As you may be aware of, making the simple tables accessible is much easier than making the complex tables accessible. In my view, there is no problem with the complex tables as long as they are accessible to the assistive technology users. Usually, complex tables would have multi-level column headers/row headers and it is one type of variety but there are many more verities within this complex tables. We are not going to discuss all the varieties of the complex table rather will discuss how one single row header becomes the row header for multiple rows in this post. Let us understand this in-details. Usually, we see the pattern like one single row header would be present for entire row and basically it is called as simple data table. In case of complex table, multiple rows/entries may have the sane row header like sidebar. To understand what are the different rows that have common row header, visually, authors need to group the related rows technically(like all the related rows need to be grouped with the corresponding row header by merging the cells with the help of CSS paddings and HTML row span techniques. When they do so, it is semantical to both sighted and assistive technology users that how many cells are spanned or so. Since the context that I have made so far is all about native data table, the semantical information is conveyed to the assistive technology users. However, the information about how many rows are spanned would not be conveyed to the assistive technology users if it is custom table as custom table is built with <div> and <span> tags and with other CSS properties and it is a problem.
In order to address this problem, aria1.1 introduced new brand attribute and it is aria-rowspan. Aria-rowspan defines the number of rows spanned by a cell or gridcell. When aria-rowspan is defined for the cells in the custom table, assistive technologies like screen reader are expected to understand how many rows are spanned and are expected to convey the same information to the users. The information about how many rows are spanned in the table enables the screen reader users to visualize the table structure very clearly than ever before. as I have explained this concept with the spanning of row headers, it does not mean that spanning the rows is not limited to row headers. Author can span any rows by using aria-rowspan attribute based on the requirement.
- Author must use this attribute on the below roles only
- Column header
- Row header
- Authors MUST set the value of aria-rowspan to an integer
- greater than or equal to 0
- less than value that prevents overlapping of other cells in the same column. In simple terms, if author wants to span 3 rows then the value of aria-rowspan must be set to 3 only but not to 4 or 5 or so.
- Aria-rowspan=”0” means the cell spans all the remaining rows in its row group.
Notes for assistive technology venders
- Assistive technologies should not expose the value of aria-rowspan for an element if equivalent host language attribute is provided rather assistive technologies should expose the value of the host language’s attribute.
Sample code snippet
<div id=”sd” role=”cell” aria-rowspan=”2″>test cell</div>
then expose aria-rowspan =”2″ on the element with id=”sd”
Even though the web is accessible, sometimes efficiency matters like how quicker the people with disabilities can perform the things on the web, especially frequent actions. Let us understand this better with the web email application as an example. There are many frequent actions in the web email application such as composing an email, sending an email, replying to an email, and so on.. author would have done those elements accessible but still navigating to those elements from the user’s current position on the web for such frequent actions would consume certain amount of time. It is always better to provide hot keys for the users to perform such frequent actions on the web in order to enhance the user’s efficiency in performing the things on the web. Hotkeys/keyboard shortcuts not only help the efficiency of the people with disabilities but also efficiency of the power users as power users take some time to locate the desired item with the mouse pointer. Web Gmail, for the instance, already implemented the hot keys(like C for compose, control enter from the message area to send the email, R for reply, and so on..) for such frequent actions. Do you think assigning and implementing the keyboard shortcuts happen just like that? Answer is no. first of all, there should be provision for author to add/define the keyboard shortcuts for an element programmatically and this provision is not present in ARIA till ARIA1.0, and it is a problem.
In order to address this problem ARIA1.1 introduced new attribute called aria-keyshortcuts. Aria-keyshortcuts Indicates keyboard shortcuts that an author has implemented to activate or give focus to an element. In other words, aria-keyshortcuts enables the author to define what keyboard shortcuts activates or takes the focus to an element. When aria-keyshortcuts attribute is defined for an element then assistive technologies like screen readers are expected to announce name of the element and it’s keyboard shortcut(for ex: compose button alt+c). to put it simpler, aria-keyshortcuts exposes the availability of the keyboard shortcut having said that, the functionality of the keyboard shortcut is completely dependent upon the web developer. Web developer needs to write the script for functioning the keyboard shortcut as expected. Author should choose the keyboard shortcut in such a way that keyboard shortcut must contain 0 or more modifier keys and exact one non-modifier key. If you are wondering that what modifier key means? Modifier key is nothing but alt, shift, control, and so on.. whereas non-modifier key is nothing but any printable character(a, b, 1, 2$, and so on..)
In addition, there is a misconception that both aria-keyshortcuts and HTML accesskey do the same thing but that is not true. Although they both do the similar kind of job like assigning/defining the keyboard shortcuts/hotkeys, the way of the implementation differs. The main difference between both of them is that, if HTML accesskey attribute is defined for an element then modifier key is decided by browser but if the aria-keyshortcuts attribute is defined for an element then modifier key is decided by the author(again, it’s author wish whether modifier key should be provided or not in the keyboard shortcut). Let us not dig more about what all HTML accesskey do in this post and let us continue to put our attention on aria-keyshortcuts attribute.
