Kategorien
Allgemein

Autowiring Vfs in a Horde App

The Horde Vfs is an abstraction around storing and retrieving files. Calling code does not care about where the Vfs is actually stored, be it a remote filesystem, a dav resource, a database or a path in the local filesystem. Autowiring means the Injector knows how to create a class using some other class without having it explicitly defined

For this article, I want to get an instance of Horde\MyApp\ReportGenerator which uses the VFS to store reports.

First let’s create the ReportGenerator.

lib/ReportGenerator.php

<php
namespace Horde\MyApp;
class ReportGenerator
{
    private $driver;
     public function __construct(\Horde_Vfs_Base $driver
     {
         $this--->driver = $driver;
     }
     ...
}

When a controller in the app wants a report generator, it would require it through the dependency injector like this:


$reportGenerator = $injector->getInstance('Horde\MyApp\ReportGenerator');

Autowiring allows the injector to return an instance even if it has not been explicitly bound to the injector. For this to work, all required dependencies must be interfaces which have either been registered with the injector or can themselves be created from registered interfaces or have no dependencies themselves.

Now, Horde_Vfs_Base is the common base class of all Horde Vfs drivers.

However, Horde does not provide a default binding for Horde_Vfs_Base even though Horde_Core has a default factory Horde_Core_Factory_Vfs.

Thus, we need to define one. In Application.php, look for a method _bootstrap(). We will use it to setup the injector binding. Normally, we would just want to use the existing factory through $injector->bindFactory($interface, $factory, $method);

We cannot do this in this case. The Vfs Factory’s create method has two string parameters to allow creating multiple Vfs instances. For our app, we just want to get the default configured in horde base. But this doesn’t work. bindFactory would automatically pass a child injector to the create method. This would override the default first parameter „horde“. In the end, we would receive the factory’s exception saying we should configure a backend first – even if we did.

To work around this, we could create an own factory class in our app which uses Horde_Core_Factory_Vfs as a dependency. Horde_Injector would just know what to do. But let’s not do this as it’s quite some boilerplate just for creating a Vfs with default configuration.

Instead, let’s use the closure binder.


protected function _bootstrap()
{
     $injector = $GLOBALS['injector'];
     $vfsClosure = function(\Horde_Injector $injector) {
     return $injector->getInstance('Horde_Core_Factory_Vfs')->create();
};
$injector->bindClosure('Horde_Vfs_Base', $vfsClosure);

Now injector knows how to provide a Horde_Vfs_Base implementation which the ReportGenerator requires. We can ask injector to provide an instance. Injector will look if it already has an instance from a previous call, otherwise runs the closure to create the dependency, then create the actual ReportGenerator instance.

Kategorien
Allgemein

Docker for Windows now runs on Windows Home

Docker for Windows used to require Hyper-V and Windows Professional. Now, you can do basic software development on Windows Home. Here’s the story.

I got hold of some older 4GB Windows convertible laptop. Unfortunately, it won’t run Linux in any useful way. In recent years, I did not really care for Windows a lot, apart from the usual „fix your parent’s gear for christmas“ routine. Looking for uses case it would possibly cover, I found Windows has improved quite a lot.

Windows 10 May 2020 Update (also known as version 2004) introduces improvements to the „Windows Sub System For Linux“ (WSL2). Recent versions of Docker Desktop CE for Windows allow to run based on WSL2. It’s even better than the original version based on Hyper-V.

To run Docker Desktop, you need to install the WSL and „Virtualization Platform“ options in Windows. This requires a reboot. Docker Desktop will ask you to download a special Linux kernel from a Microsoft website. Docker and the Kernel will require an additional reboot. Microsoft promises that the manual kernel install is a one-time issue. Future kernel releases will be published via Windows Updates.

Now why bother? With the latest Windows improvements, I can keep most of my development workflows when switching to a tiny, low-powered device which I don’t especially care for – think of spare time while traveling by train or some free time project while laying in the hammock. There’s no way I would use my bigger, more expensive equipment in such situations.

The new optional Windows Terminal is available both from the Microsoft website and from their App Store. It’s free and as close as you can get to a native KDE Konsole or Gnome Terminal. It’s not as awkward as putty nor as ugly as the classic cmd or Power Shell. Paired with Windows‘ posix-like ssh client suite, there’s little difference too remote sessions from Linux desktops .

Visual Studio Code feels exactly the same on both Linux and Windows platforms. It allows to edit code directly inside a runtime container. No need for rsync workarounds or push cycles. Keeping everything in the containers also greatly reduces the time to recover from a full reset.

In case you didn’t know, Docker Desktop has some builtin Kubernetes option. This allows development to be even closer to cloud/production scenarios. However, on a 4GB device, don’t expect too much.

The Windows Store now includes some FOSS software, even some KDE for Windows gadgets. Still no Firefox, Thunderbird, Chrome / Chromium … Microsoft has announced they will release some apt/zypper like commandline software installer later this year. Let’s hope that gets adopted more widely.

