Create an export and download a file

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1. Overview

This article will guide you through exporting a dashboard, report, or other view type to PDF and then saving it to a file using the REST API. For example, you could embed a view into another web application and trigger the file export from the parent application toolbar.

To create an export and a download a file you will need to do the following:

  • Log on and get a session
  • Create an export
  • Download the export result

2. Log on and get a session

To log on and get a session using the REST API, you will need to make a POST /API/LogOn request. The following is an example of how to accomplish this:

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using System.Net;
using System.Net.Http;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.Web.Script.Serialization;
using System.Globalization;
 
// ...
 
string baseUrl = "http://localhost:8010";
 
var cookieContainer = new CookieContainer();
 
string sessionId = string.Empty;
 
using (HttpClientHandler httpClientHandler = new HttpClientHandler())
{
    httpClientHandler.CookieContainer = cookieContainer;
 
    using (HttpClient httpClient = new HttpClient(httpClientHandler))
    {
        // Get Session ID
        string logonUri = string.Concat(baseUrl, "/Api/LogOn/");
             
        var logonOptions = new
        {
            accountName = "admin",
            password = "1234",
            cultureName = string.Empty,
            deleteOtherSessions = true,
            isWindowsLogOn = false
        };
     
        JavaScriptSerializer serializer = new JavaScriptSerializer();
        var requestBodyAsString = serializer.Serialize(logonOptions);
        StringContent content = new StringContent(
            requestBodyAsString,
            Encoding.UTF8,
            "application/json"
        );
             
        string jsonString = string.Empty;
     
        using (var response = httpClient.PostAsync(logonUri, content).Result)
        {
            jsonString = response.Content.ReadAsStringAsync().Result;
        }
     
        var obj = (Dictionary<string, object>)serializer.DeserializeObject(jsonString);
         
        sessionId = obj["sessionId"].ToString();
 
        // ...
    }
}

Tip
For multiple examples of REST logon visit the POST /LogOn/ page in the REST API documentation.

3. Create an export

After getting a session ID, you can create an export. This will be accomplished by making a POST /API/Export call to the REST API. The following example creates an export for the view with a particular ID. The providerId is 5752eb39-40b5-4d79-b96b-9f9297c67193 which is the standard PDF export provider ID. The isLegacyExport property is set to true to avoid passing the viewData property.

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string url = string.Format(
    CultureInfo.InvariantCulture,
    "{0}/API/Export/",
    baseUrl
);
 
var exportRequestOptions = new
{
    __classType = "dundas.export.ExportRequest",
    isLegacyExport = true,
 
    // PDF Exporter
    providerId = "5752eb39-40b5-4d79-b96b-9f9297c67193",
    viewId = "e16138cd-b78f-4c43-9b2d-d0e68f427998"
};
 
requestBodyAsString = serializer.Serialize(exportRequestOptions);
 
string exportResultId = string.Empty;
 
// Add an Authorization header (v10 and higher)
httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", sessionId);
 
// Define the request body
HttpContent requestBody = null;
requestBody = new StringContent(requestBodyAsString, Encoding.UTF8," application/json");
using (var response = httpClient.PostAsync(url, requestBody).Result)
{
    if (response.StatusCode == HttpStatusCode.OK)
    {
        Console.WriteLine("Success");
 
        string jsonObject = response.Content.ReadAsStringAsync().Result;
         
        exportResultId = jsonObject.Trim('\"');
    }
}

Note
Passing the session ID in an authorization header requires version 10 or higher. In earlier versions, you can pass it as a query string parameter in the URL: ?sessionId={1}

4. Download the export result

Now that you have the export ID, you can make the following request to GET /Export/Result/{id}/ to get the file from the REST API. The following is an example of how to download the export file, and then save it to C:\Temp\file.pdf:

