All posts by Inder

I am a programmer. I have Bachelors in Computer Science from Tufts University. I currently work full-time at Boston University developing their websites.
Passion

Include admin scripts/styles in WordPress plugin

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There are two ways of including custom scripts/styles in an admin page for a WordPress 3 plugin.

Solution 1 (Deprecated):


$slug = add_submenu_page('myplugin.php', 'My Plugin', 'My Plugin', 'upload_files', __FILE__, 'myplugin_options');

add_action('admin_print_scripts-'. $slug, 'myplugin_enqueue_admin_scripts');
add_action('admin_print_styles-'. $slug, 'myplugin_enqueue_admin_styles');

function myplugin_enqueue_admin_scripts($suffix) {
	$plugin_path = plugin_dir_url(__FILE__) . 'resources/';
	wp_enqueue_script('jquery.js', $plugin_path . 'jquery.pack.js');
}

function myplugin_enqueue_admin_styles($suffix) {
	$plugin_path = plugin_dir_url(__FILE__) . 'resources/';
	wp_enqueue_style('jquery.css', $plugin_path . 'jquery.css');
}

Solution 2 (recommended):

$slug = add_submenu_page('myplugin.php', 'My Plugin', 'My Plugin', 'upload_files', __FILE__, 'myplugin_options');

add_action('admin_enqueue_scripts', 'myplugin_enqueue_admin_scripts');


function myplugin_enqueue_admin_scripts($hook_suffix) {
	if ($hook_suffix == 'myplugin/slug') {
		$plugin_path = plugin_dir_url(__FILE__) . 'resources/';
		wp_enqueue_script('jquery.js', $plugin_path . 'jquery.pack.js');
		wp_enqueue_style('jquery.css', $plugin_path . 'jquery.css');
	}
}
Helpful Tips

Can’t download executables on a Sonicwall corporate network

1 Comment

We have a SonicWall corporate network at our local Gurdwara. It for some reason prohibits some .exe files from being downloaded. Although some executables work just fine. For some executables, only an empty (0 byte) file is downloaded. For some files, my Chrome browser returns Error 101 (net::ERR_CONNECTION_RESET): Unknown error. My ftp (filezilla) fails with the following error:

Response: 150 Opening BINARY mode data connection for mp3DC213.zip (242059 bytes).
Error: Transfer connection interrupted: ECONNABORTED - Connection aborted
Response: 426 Failure writing network stream.
Error: File transfer failed

Clearly the router/gateway is blocking the files. And it is smart enough to scan the files and knows when the same executable file has been named test.mp3 and it can even read zip archive files.

Solution:
In times of need, the one sure way of getting files is to fire up a remote desktop connection or vnc or ssh session, download the file to that remote machine, compress it either 7zip (.7z extension), tarfile (.tar extension) or bzip2 (.bz2 extension) format, and then download to local computer using ftp or upload to any file uploading site.

PS: I have not tested .rar (winrar format). If anybody can test this, let me know if it works.

Helpful Tips

No php53-pear for RHEL 5.6, download it the traditional way!

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I had to update to the latest vBulletin 4, but for that I needed php5.3. Luckily, RHEL has put out php53-* packages (I installed php 5.3.3-1.el5_6.1 btw). I downloaded them all but they were missing php53-pear* package. I’m not sure if this is just the case for x86_64.

So the main problem was getting PEAR packages to install. I tried to get the newer way of downloading pear packages, pyrus (pear2). However, the command php pyrus.phar install ___ resulted in messages like these:
The sqlite3 extension is required.
You must compile PHP with sqlite3 enabled, or install the necessary extension for your distribution.
(Not sure which extension of php53 would resolve this)

The sqlite3 extension is required.
You must compile PHP with sqlite3 enabled, or install the necessary extension for your distribution.
(This one is resolved by downloading php53-xml, thankfully available)

Anyhow, I didn’t want to go on a hunt to try to get these php53 special packages by following the instructions listed in the manual. However, the url listed in the manual http://pear.php.net/go-pear.phar makes php-fcgi put up a blank/empty page. I had a feeling it’s these .phar (weird php compressed archives) files that they’re using. Luckily in the comments, I noticed somebody said to get http://pear.php.net/go-pear. Now that my friends worked like a charm. All I had to do was download that to the server, open it up in the browser and follow the steps as it shows.

The rest comes easy. If you got questions, fire away.

