Unit introduction
You are now at the third unit of the second course within Make Basics.
In our previous unit you covered the different data types in Make, and advanced data types.
In this unit, you will build on this knowledge.
You will learn about how to map data items, and where these would be useful.
Element - MCQ
Before we make a start, let’s refresh your knowledge of mapping.
What is mapping in Make?
The process of connecting modules and moving data from one module to another.
Mapping involves generating items of information from one module, and telling Make where we want the information to appear in the next module(s).
Mapping Recap
Let’s explore a high-level overview of mapping before you jump into further detail.
Mapping
Mapping makes a bridge between two systems, or modules, so that when data is moved from a source module, it is accurate and usable at the target module.
Mapping informs a module about how to use the data from previous module(s).
Examples you may have experienced so far within the Make Foundation and Make Basics courses are mapping the temperature and time.
Real World Comparison
Let’s think of this in a real world scenario: you are moving home (source module) and you only want to take one item with you.
You would load this item on to the delivery van (the scenario), with the instruction of where it needs to be placed in your new home (mapping).
The delivery van would drive to your new home (target module), and unload the item according to your instructions.
Mapping within Make
Within Make, we’ll use the Weather and Email modules as an example. Imagine that you are working at a beach resort and you want to get the daily weather report on your email.
Your first (source) module will get the daily forecast according to the location and time you set. It will output temperature and weather condition, which you can use and map in your email (target) module.
The email module performs the action ‘automatically send an email’. Within this module you would take some data from the weather output such as temperature, humidity, wind. Then, you would map it within the email, so that it would change dynamically every day and send you the weather report.
Element - text / text and image (Portrait) - LARGE
As you might remember from the previous unit, when you map data items, you can see the data type which the specific field requires, as well as the data type of the individual pieces of data.
The data types help you to assure the app you are using understands your data.
Hover over the input fields and mappable items to see their data type. Check the image to your left to see it in action.
This will help you make sure you’re mapping items with the correct data type that match what’s expected by the input field.
Mapping example - Weather
Let’s look at some use cases where you can see how to map different data type items.
Work through each stage to learn more.
Text
If you previously built the Make Foundation Use Case, now would be a great opportunity to revisit it and have a look.
In the Weather app there are 2 ways you can enter a location. If you choose “cities”, you would need to type your location as text. An example would be Prague, CZ.
Notice how the data type (text) shows when you hover over the field name? This way you know which data type the field expects you to enter.
In the case you type a non-existing city or country, Make will automatically identify an error.
In the Weather app, if you enter a wrong country code or misspell the city name, you’ll get an error on the module saying “404: City not found.”
Here we have “CR”, instead of “CZ”, that’s why we are getting an error, because “CR” is the wrong country code so Make cannot find the city.
Go on to see the alternative way of entering location.
Numbers
Another way to enter the location is by coordinates. This might be useful if a place is small, you don’t know how to spell it right or are not sure about the country code.
Notice how the number data type appears when you hover over the field name?
If you decide to use coordinates, the fields expect number data type in the latitude and longitude fields. If you try to use text, as in our example, you will get the “invalid number” error.
Identifying the item type
As you might remember, you can map individual items by clicking on them or dragging them.
If you want to know the data type of each item, simply hover over the item.
Notice how the data types appear in angle brackets when you hover over it? This way you can make sure that the item data type matches the field data type.
Element - text / text and image (Portrait) - LARGE
Type conversion is the process of converting values from one data type to another.
Make tries to convert data automatically. If you map a data type in a field that expects a different data type, Make will attempt to correct this. For example:
- If you enter numbers (e.g.
123) in a text field, it is okay because the text data type accepts all the letters, numbers, and special characters. - If you enter text with only numbers (e.g.
123) in a number field, Make will automatically convert it into a number. - If you enter text (e.g.
Make Academy) in a number field, Make will return a validation error.
Think of this in the context of a shape sorting toy; it will only accept certain shapes!
If the conversion fails, parsing or formatting functions can help. These are very useful and you will learn about them in our next course.
Mapping collections
Let’s take a look at how to map a collection/array. It requires a bit of extra clicks, but it’s nothing too hard!
As you might remember from the previous lesson “Brief introduction to data types”, a collection is a data structure that groups multiple different items into a single unit.
Going back to the image of a collection as a kitchen drawer, imagine you only want to get a spoon from the drawer. You don’t need other items inside it.
Let’s go on to see how to map an item inside a collection in Make. You do not need to build this yourself, but feel free to open Make and follow what you see on screen.
Let’s take the Weather - Get daily weather forecast module as an example. You want to get the weather forecast for today, tomorrow, and the day after tomorrow for Paris, France. Then, you want to send the data from the weather app to a Google Sheet.
Your Google Sheet should have columns that represent the data you want to get, such as: Date / Daily temperature / Wind Speed / Description. You’ll need to map the field names with items. Notice how in the Google Sheet example all the fields require text type data? However, even if you enter Date or Daily temperature, it’s okay. This is because of data type conversion mentioned before. Also, the text data type includes numbers and special characters too, which makes our life easier in this case!
In Google Sheets, you’d want to map the daily temperature. Notice the arrow in front of “Temperature”? The arrow is a visual indicator of a collection (or an array). It means there are more items inside.
A collection is one element in itself containing different items. Here, the “Temperature” is our collection and all the items under belong to it (e.g., day, night, morning, and evening temperature).
If you need to map a value that is nested in a collection, make sure to choose the exact item inside it. If you want to map the daily temperature, it is not enough to choose the “Temperature” item because this is the overarching collection/folder. If you map this item, you’ll receive an error when you run your scenario. Instead, you should map a specific value inside the collection if you want to retrieve the temperature during the day, you should select “Day”.