Windows Store offers some mainstream linux distributions like openSUSE Leap or ubuntu to run on top of WSL/WSL2. I have decided to postpone experimenting with these. Microsoft has announced they want to enable true, builtin capabilities for graphic applications on X/Wayland. I will give this a try when the time is right. It might also make sense to drop Docker Desktop for some podman or other runtime running inside such a linux platform. But for now, that’s out of scope.

While I’m still not ready to embrace Windows as a first-class development platform, I must concede it has become a viable option.

Update 2020/10: I just read an article on Medium which I totally agree with: https://levelup.gitconnected.com/this-is-why-developers-will-embrace-microsoft-windows-again-7437e494159d

They also point out what I am currently doing, using WSL2, docker desktop (with Kubernetes) and VS Code for an integrated environment.

Kategorien
Allgemein horde Tech

Heads Up: Cannot login as horde admin anymore?

Please be careful: Horde has introduced a new default setting $conf[‚auth‘][‚lowercase‘] which acts like the auth hook used to do.

This might lead to issues when your default admin account is named „Administrator“.

It is actually a very useful setting. It ensures that any prefs and other profiles also work with case-insensitive backends regardless of how you type the user name.

How to fix?

a) Lowercase all admin names in your $conf[‚auth‘][‚admin‘] settings in conf.php

b) disable $conf[‚auth‘][‚lowercase‘] by setting it to false value.

Kategorien
Allgemein

The state of horde composer deployments

In early 2019 I first wrote a few lines on migrating horde to composer based setups.

Even though I was too occupied with other business for several months, I have something to show and it is time to review what we have and what we don’t have.

The good news is, it really runs as far as I am concerned. For the mainstream apps, the Web UI works correctly as well as caldav/carddav access, handling of db schema migrations, some critical commandline scripts. There is still a lot of scripts to check and possibly fix.

The Horde Components helper has been modified to be run as a part of a horde deployment or standalone. It can also still be run from git-tools. I added some code to git-tools to improve the way it wraps horde-components. However, most things git-tools provides are no longer that interesting to the casual developer or to deploying horde master tree installations.

I also improved the horde Controller/Routes core. It is now more successful in detecting which app handles a request. Also, a new option for unauthenticated routes and for „API style“ auth handling has been included. This enables REST interfaces.

I finally did a small proof of concept app which is completely based on the controller/routes core and does not have a single traditional „page“ file. Maybe this should be provided as an alternative skeleton.

How to run your own composer based install

Running a new horde install for development or CI purpose is as easy as:

cd your/web/root/
git clone https://github.com/maintaina-com/horde-deployment.git .
composer install
cp web/horde/config/conf.php.dist web/horde/config/conf.php

For using a database, provide a config with a db backend instead.
You might also want to run web/horde/bin/horde-db-migrate.

I intend to improve the installer a little to detect if pre-made configs have been put into expected locations of the deployment and use them.

Why you should not use this in production

This deployment comes „as is“. It is still dependent on a satis server not controlled by the horde organisation, running a no-warranties fork of the unreleased git master code. If you run this in production, you need to do a lot of QA for your specific use case. Patches welcome. You may also encounter features not part of official horde releases because they are incomplete, lacking tests or else.

I am still trying to get this upstream. Dealing with a downsteam horde distribution of 150+ repos is tedious work. I’d rather invest time in actual software development. In case you really need to, contact me about commercial support options.

Kategorien
Allgemein horde OpenSUSE Tech

PEAR down – Taking Horde to Composer

Since Horde 4, the Horde ecosystem heavily relied on the PEAR infrastructure. Sadly, this infrastructure is in bad health. It’s time to add alternatives.

Everybody has noticed the recent PEAR break-in.

A security breach has been found on the http://pear.php.net webserver, with a tainted go-pear.phar discovered. The PEAR website itself has been disabled until a known clean site can be rebuilt. A more detailed announcement will be on the PEAR Blog once it’s back online. If you have downloaded this go-pear.phar in the past six months, you should get a new copy of the same release version from GitHub (pear/pearweb_phars) and compare file hashes. If different, you may have the infected file.

While I am writing these lines, pear.php.net is down. Retrieval links for individual pear packages are down. Installation of pear packages is still possible from private mirrors or linux software distribution packages (openSUSE, Debian, Ubuntu). Separate pear servers like pear.horde.org are not directly affected. However, a lot of pear software relies on one or many libraries from pear.php.net – it’s a tough situation. A lot of software projects have moved on to composer, an alternative solution to dependency distribution. However, some composer projects have dependency on PEAR channels.