- Author can use this attribute on any element of the base markup
- Author must ensure that the value of this attribute is string
- string may contain more than one keyboard shortcuts with space-delimited
- Each keyboard shortcut consists of one or more tokens delimited by the plus sign(ex: alt+shift+t)
- Authors must ensure that the modifier key comes first and non-modifier key comes last as part of the keyboard shortcut(for ex: it should be “alt+c” but it should not be “c+alt”)
- It is author responsibility to make the keyboard shortcut functional as expected with the help of java script or with the help of other relevant programming techniques
- Authors must ensure that both upper and lower letter of the non-modifier key in the keyboard shortcut function the same
- Authors should implement the keyboard shortcuts by keeping the below points in the mind
- Keyboard shortcuts should not produce unintended results when they are activated as different languages have the different keyboards
- It is always better to have the ASCII letters instead of other keys in the keyboard shortcuts to prevent the conflicts from the international keyboards as numbers characters and common punctuation often require modifiers in the international keyboards(for ex: German keyboard).
- The keyboard shortcuts developed by author should not conflict with the keyboard shortcuts of assistive technology, user agent, and operating system
- The keys defined in the shortcuts represent the physical keys pressed and not the actual characters generated(ex: the keys in the keyboard shortcut should be “shift+5” but should not be “%”)
- Authors should expose the keyboard shortcuts for the sighted keyboard users too by using tooltip or other techniques
Sample code snippet
<div id=”sd” tabindex=”0″ role=”button” aria-keyshortcuts=”alt+c”>compose
then the element with role=”button” and id=”sd” exposes aria-keyshortcuts=”alt+c”
Can you imagine a form without a text fields? I think answer is no. usually, there are number of text fields present on the form. we commonly see the text fields, such as first name, last name, date, email, phone number, and so on.., on the form. Out of all the text fields, few text fields, such as date, phone number, email and so on.., require the hint to fill the data. Let us take date as an example. date fields are ambiguous in nature if hint/format is not provided to fill the date. The reason is that each country follows certain date format. For an instance, USA follows MM/DD/YYYY whereas India follows DD/MM/YYYYY. Thus, it is important to have accepted format as a hint for the date text field in order to enable the user to fill the data appropriately. To provide such hints for any text fields, authors use the HTML placeholder attribute. HTML placeholder attribute can be used only if it is native control. However, Authors cannot use same placeholder attribute if it is custom control and it is a problem.
In order to address this problem, ARIA 1.1 introduced new attribute called aria-placeholder and it is equivalent to HTML placeholder attribute. Aria-placeholder defines a short hint (a word or short phrase) intended to aid the user with data entry when the control has no value. A hint could be a sample value or a brief description of the expected format. It is important to remember that aria-placeholder is not the replacement of the label. Both aria-placeholder and label for the control serve the different purpose. To put it simpler, label is something that helps what type of the information expected whereas aria-placeholder is something that enables the user to fill the data with the help of the hint.
When aria-placeholder attribute is defined for the control and control has no value then assistive technologies like screen readers are expected to announce label and aria-placeholder text together. Similarly, when aria-placeholder attribute is defined for the control and control has value then screen readers are expected to announce both label and it’s value together but not label and aria-placeholder text together.
- Author must use this attribute in the below roles only
- Author should present this hint to the users only when control has no value. this includes
- When the control first receives the focus
- When user erases the previously entered value
- Authors must ensure that the value of the aria-placeholder is string
- Authors must implement necessary scripts and functionality for the hint to simulate how HTML placeholder behaves
- Authors should avoid using aria-placeholder attribute for the native controls(input types and <textarea>)
Sample code snippet
<div contenteditable=”true” role=”textbox” aria-placeholder=”DD/MM/YYYY” id=”sd”>
then the element with role=”textbox” and id=”sd” exposes aria-placeholder=”DD/MM/YYYY”
As you are aware of, making the images accessible is the first and foremost principle of the web accessibility. To make the images accessible, there are number of techniques available. HTML alt attribute can be used to make the simple images accessible by providing the short description. Similarly, HTML longdesc attribute can be used to make the complex images(such as graphs, charts, diagrams, and so on..) accessible by providing the detailed description. Of course, There are number of accessibility challenges with longdesc attribute like sighted users cannot understand existence of long description for the image and so on.. but we are not going to discuss them as part of this post. In any case, there is no such equivalent attribute like longdesc in aria till aria1.0
Aria1.1 introduced aria-details(property) and it is kind of the equivalent to HTML longdesc attribute. Aria-details attribute Identifies the element that provides a detailed, extended description for the object. The value of the aria-details is the ID reference of the element. Unlike aria-describedby attribute, assistive technologies do not present the content of the element referenced by aria-details when the object is in the focus. the reason is that The content of the element referenced by aria-details would not passed into accessibility API as accessible name or accessible description and this is how it is constructed. Let us understand how it works. When aria-details is given for an object and that object receives the focus then assistive technologies like screen readers are expected to announce it as so and so object has detailed description. with this announcement, users of assistive technology would understand that there is detailed description for this particular object and it is kind of awareness for the user. In addition, assistive technologies must provide the mechanism to navigate from the object to the detailed description section as well as mechanism to navigate back from the detailed description section to the object. when assistive technology users navigate to detailed description section then content must be presented with the semantical structure if the content has any semantics. In contrast, the content of the element referenced by aria-describedby is going to be presented as a string to the assistive technology users without any semantics.
