如何从Jsonix生成的.js映射文件获取元素数据类型及XSD相关问题

Great question! Jsonix mappings encapsulate all the XSD metadata you need, including data types—here's how to extract that information effectively:

1. Navigate the Mapping Structure #

Jsonix generates a structured object with two core sections:

• elementInfos: Defines top-level XML elements, each linking to its associated type.
• typeInfos: Contains detailed schema for complex/simple types, including property data types and constraints.

2. Access Type Details Programmatically #

Let's use your XSD example (with DocumentElement and Item) to illustrate. Assume your generated mapping is stored in a variable MySchemaMapping:

// Load your generated Jsonix mapping
const MySchemaMapping = require('./path/to/your/generated-mapping.js');

// Find the type info for the "Item" complex type
const itemType = MySchemaMapping.typeInfos.find(info => info.name === 'Item');

// Loop through Item's properties to get their data types
if (itemType) {
  itemType.properties.forEach(prop => {
    console.log(`Property: ${prop.name}`);
    console.log(`Data Type: ${prop.type}`);
    
    // For restricted simple types (like your Text_1 element), check base type and facets
    if (prop.baseType) {
      console.log(`Base Type: ${prop.baseType}`);
      if (prop.facets) {
        console.log(`Restrictions:`, prop.facets);
      }
    }
  });
}

What to Look For: #

• Simple types: The type field will directly reference XML Schema types (e.g., xs:string, xs:int).
• Complex types: type will point to another entry in typeInfos—you can recursively traverse these to get nested property types.
• Unbounded elements: For elements like your Item (with maxOccurs="unbounded"), the mapping will set maxOccurs to Number.POSITIVE_INFINITY or the string "unbounded".

3. Inspect the Mapping Directly #

If you don't need to do this programmatically, you can just open the generated .js file in a text editor. Search for your element/type name, and you'll see the type or baseType fields clearly listed alongside the property definitions.

Your partial XSD shows a Text_1 element with a restricted xs:string type. When Jsonix generates the mapping for this, it will include a facets array in the type info for Text_1 that lists all the restriction rules (e.g., pattern, maxLength) from your full XSD. This lets you verify exactly how the type is constrained.

内容的提问来源于stack exchange，提问作者dityagow