I've come across numerous inquiries regarding this issue, but I can't seem to find a solution (the abundance of questions on the internet about this topic is astonishing!!). Let me be direct:
test.asmx
'Simple POST method with parameters
<WebMethod(EnableSession:=True)>
<ScriptMethodAttribute(ResponseFormat:=ResponseFormat.Json)>
Public Function TestarPost(ByVal Valor as String) As String
Dim x
End Function
'Simple GET method without parameters
<WebMethod(EnableSession:=True)>
<ScriptMethodAttribute(ResponseFormat:=ResponseFormat.Json, UseHttpGet:=True)>
Public Function Testar() As String
return "ok ;>D"
End Function
'GET method with parameters
<WebMethod(EnableSession:=True)>
<ScriptMethodAttribute(ResponseFormat:=ResponseFormat.Json, UseHttpGet:=True)>
Public Function TestarGet(ByVal Valor as String) As String
return Valor
End Function
Testing it in the JavaScript console:
obj = { Valor: "x" }
$.ajax({
type: "POST",
url: "test.asmx/TestarPost",
dataType: "json",
data: JSON.stringify(obj),
contentType: "application/json; charset=utf-8",
success: function(ret) {
console.log(ret.d);
},
error: function(xhr,textStatus,errorThrown) {
console.log(xhr.status + "||" + xhr.responseText);
}
});
Success!
$.ajax({
type: "GET",
url: "ServerSide.asmx/Testar",
contentType: "application/json; charset=utf-8",
success: function(ret) {
console.log(ret.d);
},
error: function(xhr,textStatus,errorThrown) {
console.log(xhr.status + "||" + xhr.responseText);
}
});
Success! Returns the data correctly in JSON format
$.ajax({
type: "GET",
url: "test.asmx/TestarGet",
dataType: "json",
data: JSON.stringify(obj),
contentType: "application/json; charset=utf-8",
success: function(ret) {
console.log(ret.d);
},
error: function(xhr,textStatus,errorThrown) {
console.log(xhr.status + "||" + xhr.responseText);
}
});
Fails! Same approach as with POST
The error message states "Invalid web service call, missing value for parameter: \u0027Valor\u0027." It also fails when sending an object literal ("Invalid JSON primitive"). However, accessing the URL .../ServerSide.asmx/TestarGet?Valor=x returns "opa" (perhaps a clue?)
It's perplexing why it fails to work, given that the approach is similar to the one used in POST. Maybe because the POST method isn't affecting anything visibly (although no errors are returned).
My objective is to develop a function serverSide(asmxMethod, obj) to establish a generalized connection between client and server functions.