Data types
Parse Data Types in a React Native component
Introduction
In the heart of Parse Core feature is the data objects management. Parse allows you to store and query its data straightforwardly using its SDKs or APIs(REST or GraphQL). All the data object features are built using the Parse.Object class, which fields may contain key-value pairs of several JSON-compatible data types. The primary data types that can be assigned to the object fields are the following:
- Number: integer (42) or floating-point (42.5) numbers, as long as ‘.’ is the decimal separator;
- boolean: true or false values;
- string: a string that can be as long as 2147483647 characters. Be aware that values this huge will slow down data operations;
- DateTime:DateTimeobjects stored in UTC format as default. If you need to use another timezone, conversion should be done manually;
- array: an array containing data in any Parse compatible data.
- object:a JSON object also containing any Parse data. When available in SDK, aninclude()call will bring details from the Object property.
When you choose to use the Array type, we recommend keeping array objects small as this can affect your data operations’ overall performance. Our recommendation is to use the Array type if it does not exceed 20 elements and does not grow over time. Instead of the Array type, you can use the Pointer and Relations types as an alternative.
In this guide, you will learn how to store data in each of the basic data types listed above. You will build a React Native product registration component, which will show you how to format, convert and save data to your Parse Server in React Native.
Parse also offers the datatypes GeoPoint to use the power of geolocation resources, and the Parse-specific relational data using the types Pointer or Relation. You will see both covered in the next following guides.
Prerequisites
Goal
To understand the Parse-compatible basic data types, and to store each data type on Parse froma React Native component.
1 - The Product Creation Component
Let’s first create the component structure. Let’s make it simple and create a form screen with one text inputs to each data type, one switch toggle, and a submit button to save the object. These inputs will collect your Product field values: name(string), quantity(number), price(number), available(boolean), expiration date(DateTime), and categories(array). Also, you will save an additional object type field in your saving method as well, but this one won’t need an input field.
Create a separate component in a file called ProductCreation.js/ProductCreation.tsx including the following code, or add it to your main application file (App.js/App.tsx or index.js). You can use this layout with complete stylings using react-native-paper or set up your custom form.
1 import React, {useState} from 'react';
2 import {
3 Alert,
4 Image,
5 SafeAreaView,
6 StatusBar,
7 StyleSheet,
8 View,
9 } from 'react-native';
10 import Parse from 'parse/react-native';
11 import {
12 Button as PaperButton,
13 Switch as PaperSwitch,
14 Text as PaperText,
15 TextInput as PaperTextInput,
16 } from 'react-native-paper';
17
18 export const ProductCreation = () => {
19 // State variables
20 const [productName, setProductName] = useState('');
21 const [productQuantity, setProductQuantity] = useState('');
22 const [productPrice, setProductPrice] = useState('');
23 const [productAvailable, setProductAvailable] = useState(false);
24 const [productExpirationDate, setProductExpirationDate] = useState('');
25 const [productCategories, setProductCategories] = useState('');
26
27 const toggleProductAvailable = () => setProductAvailable(!productAvailable);
28
29 return (
30 <>
31 <StatusBar backgroundColor="#208AEC" />
32 <SafeAreaView style={Styles.container}>
33 <View style={Styles.header}>
34 <Image
35 style={Styles.header_logo}
36 source={ { uri: 'https://blog.back4app.com/wp-content/uploads/2019/05/back4app-white-logo-500px.png', } }
37 />
38 <PaperText style={Styles.header_text_bold}>
39 {'React Native on Back4App'}
40 </PaperText>
41 <PaperText style={Styles.header_text}>{'Product Creation'}</PaperText>
42 </View>
43 <View style={Styles.wrapper}>
44 {/* Boolean type input */}
45 <View style={Styles.switch_container}>
46 <PaperText>{'Available?'}</PaperText>
47 <PaperSwitch
48 value={productAvailable}
49 onValueChange={toggleProductAvailable}
50 />
51 </View>
52 {/* String type input */}
53 <PaperTextInput
54 value={productName}
55 onChangeText={(text) => setProductName(text)}
56 label="Name"
57 mode="outlined"
58 style={Styles.form_input}
59 />
60 {/* Number type input (integer) */}
61 <PaperTextInput
62 value={productQuantity}
63 onChangeText={(text) => setProductQuantity(text)}
64 label="Quantity"
65 mode="outlined"
66 keyboardType={'number-pad'}
67 style={Styles.form_input}
68 />
69 {/* Number type input (float) */}
70 <PaperTextInput
71 value={productPrice}
72 onChangeText={(text) => setProductPrice(text)}
73 label="Price"
74 mode="outlined"
75 keyboardType={'numeric'}
76 style={Styles.form_input}
77 />
78 {/* Date type input */}
79 <PaperTextInput
80 value={productExpirationDate}
81 onChangeText={(text) => setProductExpirationDate(text)}
82 label="Expiration Date (mm/dd/yyyy)"
83 mode="outlined"
84 keyboardType={'numbers-and-punctuation'}
85 style={Styles.form_input}
86 />
87 {/* Array type input */}
88 <PaperTextInput
89 value={productCategories}
90 onChangeText={(text) => setProductCategories(text)}
91 label="Categories (separated by commas)"
92 mode="outlined"
93 style={Styles.form_input}
94 />
95 {/* Product create button */}
96 <PaperButton
97 onPress={() => createProduct()}
