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diff --git a/tests/FunctionalTests/selenium/doc/developingdrivers.html b/tests/FunctionalTests/selenium/doc/developingdrivers.html new file mode 100644 index 00000000..4c2594d9 --- /dev/null +++ b/tests/FunctionalTests/selenium/doc/developingdrivers.html @@ -0,0 +1,134 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<html> +<head> + <meta content="text/html; charset=ISO-8859-1" + http-equiv="content-type"> + <title>Developing Drivers</title> +</head> +<body> +<h2>Overview</h2> +This page details important information for people developing drivers +for Selenium.<br> +<h2>Same Origin Policy</h2> +This is a security issue that affects all modern browsers. It is well +described <a + href="http://www.mozilla.org/projects/security/components/same-origin.html">here</a>, +but for our purposes, it constrains the way that a +JavaScript in a browser may interoperate with other open frames and +windows. In short, the Selenium JavaScript app must come from (or +appear to) the same origin as the AUT.<br> +<h2>The Driver</h2> +The driver has a number of duties. These are typically.. <br> +<ul> + <li>Instantiating the web server with a dynamic app (servlets for +Java) </li> + <li>Launching a browser with a with a URL that makes sense for +connecting to that server </li> + <li>providing an API to such that commands can be routed though the +dynamic app to the browser</li> +</ul> +<h2>Local, Remote and URLs<br> +</h2> +An application may be testable in a remote location by humans, but for +scripted testing and the need for the driver to dynamically drive the +browser, it is optimal for the driver to be on the same machine as that +serving the AUT and the browser testing it. <br> +<br> +Thus, an application as deployed ...<br> +<br> +<img alt="http://localhost:8080/" src="images/stockmeister.png" + style="width: 361px; height: 68px;"><br> +<br> +... would appear like so for the purposes of testing ...<br> +<br> +<img alt="http://localhost:8080/" src="images/localhostAut.png" + style="width: 346px; height: 43px;"><br> +<br> +As with the standalone version of Selenium, there are a number of files +(HTML and JavaScript) that comprise the bulk of the testing framework +and sit in the browser as testing occurs. It makes most sense to put +these in a virtual directory on the same server ...<br> +<br> +<img alt="http://localhost:8080/selenium/" + src="images/localhostSelenium.png" + style="width: 326px; height: 57px;"><br> +<br> +The dynamic webapp needs to be similarly mounted ...<br> +<br> +<img alt="http://localhost:8080/selenium/driver?..." + src="images/localhostDriver.png" style="width: 318px; height: 52px;"><br> +<br> +As the dynamic is the link between what is happening in the browser and +the driving process, it we need to somehow have an instance reference +to it. This is easier in some languages and web servers than +others. Also full programatic start/stop control over the web +server is not always possible for some larger web servers +implementations.<br> +<h2>Reply/Request Architecture</h2> +Because a browser cannot open a socket and listen on it, we must +effectively initiate communication thru the driver on the browser side. +Ignoring the possibilities granted by keep-alive, we simply poll from +the browser to the server and pick up commands to process inside the +browser. Results of commands are also passed back to the dynamic +hander over the same mechanism. These are in fact done in the same HTTP +request. The results from the <span style="font-style: italic;">previous</span> +command go back as query string parameters, and the <span + style="font-style: italic;">next</span> command is communicated in a +text/plain document<br> +<br> +The previous/next business introduces some complexity on the driver +side of the design. Namely hidden behind the API, the driver must +manage queues for the outgoing commands and the (some time later) +incoming responses. Java, until 1.5, did not have a blocking +queue to make this easy. Most other languages did.<br> +<h2><span style="font-weight: bold;">Selenese</span></h2> +<table style="width: 100%;" border="1" cellpadding="2" cellspacing="2"> + <tbody> + <tr> + <td>Selenese is the contrived (and mostly hidden) wire language +that the +driver uses to speak to the browser-bot through the dynamic +handler. It uses HTTP for its transport, and is quite +simple. <br> + <br> +Responses come from the browser to the driver in a query +string like <br> + <br> + <span style="font-family: monospace;">commandResult=OK</span>, <br> + <br> +Commands go from the driver to the +browser-bot in a text/plain document:<br> + <br> + <span style="font-family: monospace;">| open | /foo/bar.html | |</span><br + style="font-family: monospace;"> + <br> +This two way communication is of course invisible to the observer.</td> + <td style="width: 30%; background-color: rgb(255, 153, 102);">The +BrowserBot, by understanding Selenese, allows a process other than the +browser itsself to direct events on the Application Under Test. <br> + <br> +The Selenese language is simple enough to be commandable by any +language that has an API that can handle HTTP requests. <br> + <br> +Thus, Selenese allows many different open, free or closed license +drivers to interoperate with the BrowserBot.</td> + </tr> + </tbody> +</table> +<h2>Choregraphy</h2> +The driver cleary has some fairly heavy things to do. It is +important for some robustness to be built into the design. For example +it may take a long time for the browser to be instantiated on a +particular platform. It is appropriate for wait timeouts to be +generous here. Similarly whilst issuing individual commands it is +important for the driver to wait a sufficient amount of time for a +command to execute (and its result to come back). For the most +part on a localhost setup, it will be because the AUT is slow, but it +could be because some break in the app means that there will be no +subsequent response. Some timeout regime should be able to +recover from, mark a test as failed (for reasons of timeout), and start +again with the next test.<br> +<br> +<br> +</body> +</html> |