (data.success)
            Serial.println(data.stringValue);

        json.get(data, "fields/Singapore/mapValue/fields/population/integerValue");
        if (data.success)
            Serial.println(data.stringValue);

        Serial.println("------------------------------------");
        Serial.println();
    }

[ev-olution]

Unfortunately this does not work with Firestore>DataQuery example code. I noticed that Serial.printf("ok\n%s\n\n", fbdo.payload().c_str()); gives output that starts with [. I guess it marks where document starts. So the only way I can extract value from payload is to use ArduinoJson libraty and use the following code:

  sprintf(buffer, fbdo.payload().c_str());
  String myString = String(buffer);
  myString.remove(0, 1);
  sprintf(buffer, myString.c_str());

  DeserializationError error = deserializeJson(doc, buffer);

  if (error) {
    ...............
  }

  JsonObject document = doc["document"];
  const char* document_name = document["name"];
  JsonObject document_fields = document["fields"];
  const char* document_fields_checkoutSessionId_stringValue = document_fields["checkoutSessionId"]["stringValue"];
  const char* document_fields_amountTotal_integerValue = document_fields["amountTotal"]["integerValue"];
  const char* document_fields_paymentLink_stringValue = document_fields["paymentLink"]["stringValue"];
  const char* document_fields_paymentStatus_stringValue = document_fields["paymentStatus"]["stringValue"];

And this is the code that won't work:

  FirebaseJson json;
  json.setJsonData(fbdo.payload());
  
  FirebaseJsonData data;
  json.get(data, "document/fields/checkoutSessionId/stringValue");


  if (data.success) {
    Serial.println("Data Success");
    .......................
  } 
  else Serial.println("Data Error");`

It returns Data Error. I am not sure what I am doing wrong.

[ev-olution]

I think I figured it out. I was using incorrect path. Because query can return few documents, path should look something like this:
json.get(data, "[0]/document/fields/checkoutSessionId/stringValue");

[mobizt]

All examples were tested and worked normally.

You have to print your data to check instead of thinking of impossible assumption.

If the response payload was too large the data can be truncated, you should extend the response size limit via setResponseSize of FirebaseData object.

[ev-olution]

Thanks for response. DataQuery example was working fine, until I tried to extract some values from payload by using another example. As in my previous comment, I already found my mistake, path for required value was incorrect. It was missing a document pointer "[0]", as fbdo.payload() in DataQuery can return more than just a one document in my case. Unfortunately I was unable to find correct example of required value extraction path declaration for DataQuery payload in existing examples. So it was just a wild guess, which fortunately worked for me.

[mobizt]

You're already know even from your mistake that the Firestore document structure can be simple to complex which are very customizable.

You have to know the response payload based on your data structure designed before parsing it.

Nobody known your data structure but you.

I often mentioned about this here if you search it.

That is why the result of Firestore function is the payload string to allow custom parsing by JSON library.

[fooballs]

I could get the information with Arduinojson library. but your way is better. Thanks!!!
StaticJsonDocument<512> doc;

        DeserializationError error = deserializeJson(doc, fbdo.payload());
        
        if (error) {
          Serial.print(F("deserializeJson() failed: "));
          Serial.println(error.f_str());
          return;
        }
        
        const char* time_zone = doc["fields"]["Singapore"]["mapValue"]["fields"]["time_zone"]["integerValue"];
        const char* population = doc["fields"]["Singapore"]["mapValue"]["fields"]["population"]["integerValue"];
        const char* createTime = doc["createTime"]; 
        const char* updateTime = doc["updateTime"];
        Serial.println(time_zone);
        Serial.println(population);
        Serial.println(createTime);
        Serial.println(updateTime);