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 in_module(null);
  13
  14 require("element.js");
  15
  16 const RELATIONSHIP_NEXT = 0;
  17 const RELATIONSHIP_PREVIOUS = 1;
  18
  19 var browser_relationship_rel_regexp = ["next", "prev|previous"];
  20 var browser_relationship_rev_regexp = ["prev|previous", "next"];
  21
  22 define_variable("browser_relationship_patterns", {},
  23     "Patterns used by `follow-next' and `follow-previous'. "+
  24     "User value may be overridden for specific websites by "+
  25     "page-modes.");
  26
  27 browser_relationship_patterns[RELATIONSHIP_NEXT] =
  28     [/^next$/i,
  29      new RegExp("^>$","i"),
  30      new RegExp("^(>>|»)$","i"),
  31      new RegExp("^(>|»)","i"),
  32      new RegExp("(>|»)$","i"),
  33      new RegExp("\\bnext","i")
  34     ];
  35
  36 browser_relationship_patterns[RELATIONSHIP_PREVIOUS] =
  37     [/^(prev|previous)$/i,
  38      new RegExp("^<$","i"),
  39      new RegExp("^(<<|«)$","i"),
  40      new RegExp("^(<|«)","i"),
  41      new RegExp("(<|«)$","i"),
  42      new RegExp("\\bprev|previous\\b","i")
  43     ];
  44
  45 function document_get_element_by_relationship (doc, patterns, relationship) {
  46     patterns = patterns[relationship];
  47     var rel_name = new RegExp(browser_relationship_rel_regexp[relationship], "i");
  48     var rev_name = new RegExp(browser_relationship_rev_regexp[relationship], "i");
  49
  50     var elems = doc.getElementsByTagName("link");
  51     // links have higher priority than anchors
  52     for (var i = 0; i < elems.length; i++) {
  53         if (rel_name.test(elems[i].rel) || rev_name.test(elems[i].rev))
  54             return elems[i];
  55     }
  56
  57     // no links? look for anchors
  58     elems = doc.getElementsByTagName("a");
  59     for (var i = 0; i < elems.length; i++) {
  60         if (rel_name.test(elems[i].rel) || rev_name.test(elems[i].rev))
  61             return elems[i];
  62     }
  63
  64     for (var j = 0; j < patterns.length; ++j) {
  65         var pattern = patterns[j];
  66         for (var i = 0; i < elems.length; i++) { // loop through list of anchors again
  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                 if (children[k].alt && pattern.test(children[k].alt))
  74                     return elems[i];
  75             }
  76         }
  77     }
  78     return null;
  79 }
  80
  81 define_browser_object_class("relationship-next", null,
  82     function (I, prompt) {
  83         var doc = I.buffer.document;
  84         for (let frame in frame_iterator(I.buffer.top_frame, I.buffer.focused_frame)) {
  85             let elem = document_get_element_by_relationship(
  86                 frame.document,
  87                 I.local.browser_relationship_patterns,
  88                 RELATIONSHIP_NEXT);
  89             if (elem)
  90                 yield co_return(elem);
  91         }
  92         throw interactive_error("No \"next\" link found.");
  93     });
  94
  95 define_browser_object_class("relationship-previous", null,
  96     function (I, prompt) {
  97         var doc = I.buffer.document;
  98         for (let frame in frame_iterator(I.buffer.top_frame, I.buffer.focused_frame)) {
  99             let elem = document_get_element_by_relationship(
 100                 frame.document,
 101                 I.local.browser_relationship_patterns,
 102                 RELATIONSHIP_PREVIOUS);
 103             if (elem)
 104                 yield co_return(elem);
 105         }
 106         throw interactive_error("No \"previous\" link found.");
 107     });
 108
 109 provide("follow-relationship");