dynamically adding forms

MCS has asked for the wisdom of the Perl Monks concerning the following question:

I'm creating a little web based recipe database program and I have the majority of it done and working. I initially created a script to parse existing txt files (and thanks to antiword, word files) and insert them into the database. I then added a editform.pl cgi script to edit the values in case something went wrong. Now I want to add the ability to enter in a new recipe via a web form. Now I could have two text boxes and then parse the ingredients but that can be prone to errors when things don't follow the standard qty, amt, description (like 1 cup sugar). Therefore I want to do fields for the qty (1) amt (cup) and description (sugar). However there is no telling how many ingredients there are.

I thought the best way to handle this would be to have a few fields up and if they are blank, just not use them. However, if the user has a long list of ingredients, I would like the ability to add a set of three text fields. What would be the best way to go about this?

My edit recipe forms look like this:

print "Qty:", $query->textfield(-name=>"qty$ingredientAoH[$i]{ingID}",
                                        -default=>"$ingredientAoH[$i]{
+qty}", -size=>'10',
                                        -maxlength=>'20', "\n");
        print "Amt:", $query->textfield(-name=> "ammount$ingredientAoH
+[$i]{ingID}",
                                        -default=> "$ingredientAoH[$i]
+{amt}", -size=>10, -maxlength=>100, "\n");
        print "Des:", $query->textfield(-name=> "description$ingredien
+tAoH[$i]{ingID}",
                                        -default=> "$ingredientAoH[$i]
+{des}", -size=>50, -maxlength=>100), "\n";
        print $query->hidden(-name=>"ingID$ingredientAoH[$i]{ingID}", 
+-default=>"$ingredientAoH[$i]{ingID}"), "<br>\n";
[download]

Just some references: the $ingredientAoH is an array of hashes where qty, amt and des are the three keys and each element of the array indicates a seperate ingredient. Then there is also the ingID key which is a unique ingredient key from the database... it is naturally hidden from the user and is just used for updating the database.
I call each field qtyn, ammountn, descriptionn where n is the ingID. (Used to tell which one's which)

Should I just have a parameter indicating the number of fields and then just increment that on a add ingredient button and reload the form? If so how do I keep already existing values from disapearing? Should I pass my ingredientsAoH as a parameter?

Comment on dynamically adding forms Download Code

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Re: dynamically adding forms by BUU (Prior) on Mar 02, 2004 at 21:13 UTC
The simplest/easiest would be to just offer a text field called "number of items" that submits to the next page which has the actual recipe submission, preferably via get. After that you can just have a button at the bottom that looks like `<input type='submit' name='add_item' value='Add Ingredient'>` and when the form is submitted check for param('add_item'), and if it's found simply redisplay the form with the elements already submitted redisplayed. (Btw, I suggest giving all the ingredients the same "form name", that way the various cgi-processing modules will give you all of the ingredients as a list. Although I'm not sure what order the list is in.)	[reply] [d/l]

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Re: dynamically adding forms
by BUU (Prior) on Mar 02, 2004 at 21:13 UTC

<input type='submit' name='add_item' value='Add Ingredient'>

[reply]
[d/l]