Monthly Archives: September 2010

Magento: Redirecting from inside a view

Posted on by

To redirect before headers are started to be sent (for instance from inside a controller) the following works:

Mage::app()->getFrontController()->getResponse()->setRedirect(Mage::getUrl('portal'));

This will redirect to the page called portal.

However if you try to do this from a view then you will get an error message about headers already having been sent.
If you need to do a redirect form inside a view then using javascript is one way to do this:

echo 'Due to SOMEREASON you are being redirected <a herf="' . Mage::getUrl('portal') . '">Please click here if nothing happens</a>';
		echo '<script type="text/javascript">
		<!--
		window.location = "' . Mage::getUrl('portal') . '"
		//-->
		</script>';

However a tip is to reconsider if you really need to do the redirect from the view, doing it from the controller is a lot easier and quicker.

Magento: Loading a store by store_id

Posted on by

Sometimes there is a need to load a store from the store id, this is not hard to do once you find the right function.

Mage::getModel('core/store')->load($storeId); //a store object

A store object might look like this. Each of the data has a get and a set fucntion (so getIsActive() returns if the store is active or not)

 
 
Mage_Core_Model_Store Object
(
    [_cacheTag:protected] => 1
    [_eventPrefix:protected] => store
    [_eventObject:protected] => store
    [_priceFilter:protected] => 
    [_website:protected] => 
    [_group:protected] => 
    [_configCache:protected] => 
    [_configCacheBaseNodes:protected] => Array
        (
            [0] => catalog/price/scope
            [1] => web/secure/base_url
            [2] => web/secure/use_in_adminhtml
            [3] => web/secure/use_in_frontend
            [4] => web/url/use_store
            [5] => web/unsecure/base_url
            [6] => web/seo/use_rewrites
            [7] => web/unsecure/base_link_url
            [8] => web/secure/base_link_url
            [9] => general/locale/code
        )
 
    [_dirCache:protected] => Array()
 
    [_urlCache:protected] => Array()
 
    [_baseUrlCache:protected] => Array()
 
    [_session:protected] => 
    [_isAdminSecure:protected] => 
    [_isFrontSecure:protected] => 
    [_isReadOnly:private] => 
    [_resourceName:protected] => core/store
    [_resource:protected] => 
    [_resourceCollectionName:protected] => core/store_collection
    [_dataSaveAllowed:protected] => 1
    [_data:protected] => Array
        (
            [store_id] => 64
            [code] => mystore
            [website_id] => 1
            [group_id] => 25
            [name] => mystore
            [sort_order] => 0
            [is_active] => 1
        )
 
    [_origData:protected] => Array
        (
            [store_id] => 64
            [code] => mystore
            [website_id] => 1
            [group_id] => 25
            [name] => mystore
            [sort_order] => 0
            [is_active] => 1
        )
 
    [_idFieldName:protected] => 
    [_isDeleted:protected] => 
)

An an example code to find if the store with id 5 is active or not

if (Mage::getModel('core/store')->load($storeId)->getIsActive())
    //do something if we are active
else
    //do something else if the store is not active

.forward to several recipients

Posted on by

On *nix environments it is possible to forward the mail to one account to another user (or another email address if external mail is supported).
This is done by adding the recipient in a file called .forward in the home directory.

Example To simply forward to another address:

user@server$ echo recipient@mail.com > ~/.forward
user@server$ chmod go-w ~/.forward

In order to forward to several addresses coma (,) is used as a delimiter between the different recipients.

Example To forward to two addresses at the same time:

user@server$ echo recipient1@mail.com,recipient2@mail.com > ~/.forward
user@server$ chmod go-w ~/.forward

Executing rsync as sudo

Posted on by

A quick way to run rsync (via sudo on the remote server) is to use the –rsync-path option (asuming that sudo is configured to run without a password) also verify that you have !tty_tickets in your sudoers file.

rsync -avz --rsync-path='sudo rsync' user@server:/dir/to/backup /destination/directory/

To do this interactivly (without being able to do it password less)

user@bacup$ stty -echo;ssh user@server sudo -v; stty echo
user@bacup$ rsync -avz --rsync-path='sudo rsync' user@server:/dir/to/backup /destination/directory/

(Or as one line)

stty -echo; rsync -azv --rsync-path='sudo rsync' user@server:/dir/to/backup /destination/directory/; stty echo

“stty -echo” turns off input echo (so that your password will not be shown as you type it)
“stty echo” turns the input echo back on (so you can see what you are doing)

Creating sitemap(s) in magento

Posted on by

A sitemap is a xml file that is used by (for instance) search engines to get a better overview of your site. It gives details about what pages exists and how ranks the pages towards themselves.
Despite the name the sitemap is not Google specific, it can be used for any search engine, or any other reason that you need a sitemap.

Create a folder for the site map and make it writable

First figure out where to place the sitemap(s) and make that location writable by the webserver.
In a Linux environment this is done from the console this is done like:

mkdir sitemap
sudo chown admin:www-data sitemap
sudo chmod 775 sitemap
touch sitemap/index.php

The touch index.php will create a empty index file (that keeps the folder from being listed.

