Automated Page Load Testing With Chrome and HttpWatch 1.1

calendarDecember 12, 2017 in Automation , C# , Chrome , HttpWatch

HttpWatch added Chrome support earlier this year and with version 11.1 it now also supports the use of Chrome through the automation API.

In a previous blog post we covered how to measure page load times with HttpWatch for new and existing users by clearing the cache to simulate a new user. Adapting this code for Chrome is as simple as changing one line of code to use the Chrome property.

Here’s the C# code for measuring the page load time for a new user:

// Set a reference to the HttpWatch COM library
// to start using the HttpWatch namespace
//
// This code requires HttpWatch version 11.1
//
 
using HttpWatch;                
 
namespace EmptyCacheTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string url = "https://www.httpwatch.com/download/";
            Controller controller = new Controller();
 
            // Create an instance of Chrome
            Plugin plugin = controller.Chrome.New();                
 
            // Clear out all existing cache entries
            plugin.ClearCache();                
 
            plugin.Record();
            plugin.GotoURL(url);                
 
            // Wait for the page to download
            controller.Wait(plugin, -1);                
 
            plugin.Stop();                
 
            // Find the load time for the first page recorded
            double pageLoadTimeSecs =
                plugin.Log.Pages[0].Entries.Summary.Time;                
 
            System.Console.WriteLine( "The empty cache load time for '" +
                url + "' was " + pageLoadTimeSecs.ToString() + " secs");                
 
            // Uncomment the next line to save the results
            // plugin.Log.Save(@"c:\temp\emptytestcache.hwl");                
 
            plugin.CloseBrowser();
        }
    }
}

And here’s the code to measure the page load time after priming the cache:

// Set a reference to the HttpWatch COM library
// to start using the HttpWatch namespace
//
// This code requires HttpWatch version 11.1
//
using HttpWatch;               
 
namespace PrimedCacheTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string url = "https://www.httpwatch.com/download/";
            Controller controller = new Controller();               
 
            // Create an instance of Chrome
            Plugin plugin = controller.Chrome.New();               
 
            // Visit the page to prime the cache
            plugin.GotoURL(url);
            plugin.Record();
            controller.Wait(plugin, -1);               
 
            // Shutdown Chrome and create a new instance
            plugin.CloseBrowser();
            plugin = controller.Chrome.New();               
 
            plugin.Record();               
 
            // Visit the page a second time with the cache primed
            plugin.GotoURL(url);
            controller.Wait(plugin, -1);               
 
            plugin.Stop();               
 
            // Find the load time for the first page recorded
            double pageLoadTimeSecs =
                plugin.Log.Pages[0].Entries.Summary.Time;               
 
            System.Console.WriteLine( "The primed cache load time for '" +
                url + "' was " + pageLoadTimeSecs.ToString() + " secs");               
 
            // Uncomment the next line to save the results
            // plugin.Log.Save(@"c:\temp\emptytestcache.hwl");               
 
            plugin.CloseBrowser();
        }
    }
}

By default the Chrome.New() method creates a new tab in the official release of Chrome installed on your PC but by passing a Chrome channel name you can also use other installed versions:

// Create an instance of Chrome (Beta channel)
Plugin plugin = controller.Chrome.New("Beta");

There’s more information available in the documentation for the New method.

Automating HttpWatch with PowerShell

calendarApril 12, 2013 in Automation , HttpWatch

Some customers have asked recently about whether HttpWatch can be automated with PowerShell. This is possible but we don’t have any samples or supporting documentation.

If you’re interest in driving HttpWatch with PowerShell please take a look at this excellent post on F5 DevCentral by Joe Pruitt:

Project Acceleration: Programmatic Performance Testing with HTTPWatch

 

A Guide to Automating HttpWatch with PHP

calendarMarch 11, 2011 in Automation , HttpWatch

Stoyan Stefanov, the creator of smush.it, architect of YSlow 2.0 and engineer at Facebook, has written an excellent three part guide to controlling HttpWatch from PHP:

He’s even published a class that wraps the HttpWatch API and makes it easier to use from PHP.

In the rest of this blog post we wanted to follow up on a few points mentioned in Stoyan’s blog posts. These items don’t just apply to PHP. You may find them useful when automating HttpWatch using other languages such as C# or Ruby.

Hiding the IE window

The ‘A better experience in IE’ section of Automating HttpWatch with PHP shows how you can hide the IE browser window during tests by separately creating IE and attaching HttpWatch to it.

It’s also possible to do this using the Container property without having to separately create and attach to IE:

$controller = new COM("HttpWatch.Controller");
$plugin = $controller->IE->New();
$browser = $plugin->Container; // Only works with IE
$browser->Visible = false;

If you do decide to do this in order to stop windows popping up during a test please bear these points in mind:

  1. Orphaned instances of iexplore.exe will be left running in the background if your script ever terminates before calling CloseBrowser.
  2. In IE 8 and earlier, HttpWatch will not record a Render Start event because the hidden IE window does not get updated by Windows. However, the event will be recorded in Firefox 3.5+ and IE 9.
  3. Your performance measurements may not directly match user experience. It’s possible that current or future browsers may avoid certain rendering and processing actions if they detect that the output will not be in a visible window. For that reason, we recommend running tests in visible browser windows on a normal interactive desktop either on a physical machine or VM. Also, viewing a browser test through Remote Desktop is likely to have a significant negative impact on performance as the graphics and text making up the page have to be transferred over the network.

Opening the HttpWatch Plugin Window

It’s often handy to open the HttpWatch window in the browser when you are developing an automation script so that you can check that it is working as expected.

The OpenWindow method allows you to do this and specify whether you want the HttpWatch window docked or undocked. For example, here is the PHP code to open HttpWatch as an embedded window in the browser:

...
// Open docked HttpWatch window in browser
$plugin->OpenWindow(false);
...

Handling Differences Between HttpWatch Basic and Professional Editions

In part 3, Stoyan mentions using try-catch to handle the errors that occur when attempting to access data that is restricted in HttpWatch Basic Edition. While this is a valid approach, there is a risk of hiding other errors that might be occurring that are not due to the restrictions in HttpWatch Basic edition.

There are a couple of properties in the HttpWatch automation interface that help you handle the differences. The first is the IsBasicEdition property on the Controller class.

For example, here’s a high level test in PHP:

$controller = new COM("HttpWatch.Controller");
if ( $controller->IsBasicEdition )
{
    echo "\nThis test requires HttpWatch Professional Edition";
}

At a lower level, you can also check each request to see if it has been restricted using the IsRestrictedURL property:

...
if ( $entry->IsRestrictedURL)
{
    // Goes here in HttpWatch Basic Edition for URLs outside Alexa Top 20
    echo "\nSome of the properties for this request are restricted";
}
else
{
    // Goes here in HttpWatch Basic Edition for URLs in Alexa Top 20
    // or in HttpWatch Professional Edition for any URL
    echo "\nAll the properties of this request are available";
}
...

Ready to get started? TRY FOR FREE Buy Now