(Node.js) Xero Download Attachment for an Item (such as an Invoice)

Demonstrates how to download a particular attachment for a particular Xero item.

For more information, see https://developer.xero.com/documentation/api/attachments#GET

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.

    var http = new chilkat.Http();

    var jsonToken = new chilkat.JsonObject();
    var success = jsonToken.LoadFile("qa_data/tokens/xero-access-token.json");
    if (success == false) {
        console.log(jsonToken.LastErrorText);
        return;
    }

    http.AuthToken = jsonToken.StringOf("access_token");

    // Replace the value here with an actual tenant ID obtained from this example:
    // Get Xero Tenant IDs
    http.SetRequestHeader("Xero-tenant-id","83299b9e-5747-4a14-a18a-a6c94f824eb7");

    http.Accept = "application/json";

    // The example to list Xero attachments shows how to get attachment information.
    // Here's a sample JSON response obtained form listing attachments:
    // Your application can get the AttachmentID's and filenames from it.

    // {
    //   "Id": "24bfbcb9-dec9-4d33-835c-8f165d776766",
    //   "Status": "OK",
    //   "ProviderName": "Chilkat2222",
    //   "DateTimeUTC": "\/Date(1587213296972)\/",
    //   "Attachments": [
    //     {
    //       "AttachmentID": "daf106e2-8634-4349-bfcc-86c1df0793b2",
    //       "FileName": "penguins.jpg",
    //       "Url": "https://api.xero.com/api.xro/2.0/Invoices/0032f627-3156-4d30-9b1c-4d3b994dc921/Attachments/penguins.jpg",
    //       "MimeType": "image/jpg",
    //       "ContentLength": 777835
    //     }
    //   ]
    // }

    var url = "https://api.xero.com/api.xro/2.0/{$Endpoint}/{$Guid}/Attachments/{$AttachmentId}";

    // Endpoint can be Invoices, Receipts, CreditNotes, PurchaseOrders, etc.
    http.SetUrlVar("Endpoint","Invoices");

    // Guid is the ID of the item, such as the InvoiceID.
    http.SetUrlVar("Guid","0032f627-3156-4d30-9b1c-4d3b994dc921");

    // AttachmentId is the ID of the particular attachment to be downloaded
    http.SetUrlVar("AttachmentId","daf106e2-8634-4349-bfcc-86c1df0793b2");

    // Download the attachment data into bd.
    var bd = new chilkat.BinData();
    success = http.QuickGetBd(url,bd);
    if (success == false) {
        console.log(http.LastErrorText);
        return;
    }

    console.log("Response Status Code: " + http.LastStatus);

    if (http.LastStatus == 200) {
        // Success
        // Save to a file..
        success = bd.WriteFile("qa_output/penguines.jpg");
    }
    else {
        // Failed.  bd contains error information..
        console.log(bd.GetString("utf-8"));
    }


}

chilkatExample();