Export Dynamic LINQ to CSV

By , September 8, 2019 3:22 am

LINQ allows to perform various queries against different data structures. Wouldn’t it be great if you could easily export result of a LINQ query to CSV? Fortunately you can! This article by Scott Hanselman explain how and culminates in cool in its simplicity code:

namespace FooFoo
{
    public static class LinqToCSV
    {
        public static string ToCsv<T>(this IEnumerable<T> items)
            where T : class
        {
            var csvBuilder = new StringBuilder();
            var properties = typeof(T).GetProperties();
            foreach (T item in items)
            {
                string line = string.Join(",",properties.Select(p => p.GetValue(item, null).ToCsvValue()).ToArray());
                csvBuilder.AppendLine(line);
            }
            return csvBuilder.ToString();
        }
 
        private static string ToCsvValue<T>(this T item)
        {
            if(item == null) return "\"\"";
 
            if (item is string)
            {
                return string.Format("\"{0}\"", item.ToString().Replace("\"", "\\\""));
            }
            double dummy;
            if (double.TryParse(item.ToString(), out dummy))
            {
                return string.Format("{0}", item);
            }
            return string.Format("\"{0}\"", item);
        }
    }
}

This code adds .ToCsv() extension method to any IEnumerable so you can run something like

string csv = linqQuery.ToCSV()

Unfortunately this doesn’t work if your query is Dynamic LINQ query Continue reading 'Export Dynamic LINQ to CSV'»

Dynamic LINQ to XML

By , September 8, 2019 1:59 am

Language Integrated Query (LINQ) is a cool feature of .NET languages like C# that allows you to perform SQL-like query right within the language against language’s data structures (lists, arrays etc.) But one drawback of LINQ – you have to know in advance, at compile time which fields to select, what filter conditions would be. Sometimes there’s a need to supply these at runtime – e.g. user selects which fields they want to see

Thankfully there exists Dynamic LINQ Library that allows you to supply LINQ parameters as a string akin Dynamic SQL. Here’s an example of such query from the library’s homepage:

var query = db.Customers
    .Where("City == @0 and Orders.Count >= @1", "London", 10)
    .OrderBy("CompanyName")
    .Select("new(CompanyName as Name, Phone)");

Now, one thing that LINQ can do is query XML. So in theory if we load, say, this XML:

<DATA_CENTER>
   <SERVER IP="1.2.3.4">
      <OS>Windows</OS>
   </SERVER>
   <SERVER IP="5.6.7.8">
      <OS>Linux</OS>
   </SERVER>
</DATA_CENTER>

into an XElement and run something like this

var query0 = myXElement.Elements()
          .AsQueryable()
          .Select("new (Attribute(\"IP\").Value as IP, Element(\"OS\").Value as OS)")

it would produce list of IPs and OSes. Unfortunately this doesn’t work. Continue reading 'Dynamic LINQ to XML'»

Keep animated images after uploading to WordPress

By , May 11, 2019 5:32 pm

Haven’t written in a while. Not that nothing interesting happened, but never got around to. But I finally moved my blogs to AWS Lightsail (very smooth process, by the way) and experienced only one hurdle I wanted to write about (surprisingly, not related to AWS).

After the migration, I noticed that all images on my Fitbit Clock Faces site lost their animation. When I inspected an image – I found that it’s source goes thru some kind of a proxy “i1.wp.com”. After digging a bit I found that it is used by JetPack site acceleration service – it caches images to serve them faster. Unfortunately cached copies seem to lose some of their properties (like animation).

To fix it – go to JetPack settings and turn “Speed up image load times” off

Disable JetPack image caching

Happy blogging!

Copy/Paste image into an editable DOM element in Chrome

By , September 11, 2017 4:29 pm

All major browsers allow to paste image directly into a DOM element with contentEditable property set to true. They automatically convert it into IMG element with source pointing to base64 encoded DataURI of the pasted image. That is all browsers, but Chrome. Chrome needs a little help.

In my particular case I need to be able to paste image into an IFRAME with editable body of the content document (for some reason Infragistics WebHtmlEditor ASP.NET control renders itself as this contraption). But the code below applies (with small changes) to any editable DOM element.

To achieve the result we need to perform 3 tasks:

  1. Capture image from the clipboard
  2. Convert the image to DataURI format
  3. Create IMG element with the DataURI source and insert it into the DOM

Take a look at the code below: Continue reading 'Copy/Paste image into an editable DOM element in Chrome'»

April Fools has been canceled this year.

