How to Parse Data from Payload Firestore

[rizemmahendra]

I managed to get response data from firestore with string data type (as described in the readme file), but I am still confused about how to parse or deserialize the response payload into json objects for easy use. please give advice on how to parse the payload response obtained.

besides that I also get some other problems related to the payload response obtained from the server. here I use the firestore runQuery method. some of the problems / obstacles that I encountered when receiving the response were.

1. the payload only displays 1 data, even though the data that matches the conditions is more than 1
2. the payload string does not have a closing square bracket “]”, here is an example of a payload response

[{
        “document” : {
            “name” : “projects/fbtest-fb649/databases/(default)/documents/users/6MYEgJ**********KpjwL0yT9Yq1”,
            “fields” : {
                “uid” : {
                    “stringValue” : “6MYEgJ**********KpjwL0yT9Yq1”
                }
            },
            “createTime” : “2024-11-10T11:51:41.724626Z”,
            “updateTime” : “2024-11-10T11:52:38.618613Z”
        },
        “readTime” : “2024-11-18T11:15:31.423048Z”
    }

those are some of the problems / obstacles that I encountered when using this library to query the firestore. for the suggestions and solutions provided, I thank you.

[mobizt]

You can't use Firebase.printf to print or display the payload in case of large string because it will print only partial string based on the limited buffer of 1k or 4k (in ESP32) because it uses stack.

You should use Serial.print(aResult.c_str()) to print instead which you can parse it with any JSON libraries.

[mobizt]

After checking, I agree that the issue still exists, and I will investigate further to fix this.

[mobizt]

This issue introduced by this PR related to chunk decoding in v1.4.7.

In v1.4.6, this issue never existed.

[mobizt]

Now the issue was fixed in v1.4.8, please update.

Now the response payload is a valid JSON which you can parse it with any JSON library.

[mobizt]

There are no chances for incomplete response to be fulfill the buffer, if the response was not completed in time, it will fail with nothing returns instead.

The network does not involve this issue. The library was intensively tested in all network types and conditions.

The issue of response payload is because the chunked transfer decoding which the update is not properly fix which you can try v1.4.6.

This issue introduced by this PR related to chunk decoding in v1.4.7.

In v1.4.6, this issue never existed.

[rizemmahendra]

I don't know where the problem is, but I have made several attempts with different wifi connections, but only with a laptop tethering connection that gets the full payload string. I have also tried the library v1.4.6 as you suggested, and have also tried it with several different wifi connections, but the results remain the same.

[mobizt]

Library does nothing with your network. It's your hardware. You have to solve your network issue instead.

You should know that the WiFiClientSecure that used for server connection is on your side.

[mobizt]

You are talking off topic about network and library provides the FAQ and documentation on this, you have to read in case you have the network problem.

[mobizt]

This is async library, you will never miss any data unless the TCP session timed out occurred by network interruption and your blocking code.

You should test your code with v1.4.6 for the valid JSON response instead of talking for the mobile WiFi hotspot which is off topic, and it is not related to anything you understand.

The issue here is the problem for decoding the chunked transfer encoding response payload which is why you get missing last byte of data or get extra data.

[mobizt]

1. the payload only displays 1 data, even though the data that matches the conditions is more than 1

This depends on Firestore REST APIs.

The Request body for the runQuery method was set by QueryOptions class object that represents the JSON request body.

You also can print the QueryOptions object to Serial to see how the Request body was constructed.

For the Response body, the information is here.

[mobizt]

The chunked decoding issue was fixed in v1.4.9.