Category: Level: Intermediate

Level: Intermediate

Sometimes Less Is More Reliable

Kevin Frank

Update: Make sure to read Tony White’s comment below. It contains important additional information re: the behavior described in this article.

Recently I noticed some code that had worked flawlessly for years was suddenly returning “?” instead of valid values. What it came down to was that I had renamed my file from “JSON Custom Functions” to “JSON Custom Functions for FM 19.5”

Well you know those functions like ValueListItems…

ValueListItems ( fileName ; valueListName )

…that have a fileName argument? The culprit turned out to be that I was using Get(FileName) for that argument, and I needed to instead use "".

All 21 of the design functions are vulnerable to this, ahem, behavior. From the online help —

  • If you specify a filename that contains a period, include the filename extension in the parameter. Otherwise, functions may interpret the period in the filename as the beginning of the filename extension, which can lead to unexpected results.
  • If you specify no filename (""), functions return results for the current file.

Source:  https://help.claris.com/en/pro-help/content/design-functions.html

Bottom line:  When using a design function and referencing the current file, use "" instead of Get(FileName). There’s no down side, and your code won’t break if you decide to add a period to the file name.

JSON, Level: Intermediate, Version: FM 19.5 or later

Thinking About JSON, part 4

Kevin Frank

This article is part of a series. See also…
•  Thinking About JSON, part 1
•  Thinking About JSON, part 2
•  Thinking About JSON, part 3

Demo Files

Make sure to download the correct version for your locale:

Introduction

Welcome back to the fourth installment in this ongoing series. It’s hard to believe it’s been four years since the last segment, but in the meantime some exciting developments have occurred at the intersection of FileMaker and JSON, including… Continue reading “Thinking About JSON, part 4” →

Level: Intermediate

Button Bar Segment Fun, part 2

Kevin Frank

This is a quick follow up to Tuesday’s article, and to avoid unnecessary repetition I will assume the reader is familiar with that material.

Demo Files

There were some things in v3 I wasn’t completely happy about, and I realized this morning that they would be easy to fix, and that the act of fixing them would help demonstrate the power of using this approach in the first place. Continue reading “Button Bar Segment Fun, part 2” →

JSON, Level: Intermediate, Version: FM 18 or later, Virtual List

Virtual List Reporting, part 4

Kevin Frank

Introduction

Back in 2017 I wrote about a technique to enable users to a) produce multiple on-screen reports, and b) interact with those reports in browse mode. The article was called Virtual List Reporting, part 3, and while the approach it advocated works well enough under most circumstances, today I’d like to share some fresh ideas.

Note: as you might guess from the title of this article, implementing this technique in your solution, and/or understanding what’s going on under the hood, requires some knowledge of virtual list. If you are not familiar with virtual list, or need a refresher, you may find this article helpful: Virtual List Simplified.

Demo Files (require FM 18 or later)

Continue reading “Virtual List Reporting, part 4” →

Level: Intermediate, Version: FM 13 or later

PSOS – Run Script in File not open Locally

Kevin Frank

Update: See Jason Wood’s suggestion in the comments section for making this technique more secure.

INTRODUCTION

Today I want to take a look at a certain Perform Script On Server (PSOS) behavior, and for those who find this behavior to be inconvenient, propose a work around.

Here’s the behavior, or misconception, actually: a server side script initiated via PSOS (apparently) cannot access files on the server unless the user already has those files open locally. But of course there may be circumstances where you’d like to be able to access files server side that the user does not have open client side, either because the user’s credentials do not allow access to those files, or because you’d rather not have to open the files client side merely to facilitate a PSOS call.

If we consult the online help entry for running scripts on server, the official word is that server-side scripts can access other FileMaker files only when…

…in other words, if you want PSOS to be able to access files, you need to either a) already have the files open client side, or b) throw caution to the wind, and configure the hosted files to auto-open with pre-entered credentials.

Hmmm… I think we can agree that from a security standpoint “b” is a non-starter, and the whole point of this article is to avoid “a”. Fortunately there is a “c” option not mentioned above which I’ll get to shortly, but first let’s demonstrate the issue. Continue reading “PSOS – Run Script in File not open Locally” →

Level: Intermediate

When 2 is greater than 10

Kevin Frank

Today we’re going to take a quick look at a potential “gotcha” that can occur when performing numeric comparisons. Jason DeLooze and I discussed the general behavior back in 2011 (Space Is The Place), but this time around I want to focus on one particular set of circumstances where the problem can arise.

At first glance this may appear to apply to beginner-level developers only, but the problem is nuanced, and I have occasionally seen it crop up in solutions written by experienced developers as well as those created by newbies.

Specifically, when comparing two variables, for example…

ExitLoopIf [ $counter >= $rows ]

…FileMaker must determine whether to do a text comparison or a number comparison, and under certain circumstances, contrary to developer expectations, may perform the comparison in “text space” rather than in “number space”.

Of course we can explicitly ensure that all comparisons take place in “number space” like so…

ExitLoopIf [ GetAsNumber ( $counter ) >= GetAsNumber ( $rows ) ]

…but let’s dig a little deeper to see the circumstances under which GetAsNumber is actually necessary. Continue reading “When 2 is greater than 10” →

Level: Intermediate, Version: FM 18 or later

A Value List Experiment

Kevin Frank

Demo file: a-value-list-experiment.zip

Note 1: today’s demo is recycled from the one that accompanied Virtual Portal, part 2. All we care about this time around is how we assign the parent company; the remainder can be ignored.

Note 2: if you’re unclear on value list basics, check out Thinking About Value Lists, part 1.

“I want it to work like it does in Quickbooks.” Based on a client request I recently implemented a Quickbooks-like picker… shown here enabling the user to easily assign a parent company via auto-complete as the user types the first few letters of the company name.

To be clear, we aren’t actually storing the parent company name, merely using it as a selection mechanism. When a name is chosen via this interface, the corresponding foreign key is immediately auto-entered into “id_parent”… Continue reading “A Value List Experiment” →

JSON, Level: Intermediate, Version: FM 16 or later

JSON Currency Exchange Rates

Kevin Frank

Update 11 Apr 2021: as per comments below, demo has been updated to use a new service: openrates.io.

Welcome back for another exciting round of JSON exploration. Last time we discussed a JSON-related bug fix in FM 19, as well as a free package tracking service that returns results in JSON format. Today we’re going to look at a free currency exchange rate service.

Demo file: json-exchange-rates-via-openrates.zip

2020-08-24_09-12-59 Continue reading “JSON Currency Exchange Rates” →