Author: Kevin Frank

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

Connecting Portals to JSON Arrays

Kevin Frank

Have you ever wished you could connect a portal to a JSON array? Portals and JSON arrays seem like they should be a natural fit, but FileMaker doesn’t offer us an obvious way to connect one to the other.

(Why would you want to do this? One use case would be to provide dynamic scrollable selection criteria for a report.)

At any rate, today we’re going to take a look at a little proof-of-concept I threw together to enable portals to display and edit data in JSON arrays. In a real-world implementation, the JSON would likely be sitting in a $$variable, which, among other things, would help make the technique multi-user friendly. Here, in the interest of simplicity, I’ve opted to store the JSON in a regular text field. A couple benefits of doing so:

  • You will see changes made in the portal immediately reflected in the JSON, and vice-versa.
  • As you navigate from record to record within the demo, the portals will reconfigure themselves to accommodate the corresponding JSON.

(Yes, it’s possible to accomplish the preceding with variables as well, but the aim here is to keep things simple).

Demo file: connecting-portals-to-json-arrays.zip

Continue reading “Connecting Portals to JSON Arrays” →

JSON, Level: Advanced, Version: FM 18 or later

JSONQuery, part 2

Kevin Frank

Continuation of interview with Steve Senft-Herrera

[Editor’s note: the demo file and custom function have been significantly updated since part 1.]

Demo file:  CF_JSONQuery_20211130_0120_PUBLIC.fmp12.zip

KF: Welcome back Steve for part 2 of our JSONQuery conversation.

SSH: Thank you, Kevin.

KF: One thing we didn’t mention last time, because they were late-breaking additions, were the inequality operators.

Continue reading “JSONQuery, part 2” →

JSON, Level: Advanced, Version: FM 18 or later

JSONQuery, part 1

Kevin Frank

Interview with Steve Senft-Herrera

[30 Nov 2021: Custom function and demo file have been updated. Some of the screen shots and example numbers referenced here in part 1 will deviate slightly from what you will find in the updated demo.]

Demo file:  CF_JSONQuery_20211130_0120_PUBLIC.fmp12.zip

KF: Good afternoon, Steve. You’ve been developing JSONQuery over the last few years, and today I have the honor of presenting and discussing it here with you on FileMaker Hacks. I was wondering if you could start out with a brief description of what JSONQuery is?

SSH: Sure. JSONQuery is a custom function, and it operates on JSON. Typically you’re going to be feeding it a large JSON array you’ve received back from the FileMaker Data API, or somebody else’s API, where each record is a JSON object within a larger parent JSON array, and the purpose of this function is to be able to find child elements in that parent array that match certain criteria and return just those elements to you. 

Above and beyond that it has a lot of bells and whistles, some of which I’m sure we’ll cover, but the main impetus for writing it was giving you an easy and fast way to essentially query a JSON array.

For example, let’s say you have an array filled with a lot of orders, but you only need to get the order items that are being shipped to a certain city, or to a certain state, then this function would allow you to easily obtain those elements in an efficient manner. Continue reading “JSONQuery, part 1” →

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: Advanced, Version: FM 16 or later

Set Variable By Name Re-Revisited

Kevin Frank

Demo files: set-var-by-name-v4 and set-var-by-name-md5

Background

This is a quick follow up to last December’s Set Variable By Name Revisited, and to avoid repetition will assume the reader is familiar with the material that was presented in that article. But to briefly recap:

1. FileMaker does not provide an obvious way to programatically name a variable.

Continue reading “Set Variable By Name Re-Revisited” →

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” →

JSON, Level: Advanced, Version: FM 19 or later

FileMaker 19 + JSONata

Kevin Frank

Introduction

Recently I had the pleasure of speaking with Jeremy Brown on The Context Podcast about an open-source project called JSONata that enables you to query and transform JSON.

The JSONata site is packed with useful information, including this short video…

…as well as…

  • Extensive documentation
  • A link to the Stack Overflow forum, where you can ask questions (which may or may not get answered), and
  • The JSONata Exerciser, where you can experiment with pre-existing examples, or with your own pasted in JSON

Okay, a JSON query and transformation language sounds intriguing, at least in theory, but wouldn’t it be great if we could harness that power from within FileMaker? Well, now we can, utilizing techniques in this demo, built by Jeremy and shared here with his permission.

Demo file: JSONata.zip (requires FM 19+ on Mac, 19.3+ on Windows)

As you’ve probably surmised, the demo makes use of the Perform JavaScript in Web Viewer script step. If you’d like to learn more re: what’s going on under the hood, Jeremy goes into specifics here: Towards a Better JS Development Environment.

Note: the demo requires an online connection to access the JSONata library. Continue reading “FileMaker 19 + JSONata” →

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” →

ExecuteSQL, Level: Advanced, SQL, Version: FM 18 or later

Fun with SQL Joins and Currency Formatting

Kevin Frank

Demo file: sql-join-fun-etc-v2.zip requires FM 18 or later.

[26 Feb 2022: demo file has been updated to v2 to address the concern raised by Phil McGeehan in the comments section. Screen shots have not been updated.]

Recently I was asked to create a mini-report combining data from a pair of related tables via ExecuteSQL.

This provided an opportunity to think about SQL joins, and also to come up with a way to apply currency formatting to dollar amounts in the SQL query result, given that FileMaker’s SQL implementation does not support the standard SQL way of accomplishing this (e.g., CAST AS NUMERIC or CAST AS DECIMAL) . Continue reading “Fun with SQL Joins and Currency Formatting” →