Define a sitemap

In the admin panel go to “Catalog->Goolge Sitemap->Add sitemap”

Fill out this form with values that makes sense to you.
Note: If you have sveral stores one website, then all product that are visible on that website is added to the sitemap.

Make the site map update automatically

In the admin pangel go to “System->Configuration->Google sitemap”

As always, change to values that makes sense to you

Another (older) way of doing this is described by the guys at inchoo

Mediawiki turning on interwiki imports

Posted on by

If you wish to import data from another wiki running MediaWiki or for that matter from one or several wiki’s on wikipedia then there is a quick way to import page by page.

This functionality is in MediaWiki by default, but needs to be initiated. This is done by adding the following in LocalSettings.php

$wgImportSources = array(
      'wikinews',
      'wikiquote',
      'wikipedia',
);

The ImportSources are interwiki links from the database.

6 opto endstops for fermat

Posted on by

Endstops are used so that the machine using them to know where the ends of an area is. The opto endstop uses a Transmissive Opto Sensor and a flag that tells the machine that the limit is reached.

A opto endstop also needs a flag to break to break the optical sensor, but that is a later thing to do; also needs a bunch of cables for the installation…

This is the components for one endstop laid out:
opto endstops kit

And the finished result:
6x opto endstops

sudo: cd: command not found

Posted on by

If you try to use sudo to get to a directory (for instance if the user calling sudo don’t have permissions for that folder) then you will see an error message like this

user@server:~$ sudo cd /var/log/
sudo: cd: command not found

While I don’t know how to get sudo to work with cd I can offer some workarounds.
As far as I can tell the problem with sudo cd is that if it would have worked the user would be in a directory that he/she has no permissions to so nothing is gained and having a folder that the user don’t have permissions to as the working directory might cause problems in more way than one.

  • Use “sudo ls” and then continue with the next command as sudo without entering that folder; for instance 
      sudo ls /var/log
sudo cat /var/log/syslog
  • Open a shell using sudo: 
     sudo -s

    this will give you a shell with su permissions

  • simulate initial login using sudo: 
     sudo -i

    this will also give you su permissions but with the difference that it will be like logging in like root (home dir, profile, variables etc) [this would be equivalent of running “sudo su”]

  • Use sudo to start a new shell and do all you need to do in this shell 
     sudo sh -c 'cd /var/spool/exim4/;ls'

    (don’t miss the single quotes in the command)

To give some more details on the difference between -i and -s here is a excerpt from the man pages

-i [command]
The -i (simulate initial login) option runs the shell specified in the passwd(5) entry of the target user as a login shell. This means that login-specific resource files such as .profile or .login will be read by the shell. If a command is specified, it is passed to the shell for execution. Otherwise, an interactive shell is executed. sudo attempts to change to that user’s home directory before running the shell. It also initializes the environment, leaving DISPLAY and TERM unchanged, setting HOME, SHELL, USER, LOGNAME, and PATH, as well as the contents of /etc/environment on Linux and AIX systems. All other environment variables are removed.
-s [command]
The -s (shell) option runs the shell specified by the SHELL environment variable if it is set or the shell as specified in passwd(5). If a command is specified, it is passed to the shell for execution. Otherwise, an interactive shell is executed.

MD Replacing a drive in a degraded array

Posted on by

You get a email from the mdadm monotor telling you that one array is degraded (will look something like this)
DegradedArray event on /dev/md4:jontas02

This is an automatically generated mail message from mdadm
running on theserver
 
A DegradedArray event had been detected on md device /dev/md4.
 
Faithfully yours, etc.
 
P.S. The /proc/mdstat file currently contains the following:
 
Personalities : [raid1] [raid6] [raid5] [raid4] 
md4 : active raid1 sdb1[1]
      1465135936 blocks [2/1] [_U]

In this case I know from before – you make notes of how the md’s are located to drives, right 😉 – that md4 should be sda1 & sdb1
I also know from other logs that there is an error with sda1.

After physically replacing the drive the new disk needs to be added to this array in order to rebuild the array.

This is quick to do

admin@theserver:~$ sudo mdadm --add /dev/md4 /dev/sda
mdadm: added /dev/sda

And then a check of /proc/mdstat lets me know that it was added correctly and that the array is building

cat /proc/mdstat
Personalities : [raid1] [raid6] [raid5] [raid4]
md4 : active raid1 sda[2] sdb1[1]
      1465135936 blocks [2/1] [_U]
      [>....................]  recovery =  0.0% (473408/1465135936) finish=463.9min speed=52600K/sec

WordPress 3: Super Admin pulled a disappearing act

Posted on by

Had a slight problem after the database server had to make a unplanned reboot.
I have a Network running on the WordPress installation; the sites were working, the dashboard was working however I did not have the insert image icon in the posts and the Super Admin was not visible.

For me this turned out to be a simple. The database table “wp_sitemeta” was marked as crashed and could not be read by WordPress.

This is likely to be the problem if the Super Admin disappeared after a hard shutdown of the database server. (By hard I mean that the database didn’t have time to close tables, finish writing to tables etc)