A parent / child solution is when you have a one-to-many relationship. Say you want to have an event management solution that includes registrations for those events. Each event could have many registrations. Or maybe clients and invoices – each client could have many invoices.

The answer in Xmod is to have one form for events and one form for registrations and then relate the two. The example on the right shows the detail view of an electrical component in a online maintenance management system. It first shows the details of the electrical item. Below that are three Xmod modules inside a Tabs module. Each showing a different child form (IR Scans, Work History, and PM History) filtered to show only the records that relate to that electrical item.

This tutorial will explain, in a step by step process how to build a relational events management solution in Xmod.

Hint

We custom build our own record ID instead of using Xmod’s built in record ID because it is easier to filter on a form field. Plus it gives us extra flexibility should we need it down the road. ID fields need to have values that are unique so no two records are the same. You can get Xmod to automatically add a unique value in your EventID field by combining the {XMOD_UserId} constant with the {XMOD_Now:format} constant with no formatters in the XMOD:Now constant. This will produce one long number that will be unique. If you want to hide this field from your users do NOT use an Xmod hidden field. Just add a style of display;none to a regular Xmod input field. In your form it would look like this:

<input ref=”EventID” width=”100” maxlength=”25” style=”display:none;”>
<default>{XMOD_UserId}{XMOD_Now:MMDDyyyyhhmmss}</default> </input>

Hint #1

You can do all of this on a single page by adding the Detail View module right below your parent grid/list view module and configuring your target URL for the View Details link to be the same page that the grid/list view is on.

Hint#2

Adding child records. If a end user adds a child record and fails to input the eventid then the child record will be orphaned. To keep this from happening we usually include an Add New Record (Registration) button to our detail view page that automatically inserts the eventid of the shown parent (event) record into the Event ID field of the child (registration). Xmod 5.5 now has the ability to pass parameters via the Add button or edit button. You can read about this in the help file.

Once you have the eventid parameter being passed via the add button you will need to add the <parameter> tag to your child form to grab the parameter we are passing to it. Then you add the parameter as a default value to the Event ID field. Your form should look something like this:

<form format=”custom”>
<parameters>
<parameter name=”EventID” alias=”eid” default=”Enter Event ID”></parameter>
</parameters>
<controls>
<input ref=”EventID” width=”150” maxlength=”35”>
<default>{eid}</default></input>
!--- The rest of your form --!
</controls>
</form>

Now when you click the add new child (registration) button you will be taken to the registration form and the EventID will automatically be filled in.

Hint #3

Buy Fatgeorge’s Housekeeper add-on. What this add-on does is keep track of all your relationships and when a parent (event) record gets deleted it will automatically delete all of the associated child (registration) records at the same time. Housekeeper can also keep track of all file and picture uploads for a record and ensure they get deleted when the record they were attached to is deleted. Pretty cool.

Hint #4

If you have several child grid/list views you would like to associate with a parent you can buy the Tab Aggregator module from www.dnnstuff.com and place your Xmod modules in tabs below the parent detail view module. This is what was done on the screen shot on the first page.

Hint #5

To make all the modules on the detail page look as if it is just one form / template just turn off the containers on the modules and place them next to each other.