What is a JSON Schema? Intro to JSON

Summary

In this educational video, Matt Collins Jones, known as MCJ, explains the concept of JSON Schema, which acts as a blueprint for JSON data. He emphasizes its importance in pre-validating JSON to ensure data integrity and compatibility with applications. Through examples, Matt illustrates how JSON Schema specifies data types and structures, including strings, numbers, booleans, and arrays. He also discusses optional and required properties within arrays and how to handle different data types, such as allowing null values alongside booleans. The video aims to demystify JSON Schema for viewers, providing clarity on its components and practical applications, particularly in APIs and platforms like the Power Platform.

Takeaways

• 📚 JSON stands for JavaScript Object Notation, a common data format used in APIs and platforms like the Power Platform.
• 🛠 A JSON Schema acts as a blueprint for JSON, defining the structure and validating the format of JSON data before it's processed.
• 🔍 Pre-validation using JSON Schema helps to ensure that the JSON data is in the correct format and can be processed by the receiving application.
• 📝 JSON Schema allows you to specify the type of data each key should contain, such as strings, integers, booleans, or arrays.
• 📑 The schema uses a structure similar to JSON, with type-value pairs to define the expected data types for each property.
• 📈 The 'type' property in a schema indicates the kind of data expected (e.g., object, array, string, integer, boolean, or null).
• 🔑 The 'properties' section of a schema outlines the keys and their corresponding data types within a JSON object.
• 👥 The 'items' keyword in a schema is used to define the structure of the elements within an array.
• 📌 The 'required' keyword can be used to specify which properties must be included in an array for the data to be valid.
• 💡 JSON Schema can also account for optional values or the possibility of null values using type arrays, like ["boolean", "null"].
• 🛑 Understanding JSON Schema is crucial for developers to correctly interpret and manipulate JSON data, ensuring compatibility and functionality in applications.

Q & A

What is JSON used for according to the video?

JSON is used for writing and notating different pieces of information that various systems can use, such as APIs and platforms like the Power Platform.

What does JSON stand for?

JSON stands for JavaScript Object Notation.

What is a JSON Schema according to the video?

A JSON Schema is like a blueprint for JSON, which is used to pre-validate the JSON data to ensure it is in the correct format before it is processed by an application or program.

Why is JSON Schema important?

JSON Schema is important because it allows you to pre-validate JSON data, ensuring that the data received is in the correct format and can be processed by the application at the other end.

What is an example of a JSON object mentioned in the video?

An example of a JSON object mentioned in the video includes properties like 'name', 'occupation', 'age', 'is a dev', and an 'array' containing 'friends' with their respective 'name' and 'occupation'.

What does the video suggest for handling JSON data that may not have a value?

The video suggests using JSON Schema to specify that certain values can be null, ensuring that the application can still process the data even if some values are missing.

What is the purpose of the 'required' keyword in a JSON Schema?

The 'required' keyword in a JSON Schema specifies that certain properties must be included in the JSON data for it to be considered valid.

How can you specify that a property in a JSON object can be of multiple types?

You can specify that a property can be of multiple types by using an array notation in the JSON Schema, listing the possible types.

What tool did the video presenter use to generate the JSON Schema example?

The video presenter used Power Ultimate to generate the JSON Schema example.

What is the significance of the 'type' keyword in a JSON Schema?

The 'type' keyword in a JSON Schema is used to define the data type that a property should have, such as 'string', 'integer', 'boolean', or 'null'.

Can JSON Schema help in cases where the JSON data structure is complex?

Yes, JSON Schema helps in handling complex JSON data structures by providing a clear definition and validation rules for the data, making it easier to understand and process.

Outlines

00:00

📚 Introduction to JSON Schema

Matt Collins Jones, also known as MCJ, introduces the concept of JSON Schema in this video. He builds upon the previous video's content about JSON (JavaScript Object Notation) and explains that JSON Schema acts as a blueprint for JSON data. It allows for pre-validation of JSON data to ensure it is in the correct format before it is processed by applications or programs. MCJ emphasizes the importance of JSON Schema for developers working with APIs and platforms like the Power Platform. He then provides an example of a JSON object containing various data types and proceeds to explain how a corresponding JSON Schema is structured.

05:00

🔍 Exploring JSON Schema Structure

This paragraph delves deeper into the structure of a JSON Schema. MCJ explains the schema's role in defining the types of data expected in a JSON object, such as strings, integers, booleans, and arrays. He illustrates how each property within the JSON object is represented in the schema with its corresponding data type. The video script includes an example schema that mirrors the JSON object from the previous video, showing how properties like 'name', 'occupation', 'age', 'is a dev', and 'friends' are defined with their respective types. MCJ also discusses the use of 'required' to specify which properties must be included in an array.

