(DataFlex) Facebook Download all Photos to Local Files

Demonstrates how to download all of one's Facebook photos to a local filesystem directory. This sample code keeps a local cache to avoid re-downloading the same photos twice. The program can be run again after a time, and it will download only photos that haven't yet been downloaded.

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

Use ChilkatAx-9.5.0-win32.pkg

Procedure Test
    Handle hoFbCache
    Variant vOauth2
    Handle hoOauth2
    Handle hoRest
    Boolean iSuccess
    String sResponseJson
    Handle hoPhotoJson
    Handle hoSaPhotoUrls
    Handle hoSbPhotoIdPath
    Handle hoJson
    Integer i
    String sPhotoId
    String sImageUrl
    String sAfterCursor
    Integer iNumItems
    String sPhotoJsonStr
    Handle hoImgUrlJson
    Handle hoHttp
    Integer iNumUrls
    Handle hoUrlJson
    Variant hoImageBytes
    Handle hoFac
    Handle hoSbImageUrl
    String sExtension
    Handle hoSbLocalFilePath
    String sTemp1
    Boolean bTemp1

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

    // This example will use a local disk cache to avoid re-fetching the same
    // photo id after it's been fetched once.
    Get Create (RefClass(cComChilkatCache)) To hoFbCache
    If (Not(IsComObjectCreated(hoFbCache))) Begin
        Send CreateComObject of hoFbCache
    End
    // The cache will use 1 level of 256 sub-directories.
    Set ComLevel Of hoFbCache To 1
    // Use a directory path that makes sense on your operating system..
    Send ComAddRoot To hoFbCache "C:/fbCache"

    // 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

    // There are two choices:  
    // We can choose to download the photos the person is tagged in or has uploaded
    // by setting type to "tagged" or "uploaded".
    Get ComAddQueryParam Of hoRest "type" "uploaded" To iSuccess

    // To download all photos, we begin with an outer loop that iterates over
    // the list of photo nodes in pages.  Each page returned contains a list of 
    // photo node ids.  Each photo node id must be retrieved to get the download URL(s)
    // of the actual image.

    // I don't know the max limit for the number of records that can be downloaded at once.
    Get ComAddQueryParam Of hoRest "limit" "100" To iSuccess

    // Get the 1st page of photos ids.
    // See https://developers.facebook.com/docs/graph-api/reference/user/photos/ for more information.
    Get ComFullRequestNoBody Of hoRest "GET" "/v2.7/me/photos" 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 hoPhotoJson
    If (Not(IsComObjectCreated(hoPhotoJson))) Begin
        Send CreateComObject of hoPhotoJson
    End
    Get Create (RefClass(cComCkStringArray)) To hoSaPhotoUrls
    If (Not(IsComObjectCreated(hoSaPhotoUrls))) Begin
        Send CreateComObject of hoSaPhotoUrls
    End
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbPhotoIdPath
    If (Not(IsComObjectCreated(hoSbPhotoIdPath))) Begin
        Send CreateComObject of hoSbPhotoIdPath
    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

    // Get the "after" cursor.
    Get ComStringOf Of hoJson "paging.cursors.after" To sAfterCursor
    While ((ComLastMethodSuccess(hoJson)) = True)

        Showln "-------------------"
        Showln "afterCursor = " sAfterCursor

        // For each photo id in this page...
        Move 0 To i
        Get ComSizeOfArray Of hoJson "data" To iNumItems
        While (i < iNumItems)
            Set ComI Of hoJson To i
            Get ComStringOf Of hoJson "data[i].id" To sPhotoId
            Showln "photoId = " sPhotoId

            // We need to fetch the JSON for this photo.  Check to see if it's in the local disk cache,
            // and if not, then get it from Facebook.
            Get ComFetchText Of hoFbCache sPhotoId To sPhotoJsonStr
            Get ComLastMethodSuccess Of hoFbCache To bTemp1
            If (bTemp1 = False) Begin
                // It's not locally available, so get it from Facebook..
                Send ComClear To hoSbPhotoIdPath
                Get ComAppend Of hoSbPhotoIdPath "/v2.7/" To iSuccess
                Get ComAppend Of hoSbPhotoIdPath sPhotoId To iSuccess

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

                Showln "Fetching photo node from Facebook..."

                // This REST request will continue using the existing connection.
                // If the connection was closed, it will automatically reconnect to send the request.
                Get ComGetAsString Of hoSbPhotoIdPath To sTemp1
                Get ComFullRequestNoBody Of hoRest "GET" sTemp1 To sPhotoJsonStr
                Get ComLastMethodSuccess Of hoRest To bTemp1
                If (bTemp1 <> True) Begin
                    Get ComLastErrorText Of hoRest To sTemp1
                    Showln sTemp1
                    Procedure_Return
                End

                // Add the photo JSON to the local cache.
                Get ComSaveTextNoExpire Of hoFbCache sPhotoId "" sPhotoJsonStr To iSuccess
            End

            // Parse the photo JSON and add the main photo download URL to saPhotoUrls
            // There may be multiple URLs in the images array, but the 1st one is the largest and main photo URL.
            // The others are smaller sizes of the same photo.
            Get ComLoad Of hoPhotoJson sPhotoJsonStr To iSuccess
            Get ComStringOf Of hoPhotoJson "images[0].source" To sImageUrl
            Get ComLastMethodSuccess Of hoPhotoJson To bTemp1
            If (bTemp1 = True) Begin