Helpful Tips

Virtualenvwrapper on CentOS/RHEL with Virtualmin

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I used the IUS Community and EPEL repositories to install python 2.6 on my RHEL 5.6 Tikanga box. However I faced some errors, which I didn’t see fully documented online so I figured they would come handy to myself and whoever else tries to do similar things.

Problem 1: Error on mkvirtualenv and other commands: No module named virtualenvwrapper.hook_loader
Resolution: After looking at the source code, virtualenvwrapper can’t find our special python installation. Put the following line in your .bashrc:

VIRTUALENVWRAPPER_PYTHON=/usr/bin/python26

along with the other two lines that everybody tells you to put in:

export WORKON_HOME=$HOME/.virtualenvs
source <strong>/usr/bin/virtualenvwrapper.sh</strong>

(Note that virtualenvwrapper was installed to the above location, this is a different location than the one that everybody else (who is documenting the procedure) is installing at. I’m not sure if this is a new change in virtualenv or because of our special python26 installation. So use locate to find your location properly.)

Problem 2: Virtualenvwrapper commands do not auto-complete or can’t be found also unless .bashrc is sourced manually.
Reason: .bashrc is not executed when logging in to the box (like it should be because it is listed inside .bash_profile, which should be executed also)
Solution: This happens because virtualmin setup’s default $SHELL for each non-root user is /bin/sh. To fix this for on user, open up /etc/passwd, find the user that you are interested in, and change the /bin/sh part to /bin/bash. To fix the default for each virtualmin created user, go to virtualmin’s admin page, under System Customization > Custom Shells > Choose the /bin/bash custom shell.

Downloads

Protoaculous 1.9.0 Minified

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Premise
I used to download the updated versions of protoaculous from Prototype Core Google Group. Recently, Google announced that the Files section of the Google Groups will be deprecated. Also, nobody has been updating the copy of protoaculous in that group (or anywhere else on the public google-searched internet for that matter).

Instructions
The instructions to create it are really simple and so you can do it yourself. You can read them at Boog Design.

Download
For the lazy (like me), here’s the minified version of Prototype.js 1.7.0 (using the new Sizzle CSS Selector Engine – v1.0) + Scriptaculous 1.9.0:
Download

Coral CDN
Cached version (similar to ajax.googleapis.com versions):
http://inderpreetsingh.com.nyud.net/wp-content/uploads/protoaculous.1.9.0.min_.js

Other info
Size of Prototype.js + Scriptaculous = 287,939 bytes
Size of Protoaculous.js Minified = 168,754 bytes

Packed: prototype.js + scriptaculous.js + builder.js + effects.js + dragdrop.js + controls.js + slider.js + sound.js

Downloads

Profile Visitors 4.1 Mod for SMF 2.0

8 Comments

Profile Visitors mod description:

This modifications logs the visitors for all members’ profile with the time of their last visit. Additionally it gives you the ability to see the total visit count for the profile.

Version 4.1

At last, version 4.1, which is an SMF 2.0 only package is released. This version does not log 20, but all visitors of a user. Also it keeps the total visit count for each visitor and total visit count for each profile.

It, as usual, has own/any profile view option and improved remove visitor permissions. Also it includes “Avoid logging permission”, which allows users to select if they want to be logged or not. User can set it from “Look and Layout” area of their profile.

And some bad news… There won’t be any updates for the SMF 1.x version, but I’ll continue supporting that too.

-Blue Dream

This mod is one of the most requested features on my social networking site, Punjabi Janta. So when I went to look for the mod (http://custom.simplemachines.org/mods/index.php?mod=1150), I noticed that the mod coder, [SiNaN], had ended development for a lot of his mods. A couple of users reuploaded the mod to the forum on user’s requests, but moderators were quick to remove it claiming that mods can’t be distributed without owner’s permission.

Anyhow, I had requested a copy from MasterD, and he was helpful in sharing it with me. Here’s an archived copy of it, you won’t find it on Simple Machine’s Forum.

Download:
http://rapidshare.com/files/452804270/ProfileVisitors4.1.zip

PS: The Profile.template.php edit may fail. Just replace the leading spaces with tabs on the following lines:

 
      <div id="detailedinfo">
         <div class="windowbg2">

Edit June 4, 2011: Here’s the edited version to work with SMF 2.0 with the above fix: ProfileVisitors4.1-IPS

Helpful Tips

Fix Pear/Mail due to CentOS/RHEL repos using old pear

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I couldn’t install the Mail PEAR package because the pear version shipped with the current CentOS/RHEL is 1.4.9, whereas the required version is 1.5.6 or above. The following is the error that you may see.

