Display articles randomly and periodically

Saturday 26 September 2009 3:22:35 am

Hi,

I need to display an article on my frontpage that:
1) Is fetched randomly from a certain part of the node tree
2) Changes everyday automatically

I implemented the following solution:

{set-block scope=root variable=cache_ttl}0{/set-block}  <!-- This is to disable the view caching  -->
{def $articles_list=fetch( 'content', 'tree', hash( 'parent_node_id', 234,
                                               'sort_by', $node.sort_array,
                                               'class_filter_type', 'exclude',
                                               'class_filter_array', 'folder'))
                         $rand=rand(0,count($articles_list)|sub(1))}
{cache-block expiry=86400}
	<h2>{attribute_view_gui attribute=$articles_list[$rand].object.data_map.title}<h2>
        <div class="attribute-short">{attribute_view_gui attribute=$articles_list[$rand].object.data_map.intro}</div>                        
{/cache-block}
{$undef}

My questions are:
a) Setting the cache_ttl variable to 0 will decrease the performance of the site (as it is disabled for the frontpage file). So, is there any other way to disable the view caching for only a certain part of the code?
b) To have my random article changed everyday, I used the {cache-block expiry=86400} (as the content will change every 24 hours). But with this solution, whenever I make any alteration on the code or update the content, and I clear the cache, the article will also change. Have you guys got an other idea to help me solve this?

Thanks in advance for any answer.

Saturday 03 October 2009 3:32:47 am

Hi Fabien,

Thanks for your answer. I'm trying to develop my own attribute filter as you suggested, but still in a nightmare because I don't know very well how to that and can't find appropriate documentation for that. Can you please give me some ideas or links with documentation.

Wednesday 07 October 2009 4:45:37 am

Piotrek, I made some tests using the ignore_content_expiry parameter, but it doesn't solve my problem because every time I clear the cache my content changes. I think I'll have to create a javascript or php solution.

Wednesday 07 October 2009 11:05:57 am

in your code the fecth should be inside the cache-block anyway, otherwise you will be executing useless sql queries all the time

Wow, I actually missed that and that's obviously completely against caching idea ;)

Piotrek, I made some tests using the ignore_content_expiry parameter, but it doesn't solve my problem because every time I clear the cache my content changes. I think I'll have to create a javascript or php solution. 

I don't quite understand what's the problem with it...
But before you dive into producing some custom solutions, really study all built-in solutions (cache blocks, view cache, smart view cache clearing, persistent variables, cache block nesting) as they satisfy majority of possible scenarios and with little expertise can lead to great optimization. Of course, dynamic injection of HTML based on JavaScript is a great way, but only if all other things are well optimized.

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