I am currently submitting some changes to Horde upstream to make Horde libs (both released and from git) more usable from composer projects.
Short-term goal is making use of some highlight libraries easier in other contexts. For example, Horde_ActiveSync and Horde_Mail, Horde_Smtp, Horde_Imap_Client are really shiny. I use Horde_Date so much I even introduced it in some non-horde software – even though most functionality is also somewhere in php native classes.

The ultimate goal however is to enable horde groupware installations out of composer. This requires more work to be done. There are several issues.

  • The db migration tool checks for some pear path settings during runtime https://github.com/horde/Core/pull/2 Most likely there are other code paths which need to be addressed.
  • Horde Libraries should not be web readable but horde apps should be in a web accessible structure. Traditionally, they are installed below the base application („horde dir“) but they can also be installed to separate dirs.
  • Some libraries like Horde_Core contain files like javascript packages which need to be moved or linked to a location inside another package. Traditionally, this is handled either by the „git-tools“ tool linking the code directory to a separate web directory or by pear placing various parts of the package to different root paths. Composer doesn’t have that out of the box.

Horde already has been generating composer manifest files for quite a while. Unfortunately, they were thin wrappers around the existing pear channel. The original generator even took all package information from the pear manifest file (package.xml) and converted it. Which means, it relied on a working pear installation. I wrote an alternative implementation which directly converts from .horde.yml to composer.json – Calling the packages by their composer-native names. As horde packages have not been released on packagist yet, the composer manifest also includes repository links to the relevant git repository. This should later be disabled for releases and only turned on in master/head scenarios. Releases should be pulled from packagist authority, which is much faster and less reliant on existing repository layouts. https://github.com/horde/components/pull/3

To address the open points, composer needs to be amended. I currently generate the manifests using package types „horde-library“ and „horde-application“ – I also added a package type „horde-theme“ for which no precedent exists yet. Composer doesn’t understand these types unless one adds an installer plugin https://github.com/maintaina-com/installers. Once completed and accepted, this should be upstreamed into composer/installers. The plugin currently handles installing apps to appropriate places rather than /vendor/ – however, I think we should avoid having a super-special case „horde-base“ and default to installing apps directly below the project dir. Horde base should also live on the same hierarchy. This needs some additional tools and autoconfiguration to make it convenient. Still much way to go.

That said, I don’t think pear support should be dropped anytime soon. It’s the most sensible way for distribution packaging php software. As long as we can bear the cost involved in keeping it up, we should try.

Kategorien
OpenSUSE

Current (10/2018) Tumbleweed on Raspberry Pi 1

Hallo,

I just had a little struggle getting the current tumbleweed to run on the original Raspberry Pi (first generation, though the revision with larger RAM).

Just in case this helps anybody: I did not have any luck with a fresh openSUSE Tumbleweed image of one of the current arm6 builds. Don’t know why.

Here’s what I did:
– Download a pretty old known-good OpenSUSE 13.1 built by Bernhard Wiedemann

http://www.zq1.de/bernhard/linux/opensuse/raspberrypi-opensuse-latest.img.xz

Unzip, dump it to SD Card

xz -d raspberrypi-opensuse-latest.img.xz
dd if=raspberrypi-opensuse-latest.img of=/dev/mmcblk0 bs=8M

Boot up, change to text console (CTRL + ALT + F2)
Log In (root/linux)

Change Password (passwd)

nano /etc/zypp/repos.d/oss131.repo
Change baseurl line to
baseurl=http:/download.opensuse.org/ports/armv6hl/tumbleweed/repo/oss/
Save and get out (CTRL+X, Y)

#Resize partition and FS as this build won’t do:
# Adjust to more if your card is larger or to less if you need a more advanced partitioning scheme

parted resize 3 16G

resize2fs /dev/mmcblk0p3

zypper ref

zypper up gzip rpm

zypper dup –download in-advance

#(super conservative, get all needed packages first) – This is going to take quite a while

reboot, power cycle

Note that you will end up with a system booting into X11 login. You should probably change the default systemd target and maybe also get rid of some software. And you really don’t want a server with ssh password „linux“, so better don’t skip changing the PW

 

Kategorien
horde OpenSUSE Tech

horde trustr – A new horde CA app step by step

Trustr is my current project to create a simple certificate management app.
I decided that it is just about the right scope to demonstrate a few things about application development in Horde 5.

I have not made any research if the name is already occupied by some other software. Should any problems arise, please contact me and we will find a good solution. I just wanted to start without losing much time on unrelated issues.

My goals as of now:

– Keep everything neat, testable, fairly decoupled and reusable. The core logic should be exportable to a separate library without much change. There won’t be any class of static shortcut methods pulling stuff out of nowhere. Config and registry are only accessed at select points, never in the deeper layers.
– Provide a CLI using Horde_Cli and Horde_Cli_Application (modeled after the backup tool in horde base git)
– Store to relational database using Horde_Db and Horde_Rdo for abstraction
– Use php openssl extension for certificate actions, but design with future options in mind
– Rely on magic openssl defaults as little as possible
– Use conf.xml / conf.php for any global defaults
– Show how to use the inter-app API (reusable for xml-rpc and json-rpc)
– Showcase an approach to REST in Horde (experimental)

The app is intended as a resource provider. The UI is NOT a top priority. However, I am currently toying around with a Flux-like design in some unrelated larger project and I may or may not try some ideas later on.

