As I have covered in previous blogs, Greasemonkey is a powerful client-side tool for augmenting web sites or creating mashups. It consists of a Firefox plugin coupled with scripts that are written and installed to modify web pages as they return from a web server. Greasemonkey generally is a tool for techies who want to tweak their favorite sites around the web. But does Greasemonkey have a place in the toolbox of IT departments in the enterprise? My next few blog entries will work towards an answer to that question. In this installment I will introduce a framework for measuring whether Greasemonkey is a good solution for a specific enterprise project.
NOTE: this blog entry was originally posted August 17th, 2007 on my previous blogging system (dev2dev.bea.com). Comments on the old blog were not transferred.
This is part 3 of a series of blog entries on Greasemonkey mashups.
- Blog 1: More Mashups: Using Greasemonkey to Weave New Features into Web Sites
- Blog 2: Building a Greasemonkey Mashup Tutorial
- Blog 3: Greasemonkey in the Enterprise: When is GM the Right Tool for IT?
- Blog 4: Beware of Greasemonkey's Inverted Security Model
- Blog 5: Solving the Greasemonkey Script Versioning Problem
An Enterprise Use Case for Greasemonkey
You probably did not learn about Greasemonkey (GM) in a Computer Science class at University. When drawing up an ideal solution for delivering a web application, Greasemonkey is probably no where in sight. The truth is Greasemonkey is a pragmatic solution for real world problems when other options aren't available. It is not the cleanest solution, but it makes up for that by being effective. It will always have detractors who will dismiss it as a hack, and an evil one at that. While its shortcomings cannot be denied, it is a mistake to dismiss it.
Greasemonkey has the potential of fast tracking IT projects that would otherwise never get implemented. It can also lower the bar for IT skill sets - a junior scripter can use it to modify the most complex of web applications. I feel that Greasemonkey deserves a place in your IT toolbox, and should be an option when it is an appropriate solution.
But I will be the first to say that Greasemonkey is not for everyone, and is not for every project. Greasemonkey definately has a sweet spot. Outside of that sweet spot, you are best off looking at another solution like other mashup tools or custom development.
For a quick example of good GM use case, imagine a web application in the enterprise with these characteristics:
- It is a closed source packaged application, purchased and installed from an external vendor by IT.
- It is used by a modest sized group of users, all of which are comfortable with computers and web browsing
- There are a couple of missing features that dramatically hurt productivity
- Those features can be easily woven into the application using a Greasemonkey script
This web application would make a good candidate for augmentation with Greasemonkey. A GM script could be quickly created that would add the missing features without needing to acquire the source code for the application. The deployment of the script would be relatively simple - the user population is modest in size and are technically competent. IT could be a hero by providing a quick solution to an expensive problem.
But what makes this use case a good fit for Greasemonkey? What other applications are good candidates for a Greasemonkey mashup/augmentation? What guidelines should you use when deciding if Greasemonkey is right for a given project? This blog will answer these questions.
Greasemonkey Selection Framework
This section provides a framework for evaluating whether Greasemonkey is a good fit for an enterprise project. Like any software selection process, you must consider many factors before choosing a best fit solution. You cannot base your decision on a single factor; you must sum the overall suitability against the project requirements. The list below enumerates a number of factors to look at before making your choice. For each factor, I explain when Greasemonkey is best suited.
Description: IT brings in many packaged applications from external vendors. In such cases, IT may not have access to any source code, or only a partial set (like the HTML files). For applications home grown within IT, this is not an issue as the source code is available.
Greasemonkey Fit: When the source code is available, it may be easier to just update the original application. Greasemonkey is indicated more when the source code is unavailable.
Description: Even if the source code for an application is available, it may not be cost effective to update the application directly. Perhaps all of the original developers are gone, and there is little documentation on how the site was built. Or perhaps the current staff is unfamiliar with the technology that was used to implement the site. If the code base is complex, it may be risky to make any modification to the source code.
Greasemonkey Fit: Greasemonkey can be a safer solution for adding new features to web applications that are risky to touch. The Greasemonkey script is externalized from the web application, and so the new development is clearly separated from the legacy application.
Description: Is the feature a productivity enhancement, or is the application as-is no longer valid without the update? An example of the latter would be a feature related to a compliance project. In order for the legacy application to update company financial data, a new "explanation" field needs to be added to a web form for auditing purposes. Users must not submit this form without the added field.
Greasemonkey Fit: It would be difficult to enforce that a user have the Greasemonkey installed and up to date (although the last blog entry in this series will offer a possible solution for this). Therefore, if an application is not valid without the new feature, Greasemonkey may not be the right solution for implementing that feature. For optional features such as productivity enhancements, Greasemonkey is a great solution.
Description: This factor is obvious, but be careful not to miss this in your software selection. Greasemonkey requires Firefox (there have been attempts to port to IE (gm4ie, GreasemonkIE), but are they complete/solid?). Also, some web applications may not work correctly with Firefox.
