为什么 schema.org JSON-LD 表示这么小?

Why is the schema.org JSON-LD representation so small?

请求 JSON-LD 形式的 schema.org 词汇时(可以通过以下请求 headers 完成):

Accept: application/ld+json, application/json;q=0.9, application/javascript;q=0.5, text/javascript;q=0.5, text/plain;q=0.2, */*;q=0.1

回复文件(截断在底部)乍一看似乎非常小且不完整。它只列出了一些属性,并且似乎没有像 full hierarchy. Even looking at a single type, http://schema.org/CreativeWork, there are many attributes that don't appear in the document (ex: keywords). Even the attribute name 中显示的任何类型,这应该是每个事物的一部分,但没有出现在结果中。

为什么 schema.org 中提到的所有属性都没有包含在本文档中?

{
    "@context":    {
        "@vocab": "http://schema.org/",
        "acceptsReservations": { "@type": "@id" },
        "additionalType": { "@type": "@id" },
        "applicationCategory": { "@type": "@id" },
        "applicationSubCategory": { "@type": "@id" },
        "arrivalTime": { "@type": "DateTime" },
        "artform": { "@type": "@id" },
        "availabilityEnds": { "@type": "DateTime" },
        "availabilityStarts": { "@type": "DateTime" },
        "availableFrom": { "@type": "DateTime" },
        "availableThrough": { "@type": "DateTime" },
        "birthDate": { "@type": "Date" },
        "bookingTime": { "@type": "DateTime" },
        "checkinTime": { "@type": "DateTime" },
        "checkoutTime": { "@type": "DateTime" },
        "codeRepository": { "@type": "@id" },
        "commentTime": { "@type": "Date" },
        "contentUrl": { "@type": "@id" },
        "dateCreated": { "@type": "Date" },
        "dateIssued": { "@type": "DateTime" },
        "dateModified": { "@type": "Date" },
        "datePosted": { "@type": "Date" },
        "datePublished": { "@type": "Date" },
        "deathDate": { "@type": "Date" },
        "departureTime": { "@type": "DateTime" },
        "discussionUrl": { "@type": "@id" },
        "dissolutionDate": { "@type": "Date" },
        "doorTime": { "@type": "DateTime" },
        "downloadUrl": { "@type": "@id" },
        "dropoffTime": { "@type": "DateTime" },
        "embedUrl": { "@type": "@id" },
        "endDate": { "@type": "Date" },
        "endTime": { "@type": "DateTime" },
        "expectedArrivalFrom": { "@type": "DateTime" },
        "expectedArrivalUntil": { "@type": "DateTime" },
        "expires": { "@type": "Date" },
        "featureList": { "@type": "@id" },
        "foundingDate": { "@type": "Date" },
        "gameLocation": { "@type": "@id" },
        "gamePlatform": { "@type": "@id" },
        "guidelineDate": { "@type": "Date" },
        "hasMap": { "@type": "@id" },
        "image": { "@type": "@id" },
        "installUrl": { "@type": "@id" },
        "isBasedOnUrl": { "@type": "@id" },
        "labelDetails": { "@type": "@id" },
        "lastReviewed": { "@type": "Date" },
        "license": { "@type": "@id" },
        "logo": { "@type": "@id" },
        "map": { "@type": "@id" },
        "maps": { "@type": "@id" },
        "material": { "@type": "@id" },
        "memoryRequirements": { "@type": "@id" },
        "menu": { "@type": "@id" },
        "modifiedTime": { "@type": "DateTime" },
        "namedPosition": { "@type": "@id" },
        "orderDate": { "@type": "DateTime" },
        "ownedFrom": { "@type": "DateTime" },
        "ownedThrough": { "@type": "DateTime" },
        "paymentDue": { "@type": "DateTime" },
        "paymentUrl": { "@type": "@id" },
        "pickupTime": { "@type": "DateTime" },
        "prescribingInfo": { "@type": "@id" },
        "previousStartDate": { "@type": "Date" },
        "priceValidUntil": { "@type": "Date" },
        "publishingPrinciples": { "@type": "@id" },
        "relatedLink": { "@type": "@id" },
        "releaseDate": { "@type": "Date" },
        "releaseNotes": { "@type": "@id" },
        "replyToUrl": { "@type": "@id" },
        "requirements": { "@type": "@id" },
        "roleName": { "@type": "@id" },
        "sameAs": { "@type": "@id" },
        "scheduledPaymentDate": { "@type": "Date" },
        "scheduledTime": { "@type": "DateTime" },
        "screenshot": { "@type": "@id" },
        "serviceUrl": { "@type": "@id" },
        "significantLink": { "@type": "@id" },
        "significantLinks": { "@type": "@id" },
        "sport": { "@type": "@id" },
        "startDate": { "@type": "Date" },
        "startTime": { "@type": "DateTime" },
        "storageRequirements": { "@type": "@id" },
        "surface": { "@type": "@id" },
        "targetUrl": { "@type": "@id" },
        "temporal": { "@type": "DateTime" },
        "thumbnailUrl": { "@type": "@id" },
        "ticketToken": { "@type": "@id" },
        "trackingUrl": { "@type": "@id" },
        "uploadDate": { "@type": "Date" },
        "url": { "@type": "@id" },
        "validFrom": { "@type": "DateTime" },
        "validThrough": { "@type": "DateTime" },
        "validUntil": { "@type": "Date" },
        "warning": { "@type": "@id" },
        "webCheckinTime": { "@type": "DateTime" }
    }
}

因为这不是词汇表的定义,而只是 Schema.org 的 JSON-LD 上下文,即从漂亮、简短的 JSON 术语到完整 URL 的映射。有关详细信息,请参阅 http://www.w3.org/TR/json-ld/#the-context

它没有将每个 属性 和 class 一个一个映射的原因是它使用了 @vocab 快捷方式,这也在规范中进行了描述:http://www.w3.org/TR/json-ld/#default-vocabulary