Inside the Mind of Justas

LINQ in JavaScript - linq.js

2010-12-07T20:19:00.000-08:00

I love LINQ and love JavaScript. Now you can enjoy all the wonders of LINQ in JavaScript by using linq.js:

var queryResult = Enumerable.From(jsonArray)
    .Where(function (x) { return x.user.id < 200 })
    .OrderBy(function (x) { return x.user.screen_name })
    .Select(function (x) { return x.user.screen_name + ':' + x.text })
    .ToArray();

There is a standalone JavaScript library, a jQuery plugin, and an editor with reference to try out your linq.js queries.

Search Legitimate Encyclopedias Only

2010-11-06T14:34:00.000-07:00

Tired of searching for something and only getting "answers" from bored 8-year-olds on Yahoo Answers?

Me too.

Try blekko.com filtered search that will search only legitimate encyclopedias (Wikipedia, Yahoo Answers, and other self-professed "expert" sites are excluded).

Compare blekko & google search results:

"Time Travel" on Google
"Time Tavel" on Blekko

Notice how this gem will not be included in Blekko results:

The Time Travel Fund[tm]

We believe Time Travel will one day be possible, so we have started an investment fund that may one day pay for you to travel to the future.
www.timetravelfund.com/ - Cached - Similar

I love Google, but unless they do something about the amount of garbage and spam in their search results, the smaller search engines that put more focus on quality will eat them alive. I feel like I'm back in the 90's where you'd try yahoo first, then lycos, then altavista to find what you're really looking for.

Web Developer Job Skills Trend Tracker - Launched

2010-04-07T21:42:00.000-07:00

To get a more objective picture of what kinds of technologies various companies are using, I've put together a small, one-pager site to get the counts of available jobs on careerbuilder.com using their API.

Keywords are organized by category and sorted by number of jobs with those keywords.

Take a look at the Web Developer Job Skills Trend Tracker

Refresh Stylesheets Bookmarket: refresh stylesheets on a page via javascript bookmarklet

2009-06-23T19:46:00.000-07:00

During web development, I sometimes need to edit the stylesheets of the page but I do not want to refresh the whole page and then repeat the steps I took to get to a particular state of the page (find a record, select, click edit, etc...). So I made a quick and dirty bookmarklet that I can click on to refresh all the stylesheets on the current page. Works like magic... tested in IE6/7, FF3 and Chrome.

Drag the link below to your bookmarks, or alternativelly, right click it and hit "Bookmark this link" (in Firefox).

Refresh Stylesheets

How it works:

(function(){   
  var s = document.getElementsByTagName("link");
  for(var i = 0; i < s.length; i++)
     s[i].href += (s[i].href.search(/\?/) >= 0 ? "&" : "?")
        + "random=" + Math.round(Math.random()*10000);
})();

It simply loops through the stylesheets in the current document and appends a random integer to their urls ("random=XYZ"). Since the stylesheet url with the extra query string parameter does not exist in the browser's cache, the browser fetches the newly updated stylesheet.

This can be repeated multiple times, the stylesheet url will just have multiple query string "random" parameters.

FreeCreditReport.com 50% discount trick

2009-02-11T12:51:00.000-08:00

Hehe, so I signed up for the FreeCreditReport.com site trial membership the other day, and of course I just wanted to get the free report to quickly check my credit score.

All nice and good, but you can only see the score based on the info from Experian, but not the other two companies. (Seems like the site is actually owned by Experian, thus only their score)

To see all three, you need to pay **$39.95**. What??? Forty friggin bucks just to see all three scores? Considering you can do the same by going to the other agencies sites and seeing their score for free.

Anyway, I promptly called the number to cancel the membership (you've got 7 days to do it), and after I entered my SSN, etc...

Surprise, surprise they offered a 50% discount.

So basically to get the 50% off, call the number they list on their site (can find it in FAQs, well hidden, non the less)

1-888-829-6560
M-F 6am-6pm PST

And once they confirm the membership, you'll get offered to take the discount.

TADA!

Slow localhost loading in Firefox when using Visual Studio Web Development Server (but not when using IE)

2009-02-04T18:19:00.000-08:00

I was trying to debug a ASP.NET project using the Visual Studio Web Development Server (WDS) and the pages in Firefox would come up extremely slow. Normal speed with all other browsers, IE 6,7 and Chrome, and Safari.

Well, it turns out that Firefox 3 by default will try to resolve IPv6 addresses when requesting a URL. When it can't find one, a time out must pass before it returns a result. The localhost address used by the WDS won't have an IPv6 address, and thus when FF asks for localhost, it gets delayed looking up the IPv6 address.

