(Node.js) 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.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function 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
    var oauth2 = new chilkat.OAuth2();
    oauth2.AccessToken = "FACEBOOK-ACCESS-TOKEN";

    var rest = new chilkat.Rest();

    // Connect to Facebook...
    var success = rest.Connect("graph.facebook.com",443,true,true);
    if (success !== true) {
        console.log(rest.LastErrorText);
        return;
    }

    // Provide the authentication credentials (i.e. the access key)
    rest.SetAuthOAuth2(oauth2);

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

    var sbPath = new chilkat.StringBuilder();
    sbPath.Append("/v2.7/");
    sbPath.Append(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/
    rest.AddQueryParam("fields","id,album,images");

    var responseJson = rest.FullRequestNoBody("GET",sbPath.GetAsString());
    if (rest.LastMethodSuccess !== true) {
        console.log(rest.LastErrorText);
        return;
    }

    var json = new chilkat.JsonObject();
    json.EmitCompact = false;
    json.Load(responseJson);

    // Show the JSON in human-readable format.
    console.log(json.Emit());

    // Get the image URL.
    var imageUrl = json.StringOf("images[0].source");
    console.log("Downloading from " + imageUrl);

    var sbImageUrl = new chilkat.StringBuilder();
    sbImageUrl.Append(imageUrl);

    // Build the output local file path.
    var sbToPath = new chilkat.StringBuilder();
    sbToPath.Append("qa_output/fb");
    sbToPath.Append(json.StringOf("id"));
    var bCaseSensitive = false;
    if (sbImageUrl.Contains(".jpg",bCaseSensitive) == true) {
        sbToPath.Append(".jpg");
    }
    else {
        sbToPath.Append(".png");
    }

    console.log("Downloading to " + sbToPath.GetAsString());

    // Download using Chilkat HTTP.
    var http = new chilkat.Http();
    success = http.Download(imageUrl,sbToPath.GetAsString());
    if (success !== true) {
        console.log(http.LastErrorText);
    }
    else {
        console.log("Downloaded.");
    }


}

chilkatExample();