Initial Steps: Creating the working environment

I set up a new horde development container using the horde tumbleweed image from Open Build Service and a docker compose file from my colleague Florian Frank. Please mind both are WIP and improve-as-needed projects.


git clone https://github.com/FrankFlorian/hordeOnTumbelweed.git
cd hordeOnTumbelweed
docker-compose -f docker-compose.yml up

This yields a running horde instance on localhost and a database container.
I needed to perform a little manual setup in the web admin ui to get the DB to run and create all default horde schemas.

Next I entered the developer container with a shell
docker exec -it hordeOnTumbelWeed_php_1 bash

There are other ways to work with a container but that’s what I did.

 

Creating a  skeleton app

The container comes with a fairly complete horde git checkout in /srv/git/horde and a clone of the horde git tools in /srv/git/git-tools

A new skeleton app can be created using

horde-git-tools dev new --author "Ralf Lang <lastname@b1-systems.de>" --app-name trustr

The new app needs to be linked to the web directory using

horde-git-tools dev install

Also, a registry entry needs to be created by putting a little file into /srv/git/horde/base/config/registry.d

cat trustr-registry.d.php

<?php
// Copy this example snipped to horde/registry.d
$this->applications['trustr'] = array(
'name' => _('Certificates'),
'provides' => array('certificates')
);

 

This makes the new app show up in the admin menu. To actually use it and make it appear in topbar, you also need to go to /admin/config and create the config file for this app. Even though the settings don’t actually mean anything by now, the file must be present.

I hope to follow up soon with articles on the architecture and sub systems of the little app.

Kategorien
Allgemein

Why upstream rejects patches

I held „12 Gründe, warum dein Patch immer abgelehnt wird“ (12 top reasons why upstream rejects your patches) at Chemnitzer Linuxtage 2018, using examples from OpenStack, Horde and nextcloud. I intend to follow up with some blog posts shortly.

Kategorien
Allgemein

Boneyard – a barebone horde „dynamic view“ app based on „skeleton“.

Boneyard – a barebone horde „dynamic view“ app based on „skeleton“.

In this article, I will show you some minimal setup for a „horde5 dynamic view“ application as demonstrated by hermes time tracking and kronolith calendar

Pre-requisite
We have a working git checkout of a 5.2 or master installation of horde with some authentication and prefs backend working and the migrations inplace.
If your setup did not involve editing install_dev.conf, you probably have something else and I cannot guarantee this walkthrough will work for you without adopting some parts.

Let’s generate a fresh application called boneyard

maintaina:/srv/git/horde5-webmail/horde # php framework/bin/horde-generate-module boneyard "Ralf Lang "
Started new Module in /srv/git/horde5-webmail/horde/boneyard!
Register the new Module with a file in the config/registry.d directory:

<?php
$this->applications['boneyard'] = array('name' => _("Boneyard"));

We put a file with this oneliner into the directory as advised

maintaina:/srv/git/horde5-webmail/horde # vim horde/config/registry.d/boneyard.php

Now let’s re-run the script generating the links for the git checkout installation

maintaina:/srv/git/horde5-webmail/horde # php framework/bin/install_dev
EMPTYING old web directory /srv/www/vhosts.d/horde.ralf-lang.de

LINKING horde
Setting static directory permissions...
LINKING applications to web directory /srv/www/vhosts.d/horde.ralf-lang.de
LINKING sam
LINKING luxor
[.. snip ..]
LINKING pastie
LINKING ingo
LINKING boneyard
LINKING hvview
LINKING sesha
LINKING passwd
LINKING operator
LINKING nag
LINKING gollem
LINKING jonah
LINKING sueporter
LINKING ulaform

LINKING framework
[ INFO ] Source directory: /srv/git/horde5-webmail/horde/framework
[ INFO ] Framework destination directory:
/srv/www/vhosts.d/horde.ralf-lang.de/libs
[ INFO ] Horde directory: /srv/www/vhosts.d/horde.ralf-lang.de
[ INFO ] Create symbolic links: Yes

[ INFO ] Package(s) to install: ALL (129 packages)
[ INFO ] Installing package ActiveSync
[.. snip ..]
[ INFO ] Installing package xxhash

Now boneyard is set up in your web-accessible dir.
Let’s make the config dir web-writeable

chown wwwrun:www /srv/www/vhosts.d/horde.ralf-lang.de/boneyard/config

This is for SUSE – debian or redhat may have different user/group for the web server.

