Files
shields/services/dynamic/dynamic-xml.service.js
2023-05-01 19:17:40 +01:00

127 lines
3.7 KiB
JavaScript

import { DOMParser } from '@xmldom/xmldom'
import xpath from 'xpath'
import { MetricNames } from '../../core/base-service/metric-helper.js'
import { renderDynamicBadge, errorMessages } from '../dynamic-common.js'
import { BaseService, InvalidResponse, InvalidParameter } from '../index.js'
import { createRoute } from './dynamic-helpers.js'
// This service extends BaseService because it uses a different XML parser
// than BaseXmlService which can be used with xpath.
//
// One way to create a more performant version would be to use the BaseXml
// JSON parser and write the queries in jsonpath instead. Then eventually
// deprecate the old version.
export default class DynamicXml extends BaseService {
static category = 'dynamic'
static enabledMetrics = [MetricNames.SERVICE_RESPONSE_SIZE]
static route = createRoute('xml')
static openApi = {
'/badge/dynamic/xml': {
get: {
summary: 'Dynamic XML Badge',
description: `<p>
The Dynamic XML Badge allows you to extract an arbitrary value from any
XML Document using an XPath selector and show it on a badge.
</p>`,
parameters: [
{
name: 'url',
description: 'The URL to a XML document',
in: 'query',
required: true,
schema: { type: 'string' },
example: 'https://httpbin.org/xml',
},
{
name: 'query',
description:
'A <a href="http://xpather.com/">XPath</a> expression that will be used to query the document',
in: 'query',
required: true,
schema: { type: 'string' },
example: '//slideshow/slide[1]/title',
},
{
name: 'prefix',
description: 'Optional prefix to append to the value',
in: 'query',
required: false,
schema: { type: 'string' },
example: '[',
},
{
name: 'suffix',
description: 'Optional suffix to append to the value',
in: 'query',
required: false,
schema: { type: 'string' },
example: ']',
},
],
},
},
}
static defaultBadgeData = { label: 'custom badge' }
transform({ pathExpression, buffer }) {
// e.g. //book[2]/@id
const pathIsAttr = (
pathExpression.split('/').slice(-1)[0] || ''
).startsWith('@')
const parsed = new DOMParser().parseFromString(buffer)
let values
try {
values = xpath.select(pathExpression, parsed)
} catch (e) {
throw new InvalidParameter({ prettyMessage: e.message })
}
if (
typeof values === 'string' ||
typeof values === 'number' ||
typeof values === 'boolean'
) {
values = [values]
} else if (Array.isArray(values)) {
values = values.reduce((accum, node) => {
if (pathIsAttr) {
accum.push(node.value)
} else if (node.firstChild) {
accum.push(node.firstChild.data)
} else {
accum.push(node.data)
}
return accum
}, [])
} else {
throw new InvalidResponse({
prettyMessage: 'unsupported query',
})
}
if (!values.length) {
throw new InvalidResponse({ prettyMessage: 'no result' })
}
return { values }
}
async handle(_namedParams, { url, query: pathExpression, prefix, suffix }) {
const { buffer } = await this._request({
url,
options: { headers: { Accept: 'application/xml, text/xml' } },
errorMessages,
})
const { values: value } = this.transform({
pathExpression,
buffer,
})
return renderDynamicBadge({ value, prefix, suffix })
}
}