Beaver6813.com » Notes

Selectors in Infinite-Scroll

Beaver6813 — Thu, 05 Jan 2012 20:33:26 +0000

I get asked a lot how/what the selectors are in infinite-scroll and how to figure them out. So lets start from the beginning.. infinite-scroll uses jQuery selectors (which are based on CSS selectors) to find content and posts in order to load the content from the next page. Because web pages are different, we need to define ourselves what selectors infinite-scroll should use.

Infinite-Scroll uses four selectors, these are:

nextSelector
navSelector
contentSelector
itemSelector

It’s probably easiest if you check out my beautiful diagram below to see what they relate to:

And now finally we get to some code (its kind of unavoidable..), you need to look at your site. (easiest way is by going to the homepage, right click and choose view source).

We’re looking for something like this:


This is my post 1, it has a lot of content in it about Bananas...
This is my post 2, it has a lot of content in it about Bananas...
This is my post 3, it has a lot of content in it about Bananas...
This is my post 4, it has a lot of content in it about Bananas...



Next Page

In jQuery/CSS if we want to select something by its ID we use ‘#’, if we want to select something by its class we use ‘.’. And finally if we want to drill into something we leave a space… see my selectors below and hopefully you’ll get it! Selectors for above:

nextSelector: #navigation .next a:first
navSelector: #navigation
contentSelector: #content
itemSelector: #content .post

Hope you enjoyed reading my self-help guide on getting to know your selectors! If you need any help just leave a comment or (preferably) open a ticket in the wordpress forums or infinite-scroll site.

PHP: unset() not freeing memory fully on objects

Beaver6813 — Sun, 05 Jun 2011 20:35:00 +0000

I spent a while trying to figure this out; but it’s quite simple (though I find rather counter-intuitive). Essentially when you create an object in PHP you are allocating memory to that object. When you want to remove that object you can use the unset() function (just like on most things in PHP). The problem occurs when there are variables stored inside the object — unset() doesn’t delete these from memory. This is because unset() doesn’t trigger the object’s destructor. A simple way around it is to explicitly call the destructor and then unset the object like so:

View Code PHP

$myobject = new CrazySystem();
$myobject->LargeVariable = file_get_contents("VeryLargeFile.txt");
//Now we want to delete the object and everything it contains
$myobject->__destruct();
unset($myobject);
//It's now all gone!

Hope that helps anyone who was wondering why unsetting object still wasn’t freeing memory!

Select/Invite all friends on Facebook automatically

Beaver6813 — Tue, 10 May 2011 21:05:44 +0000

Facebook recently updated the way they allow you to invite friends. Purposely or, as a side effect, it means that the popular javascript code that lets you select all friends no longer works. The following code courtesy of John P. allows you to select all friends on the new version. (Yay!)

There is one catch. Because Facebook now only loads a few of your friends at a time, you have to scroll all the way down the invite list until you hit the very bottom (all your friends are displayed). You then just paste the following into the URL bar and hit enter:

View Code JAVASCRIPT

javascript:function check_all_in_document(doc){var c=new Array();c=doc.getElementsByTagName('input');for(var i=0;i<c.length;i++){if(c[i].type=='checkbox'){c[i].click();}}}check_all_in_document(window.document);for(var j=0;j<window.frames.length;j++){check_all_in_document(window.frames[j].document);}

Happy inviting! (If the code doesn’t work then make sure you click “View Code” in the box above.)

Regular Expression for Passwords

Beaver6813 — Wed, 05 Jan 2011 15:49:40 +0000

This is just a note to myself really, below is the regular expression for a string or in my case password where you require it to have at least one letter, one number, a limited selection of special characters (optional) and a minimum of 8 characters in length:

View Code REGEX

1	^(?=.{8,})(?=.\d)(?=.[a-zA-Z])[a-zA-Z0-9@#$%^&+=\]$

PHP Compilation (Cannot find -lltdl)

Beaver6813 — Sat, 10 Jul 2010 18:15:10 +0000

When compiling PHP from source (in my case version 5.3.2) on CentOS 5.4 I kept getting the following error when trying to compile with mcrypt:

"/usr/bin/ld: cannot find -lltdl"

This seems to be due to a missing development library with the obscure name of libtool-ltdl-devel to fix this simply use:

yum install libtool-ltdl-devel

Which should include the package along with several dependencies.

libltdl3-dev

PHP Search and Replace Directory Recursively

Beaver6813 — Tue, 13 Apr 2010 16:04:11 +0000

On a message forum I regularily visit a member was having issues with code being placed in multiple files that he wanted to remove or change without having to edit each and every file manually. For this I created a search and replace function which will recursively search the directory and every file for a specific piece of code and will replace with whatever:

View Code PHP

GoDaddy mod_rewrite Hell

Beaver6813 — Thu, 18 Mar 2010 13:17:58 +0000

Whilst trying to install a piece of software on a GoDaddy hosted account I noticed that mod_rewrite variables were simply not being passed to the correct pages. When digging a bit deeper I found that it was effectively ignoring extensions in URLs and just displaying the file with the extension. i.e. instead of having to enter:

www.example.com/advertise.php

you could instead type

www.example.com/advertise

And it would return the same file, which is good if for some unknown reason your file doesn’t have the correct extension, but its not exactly.. good..

After trawling Google for a while I found a post by Eric Faerber that solved the problem. The strange redirects were due to Apache MultiViews being enabled, disabling this by entering

Options -MultiViews

into the .htaccess file. Solved the problem, the simplest solutions are always the best!

Case of the missing/hidden IE8 Developer Tools window

Beaver6813 — Fri, 27 Nov 2009 14:14:02 +0000

Whilst working on a current project I was trying to get cross-browser compatability working nicely. However when I came to load up IE’s Developer Tools I found it was loading up the window but nothing was there! I’m running Windows 7 and this seems to be the only version of windows the problem is affecting:

The solution I found is actually very simple, right click on that hidden window thumbnail and click maximise. If that fails then you could always try a solution outlined on StackOverflow. The best solutions are often the most simple!!

[PHP] Get current time in milliseconds

Beaver6813 — Tue, 20 Oct 2009 17:59:31 +0000

I recently needed to get the current time in milliseconds, of course this can easily be retrieved using microtime() however I needed the entire number in digits, not in decimals with seconds seperately etc. Heres how:

View Code PHP

1
2
3

$timeparts = explode(" ",microtime());
$currenttime = bcadd(($timeparts[0]*1000),bcmul($timeparts[1],1000));
echo $currenttime;

NOTE: PHP5 is required for this function due to the improvements with microtime() and the bc math module is also required (as we’re dealing with large numbers, you can check if you have the module in phpinfo).

Bash, Bad Interpreter

Beaver6813 — Mon, 12 Oct 2009 15:42:42 +0000

I recently came across:

/bin/bash^M: bad interpreter: No such file or directory

When trying to run a bash script that someone else had edited. This most commonly happens on UNIX systems if the file has been edited on MS-DOS or Mac. The cure for this is to run a simple perl script:

View Code BASH

1 2	#!/usr/bin/perl -pi s/\n/\r\n/;

Save as unix2dos.pl, chmod +x unix2dos.pl and then run like:

./unix2dos.pl filetoconvert.txt

Simples!