The content of the element referenced by aria-details or detailed or extended description of the object must be visible to all the users. Some authors may think that both aria-describedby and aria-details are one and the same as both of them are used to provide the image description. Although the purpose is kind of similar, the way the both attributes present to the accessibility API are not the same as explained above. To make it clear, aria-describedby and aria-details are not one and the same and they both serve the different purposes.
The main advantage of the aria-details property over HTML longdesc attribute is that longdesc attribute can be used only for an image element whereas aria-details attribute can be used for all the elements of the base markup.
- Author must ensure The extended or detailed description that is referenced by aria-details is visible for all the users
- Authors must provide the value of the aria-details as ID reference
- Authors must reference single element but not the multiple elements as the value of the aria-details
Notes for assistive technology vendors
- Assistive technologies must provide the
- mechanism to navigate from the image object to the extended or detailed description section
- mechanism to navigate back from the extended or detailed description to the image object
- when both aria-details and aria-describedby are present for an object and user agents do not support
- aria-details must take the precedence over aria-describedby
Sample code snippet
<img id=”sd” src=”barchart.jpg” aria-details=”bc”>
<summary>More information about barchart</summary>
then for the element of id sd expose the aria details relationships on id’s bc and sd
Let us understand how does assistive technologies like screen reader identifies the column count and row count in the table. It is very simple. Screen reader looks at the DOM and calculates how many rows and how many columns are present in the table. Based on that, screen reader would announce the no of columns and no of rows as accordingly. When table receives the focus, For the instance, screen reader would announce like “table with 16 columns and 10 rows” or something like that. The announcement of 10 rows could be appropriate as DOM contains 3 rows. Let me be very specific with the row count in this post. However, at times, author might have to hide few rows and show only few other rows. In this case, screen reader announcement may not be appropriate with respect to the total number of rows. I think I confused you a lot. Let us understand this with the simple hypothesis example.
There is table with 10 rows in total. Out of 10 rows, 6 rows are hidden and 4 of them are visually shown. Even DOM contains 4 rows itself. We see this type of show and hide rows when we apply filters in the few applications and it is kind of how we do in the MS excel. In any case, When we run screen reader on this table then obviously screen reader would announce it as “table with 4 rows”. Do you think this announcement is correct? Answer is yes and no. The reason for yes is that screen reader announces the whatever the DOM contains. The reason for no is that there are 10 rows in total but screen reader user is not aware of this information with the announcement that is being made currently(just to reiterate, the announcement from the screen reader is “table with 4 rows”). In a nutshell, the information about the total no of rows is not being announced to the screen reader users along with the visible number of rows and this is problem.
In order to address this problem, aria 1.1 introduced new attribute called aria-rowcount. When this property is applied with some integer value to the table container then screen reader would announce the visible no of columns as well as total no of columns. Let me take the same above hypothesis example. When aria-rowcount property is defined with 10 to the above table container then screen reader is expected to announce it as “table with 4 of 10 rows” something like that. With this announcement, screen reader user would understand that there are 4 visible rows out of 10 total rows. .
In a broader view, When the number of rows represented by the DOM structure is not the total number of rows available for a table, grid, or treegrid, the aria-rowcount property is used to communicate the total number of rows available, and it is accompanied by the aria-rowindex property to identify the row indices of the rows that are present in the DOM.
- Author must use this property for the below roles only
- Author should not use this property when all the rows are present in the DOM
- Author must use this property only when portion of rows is present in the DOM at a given moment,
- Authors MUST set the value of aria-rowcount to an integer equal to the number of rows in the full table.
- authors MUST set the value of aria-rowcount to -1 if the total no of rows is unknown to indicate that the value should not be calculated by the assistive technologies.
Sample code snippet
<div role=’table’ id=’sd’ aria-rowcount=’3′ aria-colcount=’2′>
then expose aria-rowcount=”3″ on the element with id=”sd”