Portal has a variety of template variable arrays that contain the data used by the HTML template pages for display. When making custom Portal sites it becomes a common need to investigate the data found in these arrays via a PHP print_r statement like the following.
<?php
print "<pre>";
#print_r($_SERVER);
#print_r($_SESSION);
#print_r($volume_info);
#print_r($dir_info);
#print_r($file_info);
#print_r($files_info);
#print_r($keywords_info);
#print_r($tmpl->variables['PORTALPAGE']);
#print_r($links_info);
#print_r($spreads_info);
print "</pre>";
?>
Through using this approach it becomes possible to display Portal’s template variables arrays directly in a web browser, which can be convenient for inspection and debugging. This article expands on alternatives and twists to this standard approach.
Alternative variable display functions
When exploring a variable's contents in PHP var_dump() and var_export() are common alternatives to the print_r() function. Each performs a similar task with a slightly different behavior. var_dump() prints slightly more informative (but less readable) information about the given variable’s data, while var_export() prints interpretable PHP code. The following table illustrates the output differences for these functions.
|
print_r()
|
var_dump()
|
var_export()
|
Array
(
[0] => Apples
[1] => Oranges
[2] => Pears
)
|
array(3) {
[0]=>
string(6) "Apples"
[1]=>
string(7) "Oranges"
[2]=>
string(5) "Pears"
}
|
array (
0 => 'Apples',
1 => 'Oranges',
2 => 'Pears',
)
|
Depending on your needs, these standard functions give a good set of options for displaying Portal template variable data for inspection and debugging.
Storing Portal variable information in a variable and/or file
Sometimes it is not always ideal to send Portal’s template variable data to the web browser for inspection and debugging. To help alleviate this issue the print_r() and var_export() functions both accept a second Boolean parameter that, when set as true, causes both of these functions to return a variable’s data from the function call instead of printing it. This allows for capturing a variable’s data in another variable and/or file for later inspection and debugging. The following snippet is an example of such an approach.
<?php
$portal_page = print_r($tmpl->variables['PORTALPAGE'], true);
file_put_contents('/some/directory/var_data.log', $portal_page);
?>
The print_r() function is called with a second parameter set to true. This cause the print_r() function to return the $tmpl->variables['PORTALPAGE’] variable information to the $portal_page variable instead of printing it. The contents of the $portal_page variable are then written to an external log file. This data could then be viewed, searched, and stored at another point in time.
Storing variable information as XML
Using PHP it is also possible to store the portal variable information in your own XML format. This XML data could then be transmitted and interpreted by any type of program geared to help inspection and debugging of Portal’s template variable arrays. The following code example could be placed inside of any one of your site’s local.inc.php files. This code snippet checks known Portal template variables arrays, and inserts their data into a hierarchical XML data structure. This file is then saved as XML on the server in the same directory as the file being executed.
<?php
$var_trees = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";
//start the xml var trees hierarchical data structure
$var_trees .= "<var_trees>";
//check the known portal variables. If they exist generate an xml tree of the data
if ($volume_info != NULL) $var_trees .= var_tree('$volume_info', $volume_info);
if ($file_info != NULL) $var_trees .= var_tree('$file_info', $file_info);
if ($files_info != NULL) $var_trees .= var_tree('$files_info', $files_info);
if ($keywords_info != NULL) $var_trees .= var_tree('$keywords_info', $keywords_info);
if ($tmpl->variables['PORTALPAGE'] != NULL) $var_trees .=
var_tree('$tmpl->variables[\'PORTALPAGE\']', $tmpl->variables['PORTALPAGE']);
if ($links_info != NULL) $var_trees .= var_tree('$links_info', $links_info);
if ($spreads_info != NULL) $var_trees .= var_tree('$spreads_info', $spreads_info);
if ($_SERVER != NULL) $var_trees .= var_tree('$_SERVER', $_SERVER);
if ($_SESSION != NULL) $var_trees .= var_tree('$_SESSION', $_SESSION);
//close the xml var_tree hierarchical data structure
$var_trees .= "</var_trees>";
//store the xml data in an external xml file
file_put_contents(dirname(__FILE__).'/var_trees.xml', $var_trees);
//recursive function to generate nested xml data structure for a given variables data
function var_tree($key, $value){
$var_tree = "";
if(is_array($value)){
$var_tree .= "<var_tree label=\"".htmlentities($key)."\" >";
foreach($value as $key => $val){
$var_tree .= var_tree($key, $val);
}
$var_tree .= "</var_tree>";
}else{
$var_tree .= "<var_node label=\"".htmlentities($key)."\" value=\"".htmlentities($value)."\" />";
}
return $var_tree;
}
Creating a variable inspection and debugging tool using XML data
Taking this one step further, you can then utilize this developed XML format to create more advanced debugging tools. One quick example for this is a small Flex application that I quickly developed to interpret the previous example’s generated XML data. This debugger interface is automatically opened in a separate window when any portal template page embeds the {varviewer} template tag, which can be generated in your site’s local.inc.php file using a code snippet similar to the following.
$tmpl->variables['PORTALPAGE']['varviewer'] =
"<SCRIPT TYPE='text/javascript'>winRef ="+
"window.open( '/VarViewer/templates/varviewer/PortalVariableViewer.html', 'varviewer',"+
"'height=450, width=750'); </SCRIPT>";
View the demo of this application HERE (user: blogdemo/pass: blogdemo). This XML variable debugger application has also been packaged as a House portal site named VarViewer that you can use and experiment with on your own portal server. You can download it HERE. This is a simple example, but illustrates the possibility of developing a more advanced and searchable Portal template variable arrays debugger.
Conclusion
There are a variety of ways to inspect and debug the Portal template variables. Using PHP’s built in variable display functions, and even custom data XML formats allows for a greater degree of flexibility when working with them. In the end these variables are an important to understand when trying to modify and extend Portal’s appearance and functionality, and using these techniques may help you during this learning process.