                // Actually, we'll add a small JSON document that contains both the image ID and the URL.
                Get Create (RefClass(cComChilkatJsonObject)) To hoImgUrlJson
                If (Not(IsComObjectCreated(hoImgUrlJson))) Begin
                    Send CreateComObject of hoImgUrlJson
                End
                Get ComAppendString Of hoImgUrlJson "id" sPhotoId To iSuccess
                Get ComAppendString Of hoImgUrlJson "url" sImageUrl To iSuccess
                Get ComEmit Of hoImgUrlJson To sTemp1
                Get ComAppend Of hoSaPhotoUrls sTemp1 To iSuccess
                Showln "imageUrl = " sImageUrl
            End

            Move (i + 1) To i
        Loop

        // Prepare for getting the next page of photos ids.
        // We can continue using the same REST object.
        // If already connected, we'll continue using the existing connection.
        // Otherwise, a new connection will automatically be made if needed.
        Get ComClearAllQueryParams Of hoRest To iSuccess
        Get ComAddQueryParam Of hoRest "type" "uploaded" To iSuccess
        Get ComAddQueryParam Of hoRest "limit" "20" To iSuccess
        Get ComAddQueryParam Of hoRest "after" sAfterCursor To iSuccess

        // Get the next page of photo ids.
        Get ComFullRequestNoBody Of hoRest "GET" "/v2.7/me/photos" To sResponseJson
        Get ComLastMethodSuccess Of hoRest To bTemp1
        If (bTemp1 <> True) Begin
            Get ComLastErrorText Of hoRest To sTemp1
            Showln sTemp1
            Procedure_Return
        End

        Get ComLoad Of hoJson sResponseJson To iSuccess
        Get ComStringOf Of hoJson "paging.cursors.after" To sAfterCursor
    Loop

    Showln "No more pages of photos."

    // Now iterate over the photo URLs and download each to a file.
    // We can use Chilkat HTTP.  No Facebook authorization (access token) is required to download
    // the photo once the URL is known.  
    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End

    // We'll cache the image data so that if run again, we don't re-download the same image again.
    Get ComCount Of hoSaPhotoUrls To iNumUrls
    Move 0 To i
    Get Create (RefClass(cComChilkatJsonObject)) To hoUrlJson
    If (Not(IsComObjectCreated(hoUrlJson))) Begin
        Send CreateComObject of hoUrlJson
    End

    Get Create (RefClass(cComCkFileAccess)) To hoFac
    If (Not(IsComObjectCreated(hoFac))) Begin
        Send CreateComObject of hoFac
    End

    While (i < iNumUrls)
        Get ComGetString Of hoSaPhotoUrls i To sTemp1
        Get ComLoad Of hoUrlJson sTemp1 To iSuccess
        Get ComStringOf Of hoUrlJson "id" To sPhotoId
        Get ComStringOf Of hoUrlJson "url" To sImageUrl

        // Check the local cache for the image data.
        // Only download and save if not already cached.
        Get ComFetchFromCache Of hoFbCache sImageUrl To hoImageBytes
        Get ComLastMethodSuccess Of hoFbCache To bTemp1
        If (bTemp1 = False) Begin
            //  This photo needs to be downloaded.

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

            // Let's form a filename..
            Move ".jpg" To sExtension
            Get ComContains Of hoSbImageUrl ".gif" False To bTemp1
            If (bTemp1 = True) Begin
                Move ".gif" To sExtension
            End

            Get ComContains Of hoSbImageUrl ".png" False To bTemp1
            If (bTemp1 = True) Begin
                Move ".png" To sExtension
            End

            Get ComContains Of hoSbImageUrl ".tiff" False To bTemp1
            If (bTemp1 = True) Begin
                Move ".tiff" To sExtension
            End

            Get ComContains Of hoSbImageUrl ".bmp" False To bTemp1
            If (bTemp1 = True) Begin
                Move ".bmp" To sExtension
            End

            Get Create (RefClass(cComChilkatStringBuilder)) To hoSbLocalFilePath
            If (Not(IsComObjectCreated(hoSbLocalFilePath))) Begin
                Send CreateComObject of hoSbLocalFilePath
            End
            Get ComAppend Of hoSbLocalFilePath "C:/Photos/facebook/uploaded/" To iSuccess
            Get ComAppend Of hoSbLocalFilePath sPhotoId To iSuccess
            Get ComAppend Of hoSbLocalFilePath sExtension To iSuccess

            Get ComQuickGet Of hoHttp sImageUrl To hoImageBytes
            Get ComLastMethodSuccess Of hoHttp To bTemp1
            If (bTemp1 <> True) Begin
                Get ComLastErrorText Of hoHttp To sTemp1
                Showln sTemp1
                Procedure_Return
            End

            // We've downloaded the photo image bytes into memory.
            // Save it to the cache AND save it to the output file.
            Get ComSaveToCacheNoExpire Of hoFbCache sImageUrl "" vImageBytes To iSuccess
            Get ComGetAsString Of hoSbLocalFilePath To sTemp1
            Get ComWriteEntireFile Of hoFac sTemp1 vImageBytes To iSuccess

            Get ComGetAsString Of hoSbLocalFilePath To sTemp1
            Showln "Downloaded to " sTemp1
        End

        Move (i + 1) To i
    Loop

    Showln "Finished downloading all Facebook photos!"


End_Procedure