Code snippets for symfony 1.x


Refine Tags

Snippets tagged "degradation"

Degradable AJAX for form_remote_tag(), link_to_remote(), button_to_remote(),etc


My Snipeet works on the premise that in the JS helpers such as form_remote_tag, or link_to_remote(), the AJAX request action is called via an OnClick/onSubmit() when JS is enabled. For the sake of our argument, we will call the AJAX request action AMod/Aaction .When JS is not enabled, usually a secondary link given via either the 'href' or 'action' attribute is called. The default secondary link for these actions is '#'. Through my classes, when JS is not enabled, the secondary link brings you to myapp/yz_degradable_ajax_module/Process_nonajax_page action. All of the pertinant information is sent to that action via the GET method. The process_nonajax_page action will also be passed AMod/Aaction and the varables that the original JS helper was trying to pass to it. AMod/Aaction will be called via getPresentation and the values usually passed to it via POST or GET will be passed via $this->getRequest->getAttributes() because that is one of the only ways to pass values from one action to another. The HTML output from getPresentation will be put into a varable and redirects back to the original page. Once back on the original page, the create_div method intercepts that variable and outputs it to the user.

So to the lay user, when JS is not active, the page dynamically loading the new contents via ajax, reloads the whole page with the desired contents.

I created 2 files, 1 class and one module(with 1 action.class.php) that lets you to easily integrate degradable AJAX many of the Javascript remote functions

Place the yzDegradableAjax.class.php class in /app/lib/ . This file contains all of the functions and methods used.

Please let me know if this works for you or if my instructions are too confusing and I'll try to clarify. All criticisms are welcome.

Since the this Symfony Snippet section likes to go crazy whenever I paste in lots of code, you can view the code and course documentation at this form:
by Drew Lipsky on 2007-01-30, tagged ajax  buttontoremote  degradable  degradation  formremotetag  graceful  linktoremote 

AJAX Degredation Helper that creates
tags with fragments inside

This helper creates a div tag tag into which links can call other actions and dynamically display its output via AJAX. When JS is not enabled, the links reload the page with GET parameters and allow this helper to load the output.

What do you think of this code? First of all, has it already been done before? And do you think it will actually be useful? How well does it conform to the MVC structure?

Actual code:

 * This file includes functions that assist in making AJAX degradable
 * These small helper functions add in some of the basic features that allow for degradable
 * JS. The idea is to dynamically load contents when JS is available and let the page reload with
 * appropriate html when JS is not.
 * @author Yining Zhao
 * @package YZ_Helpers
 * @subpackage AJAX_Degredation
 * @since 1/16/2007
 * This class creates a pair of <div> tags in which AJAX functions can input dynamic HTML.
 * Usually what happends is that a link is pressed to activate the AJAX command via its onClick method.
 * The HREF attribute is suppressed by a 'return false;' at the end of the onClick method. However
 * when JS is not available, the onClick method is not activated and thus the HREF is called. The 
 * link in the HREF reloads the page and uses GET to pass along the variables to load the designated
 * fragment.
 * If the $trigger_var is 'login_box', here is what the following GET parameters will do:
 *      login_box_display will load the fragment if it is set to 'on', otherwise div style = visibility:none and nothing is loaded
 *          e.g. URL: //will load fragment
 *      login_box_make_persistant will let set login_box_display to 'on' in the user session, so as long as
 *          login_box_make_persistant is not set to 'no', the fragment will automatically be loaded on every page 
 *          load regardless of the GET statement
 *          e.g. URL: //will load fragment on every page load
 * Sample usage of function:
 *      //This function is being called from listSuccess.php template file in my Post module    
 *      div_fragment_creater('login_box','partial','loginPartial',array('referer'=>$referer),array('id'=>'login_div_id'))
 * The source: {@source} 
 * @param string $trigger_var The variable passed via GET that determines if the partial is loaded
 * @param string $fragment_type This tells the function if you are using a partial or a component
 * @param string $fragment_filename The name of the fragment to be called
 * @param array $fragment_values_ary This passes in the values for the fragment
 * @param array $div_attr_ary This contains all the html attributes for the <div> tag
 * @return void Since this function is designed to echo the necessary html, return is void
function div_fragment_creater($trigger_var,$fragment_type, 
    //If in the GET there is a make_persistant command for the given trigger variable, then the display command for the
    //tigger is set for sessions
    } else if($sf_params->get($trigger_var.'_make_persistant')=='off')
    //If the display is set for the trigger in either sf_params or sf_user, display the fragment.
    //Otherwise, don't display the fragment and make the div attribute style = display:none
    } else
        $div_attr_arry['style'] = 'display:none';
    $div_attr_keys = array_keys($div_attr_ary);
    $div_attr_ary_size = count($div_attr_keys);
    //Cteates the attributes for the <div>
        //This creates a string where the div attribute is set to its corresponding value; e.g. id=5
        $div_attr_name = $div_attr_keys[$i];
        $div_attr_collection.=$div_attr_name . ' = "' . $div_attr_ary[$div_attr_name] . '" ';
    echo '<div '.$div_attr_collection.' >';
            case 'partial':
                echo include_partial($fragment_filename, $fragment_values_ary);
            case 'component':
                use_component($fragment_filename, $fragment_values_ary);
    echo '</div>';

Usage Example: In myApp/myModule/list.php:

Anything is possible...
//Creates div with id = myDiv. Usually this div is invisible and empty. But when the get or session variable of triggerVar_display is set to 'on', this div becomes visible and displays the whatsPossiblePartial partial file.
//Provides link to load action into myDiv. If JS is not enabled, link will reload page with triggerVar_display set to 'on'
echo link_to_remote('Click To See Whats Possible', array(
            'update'=>array('success' => 'myDiv'),
            ),          array('href'=>'list?triggerVar_display=on'));

Inside the whatPossibleSuccess.php:

<html> ...
//This file is basically just a wrapper for the whatsPossiblePartial. the reason I have this wrapper is so that I can access it from via link_to_remote() on other pages.
echo include_partial(whatsPossiblePartial,array('id'=>$this->id));
by whoknows on 2007-01-18, tagged ajax  degradation  helper  javascript