Fonctionnalité Galeries d'images

Les galeries d'images sont des collections d'images. Si la fonctionnalité de Galerie d'images est activée dans votre installation Tiki, vous pouvez créer des galeries publiques ou privées d'images et y mettre des images qui pourront provenir de vos disques locaux ou bien encore d'URL. Tiki crée automatiquement des vignettes (comparable à  une plache contact quand vous faites développer des photos) des images que vous transférez dans vos galleries; vous n'avez pas besoin de le faire vous-meme. Les Galleries peuvent être utilisées comme album photos bien sur, mais aussi for other applications such as product "showrooms".

Vue d'ensemble de la fonctionnalité Galerie d'images

Ce qui suit est une liste non exhaustive des fonctionnalités de la Galerie d'Image:

• Activation ou désactivation de la fonctionnalité Galerie d'Images.
• Set display of listing fields, such as description or created date.
• Création des galeries publiques ou privées et définition des permissions pour en controler l'accès.
• Création, modification ou suppression de galleries.
• Réglage de la fonction de création automatique de vignettes.
• Réglage du nombre de lignes et de colonnes pour afficher les vignettes.
• Categorize your galleries.
• Transfert d'images depuis des disques ou bien d'URL
• "court-circuitage" de la création automatique de vignettes par transfert des votres.
• Spécifiez un nom pour votre image ou bien laissez la Galerie d'Image prendre le nom du fichier.
• Mettez des coordonnées sur les images et affichez les en utilisant la fonctionnalité maps

Comment UTILISER les galeries d'images

Le Menu
Quand les Galeries d'Images sont activées et que les permissions d'accès sont définies, les visiteurs du site Tiki peuvent voir un menu Galerie d'Images qui peut âtre ouvert. Depuis ce menu, vous serez en mesure de créer des galeries d'Images et d'y transférer des images.

Collapsed and Expanded Menu:

Habituellement, il y a 3 options dans le menu — Galeries, Rankinks et Télécharger des images-- et les otions peuvent changer en fonction des permissions. Dans notre exemple, vous pouvez voir une autre option "Galerie Systeme". Voyons chaque option en détail.

Avant la création de galleries
Tout d'abord, avant que les galeries soient créées et les images téléchargées dedans, le panneau principal des Galeries apparait comme dans cette illustration. Notez le lien "Créer une nouvelle galerie".

Création d'une Gallerie d'Images
Cliquer sur le lien "créer une nouvelle galerie" affiche un formulaire pour créer une nouvelle galerie, avec des champs à  remplir, comme vous pouvez le voir ici;

Les champs sont explicités dans la table suivante:

Create a gallery for testing by filling in the form, and clicking Save at the bottom of the form. Once Tiki creates the gallery, it will be listed like so:

If you want to browse the gallery, click its name. On each line in the listing, depending on your permissions set you can see the "Actions" you can take on each gallery:

If you hover your mouse above each of the Actions icons, you can infer that they link to a set of tools including:

• Edit: edit the gallery information using the same form you used to create the gallery. Here, you can change gallery information, your categories or the size of existing thumbnail images.
• Delete: remove the entire gallery and its images. Use this with care, as it is a permanent operation.
• Upload: upload images to the gallery.
• List: browse the gallery's images as a list.
• Perms: configure permissions for the gallery (if you are an admin).
• Make Map: Generate a layer to be used with the maps feature (only availabl e for geographic galleries).

Let's examine some of these items in more detail:

Upload Image
The Upload Action allows you to upload images to the listed gallery, and displays a form as follows:

After selecting a gallery you create, or a public gallery created by another user, you can either enter the URL of your image or select it from your local hard disk. Use only one method for each image, as results can be unpredictable if you upload the same image using both methods.

Tiki auto-generates thumbnails for uploaded images, but if you don't like the way they look, or if you do not want a simple thumbnail of the entire image, you can also upload your own thumbnails along with the image.

