Outline

• Inline tags and entities
• Let's build something...
• More on tables
• Forms

More HTML tags (Inline tags)

• These next tags might appear within many of the block level tags we learned last day:

  Anchors

  <a href="http://www.somewhere.com/">somewhere</a>
  

  • To aid with accessibility you should always separates links with at least a little text, like a period, or other non-textual but visual separators. You might also want to indicate if a link is offsite or is to a non HTML mime-type.
    For example, IRS.1040 Form [PDF].
  • Links within pages are given with <a href="#relative link">somewhere in this page with id="relative link"</a>

  Images

  <img src="myphoto.gif" alt="This is a picture of me" />
  

  Span

  Allows you to style a region of text or to specify a tooltip for a region of text. <span title="what you see when you mouse hover">This section of text</span>

  Presentation elements

  <br /> --line break, <hr /> --horizontal rule, <b></b>, <u></u>, <i></i>,, .

Entities in HTML and XHTML

• These provide a way to describe special characters or characters, such as &, <, > which are used to describe the XHTML document itself.
• Below are some characters and their corresponding entities:

  &	&
  <	&lt;
  >	&gt;
  (hard space)	&nbsp;
  "	&quot;
  Σ	&Sigma;

Let's build something

• If you haven't already done so, sign up for an account on https://yioop.com/.
• Then join the class CS 174 Spring 2016 discussion group.
• Next I'd like you to make a simple HTML 5 page with an unordered list on it and an anchor tag that points to the main sjsu web site.
• Once you are done, upload your code to the Feb 10 Class Thread, and I'll try to look at it and give some feedback in class.

Introduction to Tables

• A table consists of a bunch of rows each of which is made up of data cells.
• A table may or may not have a caption.
• The first row of a table can (but doesn't have to) be used to specify the headings for the columns.
• Each additional row might specify the heading of that row.

Example:

<style>
table, th, td {
  border: 1px solid black;
}
</style>
<table>
    <caption>grade table</caption>
    <tr><th></th><th>Item</th><th>Value</th></tr>
    <tr><th>1.</th><td>Homeworks</td><td>50%</td></tr>
    <tr><th>2.</th><td>Exams</td><td>50%</td></tr>
</table>

More on Tables

You can make table headings or table data span more than one column or more than one row using colspan, rowspan:

<tr><th colspan="3">heading</th></tr>


<!-- if we have two levels of heading-->

<tr><th colspan="2">heading</th></tr>
<tr><th>subhead1</th><th>subhead2</th></tr>
<tr><td>1</td><td>2</td><td>3</td></tr>

An Accessibility Interlude

• I will from time to time bring up accessibility when talking about how we should write web-pages.
• By this I to a large degree mean designing our pages so that they can be understood by as large an audience as possible.
• People come to a web page with a variety of reading abilities, a variety of motor abilities, etc. -- we want the information that can be extracted from our pages to be positive, and hopefully, about the same for all people.
• Section 508 of Federal Law puts requirements on government electronic and information technology to meet accessibility standards.
• The WAI (Web Accessibility Initiative) working group provides standards for accessibility.
• They have published two commonly cited Web Content Accessibility Guidelines: WCAG 1.0 (1999) and WCAG 2.0 (2008).
• The former was more descriptive of what authors should consider, the latter tries to be more concrete so that mechanical tests of accessibility can be done.
• For dynamic pages, they WAI has also published Web Accessibility Initiative - Accessible Rich Internet Applications (WAI-ARIA) guidelines.

Tables and Accessibility

• Tables can be a nightmare for screen readers because it is very hard for them to predict the reading order of the text.
• The now obsolete summary attribute of the table tag was used for accessibility in XHTML 1.1 and below.
• Sometimes a distinction is made between data tables and layout tables. A data table always has headings for each row and column. A table which does not do this is assumed to be for layout purposes.
• Layout tables are discouraged on the WAI site, where they say CSS should be used to control presentation.
• If you want to make a data table accessible, it should have either a caption tag like we saw in the example a few slides back or the table should be surrounded by a figure tag and the figure should have a figcaption.
• For data tables to be accessible, each row and column should have a header.
• To handle fancier tables which might have nested headers or headers spanning several rows and columns, a <td> cell should use the attribute headers="" to list separated by spaces which id's of which row and column headers apply.
• Another way to achieve accessibility on <td> cells, is to use the scope="" attribute on the <th> tags with values from row, col, rowspan, colspan to say what things the cell is a header for.

