modules/follow-relationship.js

   1 /**
   2  * (C) Copyright 2007-2008 Jeremy Maitin-Shepard
   3  *
   4  * Portions of this file were derived from Vimperator,
   5  * (C) Copyright 2007 Doug Kearns
   6  * (C) Copyright 2007-2008 Martin Stubenschrott.
   7  *
   8  * Use, modification, and distribution are subject to the terms specified in the
   9  * COPYING file.
  10 **/
  11
  12 require("element.js");
  13
  14 const RELATIONSHIP_NEXT = 0;
  15 const RELATIONSHIP_PREVIOUS = 1;
  16
  17 var browser_relationship_rel_name = ["next", "previous"];
  18 var browser_relationship_rel_regexp = ["next", "prev|previous"];
  19 var browser_relationship_rev_regexp = ["prev|previous", "next"];
  20
  21 define_variable("browser_relationship_patterns", {}, "Patterns used by `follow-next' and `follow-previous'.");
  22
  23 browser_relationship_patterns[RELATIONSHIP_NEXT] =
  24     [/^next$/i,
  25      new RegExp("^>$","i"),
  26      new RegExp("^(>>|»)$","i"),
  27      new RegExp("^(>|»)","i"),
  28      new RegExp("(>|»)$","i"),
  29      new RegExp("\\bnext","i")
  30     ];
  31
  32 browser_relationship_patterns[RELATIONSHIP_PREVIOUS] =
  33     [/^(prev|previous)$/i,
  34      new RegExp("^<$","i"),
  35      new RegExp("^(<<|«)$","i"),
  36      new RegExp("^(<|«)","i"),
  37      new RegExp("(<|«)$","i"),
  38      new RegExp("\\bprev|previous\\b","i")
  39     ];
  40
  41 function document_get_element_by_relationship(doc, relationship) {
  42     var patterns = browser_relationship_patterns[relationship];
  43     var rel_name = new RegExp(browser_relationship_rel_regexp[relationship], "i");
  44     var rev_name = new RegExp(browser_relationship_rev_regexp[relationship], "i");
  45
  46     var elems = doc.getElementsByTagName("link");
  47     // links have higher priority than normal <a> hrefs
  48     for (var i = 0; i < elems.length; i++)
  49     {
  50         if (rel_name.test(elems[i].rel) || rev_name.test(elems[i].rev))
  51             return elems[i];
  52     }
  53
  54     // no links? ok, look for hrefs
  55     elems = doc.getElementsByTagName("a");
  56     for (var i = 0; i < elems.length; i++)
  57     {
  58         if (rel_name.test(elems[i].rel) || rev_name.test(elems[i].rev))
  59             return elems[i];
  60     }
  61
  62     for (var j = 0; j < patterns.length; ++j)
  63     {
  64         var pattern = patterns[j];
  65         for (var i = 0; i < elems.length; i++) // Loop through list of A elements again
  66         {
  67             if (pattern.test(elems[i].textContent))
  68                 return elems[i];
  69
  70             // images with alt text being href
  71             var children = elems[i].childNodes;
  72             for (var k = 0; k < children.length; k++)
  73             {
  74                 if (pattern.test(children[k].alt))
  75                     return elems[i];
  76             }
  77         }
  78     }
  79     return null;
  80 }
  81
  82 function browser_follow_relationship(buffer, relationship, target) {
  83     check_buffer(buffer, content_buffer);
  84     for (let frame in frame_iterator(buffer.top_frame, buffer.focused_frame)) {
  85         let elem = document_get_element_by_relationship(frame.document, relationship);
  86         if (elem) {
  87             browser_element_follow(buffer, target, elem);
  88             return;
  89         }
  90     }
  91     throw interactive_error("No \"" + browser_relationship_rel_name[relationship]
  92                             + "\" link found");
  93 }
  94
  95 default_browse_targets["follow-relationship"] = "follow";
  96
  97 interactive("follow-next", function (I) {
  98     browser_follow_relationship(I.buffer, RELATIONSHIP_NEXT, I.browse_target("follow-relationship"))
  99 });
 100
 101 interactive("follow-previous", function (I) {
 102     browser_follow_relationship(I.buffer, RELATIONSHIP_PREVIOUS, I.browse_target("follow-relationship"))
 103 });