Next go to $yourdomain/admin/config/ the admin panel and generate the conf.php file by clicking on the „boneyard“ entry and then the „create boneyard config“ button.
At this point, we do not care about the actual contents of this config – the defaults are just fine.

If you only see „horde“ and some library names, you most probably have not edited registry.local.php to contain something like:


<?php
// By default, applications are assumed to live within the base Horde
// directory (e.g. their fileroot/webroot will be automatically determined
// by appending the application name to Horde's 'fileroot'/'webroot' setting.
// If your applications live in a different base directory, defining these
// variables will change the default directory without the need to change
// every application's 'fileroot'/'webroot' settings.
$app_fileroot = '/srv/www/vhosts.d/horde.ralf-lang.de/';

Now „Boneyard“ should appear in your horde topbar with some bogus buttons and content

Let’s create the structure of a „dynamic“ application

* lib/Ajax.php – The Boneyard Ajax base class to load locale- and setting-dependent content into the browser’s javascript
* lib/Ajax/Application/Handler/Example.php – A handler for Ajax requests to load data from the server — we skip that for now
* lib/View/Sidebar.php – Boneyard_View_Sidebar – a sidebar for the dynamic view
* template/dynamic/sidebar.html.php – The template used by the sidebar view
* template/dynamic/index.inc – The main template of the dynamic view
* template/dynamic/example1.inc – One of our two example views in this demo
* template/dynamic/example2.inc – One of our two example views in this demo
* js/boneyard.js – The BoneyardCore object which contains the main click handler etc

We also need to touch the index.php file to enable the dynamic view and the lib/Application.php file to advertise that dynamic view exists.

See https://github.com/ralflang/horde-boneyard to view the code in detail.

Kategorien
horde

Horde_Rdo Many to Many relations and Horde DB Migrator

Many to Many relations btween to object types or table rows are usually saved to a database using a third table.

For example, if every server can have multiple services and each service can run on multiple computers, we need a third table to store the relations:

server table:
server_id | server_name
        1 | hoellenhund.internal.company.com
        2 | forellenfisch.internal.company.com
service table:
service_id | service_name
         1 | tomcat
         2 | dovecot
relation table:
service_id | server_id
         1 | 1
         2 | 2
         2 | 1

Horde’s ORM Layer Horde_Rdo supports creating, checking and changing such relations but it’s not very prominently documented.

Let’s look at an example.

First, we need to create the database schema. Note that the relations table has no autoincrement key, only the two columns used for lookup


/usr/share/php5/PEAR/www/horde/hvview/migration # cat 1_hvview_base_tables.php
<?php
/**
* Create Hvview base tables.
*
* Copyright 2015-2015 B1 Systems GmbH (http://www.b1-systems.de/)
*
* See the enclosed file COPYING for license information (GPL). If you
* did not receive this file, see http://www.horde.org/licenses/gpl.
*
* @author Ralf Lang
* @package Hvview
*/
class HvviewBaseTables extends Horde_Db_Migration_Base
{
/**
* Upgrade
*/
public function up()
{

$t = $this->createTable('hvview_technical_landscapes', array('autoincrementKey' => 'landscape_id'));
$t->column('landscape_name', 'string', array('limit' => 255, 'null' => false));
$t->column('period_id', 'integer', array('limit' => 11, 'null' => false));
$t->end();

$t = $this->createTable('hvview_resource_pools', array('autoincrementKey' => 'resource_pool_id'));
$t->column('pool_name', 'string', array('limit' => 255, 'null' => false));
$t->column('landscape_id', 'integer', array('limit' => 11, 'null' => false));
$t->column('period_id', 'integer', array('limit' => 11, 'null' => false));
$t->end();

$t = $this->createTable('hvview_hardware_pools', array('autoincrementKey' => 'hardware_pool_id'));
$t->column('pool_name', 'string', array('limit' => 255, 'null' => false));
$t->column('landscape_id', 'integer', array('limit' => 11, 'null' => false)); /* possibly redundant, but may speed up things */
$t->column('period_id', 'integer', array('limit' => 11, 'null' => false));
$t->end();

/*Relations table*/
$t = $this->createTable('hvview_rp_hwps', array('autoincrementKey' => false));
$t->column('resource_pool_id', 'integer', array('limit' => 11, 'null' => false));
$t->column('hardware_pool_id', 'integer', array('limit' => 11, 'null' => false));
$t->end();

$t = $this->createTable('hvview_periods', array('autoincrementKey' => 'period_id'));
$t->column('period_ts', 'integer', array('limit' => 11, 'null' => false));
$t->end();