If the image is successfully uploaded, you will see its and its thumbnail displayed, as in this graphic:

Success! The image was uploaded and stored into the Tiki database or into a folder on your server. Note the image, the thumbnail, and information about how to browse the image or include it in an HTML page or a Wiki page. Keep these links in mind for use in your Wiki pages or Blog posts.

Note: If Tiki's thumbnail is the same size as the image, there are several possible explanations:

• The image is a GIF. Tiki cannot resize GIFs do to copyright limitations regarding their format.
• Your web server's PHP installation does not have the GD or ImageMagick graphics manipulation packages installed.
• Your web server's PHP installation's GD or ImageMagick packages are too old.

Browse or List Galleries
Clicking on the gallery name link allows you to browse a listing of thumbnails for the images in the gallery. Clicking on the "List" action displays a non-graphical, quick-loading list representation of the gallery with one image per line. The list looks like this:

In List View, click "Browse Gallery" to toggle back to its Thumbnail View. In the following graphic, you will notice a horizontal menu with links to Edit the gallery, rebuild thumbnails, upload images, or toggle back to List View. Above the image list or thumbnails, there are links to sort by name, date, hits, user or size. For example, clicking Name sorts in alphabetical order, from A to Z, and clicking Name again sorts in reverse alphabetical order, from Z to A. Try sorting for all the options, once you have several images uploaded.

For each image, a thumbnail is displayed showing the image title, its size and the number of hits (a hit is computed each time the image is browsed). Under each thumbnail, you will find icons for Delete, Edit and Popup which act on that image.

Click the thumbnail to browse the image actual-size. Here, you will find image information, an option to move the image to another gallery (if you have permission), and link information to allow you to display the image in an HTML page or a Wiki page, an article or a Blog. You will also see links to the Next and Previous images in the gallery to browse all the gallery images if you like.

Individual permissions for image galleries
From the gallery listing screen, if you have the right permissions you can use the "Perms" action to set up individual permissions for an image gallery:

When you assign a individual permission for a gallery, you can override Tiki's global permissions system, so that only the users that have the permissions you have set for the gallery can view, edit or upload. This feature can be used to configure, for example, private galleries, paid galleries or galleries where only a special group of users can upload images.

The System Gallery
If enabled from the admin screen, Tiki can capture images referenced from other sites or URLs, storing them in its database, or in a folder on your webserver. Tiki displays those images in a special gallery called the "System Gallery". If you are an admin, you can browse the System Gallery, and remove images from it.

Tips & Tricks
Utility Gallery: One idea for a creative use of a Tiki Image Gallery is to upload buttons or icons that you might use in the pages on your site.

Known bugs and problems
GIF Patent Issue: Thumbnail generation does not work for GIF format, resulting in a thumbnail which is the same size as the original image. This is due to patent issues, and cannot be resolved unless the patent for GIF format expires.

• To enable Image Galleries for your site, see General Admin.
• To specify permissions for Image Gallery users, see Permissions for the general procedure.
• To administer Image Galleries, see Image Gallery Config.
• For technical details, see Image Gallery Details.

• Unisys' GIF Patent
  http://www.unisys.com/aboutunisys/lzw
• Why No GNU GIFs?
  http://www.gnu.org/philosophy/gif.html

Comment AFFICHER une image

Une fois que votre image est dans la gallerie, vous avez trois options d'affichage.

• Soit que vous créez un hyperlien
• soit que vous affichiez l'image directement sur votre page
• Soit que vous affichiez une vignette qui s'agrandit lorsqu'on clique sur celle-ci

Exemple

http://tiki.org/display331

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Comment ADMINISTRER les Galeries d'images

Note: Les fonctionnalités les plus intuitives ne sont pas listées.

Accès administration
Pour accéder à  l'administration, allez sur la Home Page et, sur le Menu, cliquez sur "Admin (click!)".

