(JavaScript) Download a File from a SharePoint Documents Library

See more SharePoint Examples

This example shows how to use Chilkat's HttpCurl class to download a file from the root of a SharePoint Documents document library. The example demonstrates how HttpCurl automatically resolves the SharePoint site name to a site ID, finds the drive ID for the Documents library, locates the file by name, and then downloads the file content using Microsoft Graph.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

// This example downloads a file named "hamlet.json" from the root of the SharePoint
// Documents document library.
// 
// The example demonstrates how HttpCurl can automatically resolve all of the
// information needed to locate and download a file:
// 
//   site_name            -> site_id
//   site_id              -> document_library_id
//   document_library_id  -> file_id
//   file_id              -> file content
// 
// The application only provides the SharePoint site name and the desired
// filename.  HttpCurl automatically executes the required Microsoft Graph
// requests to obtain the remaining values.

success = false;

// --------------------------------------------------------------------------------------------------------
// Before running this example, create an Azure App Registration and grant it
// the Microsoft Graph permissions required to access SharePoint.
// 
// The application will authenticate using OAuth2 Client Credentials.
// See:
// How to Create SharePoint App Registration for OAuth 2.0 Client Credentials
// --------------------------------------------------------------------------------------------------------

// Build a JSON authentication configuration.
// HttpCurl will use this information to automatically obtain OAuth2 access tokens.
var jsonAuth = new CkJsonObject();

// Enable secret lookup.
// 
// Instead of hard-coding sensitive values such as the client ID,
// client secret, and token endpoint, secret specification strings
// are used.  Chilkat automatically retrieves the actual values from
// Windows Credential Manager (Windows) or Apple Keychain (macOS).
// 
// See:
// Secret Specification Strings
jsonAuth.EnableSecrets = true;

success = jsonAuth.UpdateString("oauth2.client_id","!!sharepoint|oauth2|client_id");
if (success == true) {
    success = jsonAuth.UpdateString("oauth2.client_secret","!!sharepoint|oauth2|client_secret");
}

if (success == true) {
    success = jsonAuth.UpdateString("oauth2.token_endpoint","!!sharepoint|oauth2|token_endpoint");
}

if (success == false) {
    console.log(jsonAuth.LastErrorText);
    return;
}

// Request Microsoft Graph permissions that were granted to the application.
jsonAuth.UpdateString("oauth2.scope","https://graph.microsoft.com/.default");

// ---------------------------------------------------------------------------------------------------

var curl = new CkHttpCurl();

// Associate the OAuth2 configuration with HttpCurl.
// 
// When the request is executed, Chilkat automatically obtains an access token
// if needed and adds the Authorization: Bearer header to the HTTP request.
curl.SetAuth(jsonAuth);

// Define values that are already known.
// 
// These variables are referenced in curl commands using
// {{variable_name}} substitution syntax.
curl.SetVar("sharepoint_hostname","example.sharepoint.com");
curl.SetVar("site_name","test");

// The first step is to obtain the Microsoft Graph site ID.
// 
// The application only knows the SharePoint site name, so define
// a function that can retrieve the site information.
curl.AddFunction("getSite","GET https://graph.microsoft.com/v1.0/sites/root:/sites/{{site_name}}");

// Extract the site's ID and store it in the HttpCurl variable named site_id.
curl.AddOutput("getSite","id","site_id");

// The next step is to find the Documents document library.
// 
// Microsoft Graph refers to document libraries as "drives".
curl.AddFunction("getDrives","GET https://graph.microsoft.com/v1.0/sites/{{site_id}}/drives");

// Search the returned drives for the one named "Documents"
// and save its drive ID in the document_library_id variable.
curl.AddOutput2("getDrives","value","name","Documents",true,"id","document_library_id");

// Now list the contents of the Documents document library.
curl.AddFunction("getFiles","GET https://graph.microsoft.com/v1.0/sites/{{site_id}}/drives/{{document_library_id}}/root/children");

// Search the returned files for an item named "hamlet.json"
// and save its Microsoft Graph item ID in the file_id variable.
curl.AddOutput2("getFiles","value","name","hamlet.json",true,"id","file_id");

// This is the target request.
// 
// GET -L https://graph.microsoft.com/v1.0/drives/{{document_library_id}}/items/{{file_id}}/content
// 
// The /content endpoint returns the actual contents of the file.
// 
// The -L option instructs HttpCurl to follow the redirect returned by
// Microsoft Graph.  The Graph API typically responds with a redirect
// to the actual file download URL.
var curlCommand = "GET -L https://graph.microsoft.com/v1.0/drives/{{document_library_id}}/items/{{file_id}}/content";

// Execute the request.
// 
// HttpCurl examines the target request and determines that both
// document_library_id and file_id are required.
// 
// To obtain these values, it automatically builds and executes
// the following dependency chain:
// 
//   1) getSite      -> site_id
//   2) getDrives    -> document_library_id
//   3) getFiles     -> file_id
//   4) download     -> file content
// 
// The final response returned by DoYourThing is the downloaded
// file content from the target request.
success = curl.DoYourThing(curlCommand);
if (success == false) {
    console.log(curl.LastErrorText);
    return;
}

// A successful Graph response should return HTTP 200.
// Any other status code typically indicates an authentication,
// permission, site lookup, document library lookup, or file lookup error.
var statusCode = curl.StatusCode;
if (statusCode !== 200) {
    console.log(curl.ResponseBodyStr);
    console.log("status code = " + statusCode);
    return;
}

// The response body contains the contents of the downloaded file.
var sbFileContents = new CkStringBuilder();
curl.GetResponseSb(sbFileContents);

// Optionally save the downloaded content to a local file.
// 
// The third argument controls whether the file is appended.
// Passing ckfalse causes the file to be overwritten if it already exists.
success = sbFileContents.WriteFile("c:/temp/hamlet.json","utf-8",false);
if (success == false) {
    console.log(sbFileContents.LastErrorText);
    return;
}

console.log("Success.");