Theory & Decisions
Planning Form Design
Here are some questions you should consider to before you start the form design.
Static or Dynamic Form?
The terms static or dynamic are used to describe the handling of the Detail Area in a form design. In a Static form, the Detail Area is a fixed area on the page. In a Dynamic form, the size of the Detail Area will shrink and grow to accommodate different document headers and footers.
A Static form is the simplest design method. Use this approach for short documents that rarely go over one page. The static form "wastes" the space of the footer on all pages except the last but is by far the simplest to design.
A Dynamic form is more flexible but also more complex to design. You would use a Dynamic form to allow more space for details on long documents or when documents require "C/Fwd with subtotals" on intermediate pages. Dynamic forms are good with repaginated data or with Records Mode files.
For Static forms, without a repagination step, you must accommodate the number of detail lines that are printed on any one page. If all the detail lines do not fit into the detail area, FormTrap will produce an overflow page, with the same Base page information and the remaining detail lines. For Dynamic forms (including Records Mode), FormTrap calculates the "fit" and paginates when necessary.
Do I need a Detail Area?
It is not always necessary to have a Detail Area. Forms for a single transaction (like a car hire) or that are largely details about an individual (like a loan transaction) may not need a detail area.
Forms dealing with multiple products or multiple transactions require a detail area. A typical example is an invoice, where the detail area details multiple products.
In either mode, it is common to define only those lines that you require. FormTrap ignores undefined lines.
How do I identify Data Items?
While you can easily identify various items of information on an existing printed page, some fields may be uncommon and may only print when some special event occurs. Similarly, some fields may have special conditions that are not obvious.
Once you have identified all of the data fields, it is a good idea to list them and allocate a name to them. At this time you should also note the maximum number of characters in each field and any special characteristics.
Here is an example of some data fields we have extracted from an invoice and the field names we have assigned them:
| Data Field | Record Variable Name |
| invoice number | inv no |
| invoice date | inv date |
| customer name | cust name |
| customer number | cust no |
| customer address line 1 | cust add1 |
| customer address line 2 | cust add2 |
| item description | item desc |
| quantity ordered | qty ord |
| total amount | total amt |
More information on Defining Fields in Print Line Mode
More information on Defining Fields in Records Mode
How many different Detail Lines do I need?
This is again a decision you need to make to produce the clearest and most legible form possible. Good practice is to have a detail line on the form for each different type of detail line in the data. Note that a consistent block of data over more than one line should defined as a single "detail line". Highlight important information by using different font styles and sizes.
In Print Line mode, define only those detail lines that you require and remove irrelevant and unwanted lines with the Repaginator.
When do I use Headers and Footers?
Use these features when designing a Dynamic form. Headers and footers allow you to define a different amount of space at the top and bottom of given pages in a document, such as having a large space for the headers of the first page and a smaller space for the headers of the remaining pages. The same is true of footers, which allow you to define a larger space on the final page to cater for trailer details such as totals.
These options are useful when you don't need detailed information in the headers and footers on every page of a document, such as delivery address details, which would only be necessary on the opening page.
When do I use Group Headers?
Group headers appear in the Detail Area and can be considered as the table headers of a typical document. There are two types of group header, implicit, which is defined by the subsequent detail line, and explicit, which is defined by the input data.
When headers appear in the detail section of your input data, you should use an explicit header in your form design. This type of header works in the same way as a normal detail line (and repeats on subsequent pages if defined that way) and is generated when found in the input data.
When headers do not appear in the input data, you can use the successful creation of a detail line to imply the preceding header. In this case, when a certain type of detail line is created in the output, FormTrap will generate an implicit header object before printing that detail line. This is common with Repaginated data.