Visual Basic 6.0

Firebase GET - Reading Data

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Demonstrates how to read parts of a Firebase JSON database. The data used in this example is at Chilkat Firebase Pigs Database, and is shown here:

Visual Basic 6.0

Dim success As Long
success = 0

' Demonstrates how to read parts of a Firebase JSON database.

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

' This example assumes a JWT authentication token, if required, has been previously obtained.
' See Get Firebase Access Token from JSON Service Account Private Key for sample code.

' Load the previously obtained Firebase access token into a string.
Dim fac As New CkFileAccess
Dim accessToken As String
accessToken = fac.ReadEntireTextFile("qa_data/tokens/firebaseToken.txt","utf-8")
If (fac.LastMethodSuccess <> 1) Then
    Debug.Print fac.LastErrorText
    Exit Sub
End If

Dim rest As New ChilkatRest

' Make the initial connection (without sending a request yet).
' Once connected, any number of requests may be sent.  It is not necessary to explicitly
' call Connect before each request.  
success = rest.Connect("chilkat.firebaseio.com",443,1,1)
If (success <> 1) Then
    Debug.Print rest.LastErrorText
    Exit Sub
End If

' If authentication is required...
Dim authGoogle As New ChilkatAuthGoogle
authGoogle.AccessToken = accessToken
success = rest.SetAuthGoogle(authGoogle)

' Chilkat's sample data (pig-rescue data) is publicly readable at: https://chilkat.firebaseio.com/.json

' Let's get the animals with the shallow parameter so we can see how many pigs exist.
Dim jsonResponse As String
jsonResponse = rest.FullRequestNoBody("GET","/pig-rescue/animal.json?shallow=true")
If (rest.LastMethodSuccess <> 1) Then
    Debug.Print rest.LastErrorText
    Exit Sub
End If

' The JSON returned should look like this:  
' {"-KI3bD-FU_Dake7sYOiP":true,"-KI3bD-FU_Dake7sYOiT":true,"-KI3bD-FU_Dake7sYOiS":true,"-KI3bD-FU_Dake7sYOiU":true,"-KI3bD-FU_Dake7sYOiV":true,"-KI3bD-FU_Dake7sYOiR":true,"-KI3bD-FU_Dake7sYOiQ":true}
Debug.Print jsonResponse

' Parse the response so we can iterate over each pig in the database..
Dim piggyPath As New ChilkatStringBuilder
Dim shallow As New ChilkatJsonObject
Dim piggyData As New ChilkatJsonObject
success = shallow.Load(jsonResponse)
Dim count As Long
count = shallow.Size
Dim i As Long
i = 0
Do While i < count

    ' Get each individual pig's data.
    piggyPath.Clear 
    success = piggyPath.Append("/pig-rescue/animal/")
    success = piggyPath.Append(shallow.NameAt(i))
    success = piggyPath.Append("/.json")

    Dim piggyJson As String
    piggyJson = rest.FullRequestNoBody("GET",piggyPath.GetAsString())
    If (rest.LastMethodSuccess <> 1) Then
        Debug.Print rest.LastErrorText
        Exit Sub
    End If

    ' Show this piggy's data...
    ' An example of one pig's data is shown here:
    ' {"birth":"February, 1998","from":"Middle Ave.","gender":"F","in-date":"January, 2000",
    '   "name":"Molly II","picture":{"caption":"Molly in the Pasture","description":"Black pig","file":"molly_th.jpg"},
    '   "species":"pot belly pig","type":"Cathy's Herd"}
    Debug.Print "---- " & i & " ----"
    Debug.Print piggyJson

    ' Let's get the pig's name, and the caption of the picture.
    success = piggyData.Load(piggyJson)
    Debug.Print "name: " & piggyData.StringOf("name")
    Debug.Print "caption: " & piggyData.StringOf("picture.caption")

    i = i + 1
Loop

' Note: In many of the Chilkat examples, you may notice strange ways
' of doing something that should be simpler and shorter.  For example,
' building the piggyPath (above) could've been written differently,
' with some simple string concatenation.
' 
' The reason is that the Chilkat examples are written in a 
' proprietary "example code" scripting language,
' and then automatically generated to each of the different programming
' languages you see on example-code.com.  The code generation is
' limited in what it can do.  For example, string concatentation
' is not yet a feature of the "example code" scripting language (as of May 2016), 
' and therefore you won't see the use of a programming language's string
' concatentation operators in any example.  
'