Daniel Castro · Jan 11, 2022

%Net.HttpRequest and {}.%FromJSON

Hi !

 I am new to the language and I am trying to read some json data from a government site (it is public data).

The address is:,...

Here is some data sample:

[{"NC":"Nível Territorial (Código)","NN":"Nível Territorial","MC":"Unidade de Medida (Código)","MN":"Unidade de Medida","V":"Valor","D1C":"Brasil (Código)","D1N":"Brasil","D2C":"Variável (Código)","D2N":"Variável","D3C":"Mês (Código)","D3N":"Mês"},{"NC":"1","NN":"Brasil","MC":"30","MN":"Número-índice","V":"0.0000000055765","D1C":"1","D1N":"Brasil","D2C":"2289","D2N":"INPC - Número-índice (base: dezembro de 1993 = 100)","D3C":"197903","D3N":"março 1979"},{"NC":"1","NN":"Brasil","MC":"30","MN":"Número-índice","V":"0.0000000057689","D1C":"1","D1N":"Brasil","D2C":"2289","D2N":"INPC - Número-índice (base: dezembro de 1993 = 100)","D3C":"197904","D3N":"abril 1979"},{"NC":"1","NN":"Brasil","MC":"30","MN":"Número-índice","V":"0.0000000058704","D1C":"1","D1N":"Brasil","D2C":"2289","D2N":"INPC - Número-índice (base: dezembro de 1993 = 100)","D3C":"197905","D3N":"maio 1979"},{"NC":"1","NN":"Brasil","MC":"30","MN":"Número-índice","V":"0.0000000060465","D1C":"1","D1N":"Brasil","D2C":"2289","D2N":"INPC - Número-índice (base: dezembro de 1993 = 100)","D3C":"197906","D3N":"junho 1979"},

I am trying  to make a class to read some of this data:

/// Contém os dados do INPC para calculos financeiros
Class User.TabelaINPC Extends (%Persistent, %JSON.Adaptor)
{ Property Mes As %Integer [ Required ]; Index MesIndex On Mes [ Unique ]; Property Descricao As %String [ Required ]; Property Valor As %Double [ Required ]; ClassMethod leINPC() As %Status
Set result = ##class(%Net.HttpRequest).%New()
Set result.Server = ""
set result.SSLConfiguration = "padrao"
set result.Https = 1
set result.SSLCheckServerIdentity = 0
set result.FollowRedirect = $$$YES
set status = result.Get("/values/t/1736/n1/all/v/all/p/all/d/v44%202,v68%202,v2289%2013,v2290%202,v2291%202,v2292%202?formato=json")
set response = result.HttpResponse.Data
set dados = {}.%FromJSON(response) -----> THE ERROR IS HERE
CATCH erro {
write "ERRO:"
write erro.Name_", "_erro.Location_", error code "_erro.Code,!
do $system.OBJ.DisplayError()
RETURN erro.AsStatus()
Quit $$$OK

I am getting the error code 5035, Parsing error code 3.

What I am doing wrong?

Thanks in advance !

Product version: IRIS 2021.2
0 341
Discussion (15)3
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I'd recommend looking at what (other than valid JSON) is in result.HttpResponse.Data. Also worth looking at result.HttpResponse.StatusCode - is it 400 or 404?

It looks like there might be an issue with the service you're trying to use - at , pasting in "/t/1612/n2/all/v/all/p/last/c81/2702/f/u" as "Parâmetros/valores da API:" then clicking "Consultar" I get an alert saying "A solicitação de conexão com pools sofreu timeout".

I also see this from ObjectScript with Server set to instead of

Hi Timothy !

Thank´s for the help.

Yesterday the service was unstable, but today is working fine When I type de url in the browser I get the data, but in my code (I did as you told me to) HttpResponse.StatusCode returns 404.

I don´t know why...

Right - at this point I'd say set Server to instead of and see if that fixes it.


No, it din´t fix it. It didn´t find the server The correct one is
Does it make any difference if the connection is sync or async?

Do I have to change the code because of it?

Thanks !

Problem solved !

/// Contém os dados do INPC para calculos financeiros
Class User.TabelaINPC Extends (%Persistent, %JSON.Adaptor)
{ Property Mes As %Integer [ Required ]; Index MesIndex On Mes [ Unique ]; Property Descricao As %String [ Required ]; Property Valor As %Double [ Required ]; ClassMethod leINPC() As %Status
Set result = ##class(%Net.HttpRequest).%New()
Set result.Server = ""
set result.SSLConfiguration = "padrao"
set result.Https = 0 --- HTTPS MUST Be ZERO, although there is a redirect to https in the browser
set result.SSLCheckServerIdentity = 0
set result.FollowRedirect = $$$YES
set result.ContentType = "application/json"
set status = result.Get("/values/t/1736/n1/all/v/all/p/all/d/v44%202,v68%202,v2289%2013,v2290%202,v2291%202,v2292%202?formato=json")
set response = result.HttpResponse.Data
write "HTTP_CODE:"_result.HttpResponse.StatusCode,!
set dados = {}.%FromJSON(response)
set formatter = ##class(%JSON.Formatter).%New()
do formatter.Format(dados)
set iterator = dados.%GetIterator()
while iterator.%GetNext(.key, .value) { write "element:"_key_"=/"_value_"/ ",!} }
CATCH erro {
write "ERRO:",!
write erro.Name_", "_erro.Location_", error code "_erro.Code,!
do $system.OBJ.DisplayError()
RETURN erro.AsStatus()
Quit $$$OK

Thank you for the help Timothy !

Your result.HttpResponse.Data can be either a string or a stream object. If it's a stream object you'll have to handle it a little bit differently using result.HttpResponse.Data.Read():

set response=result.HttpResponse.Data.Read()
while 'result.HttpResponse.Data.AtEnd{
    set response = response_result.HttpResponse.Data.Read()

No, as long as response is json this should work - %FromJSON accepts strings, streams and even file paths as input:

set response = result.HttpResponse.Data
set dados = {}.%FromJSON(response)  

I think I am doing something wrong before 

set response = result.HttpResponse.Data
set dados = {}.%FromJSON(response)  

I am getting error 404 although the access by the browser is ok.

Thanks !

Try to set UserAgent in IRIS to your browser.

Just to add more information.

This is a C# Code that works fine :

HttpClient client = new HttpClient();
            string baseApiAddress = "";
            client.BaseAddress = new Uri(baseApiAddress);
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            HttpResponseMessage response = client.GetAsync("/api/values/t/1612/n2/all/v/all/p/last/c81/2702/f/u").Result;

It is a asynchronous connection.


One thing I always recommend is to get familiar with the API using a standalone tool before attempting to code the programmatic interface.  I like Postman as it has pretty good UI to work with.  If you are at the command line you can use curl.

Postman can also give you the code for different programming environments.  Unfortunately not Objectscript, but it is fairly easy to translate from the examples you can see.