Nested loops with HTML::Template 1

[Zhris]

Hi,

I am currently working on a project and I am trying to separate HTML code from Perl code completely, therefore HTML::Template is a suitable option.

However, I am having difficulties putting a <TMPL_LOOP> within another <TMPL_LOOP>. I tried numerous methods before returning to the documentation and realising that there was a small section devoted to nested loops. It provides an example for the perl side of things, however there is no example for the template side of things. I again tried numerous methods, with no luck, and I am still stumped.

Here is what I currently have:

push(@{$print{'Buttons'}{'Button1'}}, {
	'Action' => qq(Action), 
	'Name' => qq(ButtonName),
	'Value' => qq(ButtonValue), 
	'Other' => [
		{ 'testkey1' => 'testval1' },
		{ 'testkey2' => 'testval2' }
	]
});

$template->param ( BUTTON1 => \@{$print{'Buttons'}{'Button1'}} );

<TMPL_LOOP NAME=BUTTON1>
	<form method="post" action="<TMPL_VAR NAME=ACTION>">
	<input class="button" type="submit" name="<TMPL_VAR NAME=NAME>" value="<TMPL_VAR NAME=VALUE>" />
	<TMPL_LOOP NAME=OTHER>
		<p><TMPL_VAR NAME=TESTKEY1></p>
		<p><TMPL_VAR NAME=TESTKEY2></p>
	</TMPL_LOOP>
	</form>
</TMPL_LOOP>

I recieve the error " fatal error in loop output : HTML::Template : Attempt to set nonexistent parameter 'other'".

I am unsure how to nest loops and any example would be much appreciated.

Thank you,

Chris

 

[audiopro]

There is no template param for the 'OTHER' loop.

Keith

http://www.studiosoft.co.uk

 

[Zhris]

Hi Keith,

I'm not sure that I follow. Like the documentation shows, I have pushed all my data into an array @{$print{'Buttons'}{'Button1'}}, then passed it to a single param (so i'm assuming I can access both dimensions of the data from this single param). If I use 2 separate params (built from 2 separate data structures), the inner loop will go out of scope and I have the same issue. Would it be possible to provide me with an example?

Thanks alot,

Chris

 

[audiopro]

It was just an observation on my part that the inner loop param was not declared.
The error message you received would confirm that.
I have never had any success with nested loops and, as you have found, although the docs are written in English, they may as well be written in Medieval Greek.
I have managed to work around the need to use them so far but I can see a time when I will need to bite the bullet and work them out.
Sorry I can't be any further help but please post the solution here if you manage to sort it out.

Keith

http://www.studiosoft.co.uk

 

[Zhris]

I've managed to find a working example however I am unable to implement it with my situation. I hope you find this helpful:

my $dir_list = [
                { dir => 'foo', dir_row => [
                                            { file_row => [
                                                           { filename => 'foo0.pic' },
                                                           { filename => 'foo1.pic' },
                                                           { filename => 'foo2.pic' },
                                                           { filename => 'foo3.pic' },
                                                           { filename => 'foo4.pic' }
                                                           ] # for fil
                                            }
                                            ] # for dir_row
                                            },
                { dir => 'bar', dir_row => [
                                            { file_row => [
                                                           { filename => 'bar0.pic' },
                                                           { filename => 'bar1.pic' },
                                                           { filename => 'bar2.pic' },
                                                           { filename => 'bar3.pic' },
                                                           { filename => 'bar4.pic' }
                                                           ] # for fil
                                                           }
                                            ] # for dir_row
                }
                ];

my $tmpl = new HTML::Template(type => 'filehandle', source => *DATA);
$tmpl->param(dir_list => $dir_list);
print $tmpl->output();

__DATA__
<html>
<head>
    <title><TMPL_VAR NAME="title"></title>
</head>
<body>
    <center>
    <table>
    <TMPL_LOOP NAME="dir_list">
        <tr>
            <th colspan="5" bgcolor="#E0E0E0"><font size="+3">
        <TMPL_VAR NAME="dir"></font></th>
        </tr>
        <TMPL_LOOP NAME="dir_row">
        <tr>
            <TMPL_LOOP NAME="file_row">
            <td colspan="5"><TMPL_VAR NAME="filename"></td>
            </TMPL_LOOP>
        </tr>
        </TMPL_LOOP>
    </TMPL_LOOP>
    </table>
    </center>
</body>
</html>

Basically I am developing an eCommerce system and I am trying to build the Proceed to Checkout button with all of the field data that PayPal requires. I think I need to take a break from this and hopefully ill come back to it with a fresh head as I have wound myself up trying to construct the data into a single array/hash reference, and I can't see where I am doing it differently to the example above after I dump the hash with Data:umper.

Thanks for your input.

Chris

 

[audiopro]

Which part of the Paypal process are you creating the hash for and why do you need a nested loop?



Keith

http://www.studiosoft.co.uk

 

[Zhris]

I am trying to create the form which takes the user to the PayPal checkout page using the "upload" method. This means that I must read every product in the users shopping basket and append two hidden fields (e.g. <input type="hidden" name="item_name_1" value="Item Name 1"> AND <input type="hidden" name="amount_1" value="99.99">). Therefore as I don't want the perl script to contain any form of HTML I must build a hash containing the item name, amount and a loop count to identify each field name. There are also other fields surrounding this hence why I felt its practical to build a multidimensional hash and nest loops in the template. In the end, this is a fairly basic task, I just want my script to remain consistant and ensure all html is in the template.

As I loop through the basket, I build the pay pal fields:

push(@{$print{'Buttons'}{'PayPalFields'}}, {'Data' => [{'Product' => qq($product)}, {'TotalProduct' => qq($totalproduct)}, {'Count' => qq($count)}]});

I then attach this data to the entire form/button:

push(@{$print{'Buttons'}{'ProceedToCheckout'}}, {'Action' => qq([URL unfurl="true"]https://www.paypal.com/cgi-bin/webscr),[/URL] 'Name' => qq(ProceedToCheckout), 'Value' => qq(Proceed to Checkout...), 'PayPalFields' => \@{$print{'Buttons'}{'PayPalFields'}}});

Finally I attach to a template param:

$template->param ( PROCEEDTOCHECKOUT => \@{$print{'Buttons'}{'ProceedToCheckout'}} );

From writing this response I can see a couple of potential errors that don't coincide with the working example above, therefore I guess I will have another go at this tomorrow. I believe I haven't built the correct data structure. Maybe you know of a better way to do this?

Thanks alot,

Chris

 

[audiopro]

I am not sure if mine is a better method but I create a HTML document containing all the hidden fields and then onload.submit it to paypal.
There are 2 versions of the shopping basket (list of items) required, one for the visitor to view and one to go to Paypal. Instead of creating 2 versions, I create one version for both in a separate template and then display it on the visitor's browser as well as pass the whole template, as a var to the paypal template.
Hope that makes sense.




Keith

http://www.studiosoft.co.uk

 

[Zhris]

That made perfect sense. I've gone for your suggestion (with a couple of personal differences) and its working how I would like it to and its removed the neccessity of having to use nested loops. The only issue I have is that my target audience is retired ladies and i'm worried that they may be using old computers where the browsers javascript is disabled or the functions I use non-existant. However, i'm only a javascript rookie and I don't think this should be an issue.

Thank you very much for taking the time to give me ideas/suggestions. Got there in the end.

Chris

 

[audiopro]

Glad you got sorted.
Just put a note on that if the submit fails, Javascript needs to be turned on.



Keith

http://www.studiosoft.co.uk