A Couple Handy Domino Java String Utils

Wed Jan 25 11:08:30 EST 2012

As most developers probably do, I have a grab bag of "utility" functions/methods I use across various projects, and I figured I'd post a few of the handier ones.

The first is a basic XML-encoding function that just takes a string and returns something suitable for putting into an XML or HTML file. I've been too lazy to figure out if the standard Java library has an equivalent that doesn't involve creating an actual XML document in memory, so I just took the one I use for LotusScript and ported it over. It passes standard letter and number characters through as-is and then just encodes all others as Unicode entities. The string size increases accordingly, but it's presumably fast and it gets the job done, even if you have oddball characters.

The next set are just quick-and-dirty Java equivalents to the StrLeft, StrRight, etc. functions from LotusScript. They do more or less the same thing as in LS and make it so you don't have to worry about string indexes all the time.

The last is potentially the most useful, since it's the most esoteric: a special-text decoder. I've had a couple occasions where I want to spit out the contents of a view for the web, but also want to preserve things like child counts on categories. Fortunately, special text is stored in the view column in a workable format: a special non-alphanumeric character, a single letter indicating which function it corresponds to, a number representing the parameter count for the function, and then a delimited list of those parameters with character counts. Using that, I wrote a routine to process all of the special text functions I could think of other than @IsExpandable (since that's meant for the Notes UI). It even reproduces the weirdo behavior you get when you pass a multi-character string to @DocLevel.

StringUtils.java

Confound It; That's Two APIs Down

Sun Jan 22 23:02:37 EST 2012

Tags: domino

In the interests of getting crap done, as soon as I was finished with my previous post, I fired up TextMate and a couple Terminal windows to start writing a Ruby wrapper for the DAS API.

It started out great! Wanting to avoid the minor hassle I ran into before with Ruby's built-in Net::HTTP library, I did a quick search for Ruby HTTP/REST libraries and picked one that worked well, named HTTParty. Before long, I had the rudimentary elements of a Notes API working, with classes to represent the server connection, NotesDatabase, and NotesView.

I was about to start working on the NotesViewEntry class when I decided I'll need a way to page through the view, since the call to the view "collection" (wisely) doesn't return all of the data at once. The API developers cleverly store this information in an HTTP header:

Content-Range: items 0-9/35

Perfect! But, um... I was getting the list of available forums as Anonymous, which can only see two, not all 35. Sure enough, the results only contained the two Reader-visible entries (phew), but that left a showstopping problem: I have fairly frequent need for the count of entries, and I don't relish the notion of having to fetch all of the data to get that. Crap.

So DAS is out for now. I remembered, though, about ?ReadViewEntries, an older and thus clearly more mature data-access API. I could probably do everything view-related I need with that and then use DAS to get any non-view document data. So I hit the view with ?ReadViewEntries&OutputFormat=JSON (the results are the same with the XML version) and, lo and behold, the top-level object fields (with data snipped) revealed the same lack of Reader knowledge:

{ "@timestamp": "20120123T034916,85Z", "@toplevelentries": "35" }

Crap!

My quest to treat Domino like a standalone database is off to a rocky start. I can think of a few remaining options:

  1. COM: I don't deploy on Windows, so... that's out.
  2. C API: seems like overkill and just asking for all sorts of new bugs.
  3. Web Services: MIGHT work, but I can't imagine the performance would be anywhere near acceptable.
  4. Some sort of crazy thing with servlets: seems too crazy.
  5. JRuby and the Domino Java CORBA API.

I think the last is the most plausible. My forum app already has Java classes in between the XPages front-end and the Domino database, so I could possibly take those wholesale and just change the methods I use to get the session and current database to instead initialize a CORBA session. I'm a bit nervous about speed and running across some of the various "not implemented in CORBA" landmines hidden across the API, but it might just work. If it does, my next task will be deciding on a web server and a Ruby web framework that's not terribly SQL-centric.

More Idle Complaining About Designer

Sun Jan 22 18:35:08 EST 2012

Tags: xpages

As more and more of my Domino development has been with XPages, my databases have filled up with XPages, Custom Controls, and Java design elements. However, the more I use these, the more of a pain Designer becomes. It gets into its head on a regular basis the notion that it needs to recompile every single such design element - when I open the app in Designer (whether or not it was "greyed out" in the sidebar from before), whenever it "forgets" that I have it set to Automatically Recompile and I have to turn that back on (which is frequent), whenever classes just stop loading properly and I have to Clean the project, and sometimes just for fun.

