Silva follows the W3C HTML 4.0.1 standards for accessibility. The major goal of these standards is to promote accessibility. That is to make web content available for all users whether they are using a desktop browser, a voice browser, a mobile phone, or an automobile-based personal computer, etc. It also aims to take into account constraints people may be operating under such as noisy surroundings, under or over-illuminated rooms, in a hands-free environment, etc.
Following these W3C standards Silva allows navigation through a Silva site with browser based links. These accessibility links have a number of uses:
Fig. 1. Accessibility links in Mozilla 1.6
The following browsers can access Silva’s accessibility aids:
For Mozilla, access these aids by selecting View/ShowHide/SiteNavBar/Show Always.
There are four methods available for Silva accessibility links. The first three methods are included in the default version of Silva and can be found in the default layout_template. The fourth is not included because it is memory intensive.
For creating navigation links (next, previous, last, first) in a compliant web browser. This method only indexes documents and folders on the current level; it excludes Indexers and AutoTOCs from the links.
None
Fig. 2
If you’re looking at document (K) for example (Fig.1), you only get ‘next’ and ‘last’ links that are pointing to document (L). If you’re looking at document (P), you don’t get ‘next’, ‘previous’, ‘first’ and ‘last’ links back, because there is no other document in this current level. The only link you get is ‘up’, which points to Folder (N) and ‘first’, which points to publication root (A). Note that O in this example is a Folder.
<tal:block define="surround here/get_document_navigation_links|nothing">
<tal:repeat repeat="link surround/keys">
<link tal:attributes="rel link; href python:surround[link].absolute_url()"
tal:on-error="nothing"/>
</tal:repeat>
<link rel="up" tal:condition="python:surround.has_key('up')"
tal:attributes="href surround/up" />
</tal:block>
Indexes for every level the available folders, ghost folders, publications and returns URLs in a dictionary. The dictionary itself contains a dictionary for each book element. The value of a book element is a list containing urls.
Fig. 3
Mozilla Navigator or Firefox with Extension installed
<tal:block define="types here/get_document_chapter_links|nothing"> <tal:repeat repeat="item types/chapter" tal:condition="types/chapter|nothing"> <link rel="chapter" tal:attributes="title item/title; href item/url;"/> </tal:repeat> <tal:repeat repeat="item types/section" tal:condition="types/section|nothing"> <link rel="section" tal:attributes="title item/title; href item/url;" /> </tal:repeat> <tal:repeat repeat="item types/subsection" tal:condition="types/subsection|nothing"> <link rel="subsection" tal:attributes="title item/title; href item/url;" /> </tal:repeat> <tal:repeat repeat="item types/subsubsection" tal:condition="types/subsubsection|nothing"> <link rel="subsubsection" tal:attributes="title item/title; href item/url;" /> </tal:repeat> </tal:block>
Looks for the first Silva Indexer and Silva AutoTOC in a publication. It returns a dictionary with a link to the Indexer or AutoTOC, if there is one available in a publication.
Mozilla Navigator or Firefox with Extension installed.
<tal:block define="doclinks here/get_document_index_links|nothing"> <link rel="index" tal:attributes="href doclinks/index" tal:condition="doclinks/index | nothing" /> <link rel="contents" tal:attributes="href doclinks/contents" tal:condition="doclinks/contents | nothing" /> </tal:block>
Note: this method is not included in the Silva default. This method is memory intensive. To add the method to Silva, place this method in the layout_macro.
For creating navigation links (next, previous, last, first) in a compliant web browser. The method is looking for eg. next, previous etc objects in document order. This means, that the next object can be a document, folder or whatever comes next in the tree. If the next object is the first document in a subfolder, it dives into the subfolder and returns this as the next object. It indexes the entire site.
Fig. 4
The method indexes the documents and Folders like reading a book. The letters on Fig. 2 above are indicating the indexing order of the method. If you’re looking at Folder (B) you’ll get the following links: (Fig. 4)
Another case will be, if you’re looking at Folder (G), which then returns the following links:
Mozilla Navigator, Firefox with Extension installed, Opera
None
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