phpFlickr Class 1.4.2
Written by Dan Coulter (dancoulter@users.sourceforge.net)
Project Homepage: http://www.phpflickr.com/
Sourceforge Project Page: http://www.sourceforge.net/projects/phpflickr/
Released under GNU General Public License (http://www.gnu.org/copyleft/gpl.html)
For more information about the class and upcoming tools and applications using it,
visit http://www.phpflickr.com/ or http://www.sourceforge.net/projects/phpflickr/

Installation instructions:
1.  You have to be sure that you have the php PEAR prereq packages installed. The 
    only one you absolutely need is HTTP_Response. If you want to do any caching, 
    you'll also need to install the DB package.

    NOTE: If you have installed version 1.3.1 of phpFlickr or later with the prereqs 
    included, you can skip this step.
    
    If you have PEAR installed on your *nix server, you can run "pear install [package]" 
    from the command line. You can find much more information and documentation at 
    http://pear.php.net/. You can get detailed installation instructions there.
    
2.  Copy xml.php and phpFlickr.php into the same folder on your server.  They need to
    be readible by your web server.  You can put them into an include folder defined
    in your php.ini file, if you like, though it's not required.  
    
3.  All you have to do now is include the file in your PHP scripts and create an     
    instance.  For example:
    $f = new phpFlickr();

    The constructor has three arguments:
    A.  $api_key - This is the API key given to you by flickr.com. This argument is
        required and you can get an API Key at:
        http://www.flickr.com/services/api/key.gne
        
    B.  $secret - The "secret" is optional because is not required to make 
        unauthenticated calls, but is absolutely required for the new authentication 
        API (see Authentication section below).  You will get one assigned alongside 
        your api key.
    
    C.  $die_on_error - This takes a boolean value and determines whether the class
        will die (aka cease operation) if the API returns an error statement.  It
        defaults to true.  If you set it to false, you can still see error messages
        with the getErrorCode() and getErrorMsg() functions.
        
4.  All of the API methods have been implemented in my class.  You can see a full list
    and documentation here: http://www.flickr.com/services/api/.  To call a method,
    remove the "flickr." part of the name and replace any periods with underscores.
    For example, instead of flickr.photos.search, you would call $f->photos_search()
    or instead of flickr.photos.licenses.getInfo, you would call
    $f->photos_licenses.getInfo() (yes, it is case sensitive).
    All functions have their arguments implemented in the list order on their
    documentation page (a link to which is included with each function in the clasS).
    The only exception to this is photos_search() which has so many optional arguments
    that it's easier for everyone around if you just have to pass an associative array
    of arguments.  See the comment in the photos_search() definition in phpFlickr.php 
    for more information.
    
Authentication:
    As of this release of the phpFlickr class there is only one authentication method
    available to the API.  This method is somewhat complex, but is far more secure and
    allows your users to feel a little safer authenticating to your application.  You'll
    no longer have to ask for their username and password.
    
    Authentication API - http://www.flickr.com/services/api/auth.spec.html
        
        I know how complicated this API looks at first glance, so I've tried to
        make this as transparent to the coding process.  I'll go through the steps
        you'll need to use this.  Both the auth.php and getToken.php file will
        need your API Key and Secret entered before you can use them.
        
        To have end users authenticate their accounts:
            First, setup a callback script.  I've included a callback script that 
            is pretty flexible.  You'll find it in the package entitled "auth.php".  
            You'll need to go to flickr and point your api key to this file as the 
            callback script.  Once you've done this, on any page that you want to 
            require the end user end user to authenticate their flickr account to 
            your app, just call the phpFlickr::auth() function with whatever 
            permission you need to use.
            For example:
                $f->auth("write");
            The three permissions are "read", "write" and "delete".  The function
            defaults to "read", if you leave it blank.  
            
            Calling this function will send the user's browser to Flickr's page to 
            authenticate to your app.  Once they have logged in, it will bounce
            them back to your callback script which will redirect back to the
            original page that you called the auth() function from after setting
            a session variable to save their authentication token.  If that session
            variable exists, calling the auth() function will return the permissions
            that the user granted your app on the Flickr page instead of redirecting
            to an external page.
        
        To authenticate the app to your account to show your private pictures (for example)
            This method will allow you to have the app authenticate to one specific
            account, no matter who views your website.  This is useful to display
            private photos or photosets (among other things).
            