98 mode="contained"
99 icon="plus"
100 style={Styles.submit_button}>
101 {'Create Product'}
102 </PaperButton>
103 </View>
104 </SafeAreaView>
105 </>
106 );
107 };
108
109 // These define the screen component styles
110 const Styles = StyleSheet.create({
111 container: {
112 flex: 1,
113 backgroundColor: '#FFF',
114 },
115 wrapper: {
116 width: '90%',
117 alignSelf: 'center',
118 },
119 header: {
120 alignItems: 'center',
121 paddingTop: 10,
122 paddingBottom: 20,
123 backgroundColor: '#208AEC',
124 },
125 header_logo: {
126 width: 170,
127 height: 40,
128 marginBottom: 10,
129 resizeMode: 'contain',
130 },
131 header_text_bold: {
132 color: '#fff',
133 fontSize: 14,
134 fontWeight: 'bold',
135 },
136 header_text: {
137 marginTop: 3,
138 color: '#fff',
139 fontSize: 14,
140 },
141 form_input: {
142 height: 44,
143 marginBottom: 16,
144 backgroundColor: '#FFF',
145 fontSize: 14,
146 },
147 switch_container: {
148 flexDirection: 'row',
149 alignItems: 'center',
150 justifyContent: 'space-between',
151 paddingVertical: 12,
152 marginBottom: 16,
153 borderBottomWidth: 1,
154 borderBottomColor: 'rgba(0, 0, 0, 0.3)',
155 },
156 submit_button: {
157 width: '100%',
158 maxHeight: 50,
159 alignSelf: 'center',
160 backgroundColor: '#208AEC',
161 },
162 });After setting up this screen, your application should look like this:
Note that each Product attribute has its text input field, except for the boolean switch input, meaning that the data in them needs conversion to the corresponding data type before saving.
2 - Converting input data
Before saving your data to the Parse.object, you need to correctly format the number, DateTime, and array inputs. Let’s now create a saving function, which will retrieve data from your state variables and apply the suitable data conversion:
1 const createProduct = async function (): Promise<[boolean]> {
2 try {
3 // These values come from state variables
4 // Convert data values to corresponding data types
5 const productNameValue: string = productName;
6 const productQuantityValue: number = Number(productQuantity);
7 const productPriceValue: number = Number(productPrice);
8 const productAvailableValue: boolean = productAvailable;
9 const productExpirationDateValue: Date = new Date(productExpirationDate);
10 const productCategoriesValue: string[] = productCategories.split(',');
11 } catch (error) {
12 // Error can be caused by wrong type of values in fields
13 Alert.alert('Error!', error.message);
14 return false;
15 }
16 };The number data conversion is done casting the value as a Number JavaScript object. DateTime is converted using the Date JavaScript object constructor; the array one is created by using the String.split method in JavaScript, creating an array containing each entry of the categories field separated by commas.
Note that your data is now contained inside a single object, which can be set in a new Parse.object instance to be saved to the server using the Parse.Object.set() method, which takes two arguments: the field name and the value to be set. Let’s also set a new field called completeData, which will be your object type field, assigning the same data object to it.
Go ahead and complete the createProduct function with the following:
1 const createProduct = async function (): Promise<[boolean]> {
2 try {
3 // These values come from state variables
4 // Convert data values to corresponding data types
5 const productNameValue: string = productName;
6 const productQuantityValue: number = Number(productQuantity);
7 const productPriceValue: number = Number(productPrice);
8 const productAvailableValue: boolean = productAvailable;
9 const productExpirationDateValue: Date = new Date(productExpirationDate);
10 const productCategoriesValue: string[] = productCategories.split(',');
11 } catch (error) {
12 // Error can be caused by wrong type of values in fields
13 Alert.alert('Error!', error.message);
14 return false;
15 }
16
17 // Creates a new Product parse object instance
18 let Product: Parse.Object = new Parse.Object('Product');
19
20 // Set data to parse object
21 Product.set('name', productNameValue);
22 Product.set('quantity', productQuantityValue);
23 Product.set('price', productPriceValue);
24 Product.set('available', productAvailableValue);
25 Product.set('expirationDate', productExpirationDateValue);
26 Product.set('categories', productCategoriesValue);
27 Product.set('completeData', {
28 name: productNameValue,
29 quantity: productQuantityValue,
30 price: productPriceValue,
31 available: productAvailableValue,
32 expirationDate: productExpirationDateValue,
33 categories: productCategoriesValue,
34 });
35
36 // After setting the values, save it on the server
37 try {
38 let savedProduct: Parse.Object = await Product.save();
39 // Success
40 Alert.alert('Success!', JSON.stringify(savedProduct));
41 return true;
42 } catch (error) {
43 // Error can be caused by lack of Internet connection
44 Alert.alert('Error!', error.message);
45 return false;
46 };
47 };You can now test the component, insert the createProduct function in it, and call it inside your form submit button onPress property. After creating a product, you should see an alert containing its data like this:
To certify that your data was saved on the server using the correct data types, you can look at your Parse dashboard. Click on the Product data table and note that every column has its data type written at the header. Your class should look like this:
Conclusion
At the end of this guide, you learned how to save each of the basic data types available on Parse using a React Native component. In the next guide, you will learn about the relational data on Parse.