10:01

📝 Understanding JSON Schema for Arrays and Optional Properties

MCJ continues the explanation by focusing on arrays within JSON Schema. He clarifies how to define arrays and the objects they contain, using the 'items' keyword to denote the contents of the array. He also touches on the concept of optional properties within arrays, using the 'required' keyword to indicate which properties must be present. The video script provides an example where 'name' and 'occupation' are marked as required within an array of 'friends'. Additionally, MCJ addresses the handling of properties that may not have a value, such as booleans that could be true, false, or null, and how to specify these possibilities within the schema.

15:02

🛠 Practical Use of JSON Schema

In the final paragraph, MCJ wraps up the video by highlighting the practical applications of JSON Schema. He mentions the availability of tools that can generate JSON Schema from sample JSON payloads, which can be particularly useful for developers. MCJ also encourages viewers to understand the individual components of a schema so they can edit them as needed. He admits to using a tool called Power Ultimate to generate the schema shown in the video, emphasizing that while it's not always necessary to write schemas from scratch, understanding them is crucial. The video concludes with a call to action for viewers to share the video, like it, or comment if they find the content useful.

Keywords

💡JSON

JSON stands for JavaScript Object Notation. It is a lightweight data-interchange format that is easy for humans to read and write and easy for machines to parse and generate. In the video, JSON is the central topic, as it discusses how JSON is used to write and notate different pieces of information for APIs and platforms like the Power Platform.

💡JSON Schema

A JSON Schema is like a blueprint for JSON data. It defines the structure and validation rules for a JSON document. The video emphasizes the importance of JSON Schema for pre-validating JSON data to ensure it is in the correct format before it is processed by an application or program.

💡Pre-validation

Pre-validation refers to the process of checking data before it is used to ensure it meets certain criteria or standards. In the context of the video, pre-validation is used to verify that the JSON data conforms to the specified schema, which helps prevent errors in data processing.

💡Data Format

Data format pertains to the way data is organized, presented, or stored. The video script discusses the importance of data format in JSON, such as strings, numbers, and booleans, and how JSON Schema helps in defining and validating these formats.

💡Type

In JSON Schema, 'type' is a keyword used to specify the kind of value an item in a JSON document should be, such as 'string', 'number', 'boolean', or 'object'. The script uses 'type' to illustrate how JSON Schema defines the expected data types for different fields in a JSON document.

💡Properties

Properties in JSON refer to the key-value pairs that make up a JSON object. The video script explains how properties are defined within a JSON Schema to outline the structure of the JSON data, including the types of each property.

💡Array

An array in JSON is an ordered collection of values. The video script discusses how JSON Schema can define an array with specific types of items it should contain, and how it can specify which items in the array are required.

💡Required

The 'required' keyword in JSON Schema is used to indicate that certain properties or items within an array must be present in the JSON data for it to be considered valid. The script gives an example of how 'required' can be used to specify that 'name' and 'occupation' are essential fields in an array of objects.

💡Boolean

A boolean in JSON represents true or false values. The video script uses 'is a dev' as an example of a boolean property in a JSON object, and it also explains how JSON Schema can accommodate boolean values or null in certain cases.

💡Null

Null in JSON represents the intentional absence of any object value. The script discusses how JSON Schema can be configured to accept null as a valid value for certain properties, which is useful when the source system does not provide a value.

Highlights

Introduction to JSON Schema by Matt Collins Jones, emphasizing its importance as a blueprint for JSON.

Explanation of how JSON Schema allows pre-validation of JSON data to ensure correct format before processing.

Illustration of JSON Schema's role in identifying data format issues such as incorrect string or number types.

Overview of a JSON example with various data types including strings, numbers, booleans, and arrays.

Description of the JSON Schema structure starting with type definitions and moving to properties.

Detailing how the 'type' field in JSON Schema specifies the data type expected for each property.

Use of 'properties' in JSON Schema to define the structure and expected data types within an object.

Explanation of how 'required' in JSON Schema specifies which properties must be included in an array.

Discussion on handling optional properties and the use of 'null' as a potential value in JSON Schema.

Demonstration of how to specify multiple possible types for a value in JSON Schema using arrays.

The practicality of using tools to generate JSON Schema automatically for ease of use.

Matt's admission of using Power Ultimate to generate JSON Schema instead of writing it manually.

Importance of understanding JSON Schema components for editing and customizing to specific needs.

Invitation to watch another video by Matt on using JSON Schema in Power Automate.

Matt's call to action for viewers to share, like, and comment on the video for feedback and engagement.