In a basic app, this isn't so bad... it's pretty annoying, but at least it doesn't take too long. In my forums app, though, which contains dozens of pages, controls, and Java classes, it can take about 10 minutes when I'm not in the office. Ten minutes! Just to open the app! That's even ignoring the side effect that the app is unavailable on the web while this is happening, throwing various server errors until all the classes are back.

I've tried numerous things: switching the Java classes to and from the 8.5.3-standard Code/Java folder to a "classic" WEB-INF/src folder (the 8.5.3 folder seems to make it worse), turning off the "Automatically recompile dependent XPages" option relating to custom controls in the prefs, and creating fresh Windows VMs with entirely-clean installations of Designer. Theoretically, I could turn off automatic compilation in the "Project" menu, but then I'd have to do it manually, and I can only imagine I'd consistently run into times where it "needs" a full recompile anyway.

It's bad enough that it takes this long when I want to get hacking away at the code, but it's all the worse when I just want to go in and fix a CSS or JavaScript file, neither of which have anything to do with the big pile of Java classes Designer is so obsessed with. Nonetheless, if I'm going to get at them, I have to let Designer do its thing. There are potential workarounds - write a web-based editor for those design elements, store them in other databases, or store them as data documents - but those sacrifice either the convenience of a proper editor or of having all of the assets of my app in one place.

Other than my job, there are only a couple thing tying me to XPages for my for-fun projects: the fact that I now have a pretty huge foundation of knowledge in Domino development, the fact that XPages actually make a lot of fancy things very convenient, especially with the illustrious Extension Library, and Reader fields. The last one of these is surprisingly difficult to reproduce elsewhere. They're so elegant and bulletproof, much better than filtering results, writing giant nested SQL queries, or throwing up my hands and sticking with a basic "access level" type of restriction. And all of those would still mean I'd have to worry about ensuring that I don't accidentally select the wrong records anywhere I write a query, whereas Reader fields mean that the documents effectively don't exist, so I CAN'T screw it up.

So that leaves my main options as:

  1. Suck it up and keep using XPages
  2. Suck it up and give up Reader fields in exchange for a programming environment suitable for human use
  3. Stop being lazy and write access classes in Ruby or PHP that use the DAS API, hoping that performance is good enough
  4. Close my eyes and wish real hard that a bug fix patch will come out and magically fix all of the problems in Designer

Number 4 would be ideal, but I think number 1 is what I'll most likely do. Still, being able to use Ruby instead of Java would be such a breath of fresh air, and turning Domino into a "mere" database server via DAS both is appealing and would be mostly new ground. Given that the database-open operation I started halfway through this blog post is in its 16th minute and still going, maybe I really should get off my duff and try that out.

Edit: 32 minutes! Nice!

Keychain DB: Very Rough First Script

Sun Jan 15 16:20:31 EST 2012

Tags: domino

I've had a chance to start on my Keychain project from last week, enough to put together a thoroughly rough and unmaintainable script to do the uploading. It has all kinds of horrible properties: it doesn't do the Keychain dump itself (instead reading from a hard-coded file containing a keychain dump from the "security" tool), it doesn't abstract away any of the Domino DAS access, it doesn't check for existing versions of the items, it doesn't handle field data types properly, and it even writes to the filesystem. But hey, it's a start:

keychain-upload.rb (requires the json rubygem and uses auth information from ~/.netrc)

In spite of all its faults, it DOES push the data up to the database, and that's something. It stores the keychain file name in a field named "keychain", the "class" in one called "entry_class", the data in "data", and the rest of the arbitrary fields from the item in fields prefixed with "attr_". Once it was in the database, I set up a view called "Passwords" with the following formula:

SELECT Form="Item" & entry_class="genp" & attr_type != "\"note\""

The extra quotes around the type field's value are an artifact of the non-existent type handling in the original script - it just stores the values exactly as they appear in the dump file, rather than converting them to null, numbers, or strings.

It's not pretty, but I now have a way to view my Keychain entries on the web. I'll probably give a shot to doing this the "right" way via a Cocoa app and structured classes down the line, but for now it'll already be useful to me.

A New Personal Project With Keychain and DAS

Wed Jan 11 19:18:52 EST 2012

Tags: domino

With Apple's transition to iCloud, they're getting rid of Keychain sync. This is too bad, since that was one of the MobileMe features I actually used, loved, and never had problems with. Fortunately, all is not lost: worse comes to worse, I can pick up a copy of 1Password, which has the advantage over MobileMe of being cross-platform.

