DataFlex

Download Photo to a File

See more Facebook Examples

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

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Variant vOauth2
    Handle hoOauth2
    Handle hoRest
    String sPhotoId
    Handle hoSbPath
    String sResponseJson
    Handle hoJson
    String sImageUrl
    Handle hoSbImageUrl
    Handle hoSbToPath
    Boolean iBCaseSensitive
    Handle hoHttp
    String sTemp1
    Boolean bTemp1

    Move False To iSuccess

    // 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
    Get Create (RefClass(cComChilkatOAuth2)) To hoOauth2
    If (Not(IsComObjectCreated(hoOauth2))) Begin
        Send CreateComObject of hoOauth2
    End
    Set ComAccessToken Of hoOauth2 To "FACEBOOK-ACCESS-TOKEN"

    Get Create (RefClass(cComChilkatRest)) To hoRest
    If (Not(IsComObjectCreated(hoRest))) Begin
        Send CreateComObject of hoRest
    End

    // Connect to Facebook...
    Get ComConnect Of hoRest "graph.facebook.com" 443 True True To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Provide the authentication credentials (i.e. the access key)
    Get pvComObject of hoOauth2 to vOauth2
    Get ComSetAuthOAuth2 Of hoRest vOauth2 To iSuccess

    // Assumes we've already obtained a Photo ID.
    Move "10210199026347451" To sPhotoId

    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbPath
    If (Not(IsComObjectCreated(hoSbPath))) Begin
        Send CreateComObject of hoSbPath
    End
    Get ComAppend Of hoSbPath "/v2.7/" To iSuccess
    Get ComAppend Of hoSbPath sPhotoId To iSuccess

    // 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/
    Get ComAddQueryParam Of hoRest "fields" "id,album,images" To iSuccess

    Get ComGetAsString Of hoSbPath To sTemp1
    Get ComFullRequestNoBody Of hoRest "GET" sTemp1 To sResponseJson
    Get ComLastMethodSuccess Of hoRest To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End
    Set ComEmitCompact Of hoJson To False
    Get ComLoad Of hoJson sResponseJson To iSuccess

    // Show the JSON in human-readable format.
    Get ComEmit Of hoJson To sTemp1
    Showln sTemp1

    // Get the image URL.
    Get ComStringOf Of hoJson "images[0].source" To sImageUrl
    Showln "Downloading from " sImageUrl

    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbImageUrl
    If (Not(IsComObjectCreated(hoSbImageUrl))) Begin
        Send CreateComObject of hoSbImageUrl
    End
    Get ComAppend Of hoSbImageUrl sImageUrl To iSuccess

    // Build the output local file path.
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbToPath
    If (Not(IsComObjectCreated(hoSbToPath))) Begin
        Send CreateComObject of hoSbToPath
    End
    Get ComAppend Of hoSbToPath "qa_output/fb" To iSuccess
    Get ComStringOf Of hoJson "id" To sTemp1
    Get ComAppend Of hoSbToPath sTemp1 To iSuccess
    Move False To iBCaseSensitive
    Get ComContains Of hoSbImageUrl ".jpg" iBCaseSensitive To bTemp1
    If (bTemp1 = True) Begin
        Get ComAppend Of hoSbToPath ".jpg" To iSuccess
    End
    Else Begin
        Get ComAppend Of hoSbToPath ".png" To iSuccess
    End

    Get ComGetAsString Of hoSbToPath To sTemp1
    Showln "Downloading to " sTemp1

    // Download using Chilkat HTTP.
    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End
    Get ComGetAsString Of hoSbToPath To sTemp1
    Get ComDownload Of hoHttp sImageUrl sTemp1 To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
    End
    Else Begin
        Showln "Downloaded."
    End



End_Procedure