/* We collapse hypervisor and blade server objects into one for now - let`s see if this scales well */
$t = $this->createTable('hvview_servers', array('autoincrementKey' => 'server_id'));
$t->column('period_id', 'integer', array('limit' => 11, 'null' => false));
$t->column('hardware_pool_id', 'integer', array('limit' => 11, 'null' => false));
$t->column('hostname', 'string', array('limit' => 100, 'null' => false));
$t->column('state', 'string', array('limit' => 20, 'null' => true));
$t->column('os_release', 'string', array('limit' => 20, 'null' => true));
$t->column('comment', 'string', array('limit' => 255, 'null' => true));
$t->column('hv_free_vcpu', 'integer', array('limit' => 11, 'null' => true));
$t->column('hv_free_memory', 'integer', array('limit' => 11, 'null' => true));
$t->column('hv_free_disk', 'integer', array('limit' => 11, 'null' => true));
$t->column('hv_total_vcpu', 'integer', array('limit' => 11, 'null' => true));
$t->column('hv_total_memory', 'integer', array('limit' => 11, 'null' => true));
$t->column('hv_excluded', 'integer', array('limit' => 1, 'null' => true));
$t->column('hv_vm_count', 'integer', array('limit' => 3, 'null' => true));
$t->end();

// Indices not before we have an idea which of them we need most
// $this->addIndex('hvview_items', array('item_owner'));

}

/**
* Downgrade
*/
public function down()
{
$this->dropTable('hvview_technical_landscapes');
$this->dropTable('hvview_resource_pools');
$this->dropTable('hvview_hardware_pools');
$this->dropTable('hvview_periods');
$this->dropTable('hvview_servers');
$this->dropTable('hvview_rp_hwps');
}
}

The relations are defined in a Horde_Rdo_Mapper class which also knows how to spawn objects from the rows.

The Objects

/usr/share/php5/PEAR/www/horde/hvview/lib/Entity # cat ResourcePool.php 
<?php

class Hvview_Entity_ResourcePool extends Horde_Rdo_Base {
}

/usr/share/php5/PEAR/www/horde/hvview/lib/Entity # cat HardwarePool.php 

The Mappers:

/usr/share/php5/PEAR/www/horde/hvview/lib/Entity # cat ResourcePoolMapper.php 
<?php
class Hvview_Entity_ResourcePoolMapper extends Horde_Rdo_Mapper
{
    /**
     * Inflector doesn't support Horde-style tables yet
     */
    protected $_classname = 'Hvview_Entity_ResourcePool';
    protected $_table = 'hvview_resource_pools';
    protected $_lazyRelationships = array(
             'hwps' => array('type' => Horde_Rdo::MANY_TO_MANY,
                          'through' => 'hvview_rp_hwps',
                          'mapper' => 'Hvview_Entity_HardwarePoolMapper')
    
            );

}

/usr/share/php5/PEAR/www/horde/hvview/lib/Entity # cat HardwarePoolMapper.php 
<?php
class Hvview_Entity_HardwarePoolMapper extends Horde_Rdo_Mapper
{
    /**
     * Inflector doesn't support Horde-style tables yet
     */
    protected $_classname = 'Hvview_Entity_HardwarePool';
    protected $_table = 'hvview_hardware_pools';
    protected $_lazyRelationships = array(
             'rps' => array('type' => Horde_Rdo::MANY_TO_MANY,
                          'through' => 'hvview_rp_hwps',
                          'mapper' => 'Hvview_Entity_ResourcePoolMapper')
    
            );

}

The relation is defined in both direction and only loaded on-demand ("lazy") as opposed to upfront when the item is created from the database rows.
Now let's fetch two items and link them:

You can do this through the mapper or through one of the two partners

Adding a relation to an object using the object

// $rm is a ResourcePoolMapper instance
// $hm is a HardwarePoolMapper instance
$rp = $rm->findOne(); // In reality, you would not pick a random item but add some criteria
$hwp = $hm->findOne();
$rp->addRelation('hwps', $hwp);

Adding a relation to an object using the mapper

// $rm is a ResourcePoolMapper instance
// $hm is a HardwarePoolMapper instance
$rp = $rm->findOne(); // In reality, you would not pick a random item but add some criteria
$hwp = $hm->findOne();
$rm->addRelation('hwps', $rp, $hwp);
Kategorien
Allgemein

Thimbleweed Park angekündigt

Ron Gilbert, der Mann, der uns Maniac Mansion, Monkey Island (1+2) und Total Annihilation brachte, hat zusammen mit Gary Winnick die Entwicklung eines klassischen Point&Click-Adventures begonnen. Thimbleweed Park wird für PC, Android und iOS erscheinen und (optionale) Sprachausgabe sowie Übersetzung von Boris Schneider-Johne, der schon Monkey Island übersetzte. Mitte Juni 2016 soll das Spiel im Handel erscheinen, so der erste Zeitplan. Ich bin gespannt.