Transcripts

what's up guys it's matt collins jones

here also known as

mcj and today we have a video called

what is a json schema in the last video

we covered what is json

we learned that it stands for javascript

object notation

we learned that it is a way to write and

to

notate different pieces of information

that various things can use like

apis and we learned it's a very common

language across

apis and also things like the power

platform which might be why you're

watching this video

so what is a json steamer and why

is this important so json steamer is

the it's like a blueprint for json

so why is this important it's important

because

you can sort of pre-validate the json

that you are receiving

you can say right i want this

payload json i want to get this

information

and when you send it and it's validated

it's the schema

it goes actually this is in the wrong

format

maybe you have a string and it needs to

be a number

maybe it's a number it needs to be a

string maybe it's

blank or null and therefore

something that um the the application at

the other end

won't accept and won't be able to

process

so json schema is a way to pre-validate

that data

to say yes this is the correct format or

this is what you should be sending to us

for our application or our program to be

able to understand it

and then use it so let's take a look at

some examples today

so last time i wrote this bit of json

out

i've changed it slightly because the uh

the friends

anniversary is coming up with a new

episode and i'm very excited about it

but essentially these are the different

types of uh properties inside of our

json

so we have name which is a string

occupation which again is another string

we have age which is a number so we can

see it's kind of different from the

strings with it not being

inside double quotation marks we have is

a dev

false so again we have a boolean true or

false and then we have an array and the

array contains two things so the array

contains

two friends one joey whose occupation is

an actor

and one is chandler whose occupation is

a statistical analysis and data

reconfiguration

um i myself has a gel uh channel bing

job

is what i always explain to people

so this is this is the data that we're

going to send

somewhere so what does a steamer look

like well i've already written that out

for us so let's take a look at the other

tab

so this tab is the exact

is the the schema that'll be used for

the previous screen so it starts off we

have the curly brackets opening at the

top and the bottom

and then it goes on to what's called

types

and properties so the the

type up here is an object so what i'm

saying is

right i'm going to send you a single

piece of information an object of

information

and you're going to deal with it and

that's what the that's what the

information

i we have for the schema is and

therefore that's what this

information is going to be it's going to

be a single object

um the object may contain an array

but it's going to be an object it's

going to be a single piece of

information

properties is here this is just a way to

define that there are things underneath

it

um because we're not setting kind of a

top

level um json sort of like header

or anything like that we're just saying

right okay we need

some way to distinguish right this is

what's going on so we've just called

that properties

and then this opens a bracket here which

as you can see

doesn't close for a little bit so it

closes down here

so we have our our close bracket to

start with where we have the object

and then as soon as we hit that

properties we open it

and it's gonna close down here so that's

to say right

everything contained within this is the

properties or everything

containing this is what we're going to

send you

next we have the name so this is the

name field from the contact here so we

see name and occupation and our first

two

and we know that name is a string we

know occupation is a string

so if we go back to our um steamer we

can see name

open the open the brace here and it says

type

equals or type is string so again this

is going to look a lot like json and

that's because it

is it is a way to know what

sort of json we're getting so again we

have these t-value pairs

but instead of last time where

everything was unique we had like name

and occupation we have name which is the

the key value pair but then it's saying

right okay

that key value pair again denoted by

this

colon here and then open a brace that's

going to have a type and that type is

string

so all this is saying is for the name

the name

type is a string and we're doing the

exact same thing for occupation

and as we know there are commas after

each one again

just denote a new line so we have the

same thing for occupation there

and then we move on to age and age has a

type of integer because that is a number

and again that is taken from the last

screen

and we have is a dev type equals brutal

bullion

so again if i flip back to our example

we can see that all these things

are true so age is a number as we've

said it's not got any

double quotation marks it's just a

number and is a dev

is false so true false beings through

things that are

compatible with json without needing

quotation marks so there we have so

we have our our string we have our

integer

we have our boolean then goes down a bit

further and then we have

the the friends kind of header or the

friends

part of this which is an array and this

array

as we can see opens up here and closes

down here this friends bit will

take everything inside here and this is

saying right okay

this friends bit that key value type is

an array so again it's saying right you

you will you will get an array at some

point in this

um the array will have different objects

or different properties inside of it

but i'm telling you that there's going

to be an array coming and this is the

this is the schema or this is the format

for it

so again items is kind of denoting that

this is going to be

um one of many items um that could be

sent

in an array because we may not know how

big

or how small the array is but we can see

that we've got items

um and that's trying to denote that

level of the array

then here's the type of object so again

we know that

inside of the array we're going to be

sending an object so

inside of the array we're going to be

saying right

this is um an object so this is again

another piece of information

um and it's not and that's what we're

sending

so we're going to send an object and in

this example the object is

