My to-read shelf on GoodReads is a mix of published and unpublished books making it hard to find something published to read. I figured I could throw together a GreaseMonkey script that would change the background of the entry for the books that haven't yet been published.

This is what I have put together so far:

// ==UserScript==

// @name        Unpublished Lowlighter

// @description Makes the background of books not yet published on the Goodreads to-read shelf grey.

// @include     http://www.goodreads.com/*

// ==/UserScript==



function dateColor() {

    var books = document.getElementsByClassName('bookalike review');

    for (var book in books) {

        var dateString = book

                        .getElementsByClassName('field date_pub')

                        .getElementsByClassName('value')

                        .textContent;

        var date = new Date(dateString);

        var today = new Date();

        if (date > today) {

            book.style.backgroundColor('Lightgrey');

        }

    }

}



dateColor();

The problem is that it doesn't work. When I tried running the script in scratchpad it gives me the error: Exception: book.getElementsByClassName is not a function

I was under the impression that Firefox supports getElementsByClassName and that you can run it on the result of getElementsByClassName to get the child elements. Where am I going wrong?

EDIT: Here is a snippet of the HTML for one <tr> in the table. The reason that I didn't post this to begin with is that it is really verbose:

<tr id=review_265364012 class=bookalike review>

  <td class=field checkbox style=display: none><label>checkbox</label><div class=value>      <input id=checkbox_review_265364012 name=reviews[265364012] value=265364012 type=checkbox>

</div></td>  <td class=field position><label>position</label><div class=value>        <div class=reorderControls>

            <a class=actionLink href=# id=loading_link_434018960 method=post onclick=$(this).hide(); $('loading_anim_434018960').show(); $('hidden_link_434018960').simulate('click');; return false;><img alt=up src=http://www.goodreads.com/assets/up_arrow-7957f2bae9c3456ec7359ad79b000652.gif title=move book up></a><img alt=Loading-trans class=loading id=loading_anim_434018960 src=http://www.goodreads.com/assets/loading-trans-3e04cd6ed6ad31063972e688820d7866.gif style=display:none><a href=/shelf/move_up/174788201?redirect_url=%2Freview%2Flist%2F4111865%3Fformat%3Dhtml%26page%3D1%26shelf%3Dto-read class=actionLink data-method=post id=hidden_link_434018960 rel=nofollow style=display: none><img alt=up src=http://www.goodreads.com/assets/up_arrow-7957f2bae9c3456ec7359ad79b000652.gif title=move book up></a>

          <img src=/assets/loading.gif class=position_loading style=display: none>

          <input id=positions_174788201 name=positions[174788201] value=5 type=text>

          <script type=text/javascript>

//<![CDATA[

      var newTip = new Tip($('positions_174788201'),             <nobr>n              <a class=button href=# onclick=savePositionChanges(4111865); return false;>Save position changes</a> &nbsp;n              <a href=# onclick=$('positions_174788201').prototip.hide(); return false;>close</a>n            </nobr>n, { style: 'creamy', stem: 'leftMiddle', hook: { tip: 'leftMiddle', target: 'rightMiddle' }, offset: { x: 5, y: 5 }, hideOn: 'imaginaryelement', showOn: 'click', width: 'auto', hideOthers: true });

      $('positions_174788201').observe('prototip:shown', function() {

        if (this.up('#box')) {

          $$('div.prototip')[0].setStyle({zIndex: $('box').getStyle('z-index')});

        } else {

          $$('div.prototip')[0].setStyle({zIndex: 6000});

        }

      });



//]]>

</script>            <a class=actionLink href=# id=loading_link_434206980 method=post onclick=$(this).hide(); $('loading_anim_434206980').show(); $('hidden_link_434206980').simulate('click');; return false;><img alt=down src=http://www.goodreads.com/assets/down_arrow-61b0e7292c02b1dcfd3f75a7f9b6b7ad.gif title=move book down></a><img alt=Loading-trans class=loading id=loading_anim_434206980 src=http://www.goodreads.com/assets/loading-trans-3e04cd6ed6ad31063972e688820d7866.gif style=display:none><a href=/shelf/move_down/174788201?redirect_url=%2Freview%2Flist%2F4111865%3Fformat%3Dhtml%26page%3D1%26shelf%3Dto-read class=actionLink data-method=post id=hidden_link_434206980 rel=nofollow style=display: none><img alt=down src=http://www.goodreads.com/assets/down_arrow-61b0e7292c02b1dcfd3f75a7f9b6b7ad.gif title=move book down></a>

