(PureBasic) Download Photo to a File

Assuming we have the ID of a Photo, this example demonstrates how to download the photo image data to a file.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkHttp.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkRest.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkOAuth2.pb"

Procedure ChilkatExample()

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

    ; This example assumes a previously obtained an access token
    oauth2.i = CkOAuth2::ckCreate()
    If oauth2.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkOAuth2::setCkAccessToken(oauth2, "FACEBOOK-ACCESS-TOKEN")

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

    ; Connect to Facebook...
    success.i = CkRest::ckConnect(rest,"graph.facebook.com",443,1,1)
    If success <> 1
        Debug CkRest::ckLastErrorText(rest)
        CkOAuth2::ckDispose(oauth2)
        CkRest::ckDispose(rest)
        ProcedureReturn
    EndIf

    ; Provide the authentication credentials (i.e. the access key)
    CkRest::ckSetAuthOAuth2(rest,oauth2)

    ; Assumes we've already obtained a Photo ID.
    photoId.s = "10210199026347451"

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

    CkStringBuilder::ckAppend(sbPath,"/v2.7/")
    CkStringBuilder::ckAppend(sbPath,photoId)

    ; First we're going to get the photo informaton so we can get the URL of the image file data.
    ; Select the fields we want.
    ; See https://developers.facebook.com/docs/graph-api/reference/photo/
    CkRest::ckAddQueryParam(rest,"fields","id,album,images")

    responseJson.s = CkRest::ckFullRequestNoBody(rest,"GET",CkStringBuilder::ckGetAsString(sbPath))
    If CkRest::ckLastMethodSuccess(rest) <> 1
        Debug CkRest::ckLastErrorText(rest)
        CkOAuth2::ckDispose(oauth2)
        CkRest::ckDispose(rest)
        CkStringBuilder::ckDispose(sbPath)
        ProcedureReturn
    EndIf

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

    CkJsonObject::setCkEmitCompact(json, 0)
    CkJsonObject::ckLoad(json,responseJson)

    ; Show the JSON in human-readable format.
    Debug CkJsonObject::ckEmit(json)

    ; Get the image URL.
    imageUrl.s = CkJsonObject::ckStringOf(json,"images[0].source")
    Debug "Downloading from " + imageUrl

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

    CkStringBuilder::ckAppend(sbImageUrl,imageUrl)

    ; Build the output local file path.
    sbToPath.i = CkStringBuilder::ckCreate()
    If sbToPath.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkStringBuilder::ckAppend(sbToPath,"qa_output/fb")
    CkStringBuilder::ckAppend(sbToPath,CkJsonObject::ckStringOf(json,"id"))
    bCaseSensitive.i = 0
    If CkStringBuilder::ckContains(sbImageUrl,".jpg",bCaseSensitive) = 1
        CkStringBuilder::ckAppend(sbToPath,".jpg")
    Else
        CkStringBuilder::ckAppend(sbToPath,".png")
    EndIf

    Debug "Downloading to " + CkStringBuilder::ckGetAsString(sbToPath)

    ; Download using Chilkat HTTP.
    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkHttp::ckDownload(http,imageUrl,CkStringBuilder::ckGetAsString(sbToPath))
    If success <> 1
        Debug CkHttp::ckLastErrorText(http)
    Else
        Debug "Downloaded."
    EndIf



    CkOAuth2::ckDispose(oauth2)
    CkRest::ckDispose(rest)
    CkStringBuilder::ckDispose(sbPath)
    CkJsonObject::ckDispose(json)
    CkStringBuilder::ckDispose(sbImageUrl)
    CkStringBuilder::ckDispose(sbToPath)
    CkHttp::ckDispose(http)


    ProcedureReturn
EndProcedure