joey and uh his his occupation being an

actor

so that's an object just like this whole

json is an object as well so i'm just

really trying to use the terms of like

objects and arrays they're not big and

scary it just means

a thing you know a piece of data a thing

an array is multiple

things so an array can be multiple

objects that we're sending

so again we have uh the properties

opening up that key value pair just to

say

right we don't have like a top level

name for this this is just going to be

everything that's underneath it

and we're going to have name the name is

of type string

and then inside of this properties here

we also have

occupation again of type string so we

kind of see

that it's going to close that bracket

out and say right okay

inside of this object the things that we

are receiving

is a name which is of type string and an

object which is of type string as well

further down we actually have something

that's a little bit optional um

which is funny because it says required

so one of the things that you can

specify in your json

is um for things like arrays what

is required in those arrays and what is

optional

because you may not always get that

information back

in an array um so if it doesn't send

name for instance uh you would not

potentially receive

name so when you're creating an array

you may

not have that name field and therefore

your program may not

create a property or a key value for

name

and a value because it doesn't know it

it's kind of a unique example but what

this allows you to do saying is required

again which is inside of this um this

bracket here and

sorry this items bracket here is saying

right

in my array these are two properties

that are required name and occupation

you can remove this and you can not use

this

as being something that is required so

you can take this out

but what this allows you to do is

specify to the

program that is sending you the json hey

this is required your rain needs to

contain this

so hopefully that makes sense now that's

what you do

for an array but sometimes you may have

objects that will contain a

a value but not contained like a key

would not contain a value

so for instance one of the most common

ones is things like a boolean

so up here in my object i have a boolean

which has a which which is um is a dev

and that's my boolean

so inside my object i know i'm always

going to get these so i don't need to

say that these are required

it's just an array that i'd need to

specify that for

but i'll i may always get is a dev

but i may not get a value with it

now the reason for that is maybe it

doesn't have a value in the source

system

you know there are systems where you

don't put in a yes or no

answer um and therefore it's not

it doesn't have a value so that can

kind of lead to issues with data uh but

when you're sending it something maybe

you need to default those things or

maybe you need to do something else

so in this instance if um someone sent

a json object to me

and is a dev was blank instead of being

a true or false

um because no again is a valid value in

json

it may fall over it may not work

so one of the things you can actually do

is you can actually specify

if um a a key or a value

which would be not so for instance or

could be a different

type so in my type here um what i can do

is i can make this into an array

so put a square bracket here put a

square bracket here

and put that in and then do not like

that

so what that does is that says right is

a dev

can be one of the following types a

boolean

or a null so again i'm creating an array

to say

right there could be multiple values

here this is how you denote this

in a coding language it's an array it's

multiple things it's not a single value

if i was to try and take these scrub

brackets away

it would go um yeah i don't really know

what this is

um we've got a whole unexpected here

because it's just not really figuring it

out

if i have those square brackets straight

brackets in

it will go oh this is an array okay it

can be one of these values

so if someone was to send a json object

with a boolean

out of true or false for is a dev or not

send

that value at all we still have that as

a dev there with just a null value

this json schema would go yep that's

that's fine

that's approved we can let you through

we can

um pro we can use this information that

you've sent and do something with it

so there we have it that is a brief

introduction to

json steamers it's a little bit

complicated that you had around it

especially when you compare

something like this which may now

hopefully

seem really easy to use in terms of

this is what you're used to this is like

a name this is a

value that's all fine when you look at

this

it's a little bit more abstract i would

say but if you break it down into the

simple list components

you will you'll be able to understand

what's going on so here you know

age is an integer is a dev is a boolean

or a null value

that sort of thing plus there are loads

of

json schema creators for you so you can

load in some sample json payloads

like this contact one uh here into

something

and it will pump it out for you into the

steamer

i have a video on that here for using it

in the power platform using empower

automate

and you can check that video out and see

how

um see how these things can be used uh

which is really useful

um but there are other programs

available that will allow you to do that

as well

i will be truthful i did not write this

steamer i

just use power ultimate to generate it

for me uh because life's too short to

write your own streamers

but sometimes you need to and sometimes

you need to edit them like this because

it'll just give you the most

common uh scenario so in this instance

um my is a dev payload was a boolean

so it knew it was a boolean but it

doesn't know it can be not so you may

need to edit it

and that's why this video is really

important to be able to understand

how a streamer is put together to be

able to understand the individual

components of it

then you can edit it you can you can

understand it you know what data you

need to send

and you can edit it if needed as well

i hope you guys enjoyed this video this

is my second video

on my sort of introduction to json so i

hope it was useful

if it was if you could share it with a

friend that would be appreciated

if you could drop a like or make a

comment down below on if this is useful

or what you've maybe used this for

that would be really helpful as well and

i'll see you next time

you