Section: Panneau d'Administration Tiki
Vous accéderez aux Sections Panneau d'Administration tiki, comme montré dans cete capture:

Galerie d'Images

Image Galleries

Depuis le Panneau d'Administration Tiki, cliquez sur l'icone
From the Tiki Admin Panel, click the Image Galleries icon to display its settings panel, the top half of which appears like so:

Here you can:

• Choose a home gallery.
• Enable and disable rankings and comments.
• Set the image storage location.
• Choose the graphics library.
• Set regular expressions ("regex") to control uploaded file names.

Home Gallery (main gallery)
In the above graphic, the home gallery is set to "Rick's Pix". The home gallery is the default gallery displayed when visitors simply click the menu "Image Galleries" without expanding the menu, or when as the "top page" in your Tiki site if you set the Tiki system home page to be an Image Gallery.

• Push the button when you have finished to configure this feature.

Galleries features

Use database to store images
Use directory to store images
Choose Storage Location: You can decide for images to be stored either in the database, or in a folder on your webserver. Storing images in your database is OK for small images, but a folder is recommended for a high volume site or when your images are relatively large. Note the trailing forward slash in the path entered in the above graphic, but also here in red. Be warned, if you want to restrict access to the images, you have to choose a folder that is not browsable (not inside the document root of your webserver).

Path characteristic checklist:

• Has a trailing slash.
• Is specified from the root.
• Is in a separate folder from Tiki, for better security.
• Has its permissions set (e.g. via the chmod command) to allow uploads by the webserver user.
• Has enough space to allow storage of your expected image volume.

If you take a look at your folder after uploading some images, you can see that Tiki randomizes the filenames, as shown in this graphic:

Troubleshooting Tip: If you are having trouble with image uploads, you can edit settings in your php.ini, or, place an .htaccess file in the root of your tiki installation.

# Partial .htaccess file sample. 
#
# Override PHP.ini variables, which can be viewed using phpinfo:

<IfModule mod_php4.c>
# If you are using Apache 2, you have to use <IfModule sapi_apache2.c>
# instead of <IfModule mod_php4.c>.

php_value max_execution_time	300
php_value upload_max_filesize	"10M"
php_value memory_limit 		"32M" 
php_value session.cache_expire    20000
php_value session.gc_maxlifetime  20000
php_value session.cookie_lifetime 20000   
</IfModule>

# Zero means unlimted request body size:
LimitRequestBody 0

Troubleshooting Tip: If you encounter random errors and webserver crashes, you may have updated your apache, but forgot to update/recompile your graphics library. The apache error log will give you some hints..

Library to use for processing images

Choose Graphics Library: You can choose which software library to use for manipulating images. Currently, your choice is:

• GD
• Image Magick

See below links to the GD and Image Magick sites.

Uploaded images names must match regex

Uploaded images names cannot match regex

• Push the button when you have finished to configure these features.

Now, take a look at the bottom half of the Image Galleries admin panel, as shown in this graphic:

Remove images in the system gallery...
This is a link for removing images in the system gallery, which are "orphaned" and not used in Wiki pages, blogs or articles. A useful function for space-saving in the database.

• Click on the link to remove images

Gallery listing configuration
Here you can control the display of fields in the Gallery Listings.

• Push the button when you have finished to configure these features.

Image galleries comments settings
Here you can make settings regarding to comments.

• Push the button when you have finished to configure these features.

• To enable Image Galleries for your site, see General Admin.
• To specify permissions for Image Gallery users, see Permissions for the general procedure.

• imagick php module
  http://pecl.php.net/package-info.php?package=imagick
• Image Magick Image Software Library:
  http://www.imagemagick.org
• GD Image Software Library:
  http://www.boutell.com/gd/
• Apache WWW Server htaccess tutorial:
  http://httpd.apache.org/docs/howto/htaccess.html
• PHP htaccess information:
  http://jp2.php.net/configuration.changes
• Absolute Path Glossary Entry
  http://linux.about.com/cs/linux101/g/absolute_path.htm

• Pour activer les Galleries d'Images pour votre site Tiki, voir General Admin
• Pour en apprendre plus sur l'administration des Galleries d'Images, voir Image Gallery Config.