But I'm a programmer, right? Why buy something - especially for $50+ - when I can just write something myself? My needs at the moment are fairly simple - I only REALLY want a way to back up my Keychain and view it on the web, for when I'm in Windows or on my phone and want to check a password. I only use the one Mac currently, so I don't need proper sync, and I don't need to pull new passwords back down into the Keychain. Maybe down the line, but one step at a time.

The Keychain itself takes the form of a file housing a collection of records with a body of essentially arbitrary data (usually a string, but it can be different for certificates or notes), with a composite key consisting of, I think, the type, server, account, and maybe some other fields. The only thing that would make this a better test case for Domino 8.5.3's shiny new Data Access Services would be a 32-digit hexadecimal unique identifier, but it's pretty darn close as it is.

The main problem I have to getting starting is actually getting at the data. I think there are two main ways: the C-based security/Keychain API or using the "security" command-line tool, which is a more-or-less friendly wrapper for much of the same functionality. Being the lazy type that I am that only deals with C when I have to, I'm starting with the "security" tool. It has a handy "dump-keychain" command, so I can type something like "security dump-keychain login.keychain" and get a formatted list of all entries in that keychain, minus the "data" field. I can add the "-d" switch after "dump-keychain" to include that field, but that comes with a big caveat: you have to click an "Allow" button for every single item. Given that I have about 1,100 items, I'd rather avoid this fate. I've tried running it through sudo, but to no avail. I've tried fiddling with the "authorize" command in the tool, but also with no luck - I'm not sure if I'm just doing it wrong or if it's related to something else, which may or may not be what I want. I could use the "-r" switch instead of "-d" to get the encrypted data, which would satisfy my backup desire, but not my "check it from the web" desire. Absolute worst case, I could put on a movie or podcast and click "Always Allow" a thousand times.

However, once I get past that hurdle - whether it be via the C API or a lot of clicking - the rest should be easy. I should be able to create a basic database, grant DAS access to it, create a view sorted by the various components of the items' composite keys, and do a basic "view lookup, then update or create the doc" routine, pushing up the field values pretty much as-is. That should act as a perfect basic-case project for trying DAS out while also solving an actual problem I have.

So here's a strange new problem in my XPages forum app

Thu Dec 29 21:10:48 EST 2011

The other day, I set out to put some work into my guild's forum site. Immediately, though, I noticed that the main forum page was taking significantly longer to load on my development server than on my production server. Specifically, it was taking about five minutes to load, as opposed to about a second. That seemed... problematic. Looking at the profiler, I saw that the page was somehow making 38 million calls to Document.UniversalID, which was slightly out of proportion to the two forums listed on the page.

After a lot of trial and error to find out what the problem was, I narrowed down the culprit to the list of recently-updated topics. Each of my model elements is represented by a class implementing the List interface, which is really like a wrapper around the view. Thanks to some debugging output on the console (with apologies to my bloating log), I found that the list, which is only supposed to get the first 15 entries in the view, was repeatedly processing EVERY entry. Spitting out a stack trace revealed that the XSP list processor was converting the entire List object to a string via its own method of using the List's iterator. Huh.

I investigated a bit, looking at the resultant Java code from my custom control, renaming the property that passes in the List, and looking at the name.xsp-config file that accompanies it, all to no avail. Next, I tried re-creating the custom control, but that has the same behavior. For the time being, I've found that copying the code from the control in place of where I use it in the XPage works for some reason.

I have no idea why doing that worked, since in theory it should be performing the same thing, and I have no idea why all my other uses of similar controls--such as the one for recent posts--aren't freaking out. This will certainly bear some investigation, since until I figure it out I'll have to live in fear of the runtime stringify-ing my giant Lists at will.

Pondering RSS Syncing

Wed Nov 23 13:10:28 EST 2011

Tags: domino

I was listening to the latest episode of Build and Analyze on the way home from work yesterday and, as I am wont to do, I started yelling at my iPhone when they started talking about Google Reader and the difficulty of syncing. Admittedly, at the end, they got to the fact that, even if you could do it technically, it'd be tough to make money off of providing an RSS sync server. That part is fair enough, but I still can't let the technical difficulties stand, and I've been thinking more about how it would be done in Domino.

In the basic form, the problem in question is pretty much exactly what NSF and the Notes/Domino relationship is designed to do: seamless replication, deletion stubs, unread marks, and so forth. In fact, RSS syncing is a better fit for the model than mail, since mail required adding all kinds of extra (but useful) functionality, while RSS syncing would just be data and an agent to fetch the feeds periodically.

The way I figure it, there would only be a couple technical hurdles, both related to scaling: storing large volumes of data and fetching new feed content periodically.

