Struggling With Parameter Handling Of Controllers And Views (Newbie)

[boris.halter]

Hello together,

maybe I don't see the forest for the trees, but I'm struggling with parameter handling of controllers and views...

To start with Yii, MVC and RBAC I tried do build a simple page (something like http://mysite.domain.com/authitem) that draws the parent->childhood relations of my AuthItems using the prebuild Yii demo app.

I manualy installed the PEAR extension "Image_Graphviz" (pear install ...) to draw the graphs. I created the model with Giix and edited the AuthItemController.php manualy (I copied the stuff from other controllers

Accessing the tables, building the graph and "draw" it in the browser went fine with only one bad thing: I did it all in the controller (just to be sure Graphviz works). And it does, it works great!

After that I tried to do it the MVC style and modified .../views/authItem/index.php. Instead of doing it directly with $graph->image(), I switched to $this->render() in AuthItemController::actionIndex() (please have a look on the code snippets below). But this led me into a XML error message shown in the browser:

------------------------XML Error------------------------
XML-Verarbeitungsfehler: XML- oder Text-Deklaration nicht am Beginn der Entität
Adresse: http://localhost/stable/authItem
Zeile Nr. 49, Spalte 1:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
^
------------------------XML Error------------------------

This means translated something like: XML or text declaration not at start of entitiy (row 49, col 1)


What did I wrong?

Does the view not have access to the $graph instance forwarded from the controller? I thought this will be done with $this->render('index', array( 'graph' => $graph));?

Regards,
Boris


My code:

------------------------[controllers/AuthItemController.php]------------------------
<?php
require_once 'Image/GraphViz.php';

class AuthItemController extends GxController {

    public function filters() {
        //Nothing special
    }

    public function accessRules() {
        //Nothing special
    }

    // Here it goes...
    public function actionIndex() {

        $graph = new Image_GraphViz();

        // Get the data from table AuthItem
        $cmd = Yii::app()->db->createCommand();
        $cmd->select = 'name, type, bizrule';
        $cmd->from = 'AuthItem';
        $result = $cmd->query();

        // Build the graph nodes
        foreach ($result as $row) {
            switch ($row['type']) {
                case 0:  $shape = 'box';   break;
                case 1:  $shape = 'box';   break;
                case 2:  $shape = 'house'; break;
                default: $shape = 'box';
            }

            $graph->addNode(
                $row['name'],
                array(
                    'label' => $row['name'],
                    'shape' => $shape,
                )
            );
        }

        // Get the data from table AuthItemChild
        $cmd = Yii::app()->db->createCommand();
        $cmd->select = 'parent, child';
        $cmd->from = 'AuthItemChild';
        $result = $cmd->query();

        // Build the graph egdes
        foreach ($result as $row) {
            $graph->addEdge(
                array(
                    $row['parent'] => $row['child']
                )
            );
        }

    // "Drawing" the graph in the browser without MVC. Works fine.
        // $graph->image();

    $this->render('index', array( 'graph' => $graph));
    }
}
?>
------------------------[controllers/AuthItemController.php]------------------------



------------------------[views/authItem/index.php]------------------------
<?php
/* @var $graph GrahpViz Instance */

[...]

?>

<h1><?php echo GxHtml::encode(AuthItem::label(2)); ?></h1>

<?php $graph->image(); ?>
[...]
------------------------[views/authItem/index.php]------------------------
 

[Edward]

$this->render('index', array( 'graph' => $graph));

This statement is correct for passing standard, variables and objects.

 

Just one thing i want to say though is all that database access code in the controller is a no no anyway you need to be pushing this into some kind of model or a separate file. It looks like some kind of connection was lost with the variable when you pasted it to the views file. I think what you need to do is create a model function and then access this directly from the views file, rather than passing the $graph object from the controller to the views file.

 

Any way this was just a suggestion i haven't used those extensions you are using there so i can't give you the correct answer but something to try, hope it will help in reaching your solution.

[boris.halter]

Thank you for your reply. I will try your suggestions.

 

And I have to be more MVC...

 

Regards,

Boris

[boris.halter]

SOLVED.

 

It was more a layer 8 error, than a technical one...

 

I just called the wrong function of Graphviz to generate a graph. The function graphviz->image() generates its own html5 code with an inline  svg-"picture" between the full set of html headers (doctype, html, body, etc.). To use that as $content in a view file was a very bad idea.

 

I used graphviz->fetch() instead, that just returns the rendered "graphic data" (<svg ... </svg>).

 

This is an example of what will be rendered by grpahviz->fetch():

<svg xmlns="http://www.w3.org/2000/svg" version="1.1" height="190">
   <polygon points="100,10 40,180 190,60 10,60 160,180"
   style="fill:lime;stroke:purple;stroke-width:5;fill-rule:evenodd;">
</svg>

 

 

Btw.: is this a more "MVC style" code? Did I get it?

Is there a more secure/sophistic way than just to echo the data?

 

 

Controller:

------------------------[controllers/AuthItemController.php]------------------------

[...]
    public function actionIndex() {
        $model = new AuthItem;
        $this->render('index', array(
            'model' => $model));
    }

[...]

------------------------[controllers/AuthItemController.php]------------------------

 

 

 

View:

------------------------[views/authItem/index.php]------------------------

[...]

<h1><?php echo GxHtml::encode(AuthItem::label(2)); ?></h1>

<?php echo $model->showGraph(); ?>

[...]

------------------------[views/authItem/index.php]------------------------

 

 

 

Model:

------------------------[models/authItem.php]------------------------

<?php

require_once 'Image/GraphViz.php';

Yii::import('application.models._base.BaseAuthItem');

class AuthItem extends BaseAuthItem
{
    public static function model($className=__CLASS__) {
        return parent::model($className);
    }

    public function showGraph() {

        $graph = new Image_GraphViz();

        $cmd = Yii::app()->db->createCommand();
        $cmd->select = 'name, type, bizrule';
        $cmd->from = 'AuthItem';
        $result = $cmd->query();

        foreach ($result as $row) {
            switch ($row['type']) {
                case 0:  $shape = 'box';   break;
                case 1:  $shape = 'box';   break;
                case 2:  $shape = 'house'; break;
                default: $shape = 'box';
            }

            $graph->addNode(
                $row['name'],
                array(
                    'label' => $row['name'],
                    'shape' => $shape,
                )
            );
        }

        $cmd = Yii::app()->db->createCommand();
        $cmd->select = 'parent, child';
        $cmd->from = 'AuthItemChild';
        $result = $cmd->query();

        foreach ($result as $row) {
            $graph->addEdge(
                array(
                    $row['parent'] => $row['child']
                )
            );
        }
        return $graph->fetch();
    }

}

------------------------[models/authItem.php]------------------------