Archive for the ‘General’ Category

Farewell, Jonathan

Friday, June 17th, 2011

Heading Off width=Yesterday, Jonathan Lange our Product Strategist announced that he was leaving Launchpad after four and a half year. The fact that he’s only leaving next door to work on the Ubuntu Developer Programme from within the Platform team is only a small comfort.

Before becoming Launchpad Product Strategist, Jonathan was known for adding support for source package branches to Launchpad. He became Strategist at about the same time I took the interim leadership of Launchpad. It will interesting to see how I manage without him!

He was instrumental in most of the process changes that happened to the team in the last two years. We can thanks Jonathan for bringing us the LEP process which make sure that we focus on the right things before starting coding, the Stakeholders process to make sure that we are working on the right thing. He also brought some clarity on what Launchpad was all about! Recently, he has been working on clarifying the feature development process, so that we can deliver polished changes on a regular cadence to users. I’m probably forgetting also a lot of other changes which his constant quest for improvements suggested to us in one way or another.

Oh, and we can thank him for making sure that we didn’t move on early from daily builds, improved bug subscriptions and other changes without the polish they have today. I (and I’m sure our users) thank you!

Whoever takes that role forward, will have big shoes to fill! If you are interested by the challenge, a job opening should be posted soon!

Thanks a lot Jonathan, it was a pleasure to work with you all these years! You’ll be missed. Good luck with your new project, but I’m glad to think that the future of Ubuntu Application Development is in excellent hands!

Photo by Robin Robokow. Licence: CC BY-NC-SA 2.0.

Using visibility for rudimentary JavaScript templating

Tuesday, June 14th, 2011

DRY is one of my watchwords. That’s “Don’t Repeat Yourself“, of course.

If you’re designing your page to work with-and-without JavaScript enabled, then you’ll likely be tempted to repeat some of the
user-interface text in the template and in the JavaScript file. Especially for text that appears only some of the time.

One alternative is to render that text all the time, and only show it some of the time. In Launchpad, you add the “unseen” class to text in order to hide it.

In YUI3, it’s easy to add or remove classes using Node.toggleClass(). For example:

foo.toggleClass('unseen', baz);

This adds the ‘unseen‘ class to foo when baz is true, and removes it when baz is false.

This approach means you don’t need to repeat the text. It means your HTML stays in an XHTML file, with all the syntax-highlighting and other tool support that implies. It makes it easier to live with the fact that Launchpad don’t have a hardcore templating system in JavaScript.

It doesn’t eliminate all issues. If the page needs to have more than one instance of the text, this approach doesn’t directly apply. However, it’s easy to imagine extending it by using a hidden copy as a prototype and copying it as needed.

One disadvantage is that testing becomes harder. With conditional rendering, you can just check whether the text is rendered. With conditional visibility, you need to check whether the text has the unseen class, which is harder. If plan to apply this technique, it’s best to start out using it, or else you’ll have to rewrite all your tests when you switch approaches.

Another issue is that you will probably need to leave placeholders. For example, one of our conditionally-rendered strings included a link to a branch. When there’s no assigned branch, that text must be hidden. When someone assigns the branch via AJAX, we need to have a placeholder for the branch link, so that we can set it to the correct value with Javascript. At present, there’s no way to generate placeholders for arbitrary types, so it must be done manually.

Initializing page JavaScript from the JSONCache

Friday, June 10th, 2011

Launchpad has a nice feature for initialising on-page JavaScript, called the JSONCache. I recommend considering it as your first choice when writing JavaScript that needs to be initialised. The one downside is that due to bug #740208, it’s not available for users who aren’t logged in. But then, users who aren’t logged in don’t need a lot of JavaScript, because they can’t write to most of Launchpad.

I found out about the JSONCache when we were working on he sourcepackage +sharing-details pages recently. This JavaScript has model objects, but I didn’t know how we should initialise them. We considered initialising them from the page HTML. We considered using the web service. But it turned out there’s already a great facility for this: the JSON cache.

If you’ve hacked on Launchpad’s HTML, you probably already know that every you can get LP.cache.context and LP.cache.me from any Launchpad page. These come for free, but with a little more work, you can get any object you need:


        cache = IJSONRequestCache(self.request)
        cache.objects.update({
            'productseries': self.context.productseries,
            'upstream_branch': self.upstream_branch,
            'product': self.product,
        })

These entries will then appear in the LP.cache with the names specified in the dict.

