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 `browser-follow-next' and `browser-follow-previous'.");
  22
  23 browser_relationship_patterns[RELATIONSHIP_NEXT] =
  24     [new RegExp("\\bnext","i"),
  25      new RegExp("^>$","i"),
  26      new RegExp("^(>>|»)$","i"),
  27      new RegExp("^(>|»)","i"),
  28      new RegExp("(>|»)$","i")];
  29
  30 browser_relationship_patterns[RELATIONSHIP_PREVIOUS] =
  31     [new RegExp("\\bprev|previous\\b","i"),
  32      new RegExp("^<$","i"),
  33      new RegExp("^(<<|«)$","i"),
  34      new RegExp("^(<|«)","i"),
  35      new RegExp("(<|«)$","i")];
  36
  37 function document_get_element_by_relationship(doc, relationship) {
  38     var patterns = browser_relationship_patterns[relationship];
  39     var rel_name = new RegExp(browser_relationship_rel_regexp[relationship], "i");
  40     var rev_name = new RegExp(browser_relationship_rev_regexp[relationship], "i");
  41
  42     var elems = doc.getElementsByTagName("link");
  43     // links have higher priority than normal <a> hrefs
  44     for (var i = 0; i < elems.length; i++)
  45     {
  46         if (rel_name.test(elems[i].rel) || rev_name.test(elems[i].rev))
  47             return elems[i];
  48     }
  49
  50     // no links? ok, look for hrefs
  51     elems = doc.getElementsByTagName("a");
  52     for (var i = 0; i < elems.length; i++)
  53     {
  54         if (rel_name.test(elems[i].rel) || rev_name.test(elems[i].rev))
  55             return elems[i];
  56     }
  57
  58     for (var j = 0; j < patterns.length; ++j)
  59     {
  60         var pattern = patterns[j];
  61         for (var i = 0; i < elems.length; i++) // Loop through list of A elements again
  62         {
  63             if (pattern.test(elems[i].textContent))
  64                 return elems[i];
  65
  66             // images with alt text being href
  67             var children = elems[i].childNodes;
  68             for (var k = 0; k < children.length; k++)
  69             {
  70                 if (pattern.test(children[k].alt))
  71                     return elems[i];
  72             }
  73         }
  74     }
  75     return null;
  76 }
  77
  78 function browser_follow_relationship(buffer, relationship, target) {
  79     check_buffer(buffer, content_buffer);
  80     function helper(win) {
  81         var elem = document_get_element_by_relationship(win.document, relationship);
  82         if (elem)
  83             return elem;
  84         for (var i = 0; i < win.frames.length; ++i) {
  85             elem = document_get_element_by_relationship(win.frames[i].document, relationship);
  86             if (elem)
  87                 return elem;
  88         }
  89         return null;
  90     }
  91
  92     var elem = helper(buffer.top_frame);
  93     if (!elem)
  94         throw interactive_error("No \"" + browser_relationship_rel_name[relationship]
  95                                 + "\" link found");
  96     browser_element_follow(buffer, target, elem);
  97 }
  98
  99 default_browse_targets["follow-relationship"] = "follow";
 100
 101 interactive("browser-follow-next", function (I) {
 102     browser_follow_relationship(I.buffer, RELATIONSHIP_NEXT, I.browse_target("follow-relationship"))
 103 });
 104
 105 interactive("browser-follow-previous", function (I) {
 106     browser_follow_relationship(I.buffer, RELATIONSHIP_PREVIOUS, I.browse_target("follow-relationship"))
 107 });