How to replace plain URLs with links? (C# and Javascript)

Idea: In Suppo project we want to replace URLs in chat conversations by HTML links. Yes the first thing was to use google to find some recommendations or regular expressions BUT: On stackoverflow in article is written:

“First off, rolling your own regexp to parse URLs is a terrible idea. You must imagine this is a common enough problem that someone has written, debugged and tested a library for it, according to the RFCs. URIs are complex  … and there is multiple recommended libraries in Javascript (expect similar libraries in C#) like linkifyjs, anchorme.js, autolinker.js … OK so where is the problem?

The problem for me is that all of this libraries are huge … >30KB minified.


Because we are developing livechat window (Suppo) which is attached to every page of our clients and +30KB of javascript code is not acceptable when our solution has 63KB at all (included the core of jQuery library)

So what next?

Back to beginning and compose simple regular expression (is not so important to work on every URLs … suffice many of them)


public static string Linkify(this string text)
    // www|http|https|ftp|news|file
    text = Regex.Replace(
        @"((www\.|(http|https|ftp|news|file)+\:\/\/)[&#95;.a-z0-9-]+\.[a-z0-9\/&#95;:@=.+?,##%&~-]*[^.|\'|\# |!|\(|?|,| |>|<|;|\)])",
        "<a href=\"$1\" target=\"_blank\">$1</a>",
        .Replace("href=\"www", "href=\"http://www");

    // mailto
    text = Regex.Replace(
        @"(([a-zA-Z0-9_\-\.])+@[a-zA-Z\ ]+?(\.[a-zA-Z]{2,6})+)",
        "<a href=\"mailto:$1\">$1</a>",

    return text;


// www|http|https|ftp|news|file
text = text.replace(
    /((www\.|(http|https|ftp|news|file)+\:\/\/)[&#95;.a-z0-9-]+\.[a-z0-9\/&#95;:@=.+?,##%&~-]*[^.|\'|\# |!|\(|?|,| |>|<|;|\)])/gim,
    '<a href="$1" target="_blank">$1</a>');

// mailto
text = text.replace(
    '<a href="mailto:$1">$1</a>');

It’s simple: first part of code find www|http|https|ftp|news|file and replace it by <a href=”http(s):// and second part find email address and replace it by <a href=”mailto::.
That is all and it's less than 1KB of code. – testovacia prevádza spustená

Doménu už nejaký ten mesiac máme obsadenú, no len pred pár týždňami sme spustili testovaciu prevádzku pre vybraných zákazníkov na subdoménach ako:, … no až teraz sme updatli stránku, konkrétne časť o produkte eShop, kde už LiveChat nie je ako plánovaná novinka (vo vývoji), ale je plne funkčný a pripravený pre nových zákazníkov v balíčku Business. Samozrejmosťou je doplnenie tejto funkcionality všetkym existujúcim zákazníkom, ktorý o tento skvelý nástroj budú mať záujem. Jeden ScreenShot z aplikácie:


ASP.NET MVC - the value set on the field does not correspond to the value in the Model - what’s wrong?

While developing our brand new LiveChat called ””, I noticed interesting behaviour, what I never noticed before. In the functions like @Html.EditorFor, @Html.TextBoxFor … or @Html.TextArea, @Html.TextBox … When you do AJAX “postback” of your form like this:

			@using (Ajax.BeginForm(new AjaxOptions { HttpMethod = "Post", InsertionMode = InsertionMode.Replace, UpdateTargetId = "FormAjaxContainer" }))
				<div id="FormAjaxContainer">

					<div class="form-group">
						@Html.LabelFor(model => model.WidgetThemeColor, htmlAttributes: new { @class = "control-label col-md-2" })
						<div class="col-md-10">
							@Html.ValidationMessageFor(model => model.WidgetThemeColor, "", new { @class = "text-danger" })
							<div class="input-group BGColorPicker">
								<span class="input-group-addon"><i></i></span>
								@Html.EditorFor(model => model.WidgetThemeColor, new { htmlAttributes = new { @class = "form-control" } })


with value “A” on property WidgetThemeColor and on the server you change the value to value “B” you still see on the input field the value “A”. Its caused by interesting behaviour of the helper function of all controls like @Html.EditorFor, @Html.TextBox …
They first use the value of the POST request and after that the value in the model. This means that even if you modify the value of the model in your controller action if there is the same variable in the POST request your modification will be ignored and the POSTed value will be used. When you want to apply your new value from controller, you need to do this:

Or for particular property by this statement :

And the POSTed value will be ignored while rendering of the View or PartialView.