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if (!string.IsNullOrEmpty(exportResultId))
{
    url = string.Format(
        CultureInfo.InvariantCulture,
        "{0}/API/Export/Result/{1}/?isDownloadLink={2}",
        baseUrl,
        exportResultId,
        false
    );
         
    using (var response = httpClient.GetAsync(url).Result)
    {
        if (response.StatusCode == HttpStatusCode.OK)
        {
            byte[] fileBytes = response.Content.ReadAsByteArrayAsync().Result;
                 
            File.WriteAllBytes(@"C:\Temp\file.pdf", fileBytes);
        }
    }
}

5. Entire code

The following is the entire example together: the sample logs in, creates a PDF export for the view with ID e16138cd-b78f-4c43-9b2d-d0e68f427998, then the file is downloaded and saved:

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using System.Net;
using System.Net.Http;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.Web.Script.Serialization;
using System.Globalization;
 
// ...
 
string baseUrl = "http://localhost:8010";
 
var cookieContainer = new CookieContainer();
 
string sessionId = string.Empty;
 
using (HttpClientHandler httpClientHandler = new HttpClientHandler())
{
    httpClientHandler.CookieContainer = cookieContainer;
 
    using (HttpClient httpClient = new HttpClient(httpClientHandler))
    {
        // Get Session ID
        string logonUri = string.Concat(baseUrl, "/Api/LogOn/");
             
        var logonOptions = new
        {
            accountName = "admin",
            password = "1234",
            cultureName = string.Empty,
            deleteOtherSessions = true,
            isWindowsLogOn = false
        };
     
        JavaScriptSerializer serializer = new JavaScriptSerializer();
        var requestBodyAsString = serializer.Serialize(logonOptions);
        StringContent content = new StringContent(
            requestBodyAsString,
            Encoding.UTF8,
            "application/json"
        );
             
        string jsonString = string.Empty;
     
        using (var response = httpClient.PostAsync(logonUri, content).Result)
        {
            jsonString = response.Content.ReadAsStringAsync().Result;
        }
     
        var obj = (Dictionary<string, object>)serializer.DeserializeObject(jsonString);
         
        sessionId = obj["sessionId"].ToString();
                     
        string url = string.Format(
            CultureInfo.InvariantCulture,
            "{0}/API/Export/",
            baseUrl
        );
         
        var exportRequestOptions = new
        {
            __classType = "dundas.export.ExportRequest",
            isLegacyExport = true,
     
            // PDF Exporter
            providerId = "5752eb39-40b5-4d79-b96b-9f9297c67193",
            viewId = "e16138cd-b78f-4c43-9b2d-d0e68f427998"
        };
         
        requestBodyAsString = serializer.Serialize(exportRequestOptions);
         
        string exportResultId = string.Empty;
 
        // Add an Authorization header (v10 and higher)
        httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", sessionId);
         
        // Define the request body
        HttpContent requestBody = null;
        requestBody = new StringContent(requestBodyAsString, Encoding.UTF8, "application/json");
        using (var response = httpClient.PostAsync(url, requestBody).Result)
        {
            if (response.StatusCode == HttpStatusCode.OK)
            {
                Console.WriteLine("Success");
         
                string jsonObject = response.Content.ReadAsStringAsync().Result;
                 
                exportResultId = jsonObject.Trim('\"');
            }
        }
             
        if (!string.IsNullOrEmpty(exportResultId))
        {
             
            url = string.Format(
                CultureInfo.InvariantCulture,
                "{0}/API/Export/Result/{1}/?isDownloadLink={2}",
                baseUrl,
                exportResultId,
                false
            );
                     
                 
                     
            using (var response = httpClient.GetAsync(url).Result)
            {
                if (response.StatusCode == HttpStatusCode.OK)
                {
                    byte[] fileBytes = response.Content.ReadAsByteArrayAsync().Result;
                             
                    File.WriteAllBytes(@"C:\Temp\file.pdf", fileBytes);
                }
            }      
        }
    }
}

6. See also

Talk to us:

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M3C 1Y8

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