Xojo Plugin

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:

Xojo Plugin

Dim success As Boolean
success = False

// 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 Chilkat.FileAccess
Dim accessToken As String
accessToken = fac.ReadEntireTextFile("qa_data/tokens/firebaseToken.txt","utf-8")
If (fac.LastMethodSuccess <> True) Then
    System.DebugLog(fac.LastErrorText)
    Return
End If

Dim rest As New Chilkat.Rest

// 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,True,True)
If (success <> True) Then
    System.DebugLog(rest.LastErrorText)
    Return
End If

// If authentication is required...
Dim authGoogle As New Chilkat.AuthGoogle
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 <> True) Then
    System.DebugLog(rest.LastErrorText)
    Return
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}
System.DebugLog(jsonResponse)

// Parse the response so we can iterate over each pig in the database..
Dim piggyPath As New Chilkat.StringBuilder
Dim shallow As New Chilkat.JsonObject
Dim piggyData As New Chilkat.JsonObject
success = shallow.Load(jsonResponse)
Dim count As Int32
count = shallow.Size
Dim i As Int32
i = 0
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 <> True) Then
        System.DebugLog(rest.LastErrorText)
        Return
    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"}
    System.DebugLog("---- " + Str(i) + " ----")
    System.DebugLog(piggyJson)

    // Let's get the pig's name, and the caption of the picture.
    success = piggyData.Load(piggyJson)
    System.DebugLog("name: " + piggyData.StringOf("name"))
    System.DebugLog("caption: " + piggyData.StringOf("picture.caption"))

    i = i + 1
Wend

// 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.  
//