# pear install Mail
WARNING: channel "pear.php.net" has updated its protocols, use "channel-update pear.php.net" to update
Did not download optional dependencies: pear/Net_SMTP, use --alldeps to download automatically
pear/Mail requires PEAR Installer (version >= 1.5.6), installed version is 1.4.9
pear/Mail can optionally use package "pear/Net_SMTP" (version >= 1.4.1)
No valid packages found
install failed

There are three problems above:

  1. WARNING: channel “pear.php.net” has updated its protocols, use “channel-update pear.php.net” to update
  2. Did not download optional dependencies: pear/Net_SMTP, use –alldeps to download automatically
  3. Main problem: pear/Mail requires PEAR Installer (version >= 1.5.6), installed version is 1.4.9

To fix problem #1 (update channel pear.php.net):

# pear channel-update pear.php.net
Retrieving channel.xml from remote server
Update of Channel "pear.php.net" succeeded

To fix problem #2 (Net_SMTP is not installed), run:

# pear install --alldeps Mail 
pear/Mail requires PEAR Installer (version >= 1.5.6), installed version is 1.4.9
downloading Net_SMTP-1.4.4.tgz ...
Starting to download Net_SMTP-1.4.4.tgz (12,264 bytes)
.....done: 12,264 bytes
downloading Net_Socket-1.0.10.tgz ...
Starting to download Net_Socket-1.0.10.tgz (5,429 bytes)
...done: 5,429 bytes
downloading Auth_SASL-1.0.4.tgz ...
Starting to download Auth_SASL-1.0.4.tgz (5,795 bytes)
...done: 5,795 bytes
install ok: channel://pear.php.net/Auth_SASL-1.0.4
install ok: channel://pear.php.net/Net_Socket-1.0.10
install ok: channel://pear.php.net/Net_SMTP-1.4.4

To fix problem #3 (old pear version), first upgrade pear:

# pear upgrade pear
pear/PEAR dependency package "pear/Structures_Graph" downloaded version 1.0.4 is not the recommended version 1.0.3, but may be compatible, use --force to install
pear/PEAR dependency package "pear/Console_Getopt" downloaded version 1.3.0 is not the recommended version 1.2.3, but may be compatible, use --force to install
pear/Archive_Tar requires PEAR Installer (version >= 1.5.4), installed version is 1.4.9
pear/Console_Getopt requires PEAR Installer (version >= 1.9.1), installed version is 1.4.9
downloading Structures_Graph-1.0.4.tgz ...
Starting to download Structures_Graph-1.0.4.tgz (30,318 bytes)
.........done: 30,318 bytes
downloading XML_Util-1.2.1.tgz ...
Starting to download XML_Util-1.2.1.tgz (17,729 bytes)
...done: 17,729 bytes
upgrade ok: channel://pear.php.net/XML_Util-1.2.1
upgrade ok: channel://pear.php.net/Structures_Graph-1.0.4

But this still doesn’t update base pear, so run:

# pear upgrade --force pear
warning: pear/PEAR dependency package "pear/Console_Getopt" downloaded version 1.3.0 is not the recommended version 1.2.3
warning: pear/Archive_Tar requires PEAR Installer (version >= 1.5.4), installed version is 1.4.9
warning: pear/Console_Getopt requires PEAR Installer (version >= 1.9.1), installed version is 1.4.9
downloading PEAR-1.9.1.tgz ...
Starting to download PEAR-1.9.1.tgz (293,587 bytes)
.............................................................done: 293,587 bytes
downloading Archive_Tar-1.3.7.tgz ...
Starting to download Archive_Tar-1.3.7.tgz (17,610 bytes)
...done: 17,610 bytes
downloading Console_Getopt-1.3.0.tgz ...
Starting to download Console_Getopt-1.3.0.tgz (4,408 bytes)
...done: 4,408 bytes
upgrade ok: channel://pear.php.net/Console_Getopt-1.3.0
upgrade ok: channel://pear.php.net/Archive_Tar-1.3.7
upgrade ok: channel://pear.php.net/PEAR-1.9.1
PEAR: Optional feature webinstaller available (PEAR's web-based installer)
PEAR: Optional feature gtkinstaller available (PEAR's PHP-GTK-based installer)
PEAR: Optional feature gtk2installer available (PEAR's PHP-GTK2-based installer)
To install use "pear install pear/PEAR#featurename"