By , April 1, 2017 12:01 am

Because we live in a farce now.

That will be all.

Tweet images with Scriptr and IFTTT

By , February 28, 2017 4:34 pm

Sev Trek

Looks like everybody is doing Twitter bots these days so I decided to try my hand on one as well. And it had to be something lighthearted – to let people’s mind off things for a while. Way back in early 2000s there was a funny parody comic of Star Trek called Sev Trek. Original site is gone now, but archive of images was saved at http://sevspace.com/stupidarchive/sevtrek.asp.htm. Images are numbered sequentially – ideal for automatic processing. My bot would tweet random images every couple hours.

To host bot’s script I decided to go with Scriptr which offers powerful JavaScript backend and multiple expansion modules. And IFTTT has a cool Twitter service, one that can tweet image from an URL. So the idea was:

  1. Code hosted at Scriptr generates URL pointing to an image at sevspace.com
  2. Code then call Maker service of IFTTT – custom service capable of accepting HTTP requests
  3. Maker service triggers Twitter service and passes URL of image it got from Scriptr code
  4. IFTTT Twitter service tweets the image

Continue reading 'Tweet images with Scriptr and IFTTT'»

Full control of your LimitlessLED/Milight – v6- bulbs from Amazon Echo

By , February 24, 2017 9:42 pm

A while ago I blogged about controlling you Milight smart bulbs from Amazon Echo. This was done by sending raw UDP packets directly to Milight bridge. Since a packet consisted only of a few bytes – this was manageable.

Then we got v6 of Milight bulbs. They’re vastly superior to previous version – besides brightness and color you can set warmth and saturation among other things. But with new features came increase complexity of commands. UDP packets now consist of huge number of bytes and you cannot simple send packet and forget it, response matters too.

HA-Bridge, which is used to emulate Phillips Hue bulbs so Echo can detect the devices, is incapable of such commands. Thankfully it can run external scripts. Continue reading 'Full control of your LimitlessLED/Milight – v6- bulbs from Amazon Echo'»

Using FusionCharts in SSRS reports

By , January 30, 2017 12:11 pm

Microsoft’s SSRS is pretty advanced reporting system with multitude of advanced features. SSRS also has charting capabilities, but it’s somewhat lacking compared to more advanced desktop or web charting suites

On the other hand FusionCharts offers very cool charting package with gazillion of chart types and very cool features. But it uses JavaScript engine and renders charts client-side only!

What if there was a way to marry the two technologies together – to render cool FusionCharts in advanced SSRS repots? Continue reading 'Using FusionCharts in SSRS reports'»

There’s new reflective LCD in town (SMA Q2 vs PTS)

By , January 20, 2017 12:23 pm

I’ve been a fan of Pebble smartwatch for a very long time, both as a user and developer, but recently, even before announcement of Pebble acquisition by FitBit I got curious – what else’s out there? Two mainstream branches of smartwatches – Android Wear and “The Watch” are of no interest to me – too boring. So I looked into Samsung Gear watches – Tizen platform is very interesting, then it was Vector Watch (which ended up being bought by FitBit as well) and now a new ePaper watch from Chinese company Shenzhen – SMA Q2 (sometimes called SMA Time).

There is no question that despite obvious visual similarities, at this point in time Pebble Time Steel is vastly superior to SMA Time. PTS is on 4th generation firmware which brought many advanced features over the years, PTS has a very popular appstore and high quality developer ecosystem. SMA Time feels like Pebble circa firmware v1.x (probably even less, e.g. it has only 3 slots for watchfaces on the watch) but it seems to have great potential.

I am posting here a few pics comparing PTS with SMA Time. Continue reading 'There’s new reflective LCD in town (SMA Q2 vs PTS)'»

SSRS and HTML rendering of ordered list

By , November 14, 2016 2:02 pm

Microsoft’s SQL Server Reporting Services supports rendering of HTML tags, but for some reason that support stuck in 1990s – only very limited set is supported. And even using that set is problematic.

Case in point – ordered list. While officially supported – the way it is rendered is the stuff nightmares are made off. Jumble of original tags generously intermixed with DIVs and SPANs – it’s a wonder it renders at all.

And sometimes it doesn’t. If you try to view a report in Internet Explorer (especially from older, but still actively used versions of SSRS like 2008) numbering get screwed.
Continue reading 'SSRS and HTML rendering of ordered list'»

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