However, they are provided as plain JavaScript mappings, unlike the values returned by lp.client.Launchpad. You can use convert_cache to create a copy of the cache containing lp.client.Entry values. This allows you to intermix values from the lp.cache and the web service freely.

convert_cache currently lives in translations/javascript/sourcepackage_sharing_details.js, but should probably be moved into lp.client.

One extension I’d love to see would be a way to retrieve an updated copy of just the JSONRequestCache for a page. That way, we could reduce our number of round-trips, and also be confident that everything was up-to-date.

JavaScript development: YUI testing

Monday, June 6th, 2011

I recently came back to JavaScript, having largely ignored it for a couple of years. Development in JavaScript is much nicer than I remember. I thought I should share what I’ve learned.

The first thing I’ll mention is YUI tests. If you’re a TDD developer (and if not, why not?), YUI unit tests are the way TDD should be. The change/test cycle is very fast (to run the tests, hit “reload” in your browser). And since they’re proper unit tests, they feel like a safety net when you start to make changes.

They are a good way to test your model code and HTML changes. Other members of the Launchpad team have used them to do more integration-style testing, as well. It’s somewhat difficult to set up I/O dependent tests, but that will encourage you to make most of your code I/O-independent.

For information on how to get started with them, see: Developing with YUI.Test

Bryce Harrington appointed Ubuntu Launchpad stakeholder representative

Saturday, June 4th, 2011

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When I explained how we determined what feature to work on next, I mentioned that we were looking to add a stakeholders representative for the Ubuntu project. Well, it’s now done. The Ubuntu Technical Board delegated Bryce Harrington to that position.

So if you are part of the Ubuntu community and need something from Launchpad, you can now talk to Bryce.

I’m really glad to have him on that position. Not only is he a respected member of the Ubuntu community, but he also did a 6 months rotation within the Launchpad team, so has understanding of how our project operates.

He’ll now be in a position to escalate important bugs affecting the Ubuntu community, as well as present the community’s view on what new features should be prioritized. It won’t be an easy job, since the Ubuntu project is big and varied. The people who cares about bugs are often not the same that cares about translations nor the same that cares about package publishing or the Ubuntu distribution development toolchain. And the stakeholder representative job is to help prioritize these needs to make sure that the Launchpad team works on the most important work. Plus then he’ll have to find common grounds with the other stakeholder representatives!

Thanks Bryce for stepping up to these responsibilities!

Photo by Wally Gobetz. Licence: CC BY-NC-ND 2.0.

What does rotation to maintenance really means?

Friday, June 3rd, 2011

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I’ve been asked this question privately a few times already. What does it mean for a squad to rotate from feature-mode to maintenance-mode? The question arises as a number of folks noticed that some members of the squad continue working on feature-related bugs after they are on maintenance shift. That happened with the former Blue squad when they completed daily builds, with the Orange squad when they completed sharing translations, and with the  Yellow squad and better bug subscriptions. So let me clarify what that boundary means.

In a nutshell, it means that the squad starts new work from a different queue. After the switch, new work will come from the general maintenance queue. Because we do the switch aligned with the calendar week, there is always work related to the feature that is still in-process (code started but not reviewed, or landed but not deployed, etc.) That’s the work that continues after the transition. After the rotation, the squad also becomes on the hook to cater for the user support duties related to maintenance mode.

What are the trade-off related to this boundary definition? The main impact is that we get a dip in maintenance related bug fixes around the rotation. That’s because the new maintenance squad has still some members not ready to start new maintenance-related work. It could be argued that because of the interrupt nature of the maintenance responsibilities, it would take longer to finish off the work related to the feature. I’m not sure that happens in practice, but I make note to check the data…

The alternative  would be to only rotate after all the feature-related bugs are done-done. The rest of the squad could fix some lower priority bugs related to the feature or clean-up tech-debt accumulated during their rotation.  It would preserve the number of people effectively working on maintenance around the transitions.  But it would mean that it would take longer before we start the next feature. And given the poor state of our feature cycle time, it’s not a trade-off that I (and I guess our stakeholders) would be willing to make at this time. We might revisit this in the future though.

Photo by Camilia Hoel. Licence: CC BY-NC-SA 2.0.

Guessing relevant test modules with Fault Line

Thursday, June 2nd, 2011

Launchpad’s test suite takes a long time to run. Far too long to wait for when you’ve made a change. And the likelihood that you’ve broken any given test is pretty small. So you probably want to start by running the tests that were likely to break.