Now we can install pear’s Mail:

# pear install --alldeps Mail
downloading Mail-1.2.0.tgz ...
Starting to download Mail-1.2.0.tgz (23,214 bytes)
........done: 23,214 bytes
install ok: channel://pear.php.net/Mail-1.2.0

You might also need Mail_mime:

# pear install Mail_mime
downloading Mail_Mime-1.8.1.tgz ...
Starting to download Mail_Mime-1.8.1.tgz (31,530 bytes)
.........done: 31,530 bytes
install ok: channel://pear.php.net/Mail_Mime-1.8.1
Helpful Tips

MySQL: Drop all tables with prefix

1 Comment

I use the mysql command line tool to administrate my MySQL. I needed a quick way to drop all tables with the following prefix.

SELECT CONCAT('DROP TABLE `', TABLE_SCHEMA, '`.`', TABLE_NAME, '`;') FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME LIKE 'prefix%' and TABLE_SCHEMA = 'dbname';

Then all you have to do is take a text editor and replace all the “|” signs around the result.

PS: As you can see the query can be modified to get all tables with suffix, or all tables in a schema, or TRUNCATE all tables in the criteria.

Programming

Coldfusion Cfform bug/error: “_b is undefined”

4 Comments

While coding a HTML form using Coldfusion’s CFForm, I encountered a bug that threw a javascript error while submitting it.

"_b is undefined" from cfform.js

around line 3:

_CF_hasValue=function(_b,_c,_d){
if(_c=="TEXT"||_c=="FILE"||_c=="PASSWORD"||_c=="CFTEXTAREA"||_c=="TEXTAREA"||_c=="CFTEXTINPUT"||_c=="DATEFIELD"){
if(_b.value.length==0){
return false; 
}else{
if(_d){
str=_b.value.replace(/^\s+/,"").replace(/\s+$/,"");
if(str.length==0){
return false;
}
}

One of the problems with errors while submission is that it happens very quickly and the browser redirects. So the user doesn’t see the javascript error. It also breaks execution of any (onsubmit/event) javascript code.

I went through my cfform to find any problems code. However at the end, I noticed that the cfform tag was missing the “name” attribute, and by simply adding the “name” attribute I was able to avoid the error.

This is one of the reasons I do not like ColdFusion’s helpers, because the errors that they sometimes generate are very misleading and not documented.

Helpful Tips

Yum install rpm files manually

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I love yum on CentOS/Red Hat/Fedora. It saves so much of my time installing software on servers. Sometimes, the need comes when I cannot find the package inside the usual “safe” repositories, such as RHEL repos and RPMForge. So I search it and find it on pbone, rpmfind, or epel packages. I have always tried installing with rpm, but often end up with dependencies problems.

Example:

# rpm -Uvh icecast-2.3.2-4.el5.x86_64.rpm 
warning: icecast-2.3.2-4.el5.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID 217521f6
error: Failed dependencies:
        libogg.so.0()(64bit) is needed by icecast-2.3.2-4.el5.x86_64
        libspeex.so.1()(64bit) is needed by icecast-2.3.2-4.el5.x86_64
        libtheora.so.0()(64bit) is needed by icecast-2.3.2-4.el5.x86_64
        libtheora.so.0(libtheora.so.1.0)(64bit) is needed by icecast-2.3.2-4.el5.x86_64
        libvorbis.so.0()(64bit) is needed by icecast-2.3.2-4.el5.x86_64

Then I would have to go hunt down each of those dependencies. Too much time wasted. If only you could use yum to resolve those “resolvable” dependencies (using rpmforge/rhel repositories). Well you can:

# yum localinstall icecast-2.3.2-4.el5.x86_64.rpm
    However, there are two caveats:

  1. Sometimes yum can’t find the dependencies, so you must search those out. (obvious)
  2. You probably haven’t imported the gpgcheck for the rpm package that you are trying to download.
    Example:

    warning: rpmts_HdrFromFdno: Header V3 DSA signature: NOKEY, key ID 217521f6
Public key for icecast-2.3.2-4.el5.x86_64.rpm is not installed

    So you can either import it, or you can ignore the gpg check by doing this

    # yum --nogpgcheck localinstall icecast-2.3.2-4.el5.x86_64.rpm