Handling Json in HeliScript
Overview
This article introduces how to define and utilize Json in HeliScript.
Verification Environment
SDK Version: 15.1.0
OS: Windows 10
Unity: 2022.3.6f1
Browser: Google Chrome
Setting up Json
The Json handled on this page simulates a list of product information displayed within the shop world.
Note: The test data used on this page contains arbitrary values.
〇 List of Parameters
position: Number indicating the location in the world.
item_id: Number assigned to the product.
name: Product name.
category_name: Name of the category to which the product belongs.
item_type: Type of item (3D model, avatar, texture, etc.).
like_count: Number of likes received by the item.
price_range: Price range setting.
image: URL of the product thumbnail image.
shop_name: Name of the shop where the product is listed.
shop_icon: URL of the shop's icon image.
① Variable Definition
In HeliScript, a Json class is provided. Therefore,
Json _shopInfo;
defines a variable of the Json class.
② Inserting Data into Json Class Variables
You can insert Json into a Json class variable using hsLoadJson(string).
In this case, we use the String-type function GetRawData() provided below.
string GetRawData(){
return
"{" +
"\"status\":\"ok\"," +
"\"data\":{" +
"\"items\":[" +
"{" +
"\"position\":1," +
"\"item_id\":10," +
"\"name\":\"Test Test\"," +
"\"category_name\":\"test\"," +
"\"item_type\":\"test\"," +
"\"like_count\":2," +
"\"price_range\":\"￥0-1,000\"," +
"\"image\":\"URL\"," +
"\"shop_name\":\"URL\"," +
"\"shop_icon\":\"URL\"" +
"}," +
"{" +
"\"position\":2," +
"\"item_id\":11," +
"\"name\":\"Test2 Test2\"," +
"\"category_name\":\"test2\"," +
"\"item_type\":\"test2\"," +
"\"like_count\":3," +
"\"price_range\":\"￥3-1,000\"," +
"\"image\":\"URL2\"," +
"\"shop_name\":\"URL2\"," +
"\"shop_icon\":\"URL2\"" +
"}" +
"]" +
"}" +
"}";
}
The HeliScript code to insert the data looks like this:
_shopInfo = hsLoadJson(GetRawData());
③ Extracting Necessary Information from Json
The Json used here includes the following hierarchy:
・status
・data
├items
├position
├item_id
├name
├category_name
├item_type
├like_count
├price_range
├image
├shop_name
└shop_icon
We'll extract item_id and name in this example.
1. Extracting data from the overall Json and defining it as a new Json file
Using the Find function defined in the Json class, you can locate and define the content under a specified data type and key as a new Json file.
Therefore,
Json datablock = _shopInfo.Find(EJSONDataType_Block, "data");
defines datablock as the Json containing data.
2. Extracting items from data and defining it as a new Json file
Similarly, using the Find function, extract items from datablock.
Json items = datablock.Find(EJSONDataType_Array, "items");
Now, items is a Json file containing items.
Difference in EJSONDataType
When extracting datablock, EJSONDataType_Block is used in the Find function, and when extracting items, EJSONDataType_Array is used. These are used based on the data definition format in Json.
Use Block for elements enclosed in {}, and Array for elements enclosed in [].
3. Creating an ArrayList from items
Within items, 15 items are defined.
To access each element, you need to list them as Json.
list<Json> dataJsons = items.GetArrayList();
This creates dataJsons, listing each of the 15 items in items as separate Json.
4. Extracting data from each element of the item
After these preparations, you can finally extract the data.
For extraction, use functions like FindValueString and FindValueInt, tailored to the type of data you're extracting.
With these functions, you can assign values from specified items to variables.
Therefore, the code would look like this:
int itemId; // Variable to store item_id
string itemName; // Variable to store name
for(int i = 0; i < dataJsons.Count; i++){ // Loop through each item
itemId = -1; // Initialize variables
itemName = ""; // Initialize variables
dataJsons[i].FindValueInt("item_id",itemId); // Assign value of item_id to itemId
dataJsons[i].FindValueString("name",itemName); // Assign value of name to itemName
hsSystemOutput("dataJsons[%d] item_id : %d , name : %s\n" % i %itemId % itemName);
}
Summarizing the code, it looks like this:
component SetProductData
{
Json _shopInfo;
public SetProductData()
{
_shopInfo = hsLoadJson(GetRawData());
FindJsonContents();
}
public void Update()
{
}
string GetRawData(){
return
"{" +
"\"status\":\"ok\"," +
"\"data\":{" +
"\"items\":[" +
"{" +
"\"position\":1," +
"\"item_id\":10," +
"\"name\":\"Test Test\"," +
"\"category_name\":\"test\"," +
"\"item_type\":\"test\"," +
"\"like_count\":2," +
"\"price_range\":\"￥0-1,000\"," +
"\"image\":\"URL\"," +
"\"shop_name\":\"URL\"," +
"\"shop_icon\":\"URL\"" +
"}," +
"{" +
"\"position\":2," +
"\"item_id\":11," +
"\"name\":\"Test2 Test2\"," +
"\"category_name\":\"test2\"," +
"\"item_type\":\"test2\"," +
"\"like_count\":3," +
"\"price_range\":\"￥3-1,000\"," +
"\"image\":\"URL2\"," +
"\"shop_name\":\"URL2\"," +
"\"shop_icon\":\"URL2\"" +
"}," +
"]" +
"}" +
"}";
}
void FindJsonContents(){
int itemId;
string itemName;
Json datablock = _shopInfo.Find(EJSONDataType_Block, "data");
Json items = datablock.Find(EJSONDataType_Array, "items");
list<Json> dataJsons = items.GetArrayList();
for(int i = 0; i < dataJsons.Count; i++){ // Loop through each item
itemId = -1; // Initialize variables
itemName = ""; // Initialize variables
dataJsons[i].FindValueInt("item_id",itemId); // Assign value of item_id to itemId
dataJsons[i].FindValueString("name",itemName); // Assign value of name to itemName
hsSystemOutput("dataJsons[%d] item_id : %d , name : %s\n" % i %itemId % itemName);
}
}
}
When executed, this code produces the following output:
dataJsons[0] item_id : 10 , name : Test Test
dataJsons[1] item_id : 11 , name : Test2 Test2
Caution
When handling Json, there's a possibility of malfunction with Shift_JIS depending on the incoming data. Therefore, it's recommended to use UTF-8 for .hs file encoding.
Moreover, using JsVal for reading can offer greater convenience.