You can usually guess which tests to run; if you’ve changed “archive.py“, you should probably run “test_archive“. But some connections are easier to miss, so I’ve hacked up a Fault Line, a bzr plugin that uses past changes to guess which test files correlate to the files you’ve changed. You can run it like so:

bin/test -m $(bzr fault-line --module-regex)

This will look at all the files you’ve changed, look at their recent history, and see which files tended to change in the last 100 revisions where you changed the specified files. The --module-regex option causes it to output a regular expression, assuming that the test files are Python modules. Otherwise, it would just output a list of the test files it found.

Thanks to Jelmer Vernoij, this is even easier to achieve for testing bzr. You just need to run “bzr selftest --auto“.

To install Fault Line, just run:
bzr branch lp:fault-line ~/.bazaar/plugins/faultline

It currently requires bzr 2.3 or later (e.g. stock Natty bzr).

Fault line is pretty limited right now. For example, the way it guesses what’s a test file is hard-coded. But a few days ago, it wasn’t even a proof of concept. Who knows what the future holds?

Countdown to the pie

Friday, May 27th, 2011

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We are now one month away from the Dublin Thunderdome and the stakes of the game have increased substantially since last time! At UDS, Jonathan announced he was willing to take a pie in the face if we achieved our 0 critical bugs goal. Two others joined him in the bet.

As of this writing, we have 210 critical bugs left to fix to pie Jono, Ted and Neil. (203 actually, since  7 of those are bugs escalated after the bet announcement.) Unfortunately, their face seems pretty safe :-/ If we look at the trend of the last 4 weeks, we see that we are burning down about 12 bugs per week. At this rate, we would achieve this goal in 18 weeks, so around the end of September.  3 months too late for a pie! This week, the Yellow squad is starting on maintenance, so we’ll see if they can improve on the 12 bugs a week burn-down. I mean, that number is 3 times the long-term rate which is more like 4 a week, so we are definitively improving! Both because we are better at fixing bugs, but also because the number of newly found issues is declining. You can see the combined effect of this on the burndown graph as the slope gets much sharper on the right.

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It doesn’t look much better on our third objective which  is to have a free slot in the stakeholders Next queue. This week the Teal squad resumed work on the our project to improve Launchpad privacy features. They did an initial break-down of the project and they have work until the next UDS! The Red squad is finishing off derived distributions, probably before the Thunderdome. But even then, at that point we would be starting on adding customizable columns on search results. And the Next queue would still be full at 2 items. On the plus side, we won’t be over our work-in-process limit anymore 🙂

I’m looking forward to see how this all turns out in Dublin, but whatever happens, at the very least, we’ll have succeeded early on our 9s timeout objective.

Photo by David Muir. Licence: CC BY-NC-ND 2.0.

Tilde or not tilde

Friday, May 27th, 2011

Hand-rail shaped like a tildeWhen Launchpad shows someone’s display name, it’s not always clear who it’s referring to.

With so many people registered in Launchpad, it’s not surprising that some of them share a name. However, every Launchpad id is unique. Mine’s matthew.revell and no matter how many other Matthew Revells there might be in Launchpad, I’ll always be the only one with that ID.

To help clarify who’s who, we’re going to show the ID in more places alongside the display name. Two of those places are the person picker — so you know for sure that you’re selecting the right person — and at the top of the profile page.

There was some discussion, though, as to whether people would recognise that we were showing the person’s Launchpad ID. One way to make it clearer, it was suggested, would be to place a tilde in front of the ID.

On Wednesday I set up a survey asking which of these you prefer:

Person picker with tilde

Person picker without tilde

And which of these you prefer:

Profile header with tilde

Profile header without tilde

Rather than say it straight out — i.e. do you like the tilde? — I wanted to see if people noticed it.

The majority of people who responded to the survey said they preferred the versions without the tilde.

For the person picker, 23.6% of the respondents preferred the version with the tilde and 76.4% preferred the version without.

For the profile page it was a little different and even more in favour of the version without the tilde: 18.4% preferred the version with the tilde, whereas 81.6% preferred the version without.

Thanks to everyone who took part. It’s now over the to Teal Squad to digest the results.

Photo by Fling Poo. Licence: CC BY 2.0.

Help us test something new!

Wednesday, May 25th, 2011

A man with a clipboardMy colleagues in the Teal Squad have been working on a small change that’ll make it easier to distinguish Launchpad users who have similar names.

We’ve got two quick questions in our new survey. Help us make it easier to tell who’s who in Launchpad.

The survey is open for 24 hours only, so get in before 18.00 UTC on the 26th May.

Take our short survey to help us make it easier to tell who’s who in Launchpad!

Photo by Elizabeth M. Licence CC BY 2.0.