Storing large volumes of data might not be too bad. There are a couple ways you could do it. One would be to store the user's list of subscribed feeds and "read" stubs in one database per user, and then store the feeds and feed content in another database (or databases), and do all data access via agents or web services that would pull the data from each distinct location. Another way could be to store the feeds and entries in each user's database, keeping the feed content as attached HTML documents and letting DAOS handle efficient storage. The latter route would let you take advantage of the Domino Data Service and read marks (which DAS conveniently supports).

Updating the feeds would be rough for a single server, but the job could be farmed out to many clusters in a server. You could write agents that would determine the server they're on and, based on, say, its name, pick a slice of the feeds to check, so if you have 10 servers, each would update 10% of the feeds.

I'm sure there'd be other roadblocks during actual implementation (it IS Domino, after all), but I think that'd be basically all you'd need on the server side. The client would be a little tougher, since you couldn't just use NSF and selective replication, but that wouldn't be terribly difficult to handle.

It's too bad it's likely not profitable, between licensing, hosting, and bandwidth costs - it'd be a fun project to try out.

That Counts as Progress

Tue Nov 22 16:28:21 EST 2011

Tags: domino xpages

A while back, I described the problem I'm having in my guild-forums XPages app, which is that it very easily gets its environment out of whack, to the point where changing any design or data note from outside the XPages environment caused an "X is incompatible with X" ClastCastException. This improved gradually over time. At some point in 8.5.2, I started being able to modify data documents again without the problem. When 8.5.3 came out, it improved again: I can now replicate over changes from my development server to the production one without having to bounce HTTP on the production one. At that point, it became much less of a hassle - sure, I still had to re-save a Java class file every time I modified an XPage, but that was only in development, so I could deal.

However, I think I've found the proper solution. In 8.5.3 (I think), IBM added a custom editor for the xsp.properties file (which you can reach using the "Package Explorer" Eclipse view, in whatever.nsf/WebContent/WEB-INF). Many of the options are duplicates of what you see in the normal "Application Properties" editor (since they edit the same properties), but there are some nifty additional goodies. I won't go into them all, but I urge you to take a look. The important one here is in the "Timeouts" section of the "General" tab: "Refresh entire application when design changes" . That sounded perfect and, lo and behold, it seems to do what I want: once I turned that on, re-saving an XPage stopped causing the ClassCastException. I haven't given it a proper testing, so it might not be everything I'm looking for, but I'm thrilled at the initial results. Having to re-save a Java file for each change wasn't a HUGE problem, but it was a niggling one, and not having to jump through the hoop helps make the whole environment seem less rickety.

That's Weird

Wed Nov 09 09:35:21 EST 2011

Tags: xpages domino

Yesterday, I started working on a small sidebar widget app using an XPage, after finding out that XPages can now (as of 8.5.3) be used in the Notes sidebar in the same way that Forms could before. It's quite a simple page, very Twitter-like: one text input field and then a list of posts. However, even though it's very simple, I ran into two annoying bugs quickly.

The first of them is a Schrödinbug. I set up some code in the "onClientLoad" event to start a setInterval to do a partialRefreshGet on the list of posts, so it would keep itself up to date:

<xp:eventHandler event="onClientLoad" submit="false"> <xp:this.script><![CDATA[ setInterval(function() { XSP.partialRefreshGet("#{id:messagesPanel}") }, 2000) ]]></xp:this.script> </xp:eventHandler>

Simple, right? But I started getting errors in the status bar, along the lines of somethingorother not being defined. That's... odd. So I swapped over to Safari, figuring it'd be some XPiNC-specific thing, but I started getting similar (albeit more specific) errors there, along the lines of:

TypeError: 'undefined' is not an object (evaluating '_166.formId')

Huh. So I tracked it down and the problem was in the code called by partialRefreshGet, where "_166" is the name given to the second (optional) parameter. It makes sense when seeing it - though the code is supposed to fail over when it doesn't work, I can see why the browser would throw up its hands when you try to get a property of an un-provided parameter. But this has worked before! Just looking around on the web, you run into plenty of examples that leave out the second parameter. But sure enough, when I changed the line to XSP.partialRefreshGet("#{id:messagesPanel}", {}), it started working great. I can only think that this is either some 8.5.3-specific bug or some weird thing I managed to do in my code... but there's not even really enough code to mess up.

