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_regexp = ["next", "prev|previous"];
  18 var browser_relationship_rev_regexp = ["prev|previous", "next"];
  19
  20 define_variable("browser_relationship_patterns", {},
  21     "Patterns used by `follow-next' and `follow-previous'. "+
  22     "User value may be overridden for specific websites by "+
  23     "page-modes.");
  24
  25 browser_relationship_patterns[RELATIONSHIP_NEXT] =
  26     [/^next$/i,
  27      new RegExp("^>$","i"),
  28      new RegExp("^(>>|»)$","i"),
  29      new RegExp("^(>|»)","i"),
  30      new RegExp("(>|»)$","i"),
  31      new RegExp("\\bnext","i")
  32     ];
  33
  34 browser_relationship_patterns[RELATIONSHIP_PREVIOUS] =
  35     [/^(prev|previous)$/i,
  36      new RegExp("^<$","i"),
  37      new RegExp("^(<<|«)$","i"),
  38      new RegExp("^(<|«)","i"),
  39      new RegExp("(<|«)$","i"),
  40      new RegExp("\\bprev|previous\\b","i")
  41     ];
  42
  43 function document_get_element_by_relationship (doc, patterns, relationship) {
  44     patterns = patterns[relationship];
  45     var rel_name = new RegExp(browser_relationship_rel_regexp[relationship], "i");
  46     var rev_name = new RegExp(browser_relationship_rev_regexp[relationship], "i");
  47
  48     var elems = doc.getElementsByTagName("link");
  49     // links have higher priority than anchors
  50     for (var i = 0; i < elems.length; i++) {
  51         if (rel_name.test(elems[i].rel) || rev_name.test(elems[i].rev))
  52             return elems[i];
  53     }
  54
  55     // no links? look for anchors
  56     elems = doc.getElementsByTagName("a");
  57     for (var i = 0; i < elems.length; i++) {
  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         var pattern = patterns[j];
  64         for (var i = 0; i < elems.length; i++) { // loop through list of anchors again
  65             if (pattern.test(elems[i].textContent))
  66                 return elems[i];
  67
  68             // images with alt text being href
  69             var children = elems[i].childNodes;
  70             for (var k = 0; k < children.length; k++) {
  71                 if (children[k].alt && pattern.test(children[k].alt))
  72                     return elems[i];
  73             }
  74         }
  75     }
  76     return null;
  77 }
  78
  79 define_browser_object_class("relationship-next", null,
  80     function (I, prompt) {
  81         var doc = I.buffer.document;
  82         for (let frame in frame_iterator(I.buffer.top_frame, I.buffer.focused_frame)) {
  83             let elem = document_get_element_by_relationship(
  84                 frame.document,
  85                 I.local.browser_relationship_patterns,
  86                 RELATIONSHIP_NEXT);
  87             if (elem)
  88                 yield co_return(elem);
  89         }
  90         throw interactive_error("No \"next\" link found.");
  91     });
  92
  93 define_browser_object_class("relationship-previous", null,
  94     function (I, prompt) {
  95         var doc = I.buffer.document;
  96         for (let frame in frame_iterator(I.buffer.top_frame, I.buffer.focused_frame)) {
  97             let elem = document_get_element_by_relationship(
  98                 frame.document,
  99                 I.local.browser_relationship_patterns,
 100                 RELATIONSHIP_PREVIOUS);
 101             if (elem)
 102                 yield co_return(elem);
 103         }
 104         throw interactive_error("No \"previous\" link found.");
 105     });
 106
 107 provide("follow-relationship");