(PowerBuilder) Firebase GET - Reading Data

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:

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
integer li_Success
oleobject loo_Fac
string ls_AccessToken
oleobject loo_Rest
oleobject loo_AuthGoogle
string ls_JsonResponse
oleobject loo_PiggyPath
oleobject loo_Shallow
oleobject loo_PiggyData
integer li_Count
integer i
string ls_PiggyJson

// 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.
loo_Fac = create oleobject
// Use "Chilkat_9_5_0.FileAccess" for versions of Chilkat < 10.0.0
li_rc = loo_Fac.ConnectToNewObject("Chilkat.FileAccess")
if li_rc < 0 then
    destroy loo_Fac
    MessageBox("Error","Connecting to COM object failed")
    return
end if
ls_AccessToken = loo_Fac.ReadEntireTextFile("qa_data/tokens/firebaseToken.txt","utf-8")
if loo_Fac.LastMethodSuccess <> 1 then
    Write-Debug loo_Fac.LastErrorText
    destroy loo_Fac
    return
end if

loo_Rest = create oleobject
// Use "Chilkat_9_5_0.Rest" for versions of Chilkat < 10.0.0
li_rc = loo_Rest.ConnectToNewObject("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.  
li_Success = loo_Rest.Connect("chilkat.firebaseio.com",443,1,1)
if li_Success <> 1 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Fac
    destroy loo_Rest
    return
end if

// If authentication is required...
loo_AuthGoogle = create oleobject
// Use "Chilkat_9_5_0.AuthGoogle" for versions of Chilkat < 10.0.0
li_rc = loo_AuthGoogle.ConnectToNewObject("Chilkat.AuthGoogle")

loo_AuthGoogle.AccessToken = ls_AccessToken
loo_Rest.SetAuthGoogle(loo_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.
ls_JsonResponse = loo_Rest.FullRequestNoBody("GET","/pig-rescue/animal.json?shallow=true")
if loo_Rest.LastMethodSuccess <> 1 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Fac
    destroy loo_Rest
    destroy loo_AuthGoogle
    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}
Write-Debug ls_JsonResponse

// Parse the response so we can iterate over each pig in the database..
loo_PiggyPath = create oleobject
// Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
li_rc = loo_PiggyPath.ConnectToNewObject("Chilkat.StringBuilder")

loo_Shallow = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_Shallow.ConnectToNewObject("Chilkat.JsonObject")

loo_PiggyData = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_PiggyData.ConnectToNewObject("Chilkat.JsonObject")

loo_Shallow.Load(ls_JsonResponse)
li_Count = loo_Shallow.Size
i = 0
do while i < li_Count

    // Get each individual pig's data.
    loo_PiggyPath.Clear()
    loo_PiggyPath.Append("/pig-rescue/animal/")
    loo_PiggyPath.Append(loo_Shallow.NameAt(i))
    loo_PiggyPath.Append("/.json")

    ls_PiggyJson = loo_Rest.FullRequestNoBody("GET",loo_PiggyPath.GetAsString())
    if loo_Rest.LastMethodSuccess <> 1 then
        Write-Debug loo_Rest.LastErrorText
        destroy loo_Fac
        destroy loo_Rest
        destroy loo_AuthGoogle
        destroy loo_PiggyPath
        destroy loo_Shallow
        destroy loo_PiggyData
        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"}
    Write-Debug "---- " + string(i) + " ----"
    Write-Debug ls_PiggyJson

    // Let's get the pig's name, and the caption of the picture.
    loo_PiggyData.Load(ls_PiggyJson)
    Write-Debug "name: " + loo_PiggyData.StringOf("name")
    Write-Debug "caption: " + loo_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.  
// 


destroy loo_Fac
destroy loo_Rest
destroy loo_AuthGoogle
destroy loo_PiggyPath
destroy loo_Shallow
destroy loo_PiggyData