Controlling width

• In the older XHTML 1.1, you can control the width and border of tables using its width and border attributes. For example:

  <table width="100%" border="0"  summary="..." >
  

  the value can be a percentage or an absolute value in pixels. 0 here means no border.
• In HTML 5, the above should be done with CSS (described later). In HTML 5, the border attribute can only take a value of 0 or 1 to indicate the presence of a border or not.
• You can control the width of columns by having after the table tag a series of col tags (can also use colgroup)

  <table width="100%" border="0"  summary="..." >
  <col width="25%" /> <!-- can be a percentage or number of pixels -->
  <col width="75%" />

• Again, in HTML 5 the width attributes should not be used. The col tag still exists is one wants to apply a style to a whole column.

Still More on Tables

• The align and valign attributes of <tr><th><td> can be use to specify how data look within a cell. align has three possible values left, right, center (default) which control horizontal alignment. Again, these are XHTML 1.1, not HTML 5 attributes.
• Ex:

  <tr align="center"><td>hi<td><td>there</td></tr>
   <!-- centers whole row -->
  

• Ex:

  <td valign="top">test</td> 
  <td valign="bottom">test</td>
  

Cellpadding, cellspacing

• In XHTML 1.1 (not HTML 5), <table> also has two attributes cellpadding and cellspacing.

  cellpadding

  controls space between inner walls of cell and contents of the cell (in pixels).

  cellspacing

  controls distance between cells

• Ex:

  <table border="5" cellspacing="30" cellpadding="5" summary="..." >
  

Forms

• Forms are one of the most common ways to collect data in an XHTML page and send it back to the server.
• The basic format for a form is:

  <form name="myform" method="get" action="http://somewhere.com" >
  <!-- widgets or controls on form -->
  </form>
  

• In the case of uploading a file you also need to give the enctype attribute as "multipart/form-data"
• If the method attribute is not present it is assumed to be get, if the action attribute is absent the form is sent to where it came from when it is submitted.
• You can use relative urls such as "/formhandler.php", "/", ".", "..".

Possible methods

• The method attribute of a form can be one of "get" or "post".
• The default is get.
• If the method is "get" then data collected from the form will be appended to the URL given in the action when the form is submitted:

  http://somewhere.com/?name1=value1&name2=value2...
  

• The names and values are "urlencoded" to handle special characters like space.
• There used to be size limits on GET data.
• GET is non-stateful though so you can send the data as a url whether or not it ever came from a form.
• If the method is post. Then the HTTP POST command is used and data is sent in the body of the request after the headers.

Labels and Controls

• The basic form control is input:

  <input type="text" name="my variable" value="optional default value" />
  

• Possible values for type include: checkbox, radio, text, hidden, password, reset, submit.
• submit is used to submit the form.
• The value attribute of input must be set if the variable is checkbox or radio. The value will be what is sent if the field is checked or selected. The checked attribute controls if it is selected by default. Only one value set for radio.
• For text and password, the size and maxlength attributes control the visible size and the maximum number of input characters.
• Usually, a form item is placed by some label when it is drawn

  First Name: [             ]
  

  In order to ensure this in accessibility situations you must use the label tag:

  <label for="testid" >First Name :</label> <input type="text" 
      id="testid" name="test" value="test" />
  

• Alternatively, for some form elements like search boxes you can use a title attribute for accessibility:

  <input type="text" id="search" name="search" 
      title="Enter your search terms" placeholder="Enter your search terms"/>
  

• The placeholder attribute above is an HTML 5 attribute. It causes the provided value text to be displayed in the textfield until it is focused.

select tags

<textarea>

• This tag can be used to specify a multi-line region for text entry:

  <textarea name="life" rows="3" cols="40" >
  You can enter your life story here.
  </textarea>