Confusion on Linking forms

For the many to many link type, there was a quirk where the “show inverse relationship” needed to be toggled to reset the field on the other side of the link but that will let you map many to many on both sides.

1. If you’re on the child side of a 1:M relationship, it should be showing you a cut down view of the linked record. If you’re on the parent side or using a M:M relationship, you need to use a script field to aggregate the values and display them. On the desktop it would display a table for you but on mobile a script field is probably your best bet.

2. The experience on iOS here is a little awkward because of where the various buttons end up and the hint text pushes towards adding a new value rather than selecting an existing value. I don’t think there is a good way around this one.

3. Linked fields mess with sort and search because the linked field itself has multiple fields and if it’s a multiple relation you have multiple records as well. The solution is again to use and have that flatten the records for you. Then the search and sorting can be done on the script field once you’ve extracted the value that works for you. If you are in a 1:M relationship, the child record can use a calculation field to extract a field from the parent easily.

4. For the pick list what you could do is have a script field enforce that the value exists and resets the vendor field if an invalid item is entered and then pops up an alert to the user. That’s a reasonable amount of scripting but also doable as an extra validation step.

If you jump into the script editor and look through the snippet list, you’ll find the “Child Records Loop” snippet. If you select the linked field you’re looking to render into the other form, it’ll put in a bunch of place holder text (delete the basic boilerplate Tap Forms gives you). I just did this on a post, it looks like this:

function recordsLoop() {

	var topics_id = 'fld-fae59d1ee3184c4cbec2eac87aeaa9ae';
	var topic_title_id = 'fld-fce83c065b174df1919ada0de6e0551e';
	var topics = record.getFieldValue(topics_id);

	for (var index = 0, count = topics.length; index < count; index++){
     	var topic_title = topics[index].getFieldValue(topic_title_id);
		if (topic_title) {
			// do something
		}
	}
	return;
}

recordsLoop();

If you wanted to make a comma separated list of all of the values, the // do something needs to gather together the values. To do this add var returnValue = []; after the other line that has var topics on it, it’ll create an array we’ll use to collect values. Then change // do something to be returnValue.push(topic_title); which will add the values to the array. Then finally change the line that has return; on it to be return returnValue.join(', '); to give you a comma separated value. The final form should look like this:

function recordsLoop() {

	var topics_id = 'fld-fae59d1ee3184c4cbec2eac87aeaa9ae';
	var topic_title_id = 'fld-fce83c065b174df1919ada0de6e0551e';
	var topics = record.getFieldValue(topics_id);
	var returnValue = [];

	for (var index = 0, count = topics.length; index < count; index++){
     	var topic_title = topics[index].getFieldValue(topic_title_id);
		if (topic_title) {
			returnValue.push(topic_title);
		}
	}
	return returnValue.join(', ');
}

recordsLoop();

You can pull in multiple fields as well by following the same convention. If you click on the field you are interested in and then click on “ID”, it’ll generate the var field_name = 'field-id'; code for you. You can also double click on a field on the other side of the link and it’ll generate something like the topics[index].getFieldValue line with the field ID embedded into the generated code.

If newlines are more your thing, change returnValue.join(', ') to returnValue.join('\n'). If you want to go a little more advanced in your formatting, using the script to update the new Markdown field will give you more programmatic control over formatting.