            First, you'll have to setup a callback script with Flickr.  Once you've
            done that, edit line 12 of the included getToken.php file to reflect 
            which permissions you'll need for the app.  Then browse to the page.
            Once you've authorized the app with Flickr, it'll send you back to that
            page which will give you a token which will look something like this:
                1234-567890abcdef1234
            Go to the file where you are creating an instance of phpFlickr (I suggest
            an include file) and after you've created it set the token to use:
                $f->setToken("<token string>");
            This token never expires, so you don't have to worry about having to
            login periodically.
            

Using Caching:
    Caching can be very important to a project.  Just a few calls to the Flickr API
    can take long enough to bore your average web user (depending on the calls you
    are making).  I've built in caching that will access either a database or files
    in your filesystem.  To enable caching, use the phpFlickr::enableCache() function.
    This function requires at least two arguments. The first will be the type of
    cache you're using (either "db" or "fs")
    
    1.  If you're using database caching, you'll need to supply a PEAR::DB connection
        string. For example: 
        $flickr->enableCache("db", "mysql://user:password@server/database");
        The third (optional) argument is expiration of the cache in seconds (defaults 
        to 600).  The fourth (optional) argument is the table where you want to store
        the cache.  This defaults to flickr_cache and will attempt to create the table
        if it does not already exist.
    
    2.  If you're using filesystem caching, you'll need to supply a folder where the
        web server has write access. For example: 
        $flickr->enableCache("fs", "/var/www/phpFlickrCache");
        The third (optional) argument is, the same as in the Database caching, an
        expiration in seconds for the cache.
        Note: filesystem caching will probably be slower than database caching. I
        haven't done any tests of this, but if you get large amounts of calls, the
        process of cleaning out old calls may get hard on your server.
        
        You may not want to allow the world to view the files that are created during
        caching.  If you want to hide this information, either make sure that your
        permissions are set correctly, or disable the webserver from displaying 
        *.cache files.  In Apache, you can specify this in the configuration files
        or in a .htaccess file with the following directives:
        
        <FilesMatch "\.cache$">
            Deny from all
        </FilesMatch>
        
        Alternatively, you can specify a directory that is outside of the web server's
        document root.
        
Uploading
    Uploading is pretty simple. Aside from being authenticated (see Authentication 
    section) the very minimum that you'll have to pass is a path to an image file on 
    your php server. You can do either synchronous or asynchronous uploading as follows:
        synchronous:    sync_upload("photo.jpg");
        asynchronous:   async_upload("photo.jpg");
    
    The basic difference is that synchronous uploading waits around until Flickr
    processes the photo and returns a PhotoID.  Asynchronous just uploads the
    picture and gets a "ticketid" that you can use to check on the status of your 
    upload. Asynchronous is much faster, though the photoid won't be instantly
    available for you. You can read more about asynchronous uploading here:
        http://www.flickr.com/services/api/upload.async.html
        
    Both of the functions take the same arguments which are:
        Photo: The path of the file to upload.
        Title: The title of the photo.
        Description: A description of the photo. May contain some limited HTML.
        Tags: A space-separated list of tags to apply to the photo.
        is_public: Set to 0 for no, 1 for yes.
        is_friend: Set to 0 for no, 1 for yes.
        is_family: Set to 0 for no, 1 for yes.

Other Notes:
    1.  Many of the methods have optional arguments.  For these, I have implemented 
        them in the same order that the Flickr API documentation lists them. PHP
        allows for optional arguments in function calls, but if you want to use the
        third optional argument, you have to fill in the others to the left first.
        You can use the "NULL" value (without quotes) in the place of an actual
        argument.  For example:
        $f->groups_pools_getPhotos($group_id, NULL, NULL, 10);
        This will get the first ten photos from a specific group's pool.  If you look
        at the documentation, you will see that there is another argument, "page". I've
        left it off because it appears after "per_page".

That's it! Enjoy the class.  Check out the project page (listed above) for updates
and news.  I plan to implement file uploads and functions to aggregate data from
several different methods for easier use in a web application.  Thanks for your
interest in this project!

    Please email me or submit all problems or questions to the Help topic on
    the phpFlickr forums:
        http://www.phpflickr.com/forums/

 