The second bug is still annoying, and it's somewhere in between a bug and a security feature of Firefox/Gecko. Basically, while you can call the .click() method on a button in client-side JavaScript in Gecko, it doesn't behave exactly like clicking on the button. Specifically, I have a CSS-hidden button that executes the actual action of creating the message document from the text you type in, and I want it to happen when you hit enter. The button itself works great - if I have it show up, I can type, click, and it executes the action and partial-refreshes the list of posts. However, if I hit enter, which uses the .click() method, I get an error about not being able to refresh that part of the page, but then it forces a full-page refresh and still works. So it's KIND OF clicking it, but not quite.

I'm not sure what to do about this one. I looked up a couple things online about trying to emulate the actual click event, but with no better results. I could do a REST service on the page, but I don't want to have to roll out the Extension Library to everyone in the company. Maybe I'll look into sending along the data in a XSP.partialRefreshPost call and eliminate the button entirely. We shall see.

Trying To Escape From Designer

Tue Nov 08 11:14:30 EST 2011

Though I've grown to more or less enjoy writing Domino applications, I always feel like this is in spite of the tools, namely Designer. In a lot of ways, Designer has improved significantly over the last couple versions: as long as you ignore the speed, the Eclipse-ified Java and LotusScript editors are miles ahead of the antiquated previous ones, and it's handy to be able to switch to the Java perspective. However, so much else makes it a drag:

  • It's a Windows app. I use a Mac, so there's simply a big hurdle to using Designer. Parallels has smoothed the process greatly - running Notes in Coherence mode means I can use my preferred OS while still getting work done. However, it means that it's a big to-do whenever I want to make any tiny change in the code. For day-to-day work stuff, I can get a lot done in the Mac Notes client, since I put in a lot of work to make managing client web sites doable without going to the design side, and the Mac client still lets you edit views and agents. However, there's no XPages editor, so I can't use that for serious work.
  • It has a mind of its own. For some reason, a new clean install of Designer I made the other day got it into its head that opening any database should involve recompiling every XPage and Java class. Sometimes, it turns off "Build Automatically" for no reason, and then turning that back on also requires a full recompilation. Sometimes, it just holds up all user actions while it does... something for five minutes. What's it doing? Beats me.
  • How many times have I seen this window? A billion?
    Removing a database from the project list has about a 30% chance of causing a crash and quitting Designer has about a 50% chance. Sometimes, saving a form will do it. Sometimes, walking away from the computer to get a drink is enough. And every time it crashes, I have to dismiss the dialogs and check the task manager to get rid of any residual processes, such as an instance of nsd pegging a processor, then relaunch Notes and get back to the environment I had, which is not a speedy process.
  • I'm not that crazy about Eclipse. DDE is better than previous Designers, yes, but Eclipse is still a giant beast with the same sense of style and simplicity as the monstrous Java language that spawned it. On the plus side, the blue look that IBM came up with is actually rather attractive compared to the standard Eclipse UI, but little quality-of-life things are a drag. For example, how do you specify how many spaces a tab should take up visually? It's in a couple places in the preferences and you have to set them all, including buried inside a weird sub-preferences dialog for messing with your Java formatter. And how about changing your code syntax coloring? You have to go to a dozen places, one for each syntax type. Compare to a text editor like TextMate, where you can swap between packaged color schemes with a drop-down.

That's enough for the rant. So what is there to do about it? I give this problem a thought from time to time, and I don't think there's really a great option, but there are some places to start. The real key to any alternative scheme is DXL - using that, you can (more or less) view and modify design elements freely. I've toyed with this notion before - maybe a web UI that lets me pick the DB and design element I want so I can tweak the DXL manually for when I want to make a quick change but don't already have Windows or Designer open. It would mostly work, but it would take a lot of work to make it practical.

There's a big sticking point, too: XPages. If you export an XPage to DXL, you can see that the exporter basically punts on it - it's exported as a generic "note" type with Base64-encoded binary fields. I haven't run the field data through a decoder, so maybe one of them is the XML "source" of the page, and maybe it could be made to work, but that just raises more questions. Would that require updating the other binary fields in some way? Would importing it with a DXL importer cause it to generate and compile the Java representations? What about generic Java classes? Would those work with DXL and would they be compiled?

I'm starting to get an idea of what would be ideal and almost practical, though. One could write a WebDAV server (possibly with a complex servlet, a small web server to the side, or other trickery) that represents the design elements as editable files in a folder structure similar to the Java perspective view of the database. Traditional files and image resources could be edited as-is (which I think the built-in WebDAV server does), but design elements could be represented just as DXL and then re-imported when modified. Even if it doesn't support XPages, such a scheme might have a lot of promise and wouldn't be reliant on Designer or any other IDE.

If I ever get brave enough to delve into WebDAV or frustrated enough with Designer, I might just look into it myself.