Web Development

HTML5 Series - Forms

Forms haven't really changed in functionality since they were first invented, but with HTML5 the browser is going to add a lot of the functionality you've previously been hand coding through JavaScript/jQuery.

HTML5 now supports things like setting a field to be required or adding some html text that disappears when you click in the field. Some of the new tags include:

  • required - Determines if the field must be filled in
  • placeholder - Text to be displayed before the user enters a value
  • autofocus - Default the curser to the field with this set
  • pattern - A regex expression to validate the field
  • min / max - Specify the min and max values that can be entered

For more visit the HTML5 form attributes page on W3Schools

There are also new input types that will restrict the data that can be entered and the way the field is rendered such as:

  • colour
  • date
  • datetime
  • email
  • month
  • number
  • range
  • search
  • tel
  • time
  • url
  • week

For more view is the HTML5 form input types page on W3Schools

HTML5 Series - Semantic Tags

Before HTML5 the HTML for your page's layout was probably primarily made up of a lot of div tags with id's a class's to give them a visual structure and layout. It might look something like this...

1<div id="header">My Site Name</div>
2<div id="content">Bla bla bla site content......</div>
3<div id="footer">Privacy policy, copywrite info etc</div>

This though has 2 problems. Firstly it's not great for computers like search engines or screen readers to understand as everything is a div. There is extra code you can add to improve on this (have a look at Scheme.org). Secondly your code isn't very, again because everything is a div.

HTML5 however introduces new semantic tags like <header>and
<footer> to make your data more structured. So the above example would become...

1<header>My Site Name</header>
2<article>Bla bla bla site content......</article>
3<footer>Privacy policy, copywrite info etc</footer>

Other tags are as follows:

Tag Description

<article> For external content, like text from a news-article, blog, forum, or any other content from an external source

<aside> For content aside from the content it is placed in. The aside content should be related to the surrounding content

<details> For describing details about a document, or parts of a document

<summary> A caption, or summary, inside the details element

<figure> For grouping a section of stand-alone content, could be a video

<figcaption> The caption of the figure section

<footer> For a footer of a document or section, could include the name of the author, the date of the document, contact information, or copyright information

<header> For an introduction of a document or section, could include navigation

<hgroup> For a section of headings, using

<h1> to <h6>, where the largest is the main heading of the section, and the others are sub-headings

<mark> For text that should be highlighted

<meter> For a measurement, used only if the maximum and minimum values are known

<nav> For a section of navigation

<progress> The state of a work in progress

<section> For a section in a document. Such as chapters, headers, footers, or any other sections of the document

<time> For defining a time or a date, or both

URL parameters with Javascript

So this took me by surprise the other day. JavaScript doesn't have a function to retrieve a URL parameter value. i.e. There is no Request.Querystring command! Of course it wouldn't start Request as it's executing on the browser rather than the server but you would have thought there would be a built in command to do it.

After a bit of searching though I came across this script that does it:

1// Read a page's GET URL variables and return them as an associative array.
2function getUrlVars()
3{
4  var vars = [], hash;
5  var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&amp;amp;');
6  for(var i = 0; i &amp;lt; hashes.length; i++)
7  {
8      hash = hashes[i].split('=');
9      vars.push(hash[0]);
10      vars[hash[0]] = hash[1];
11  }
12  return vars;
13}

The function returns an array/object containing the parameters and their values. e.g. The following URL:

http://www.example.com/?Name=Tim&Sex=Male

Would return:

1{
2    "Name": "Tim",
3    "Sex": "Male"
4}

To use it in your code you would write

1var name = getUrlVars()["Name"];

And that's it

Converting users from Membership to SimpleMembership

In ASP.NET 2 Microsoft introduced the Membership provider. By many accounts it is not perfect, but as a one size fits all solution it's not bad. Plus it had a major advantage that a lot of other people would also be using it, so if you wanted to grab a forum solution to stick on your site, chances were it would use the same Membership provider.

Now though there is a second Membership provider from Microsoft called SimpleMembership. It simplifies a lot of things that weren't needed with the original Membership provider and also introduces support for working with OAuth providers. Not only that but if you create the MVC 4 project from the default template that is what your solution will be set up to use.

The problem however is Membership and SimpleMembership are not compatible. They store their information in separate tables and if you do try to copy all the users from one to the other, you will soon discover the hashing algorithm used on the password is different. You probably also had all your passwords one way hashed so you can't even generate the new ones.

There is a solution however. Paul Brown has written a nice bit of code to update the MVC 4 account controller so that when your users log in they will first be authorised against SimpleMembership, if that fails it will then authorise against the original Membership and if that succeeds it will generate the new password in SimpleMembership using the one just provided by the user.

Over time as your users log in the will be slowly migrated over. The second time the log in the SimpleMembership will authorise them and the extra code won't even be hit.

http://pretzelsteelersfan.blogspot.co.uk/2012/11/migrating-legacy-apps-to-new.html