(PureBasic) 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:

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IncludeFile "CkStringBuilder.pb"
IncludeFile "CkAuthGoogle.pb"
IncludeFile "CkRest.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkFileAccess.pb"

Procedure ChilkatExample()

    ; 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.

    success.i

    ; Load the previously obtained Firebase access token into a string.
    fac.i = CkFileAccess::ckCreate()
    If fac.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    accessToken.s = CkFileAccess::ckReadEntireTextFile(fac,"qa_data/tokens/firebaseToken.txt","utf-8")
    If CkFileAccess::ckLastMethodSuccess(fac) <> 1
        Debug CkFileAccess::ckLastErrorText(fac)
        CkFileAccess::ckDispose(fac)
        ProcedureReturn
    EndIf

    rest.i = CkRest::ckCreate()
    If rest.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; 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 = CkRest::ckConnect(rest,"chilkat.firebaseio.com",443,1,1)
    If success <> 1
        Debug CkRest::ckLastErrorText(rest)
        CkFileAccess::ckDispose(fac)
        CkRest::ckDispose(rest)
        ProcedureReturn
    EndIf

    ; If authentication is required...
    authGoogle.i = CkAuthGoogle::ckCreate()
    If authGoogle.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkAuthGoogle::setCkAccessToken(authGoogle, accessToken)
    CkRest::ckSetAuthGoogle(rest,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.
    jsonResponse.s = CkRest::ckFullRequestNoBody(rest,"GET","/pig-rescue/animal.json?shallow=true")
    If CkRest::ckLastMethodSuccess(rest) <> 1
        Debug CkRest::ckLastErrorText(rest)
        CkFileAccess::ckDispose(fac)
        CkRest::ckDispose(rest)
        CkAuthGoogle::ckDispose(authGoogle)
        ProcedureReturn
    EndIf

    ; 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 jsonResponse

    ; Parse the response so we can iterate over each pig in the database..
    piggyPath.i = CkStringBuilder::ckCreate()
    If piggyPath.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    shallow.i = CkJsonObject::ckCreate()
    If shallow.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    piggyData.i = CkJsonObject::ckCreate()
    If piggyData.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckLoad(shallow,jsonResponse)
    count.i = CkJsonObject::ckSize(shallow)
    i.i = 0
    While i < count

        ; Get each individual pig's data.
        CkStringBuilder::ckClear(piggyPath)
        CkStringBuilder::ckAppend(piggyPath,"/pig-rescue/animal/")
        CkStringBuilder::ckAppend(piggyPath,CkJsonObject::ckNameAt(shallow,i))
        CkStringBuilder::ckAppend(piggyPath,"/.json")

        piggyJson.s = CkRest::ckFullRequestNoBody(rest,"GET",CkStringBuilder::ckGetAsString(piggyPath))
        If CkRest::ckLastMethodSuccess(rest) <> 1
            Debug CkRest::ckLastErrorText(rest)
            CkFileAccess::ckDispose(fac)
            CkRest::ckDispose(rest)
            CkAuthGoogle::ckDispose(authGoogle)
            CkStringBuilder::ckDispose(piggyPath)
            CkJsonObject::ckDispose(shallow)
            CkJsonObject::ckDispose(piggyData)
            ProcedureReturn
        EndIf

        ; 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 "---- " + Str(i) + " ----"
        Debug piggyJson

        ; Let's get the pig's name, and the caption of the picture.
        CkJsonObject::ckLoad(piggyData,piggyJson)
        Debug "name: " + CkJsonObject::ckStringOf(piggyData,"name")
        Debug "caption: " + CkJsonObject::ckStringOf(piggyData,"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.  
    ; 


    CkFileAccess::ckDispose(fac)
    CkRest::ckDispose(rest)
    CkAuthGoogle::ckDispose(authGoogle)
    CkStringBuilder::ckDispose(piggyPath)
    CkJsonObject::ckDispose(shallow)
    CkJsonObject::ckDispose(piggyData)


    ProcedureReturn
EndProcedure