        </div>

</div></td>  <td class=field cover><label>cover</label><div class=value>      <a href=/book/show/12074927-the-fractal-prince><img alt=The Fractal Prince (The Quantum Thief Trilogy #2) src=http://photo.goodreads.com/books/1311105989s/12074927.jpg title=The Fractal Prince (The Quantum Thief Trilogy #2)></a>

</div></td>  <td class=field title><label>title</label><div class=value>    <a href=/book/show/12074927-the-fractal-prince title=The Fractal Prince (The Quantum Thief Trilogy #2)>

      The Fractal Prince

        <span class=darkGreyText>(The Quantum Thief Trilogy #2)</span>

</a></div></td>  <td class=field author><label>author</label><div class=value>      <a href=/author/show/2768002.Hannu_Rajaniemi>Rajaniemi, Hannu</a>

</div></td>  <td class=field isbn style=display: none><label>isbn</label><div class=value>    

</div></td>  <td class=field isbn13 style=display: none><label>isbn13</label><div class=value>    

</div></td>  <td class=field asin style=display: none><label>asin</label><div class=value>    

</div></td>  <td class=field num_pages style=display: none><label>num pages</label><div class=value>      <span class=greyText>unknown</span>

</div></td>  <td class=field avg_rating><label>avg rating</label><div class=value>    3.67

</div></td>  <td class=field num_ratings style=display: none><label>num ratings</label><div class=value>    9

</div></td>  <td class=field date_pub><label>date pub</label><div style=background: none repeat scroll 0% 0% Lightgrey; class=value>      Sep 27, 2012

</div></td>  <td class=field date_pub_edition style=display: none><label>date pub edition</label><div class=value>      <span class=greyText>unknown</span>

</div></td>    <td class=field rating><label>my rating</label><div class=value>

    <span class=stars id=stars12074927_4111865 onmouseout=mouseOutStars('12074927')><a rel=nofollow><img alt=didn't like it  class=star id=star12074927_0 onclick=submitStars('12074927', 0, '/review/rate/12074927?rating=1', 4111865);  return false; onmouseover=checkStars('12074927', 0) src=/assets/layout/gr_orange_star_inactive.png title=didn't like it height=15 width=15></a><a rel=nofollow><img alt=it was ok  class=star id=star12074927_1 onclick=submitStars('12074927', 1, '/review/rate/12074927?rating=2', 4111865);  return false; onmouseover=checkStars('12074927', 1) src=/assets/layout/gr_orange_star_inactive.png title=it was ok height=15 width=15></a><a rel=nofollow><img alt=liked it  class=star id=star12074927_2 onclick=submitStars('12074927', 2, '/review/rate/12074927?rating=3', 4111865);  return false; onmouseover=checkStars('12074927', 2) src=/assets/layout/gr_orange_star_inactive.png title=liked it height=15 width=15></a><a rel=nofollow><img alt=really liked it  class=star id=star12074927_3 onclick=submitStars('12074927', 3, '/review/rate/12074927?rating=4', 4111865);  return false; onmouseover=checkStars('12074927', 3) src=/assets/layout/gr_orange_star_inactive.png title=really liked it height=15 width=15></a><a rel=nofollow><img alt=it was amazing  class=star id=star12074927_4 onclick=submitStars('12074927', 4, '/review/rate/12074927?rating=5', 4111865);  return false; onmouseover=checkStars('12074927', 4) src=/assets/layout/gr_orange_star_inactive.png title=it was amazing height=15 width=15></a></span><script language=javascript type=text/javascript>starRatings[ratingIndex++] = [ '12074927', -1]; checkStars('12074927', -1);</script>