Vorbestellungen sind zu 25 US-$ möglich über Amazon und Paypal.

http://blog.thimbleweedpark.com/

Kategorien
Allgemein OpenSUSE Tech

Sara Golemon (Facebook) announces PHP Language Specification for OSCON 2014

For more than 10 years, PHP core developers repeatedly raised the topic of providing a formal language specification for PHP. Now a team of facebook employees has written such a specification. The spec document is currently only available as a preview chapter a preview chapter . PHP veteran Sara Golemon announced on the „PHP internals“ list that the full document will be ready for O’Reilly’s OSCON 2014. Sara Golemon published the standard book on „Extending and Embedding PHP“ some years ago and now works for Facebook’s own PHP implementation HHVM. The PHP spec defines PHP version 5.6 in about 200 pages and contains all the odd and obscure quirks of the language core. Facebook’s own HHVM aims to be as close to the spec as possible. Currently, PHP developers discuss how amending the spec can become a mandatory part of the language development process. Though some are sceptic that all developers will embrace the change in the process, everybody on the list was happy to have the new document.

Software Architect Stas Malyshev:

Thank you Sara and Facebook team for doing something we’ve been talking
about for more than a decade and before that nobody actually attempting
to do. I think it is a great development and I hope to see the first
version soon.

http://dl.hhvm.com/resources/PHPSpec-SneakPeak.pdf

Kategorien
Tech

Sara Golemon (Facebook) kündigt PHP Language Specification auf OSCON 2014 an

Seit über 10 Jahren bringen immer wieder einige der PHP-Sprachentwickler den Plan an, eine formale Spezifikation für den Sprachkern bereitzustellen. Ein Team bei Facebook hat das nun getan. Die Spezifikation, die bisher nur als Vorschau vorliegt, wurde von Sara Golemon auf der Entwickler-Liste angekündigt und soll auf der OSCON 2014 vorgestellt werden. Sara Golemon veröffentlichte schon vor einigen Jahren ein Standardwerk über die Entwicklung von PHP-Erweiterungsmodulen und arbeitet mittlerweile an Facebooks eigener PHP-Version HHVM.

Das rund 200 Seiten starke Dokument orientiert sich an der PHP-Version 5.6 und enthält auch obskure Verhaltensweisen des PHP-Sprachkerns in seltenen Randfällen. Die Facebook-eigene PHP-Version HHVM soll sich möglichst eng an diese Vorgaben halten.

Die PHP-Community berät derzeit, wie sie die Fortschreibung der Spezifikation in den Entwicklungsprozess einbinden kann. Die Ankündigung wurde mit viel Begeisterung aufgenommen.

Software-Architekt Stas Malyshev:

Thank you Sara and Facebook team for doing something we’ve been talking
about for more than a decade and before that nobody actually attempting
to do. I think it is a great development and I hope to see the first
version soon.

http://dl.hhvm.com/resources/PHPSpec-SneakPeak.pdf

Kategorien
Tech

Perl: Semantic Version Sorting via callback puts betas before releases (empty string after text)

Semantic Versioning

Semantic program versions are a great help in administration life: When done right, they help you identify if only bugs have been resolved (2.11.z) or features added (2.y.0) or the program has undergone big changes with chances that an upgrade needs a lot of admin intervention (x.0.0). For developers and early testers, additional suffixes identify alpha (early testing), beta (testing) and Release Candidate (pre-release polishing) versions which are not intended for production use.

The Problem

Sorting program versions is not exactly trivial. You cannot sort them as strings, otherwise you would put 2.2.2 after 2.12.1. You cannot sort them as numbers either, because they contain multiple dots and possibly alpha characters.

Solutions:

a) Fixed-Length Score string

A traditional method expands the version string to a fixed-format score integer or string which can be safely compared and sorted by basic sorting algorithms. This is based on the assumption that there are not more than a fixed number of values per field, i.e. not more than 99 patch versions before the next minor, not more than 99 minor versions before the next major. This is safe for most mainstream projects but corner cases may exist. It also doesn’t play well with development releases.

This solution would first split the version string into its components, then merge them to a string and then run an alphabetic sort on it:

my @versions;
foreach my $version_string (@version_strings) {
  my ($major, $minor, $patch) = split /\./, $version_string;
  push(@versions, sprintf(%02d%02d%02d, $major, $minor, $patch));
}
my @sorted_versions = sort {$a cmp $b} @versions;

This is a simplified example. You need to get back to the original string format, either by a function for reverse conversion or by storing both together in an array of hashref. I also left out handling for alpha, beta, RC versions.

b) Using a sort callback

The sort() routine allows you to specify a callback which decides for any two values $a and $b if they are equal or which is greater. This works by any criteria you can imagine and is also usable for objects and hashes.

