250 lines
9.9 KiB
TypeScript
250 lines
9.9 KiB
TypeScript
import { TextSplitter } from 'langchain/text_splitter'
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import { omit } from 'lodash'
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import { CheerioWebBaseLoader, WebBaseLoaderParams } from '@langchain/community/document_loaders/web/cheerio'
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import { test } from 'linkifyjs'
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import { parse } from 'css-what'
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import { SelectorType } from 'cheerio'
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import { ICommonObject, INodeOutputsValue, IDocument, INode, INodeData, INodeParams } from '../../../src/Interface'
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import { handleEscapeCharacters, webCrawl, xmlScrape } from '../../../src/utils'
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class Cheerio_DocumentLoaders implements INode {
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label: string
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name: string
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version: number
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description: string
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type: string
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icon: string
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category: string
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baseClasses: string[]
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inputs: INodeParams[]
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outputs: INodeOutputsValue[]
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constructor() {
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this.label = 'Cheerio Web Scraper'
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this.name = 'cheerioWebScraper'
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this.version = 2.0
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this.type = 'Document'
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this.icon = 'cheerio.svg'
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this.category = 'Document Loaders'
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this.description = `Load data from webpages`
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this.baseClasses = [this.type]
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this.inputs = [
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{
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label: 'URL',
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name: 'url',
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type: 'string'
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},
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{
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label: 'Text Splitter',
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name: 'textSplitter',
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type: 'TextSplitter',
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optional: true
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},
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{
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label: 'Get Relative Links Method',
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name: 'relativeLinksMethod',
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type: 'options',
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description: 'Select a method to retrieve relative links',
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options: [
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{
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label: 'Web Crawl',
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name: 'webCrawl',
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description: 'Crawl relative links from HTML URL'
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},
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{
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label: 'Scrape XML Sitemap',
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name: 'scrapeXMLSitemap',
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description: 'Scrape relative links from XML sitemap URL'
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}
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],
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default: 'webCrawl',
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optional: true,
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additionalParams: true
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},
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{
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label: 'Get Relative Links Limit',
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name: 'limit',
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type: 'number',
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optional: true,
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default: '10',
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additionalParams: true,
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description:
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'Only used when "Get Relative Links Method" is selected. Set 0 to retrieve all relative links, default limit is 10.',
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warning: `Retrieving all links might take long time, and all links will be upserted again if the flow's state changed (eg: different URL, chunk size, etc)`
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},
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{
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label: 'Selector (CSS)',
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name: 'selector',
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type: 'string',
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description: 'Specify a CSS selector to select the content to be extracted',
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optional: true,
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additionalParams: true
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},
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{
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label: 'Additional Metadata',
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name: 'metadata',
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type: 'json',
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description: 'Additional metadata to be added to the extracted documents',
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optional: true,
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additionalParams: true
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},
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{
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label: 'Omit Metadata Keys',
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name: 'omitMetadataKeys',
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type: 'string',
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rows: 4,
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description:
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'Each document loader comes with a default set of metadata keys that are extracted from the document. You can use this field to omit some of the default metadata keys. The value should be a list of keys, seperated by comma. Use * to omit all metadata keys execept the ones you specify in the Additional Metadata field',
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placeholder: 'key1, key2, key3.nestedKey1',
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optional: true,
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additionalParams: true
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}
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]
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this.outputs = [
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{
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label: 'Document',
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name: 'document',
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description: 'Array of document objects containing metadata and pageContent',
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baseClasses: [...this.baseClasses, 'json']
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},
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{
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label: 'Text',
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name: 'text',
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description: 'Concatenated string from pageContent of documents',
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baseClasses: ['string', 'json']
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}
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]
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}
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async init(nodeData: INodeData, _: string, options: ICommonObject): Promise<any> {
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const textSplitter = nodeData.inputs?.textSplitter as TextSplitter
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const metadata = nodeData.inputs?.metadata
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const relativeLinksMethod = nodeData.inputs?.relativeLinksMethod as string