    <span id=reviewMessage12074927_4111865></span>

    <span id=successMessage12074927_4111865></span>

</div></td><td class=field shelves><label>shelves</label><div class=value>    <span id=shelfList4111865_12074927><span id=shelf_174788201><a href=http://www.goodreads.com/review/list/4111865?shelf=to-read class=shelfLink title=View all books in Johan's to-read shelf.>to-read</a></span></span><br><a class=shelfChooserLink smallText href=# onclick=window.shelfChooser.summon(event, {bookId: 12074927, chosen: [&quot;to-read&quot;]}); return false;>[edit]</a>

</div></td><td class=field review style=display: none><label>review</label><div class=value>    <span class=greyText>None</span>

    <a class=floatingBoxLink smallText href=# onclick=reviewEditor.summon(this, 12074927, 'review', {value: null}); return false;>[edit]</a>

  <div class=clear></div>

</div></td><td class=field notes style=display: none><label>notes</label><div class=value>      <span class=greyText>None</span>

      <a class=floatingBoxLink smallText href=# onclick=reviewEditor.summon(this, 12074927, 'notes', {value: null}); return false;>[edit]</a>

</div></td><td class=field recommender style=display: none><label>recommender</label><div class=value>    <span class=greyText>none</span>

</div></td><td class=field comments style=display: none><label>comments</label><div class=value>  <a href=/review/show/265364012>0</a>

</div></td><td class=field votes style=display: none><label>votes</label><div class=value>  <a href=/rating/voters/265364012?resource_type=Review>0</a>

</div></td><td class=field read_count style=display: none><label># times read</label><div class=value>    0

</div></td><td class=field date_started style=display: none><label>date started</label><div class=value>    <span class=greyText>not set</span>

    <a class=floatingBoxLink smallText href=# onclick=reviewEditor.summon(this, 12074927, 'started_at', {value: null}); return false;>[edit]</a>

</div></td><td class=field date_read><label>date read</label><div class=value>    <span class=greyText>not set</span>

    <a class=floatingBoxLink smallText href=# onclick=reviewEditor.summon(this, 12074927, 'read_at', {value: null}); return false;>[edit]</a>

</div></td><td class=field date_added style=display: none><label>date added</label><div class=value>  <span title=January 21, 2012>

    Jan 21, 2012

  </span>

</div></td><td class=field date_purchased style=display: none><label>date purchased</label><div class=value>    <a class=smallText href=# id=add_for_date_purchased onclick=new Ajax.Request('/review/update/12074927?format=json', {asynchronous:true, evalScripts:true, onFailure:function(request){Element.hide('loading_anim_206609');$('add_for_date_purchased').innerHTML = '<span class=&quot;error&quot;>ERROR</span>try again';$('add_for_date_purchased').show();}, onLoading:function(request){;Element.show('loading_anim_206609');Element.hide('add_for_date_purchased')}, onSuccess:function(request){Element.hide('loading_anim_206609');Element.show('add_for_date_purchased');var json = eval('(' + request.responseText + ')');$('review_265364012').replace(json.html);if (typeof(toggleFieldsToMatchHeader) == 'function') {toggleFieldsToMatchHeader();}}, parameters:'owned_book[book_id]=12074927&amp;partial=bookalike&amp;view=table' + '&amp;authenticity_token=' + encodeURIComponent('J5JjYi/D31hPm9w3u8hM35umQTh8bK3md4dVzpi4eKQ=')}); return false;>(add)</a><img alt=Loading-trans class=loading id=loading_anim_206609 src=http://www.goodreads.com/assets/loading-trans-3e04cd6ed6ad31063972e688820d7866.gif style=display:none>