FF will then do this for every item on the page, image, js, css, etc...

The fix involves adjusting the Firefox settings to NOT try to resolve the IPv6 addresses for a given domain.

Derek here offers a solution to fix the problem by turning off the IPv6 lookup feature completely, however there is also a way to allow Firefox to just disable the DNS lookups for a particular domain name, not just turn off the feature all together.

To only exclude a given domain name from IPv6 lookups:

Start Firefox
In the address bar, type in "about:config"
Accept the warning
In the filter box type in: "network.dns.ipv4OnlyDomains"
Double click the one entry that should show up
Type in "localhost" and any other domains (comma separated) > OK
Changes should take affect immediately

To turn off IPv6 lookups entirely:

Start Firefox
In the address bar, type in "about:config"
Accept the warning
In the filter box type in: "Network.dns.disableIPv6"
Double click the one entry that should show up, to change it to true
Changes should take affect immediately

More info about these magic properties:

Cause of Error: ASP.NET: Object reference not set to an instance of an object.

2009-01-04T17:27:00.000-08:00

The Problem:

The obscure, and generally least informative error "Object reference not set to an instance of an object", is arguably the most annoying error an ASP.NET developer will encounter.

When initially starting .NET dev, I would encounter it daily, and it would be a major cause of headaches for me.

Here is some sample code:

The Cause:

The error is caused when one tries to access a property of an un-initialized object (the object is null).

In the code there is a class called DummyMotherClass, and it has just one property called "ChildDummy" of type DummyClass.

Above, when a variable of type DummyMotherClass is declared, the ChildDummy property is not instantiated.

So, after the line "DummyMotherClass TestInstance = new DummyMotherClass();", the TestInstance.ChildDummy is null.

If you try to access any property of the ChildDummy property, the "Object reference not set to an instance of an object" will be thrown. This happens because you're essentially trying to do something like

The Solution:

To fix the error, you can:

Check if TestInstance.ChildDummy != null, before attempting to use one of the ChildDummy's properties.
Initiallize the TestInstance.ChildDummy manually.
Surround the line in question with a try { } catch {} statement (may degrade performance though).

In the fixed code below, I addressed the problem by initializing the ChildDummy property of the DummyMotherClass in it's constructor "ChildDummy = new DummyClass();".

This also could have been done just below the "DummyMotherClass TestInstance = new DummyMotherClass();" line, if you do not have access to the constructor. Ie "TestInstance.ChildDummy = new DummyClass();"

Debugging:

I have not found a better way to check which object is null other than starting the Visual Studio debugger. The error page tells you which line is causing the problem, but it doesn't tell you which object is null. The error becomes less useful when you have the properties chained across multiple levels. Esp when using LINQ to SQL (ie: following foreign key relationships).

I usually just hover over each object in the line starting with the leftmost one, and continue sweeping right until the object in question is null.
After finding the causing object I add some if statements to check for nulls, or look for a more general solution to address the problem if it may reoccur in other places in code.

Conclusion:

Hope this helps to avoid some frustrating moments!

Palm Springs and San Diego Panoramas

2009-01-02T13:10:00.000-08:00

These are some pics from the trip to San Diego I took last week. I stitched the panoramas using Photoshop CS3. Some of these are irregularly shaped, because I didn't want to lose the part of images when pigeonholing them into a rectangular shape.

Salton Sea from Salton Sea State Recreation Area. Center facing West. The whole beach and the land around it is covered in salt deposits. Looks really crazy. It was too cold to swim, but I wonder if you could float easily, much like in the Dead Sea.

The view from Courtyard by Marriott‎ hotel we stayed at in Palm Dessert, CA. The hotel is at
74895 Frank Sinatra Drive

View of Palm Dessert, CA from a hill on the West side of town. Near Fred Waring Dr & Painters Path.
Notice how the shopping plaza buildings all have a bunch of small AC units on their roofs? I would think that one consolidated big AC unit would be more economical. Anyone know if that's not the case?

View further up the same hill. Facing North. Lots of other hikers here, esp runners.

Pacific Ocean from Point Loma. Facing North. This one was near the tide-pools that are closer down to the water. There were some pretty interesting critters in them. Def check them out if you're in the area.

View of Downtown San Diego from Point Loma. There is a historic (now non-functioning) light house with a little museum behind me. Also, the Visitor Center to the left lets you rent binoculars (free) and you can then check out the military base activity (jets, helicopters, etc... taking off), as well as the aircraft carriers and submarines stationed near by.

Facing Point Loma from Coronado island. Great beach and the little island town.