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(JavaScript) Download a SharePoint File by Path using HttpCurl
This example shows how to use Chilkat's HttpCurl class to download a file from SharePoint when the file path within the document library is already known. The example uses Microsoft Graph to automatically resolve the SharePoint site name to a site ID, find the drive ID for the Documents document library, and then download the file directly by path using the Graph root:/path:/content syntax.
var success = false;
// This example downloads a file from a SharePoint Documents document library
// when the file's path within the library is already known.
//
// The file downloaded in this example is:
//
// images/sea_creatures/starfish.jpg
//
// Unlike the previous example that searched for a file by name and obtained
// its Microsoft Graph item ID, this example uses the Graph path-based API.
//
// The example demonstrates how HttpCurl automatically resolves:
//
// site_name -> site_id
// site_id -> document_library_id
//
// and then uses the known file path to download the file directly.
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 download request requires a Microsoft Graph site ID.
//
// Because the application only knows the SharePoint site name,
// define a helper 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 download request also requires the drive ID of 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");
// This is the target Microsoft Graph request.
//
// GET /sites/{site-id}/drives/{drive-id}/root:/{path-to-file}:/content
//
// The path-based API allows a file to be downloaded directly when its
// location within the document library is known.
//
// The -L option causes HttpCurl to follow redirects.
// Microsoft Graph typically returns a redirect to the actual download URL.
//
// The -o option specifies the output filename.
// The --output-dir option specifies the directory where the downloaded
// file will be saved.
var curlCommand = "GET -L --output-dir c:/temp/qa_output -o starfish.jpg https://graph.microsoft.com/v1.0/sites/{{site_id}}/drives/{{document_library_id}}/root:/images/sea_creatures/starfish.jpg:/content";
// Execute the request.
//
// HttpCurl examines the target request and determines that both
// site_id and document_library_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) download -> file content
//
// The file is streamed directly to the output file specified by
// the curl command.
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 file has been downloaded successfully and written to:
//
// c:/temp/qa_output/starfish.jpg
//
console.log("Success.");
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