Tag Archives: JSONSetElement

Thinking About JSON, part 3

This a quick followup to last month’s part 2, because today I want to to dig a little deeper into JSONSetElement and take a closer look at the first argument:

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As I wrote last time…

Part of what makes JSONSetElement so powerful is that it can be used both to create new entries, and to update existing entries. Specify a valid address, and it will either create the entry if it doesn’t already exist, or update it if it does.

Let’s talk about the update aspect first, because it’s extremely straight forward. If you have existing JSON in a variable, for example $$simpleJSON, you can update it (i.e., add new elements or change existing elements) like so:

    • JSONSetElement ( $$simpleJSON ; etc )

In other words, you use your existing JSON as the first argument.

But when it comes to creating new JSON, there are three possible first arguments to consider.

    • JSONSetElement ( “{}” ; etc )
      …instructing FileMaker to create a JSON object
    • JSONSetElement ( “[]” ; etc )
      …instructing FileMaker to create a JSON array
    • JSONSetElement ( “” ; etc )
      …trusting FileMaker to figure out which structure to create

At the risk of stating the obvious, in the first two cases we are being explicit, but in the third case we are not. (Note: If you’re unclear on the distinction between objects and arrays, this was covered in great detail in part 1.)

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Thinking About JSON, part 2

This is a follow up to Thinking About JSON, part 1. Last time we were primarily concerned with learning about JSON paths and structures, and reading JSON. This time around we’re going to look at creating and manipulating JSON.

Demo file: winery-json.zip

(If the above screen shot looks familiar you have a good memory, because today’s demo is based on the one that accompanied this article: Summary List Fields in FM 13.)

To briefly recap, JSON is built on two structures…

  • Objects: surrounded by {} and consisting of comma-separated key:value pairs
    Simple example:  { “product” : “FileMaker Pro” , “version” : 17 }
  • Arrays: surrounded by [] and consisting of comma-separated values
    Simple example:  [ 2 , 4 , 6 ]

…and where things get interesting is that the “values” in either of the above structures can themselves be JSON (i.e., an object or an array). This defining feature of JSON, whereby a JSON structure can, and frequently does, contain embedded smaller JSON structures, was explored in detail in part 1, and we will see some examples of this today as well. Continue reading

JSON + Virtual List

31 July 2017: As per my exchange with Beverly Voth in the comments section of part 2, the date encoding technique used here is strictly intended for situations where FileMaker will both produce AND consume the JSON.

29 July 2017: demo has been updated to require a minimum version of FileMaker 16.02 as per my exchange with John Renfrew in the comments section.

One nice thing about FileMaker being on a yearly release cycle is that there is always something new to learn and write about… and, having recently attended a pair of highly informative sessions on the topic of JSON (JavaScript Object Notation) at Devcon 2017 — thank you Todd Geist and Anders Monsen — it is clear to me that JSON + virtual list is a compelling combination.

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Demo file: json-plus-virtual-list.zip

My original plan was to integrate JSON with virtual list reporting, but in the interest of clarity, I decided to save that for a future article. Today we have a straightforward demo that a) generates a small amount of JSON from a standard FileMaker table, and then b) renders it in a virtual list table. Continue reading