Greasemonkey Fit: If your enterprise does not support users on Firefox, Greasemonkey is not an available solution. Also, if the target web application does not work well with Firefox, Greasemonkey is not a great fit for the project.
Description: Within the enterprise, there is a broad range of computers skills amongst the employees. Greasemonkey does require users to be able to follow directions on installing Firefox, the Greasemonkey plugin and the required scripts.
Greasemonkey Fit: The more computer literate the user base, the better for Greasemonkey. While installing plugins and scripts seems like a no-brainer for anyone that would be reading this blog, it is a true obstacle for many within the enterprise.
Description: The appeal of web applications is in their ease of deployment. IT need only manage the application on a few server machines in the data center. Updates are efficiently deployed. Client side solutions are generally more expensive to deploy, as each client needs to be updated with each new version.
Greasemonkey Fit: The cost of deploying a Greasemonkey script to a small user population is likely modest. On the other hand, deploying a new version of a Greasemonkey script to a huge user population is an expensive proposition, particularly when computer literacy is an issue (see above). Greasemonkey is best when the user population is small.
Description: Many enterprise applications are available to a closed audience of employees and partners. But some applications are also exposed out to customers and the general public on the internet.
Greasemonkey Fit: Because Greasemonkey requires Firefox, the GM plugin, and the proper user scripts installed, Greasemonkey is a good solution when the user base is well known and constrained. Otherwise support costs and customer complaints will be high ("Hello, Avitek Industries, how may I help you?"; "Your website says I need Firefox. What is a Firefox?").
Description: Regardless of who is changing the web application (IT, or the ISV if it is a packaged application), every update has the potential of breaking existing Greasemonkey scripts. Minor changes to the content will probably be safe, but bigger changes to the page templates will almost certainly cause problems.
Greasemonkey Fit: Greasemonkey works best if the structure of the pages within the target web application is not changing substantially.
Description: Some enterprise web applications are low security risks. The site that hosts a monthly employee newsletter probably is not much of a concern from a security point of view. A payroll system is quite the opposite; the consequence of a security breach is severe.
Greasemonkey Fit: My next blog entry in this series will discuss the Greasemonkey security model and why it is not a great fit for the enterprise. Based on that analysis, Greasemonkey is not a good choice for adding features to highly sensitive enterprise web applications. Further, some IT Managers may feel GM is too risky to allow at all. More to come in the next post...
Description: Javascript can update the DOM of an HTML page quite easily. But for each update on a page, there is code involved. Writing raw HTML (in an .html file, a JSP/ASP file, etc) is far easier than a similar effort in JavaScript code.
Greasemonkey Fit: Greasemonkey is a great fit for features that can be implemented with a few snips to the target HTML. As the number of distinct changes to a page increases, the suitability of Greasemonkey decreases.
Description: The web application may have JavaScript code that modifies the page structure. This may be in support of Ajax capabilities, or just the way the initial page load was implemented. A Greasemonkey script runs before any page defined JavaScript runs. This may or may not be a good thing.
Greasemonkey Fit: Implementing a feature with Greasemonkey may be difficult if the page is already mutating itself with JavaScript.
Description: Browser based programmatic requests initiated from JavaScript (XmlHttpRequests) are restricted in their reach - they must not cross a network domain (e.g. bea.com). This is browser security, and this is generally good. But if you are adding a mashup feature to the web application, this would normally prevent the feature from being implemented in the browser. However, Greasemonkey scripts are not subject to this limitation, and can issue an XmlHttpRequest to any network domain.
Greasemonkey Fit: Greasemonkey is a good fit when you wish to implement the feature in the browser but need to connect to a different network domain.
Favorable Enterprise Greasemonkey References
To see how others have used Greasemonkey on enterprise projects, or for opinions on how Greasemonkey can add value to the Enterprise, consult these links:
Greasemonkey Improves Productivity - this company uses Greasemonkey to speed up enterprise form entry
Enterprise Greasemonkey is Inevitable - "...sooner rather than later we're going to see GM within the enterprise - if only b/c they have the potential to take some of the load off of beleaguered, shortstaffed IT staffs."
Firefox in the Enterprise Working Group - focuses on a larger issue than just Greasemonkey, but this expert group is looking at some of the issues noted above.
Using Greasemonkey to Enhance Auditing - this script adds time logging capabilities to JIRA.
Anti Enterprise Greasemonkey References
And the opposing view. There are those who think IT should stay well away from Greasemonkey:
Greasemonkey Primes Firefox For Embarrassment - this is an article you have to pay good money to read. Here is an excerpt from the abstract: "But IT managers beware: Greasemonkey will cause you nothing but headaches..."
[Greasemonkey] is Evil - "What's evil is the idea you mention that we'll end up making sophisticated infrastructure like automated script updaters in an attempt to turn a quick-and-dirty hack into a robust solution."
The Story Continues...
My next blog entry will discuss the Greasemonkey security model, and why IT will see it as "inverted" from what you would want.
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