</div></td><td class=field owned style=display: none><label>owned</label><div class=value></div></td><td class=field purchase_location style=display: none><label>purchase location</label><div class=value>    <a class=smallText href=# id=add_for_purchase_location onclick=new Ajax.Request('/review/update/12074927?format=json', {asynchronous:true, evalScripts:true, onFailure:function(request){Element.hide('loading_anim_953979');$('add_for_purchase_location').innerHTML = '<span class=&quot;error&quot;>ERROR</span>try again';$('add_for_purchase_location').show();}, onLoading:function(request){;Element.show('loading_anim_953979');Element.hide('add_for_purchase_location')}, onSuccess:function(request){Element.hide('loading_anim_953979');Element.show('add_for_purchase_location');var json = eval('(' + request.responseText + ')');$('review_265364012').replace(json.html);if (typeof(toggleFieldsToMatchHeader) == 'function') {toggleFieldsToMatchHeader();}}, parameters:'owned_book[book_id]=12074927&amp;partial=bookalike&amp;view=table' + '&amp;authenticity_token=' + encodeURIComponent('J5JjYi/D31hPm9w3u8hM35umQTh8bK3md4dVzpi4eKQ=')}); return false;>(add)</a><img alt=Loading-trans class=loading id=loading_anim_953979 src=http://www.goodreads.com/assets/loading-trans-3e04cd6ed6ad31063972e688820d7866.gif style=display:none>

</div></td><td class=field condition style=display: none><label>condition</label><div class=value>    <a class=smallText href=# id=add_for_condition onclick=new Ajax.Request('/review/update/12074927?format=json', {asynchronous:true, evalScripts:true, onFailure:function(request){Element.hide('loading_anim_990684');$('add_for_condition').innerHTML = '<span class=&quot;error&quot;>ERROR</span>try again';$('add_for_condition').show();}, onLoading:function(request){;Element.show('loading_anim_990684');Element.hide('add_for_condition')}, onSuccess:function(request){Element.hide('loading_anim_990684');Element.show('add_for_condition');var json = eval('(' + request.responseText + ')');$('review_265364012').replace(json.html);if (typeof(toggleFieldsToMatchHeader) == 'function') {toggleFieldsToMatchHeader();}}, parameters:'owned_book[book_id]=12074927&amp;partial=bookalike&amp;view=table' + '&amp;authenticity_token=' + encodeURIComponent('J5JjYi/D31hPm9w3u8hM35umQTh8bK3md4dVzpi4eKQ=')}); return false;>(add)</a><img alt=Loading-trans class=loading id=loading_anim_990684 src=http://www.goodreads.com/assets/loading-trans-3e04cd6ed6ad31063972e688820d7866.gif style=display:none>

</div></td><td class=field format><label>format</label><div class=value></div></td><td class=field actions><label>actions</label><div class=value>    <div class=actionsWrapper greyText smallText>

      <div class=editLinkWrapper><a class=actionLinkLite editLink href=# id=loading_link_818479 onclick=new Ajax.Request('/review/edit/12074927', {asynchronous:true, evalScripts:true, onFailure:function(request){Element.hide('loading_anim_818479');$('loading_link_818479').innerHTML = '<span class=&quot;error&quot;>ERROR</span>try again';$('loading_link_818479').show();}, onLoading:function(request){;Element.show('loading_anim_818479');Element.hide('loading_link_818479')}, onSuccess:function(request){Element.hide('loading_anim_818479');Element.show('loading_link_818479');}, parameters:'authenticity_token=' + encodeURIComponent('J5JjYi/D31hPm9w3u8hM35umQTh8bK3md4dVzpi4eKQ=')}); return false;>edit</a><img alt=Loading-trans class=loading id=loading_anim_818479 src=http://www.goodreads.com/assets/loading-trans-3e04cd6ed6ad31063972e688820d7866.gif style=display:none></div>

      <div class=viewLinkWrapper><a href=/review/show/265364012 class=actionLinkLite viewLink nobreak>view »</a></div>

      <a href=/review/destroy/12074927?return_url=http%3A%2F%2Fwww.goodreads.com%2Freview%2Flist%2F4111865%3Fshelf%3Dto-read class=actionLinkLite smallText deleteLink data-confirm=Are you sure you want to remove The Fractal Prince from your books? This will permanently remove this book from your shelves, including any review, rating, tags, or notes you have added. To change the shelf this book appears on please edit the shelves. data-method=post rel=nofollow>        <img alt=Remove from my books src=http://www.goodreads.com/assets/layout/delete.gif title=Remove from my books>

        <span class=label>remove book</span>

</a>    </div>

</div></td>

</tr>