This is what we do: We split the version string into a hashref of its components (and a key for the original format, for convenience) and then we define a callback.

sub release_to_version_hash {
  my $release = shift;
  my ($package, $major, $minor, $patch, $dev) = $release =~ /\/(\w+)-(\d+)\.(\d+)\.(\d+)(\w*)/;
  return { 
    major => $major,
    minor => $minor,
    patch => $patch,
    dev => $dev,
    pkg => $package,
    url => $release,
    string => sprintf("%d.%d.%d%s", $major, $minor, $patch, $dev)
  };
}

We use a regular expression to retrieve the version fields.
Note: This code is taken from an open source project of mine.
The release strings have this format:
http://pear.horde.org/get/Horde_ActiveSync-2.16.11.tgz
http://pear.horde.org/get/Horde_ActiveSync-2.4.0RC2.tgz
http://pear.horde.org/get/Horde_ActiveSync-2.3.1.tgz
If your source string is just a version, your regular expression would look like this:

/(\d+)\.(\d+)\.(\d+)(\w*)/

Now let’s get down to business. The actual sorting routine is not very exciting. It gets an Array Reference of Hash References, the hashes being in the format produced above. It returns an array reference (note the [] brackets). The sort routine gets the list (ref) of releases, dereferenced to an array and invokes the compare_versions routine many times, comparing any two values $a and $b inside the releases list which is the „bigger“ one.

sub sort_releases {
  my $releases = shift;
  return [sort compare_versions @$releases];
}

Now let’s look at that callback.

## A compare function callback for version hashes, suitable for sort
## returns -1, 0 or 1
sub compare_versions {
  return
    $a->{major} <=> $b->{major} or
    $a->{minor} <=> $b->{minor} or
    $a->{patch} <=> $b->{patch} or
    ## handle development releases
    ( !$a->{dev} && $b->{dev} ? 1 : 0 ) or
    ( !$b->{dev} && $a->{dev} ? -1 : 0 ) or
    lc($a->{dev}) cmp lc($b->{dev})
}

Now what happens here? This routine returns -1, 0 or 1 depending on which versions is „bigger“. In practice, you should never get 0 because you should never have two identic version strings. After the major versions are compared as a number via the spaceship operator (<=>), perl evaluates the result.
If version $a (major) is smaller (-1) or bigger (1) than version $b (major), then this evaluates to a true (non-zero) value. This fulfills the „or“ condition, so perl immediately stops evaluating and returns the value. If the major versions are equal, the first expression evaluates to false (0) and the next part of the comparison is evaluated. This is sufficient for sorting major, minor, patch version in that order.

If we also want to handle development releases, we also need the last three lines.
The last line sorts development releases alphabetically, sorting all alphas of the same major.minor.patch before all betas. Normally, perl would sort all empty strings before all non-empty strings, which is bad. It would sort a production version 2.0.0 before the alpha releases.

To fix this, we use the upper two lines:
If a string is empty, it evaluates to false.
So if the first string is false (empty, production) and
the second string is true (any characters, development), the first version is the preferable version. In this case the expression evaluates to 1 and returns. Otherwise it evaluates to false (0) and the next or clause is evaluated. This one checks for the opposite case where version b is the better version and returns -1. If both versions contain a dev string, we skip to alphabetic comparison.

This results in a list where the best version is the last hash entry. Getting the best version is as easy as

$version = pop @versions;
## or
$version = $versions[-1];

Bonus: A versatile filter for all sorts of tasks

This filter is best applied before sorting but it also works afterwards. It can filter out all development releases or return only releases within a specific major version etc:

sub filter_releases {
  my $releases = shift;
  my $filter = shift || 
    { stable => 1, 
      rc => 0, 
      beta => 0, 
      alpha => 0, 
      major => 0, 
      minor => 0, 
      patch => 0, 
      pkg => '' };
  my @legit;
  foreach my $pkg (@$releases) {
    ## filters
    next if ($filter->{pkg} && $pkg->{pkg} ne $filter->{pkg});
    next if ($pkg->{dev} =~ /RC/ && $filter->{'rc'} == 0);
    next if ($pkg->{dev} =~ /alpha/ && $filter->{'rc'} == 0);
    next if ($pkg->{dev} =~ /beta/ && $filter->{'rc'} == 0);
    next if ($filter->{major} && $filter->{major} != $pkg->{major});
    next if ($filter->{minor} && $filter->{minor} != $pkg->{minor});
    next if ($filter->{patch} && $filter->{minor} != $pkg->{patch});
    push @legit, $pkg;
  }
  return \@legit;
}
Kategorien
horde

Horde Recipe: Storing the last login language

A simple Horde Hook to store the last chosen login value in a user preference.
You can use this for example to determine in which language automatic messages by cron job or daemon should be sent.

// // APPLICATION AUTHENTICATED HOOK: See above for format.
public function appauthenticated()
{
global $language;
global $prefs;
if ($language) {
$prefs->setValue('language', $language);

}

// // Code to run when an application is first authenticated
}

If you want, you can modify it so it won’t overrule manual settings in the prefs UI:


if ($language && empty($prefs->getValue('language')) {
$prefs->setValue('language', $language);

}