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const selectedLinks = nodeData.inputs?.selectedLinks as string[]
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let limit = parseInt(nodeData.inputs?.limit as string)
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const output = nodeData.outputs?.output as string
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const orgId = options.orgId
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const _omitMetadataKeys = nodeData.inputs?.omitMetadataKeys as string
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let omitMetadataKeys: string[] = []
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if (_omitMetadataKeys) {
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omitMetadataKeys = _omitMetadataKeys.split(',').map((key) => key.trim())
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}
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let url = nodeData.inputs?.url as string
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url = url.trim()
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if (!test(url)) {
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throw new Error('Invalid URL')
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}
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const selector: SelectorType = nodeData.inputs?.selector as SelectorType
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let params: WebBaseLoaderParams = {}
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if (selector) {
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parse(selector) // comes with cheerio - will throw error if invalid
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params['selector'] = selector
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}
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async function cheerioLoader(url: string): Promise<any> {
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try {
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let docs: IDocument[] = []
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if (url.endsWith('.pdf')) {
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if (process.env.DEBUG === 'true')
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options.logger.info(`[${orgId}]: CheerioWebBaseLoader does not support PDF files: ${url}`)
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return docs
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}
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const loader = new CheerioWebBaseLoader(url, params)
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if (textSplitter) {
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docs = await loader.load()
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docs = await textSplitter.splitDocuments(docs)
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} else {
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docs = await loader.load()
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}
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return docs
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} catch (err) {
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if (process.env.DEBUG === 'true')
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options.logger.error(`[${orgId}]: Error in CheerioWebBaseLoader: ${err.message}, on page: ${url}`)
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return []
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}
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}
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let docs: IDocument[] = []
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if (relativeLinksMethod) {
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if (process.env.DEBUG === 'true') options.logger.info(`[${orgId}]: Start CheerioWebBaseLoader ${relativeLinksMethod}`)
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// if limit is 0 we don't want it to default to 10 so we check explicitly for null or undefined
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// so when limit is 0 we can fetch all the links
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if (limit === null || limit === undefined) limit = 10
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else if (limit < 0) throw new Error('Limit cannot be less than 0')
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const pages: string[] =
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selectedLinks && selectedLinks.length > 0
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? selectedLinks.slice(0, limit === 0 ? undefined : limit)
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: relativeLinksMethod === 'webCrawl'
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? await webCrawl(url, limit)
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: await xmlScrape(url, limit)
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if (process.env.DEBUG === 'true')
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options.logger.info(`[${orgId}]: CheerioWebBaseLoader pages: ${JSON.stringify(pages)}, length: ${pages.length}`)
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if (!pages || pages.length === 0) throw new Error('No relative links found')
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for (const page of pages) {
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docs.push(...(await cheerioLoader(page)))
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}
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if (process.env.DEBUG === 'true') options.logger.info(`[${orgId}]: Finish CheerioWebBaseLoader ${relativeLinksMethod}`)
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} else if (selectedLinks && selectedLinks.length > 0) {
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if (process.env.DEBUG === 'true')
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options.logger.info(
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`[${orgId}]: CheerioWebBaseLoader pages: ${JSON.stringify(selectedLinks)}, length: ${selectedLinks.length}`
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)
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for (const page of selectedLinks.slice(0, limit)) {
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docs.push(...(await cheerioLoader(page)))
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}
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} else {
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docs = await cheerioLoader(url)
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}
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if (metadata) {
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const parsedMetadata = typeof metadata === 'object' ? metadata : JSON.parse(metadata)
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docs = docs.map((doc) => ({
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...doc,
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metadata:
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_omitMetadataKeys === '*'
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? {
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...parsedMetadata
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}
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: omit(
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{
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...doc.metadata,
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...parsedMetadata
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},
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omitMetadataKeys
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)
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}))
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} else {
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docs = docs.map((doc) => ({
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...doc,
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metadata:
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_omitMetadataKeys === '*'
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? {}
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: omit(
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{
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...doc.metadata
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},
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omitMetadataKeys
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)
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}))
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}
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if (output === 'document') {
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return docs
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} else {
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let finaltext = ''
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for (const doc of docs) {
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finaltext += `${doc.pageContent}\n`
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}
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return handleEscapeCharacters(finaltext, false)
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}
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}
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}
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module.exports = { nodeClass: Cheerio_DocumentLoaders }
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