Feature/add ability to specify dynamic metadata to jsonlines (#3238)

* add ability to specify dynamic metadata to jsonlines

* fix additional metadata

Author: HenryHengZJ

Diff for: packages/components/nodes/documentloaders/Jsonlines/Jsonlines.ts

@@ -1,8 +1,31 @@
 import { omit } from 'lodash'
 import { ICommonObject, IDocument, INode, INodeData, INodeParams } from '../../../src/Interface'
 import { TextSplitter } from 'langchain/text_splitter'
-import { JSONLinesLoader } from 'langchain/document_loaders/fs/json'
+import jsonpointer from 'jsonpointer'
 import { getFileFromStorage } from '../../../src'
+import { BaseDocumentLoader } from 'langchain/document_loaders/base'
+import { Document } from '@langchain/core/documents'
+import type { readFile as ReadFileT } from 'node:fs/promises'
+
+const howToUseCode = `
+You can add metadata dynamically from the document:
+
+For example, if the document is:
+\`\`\`jsonl
+{
+    "source": "www.example.com", "content": "Hello World!"
+}
+{
+    "source": "www.example2.com", "content": "Hi World!"
+}
+\`\`\`
+
+You can have the "source" value as metadata by returning the following:
+\`\`\`json
+{
+    "source": "/source"
+}
+\`\`\``
 
 class Jsonlines_DocumentLoaders implements INode {
     label: string
@@ -18,7 +41,7 @@ class Jsonlines_DocumentLoaders implements INode {
     constructor() {
         this.label = 'Json Lines File'
         this.name = 'jsonlinesFile'
-        this.version = 1.0
+        this.version = 2.0
         this.type = 'Document'
         this.icon = 'jsonlines.svg'
         this.category = 'Document Loaders'
@@ -41,14 +64,20 @@ class Jsonlines_DocumentLoaders implements INode {
                 label: 'Pointer Extraction',
                 name: 'pointerName',
                 type: 'string',
-                placeholder: 'Enter pointer name',
+                placeholder: 'key',
+                description: 'Ex: { "key": "value" }, Pointer Extraction = "key", "value" will be extracted as pageContent of the chunk',
                 optional: false
             },
             {
                 label: 'Additional Metadata',
                 name: 'metadata',
                 type: 'json',
-                description: 'Additional metadata to be added to the extracted documents',
+                description:
+                    'Additional metadata to be added to the extracted documents. You can add metadata dynamically from the document. Ex: { "key": "value", "source": "www.example.com" }. Metadata: { "page": "/source" } will extract the value of the key "source" from the document and add it to the metadata with the key "page"',
+                hint: {
+                    label: 'How to use',
+                    value: howToUseCode
+                },
                 optional: true,
                 additionalParams: true
             },
@@ -96,7 +125,7 @@ class Jsonlines_DocumentLoaders implements INode {
                 if (!file) continue
                 const fileData = await getFileFromStorage(file, chatflowid)
                 const blob = new Blob([fileData])
-                const loader = new JSONLinesLoader(blob, pointer)
+                const loader = new JSONLinesLoader(blob, pointer, metadata)
 
                 if (textSplitter) {
                     let splittedDocs = await loader.load()
@@ -119,7 +148,7 @@ class Jsonlines_DocumentLoaders implements INode {
                 splitDataURI.pop()
                 const bf = Buffer.from(splitDataURI.pop() || '', 'base64')
                 const blob = new Blob([bf])
-                const loader = new JSONLinesLoader(blob, pointer)
+                const loader = new JSONLinesLoader(blob, pointer, metadata)
 
                 if (textSplitter) {
                     let splittedDocs = await loader.load()
@@ -132,7 +161,8 @@ class Jsonlines_DocumentLoaders implements INode {
         }
 
         if (metadata) {
-            const parsedMetadata = typeof metadata === 'object' ? metadata : JSON.parse(metadata)
+            let parsedMetadata = typeof metadata === 'object' ? metadata : JSON.parse(metadata)
+            parsedMetadata = removeValuesStartingWithSlash(parsedMetadata)
             docs = docs.map((doc) => ({
                 ...doc,
                 metadata:
@@ -167,4 +197,122 @@ class Jsonlines_DocumentLoaders implements INode {
     }
 }
 
+const removeValuesStartingWithSlash = (obj: Record<string, any>): Record<string, any> => {
+    const result: Record<string, any> = {}
+
+    for (const key in obj) {
+        const value = obj[key]
+        if (typeof value === 'string' && value.startsWith('/')) {
+            continue
+        }
+        result[key] = value
+    }
+
+    return result
+}
+
+class TextLoader extends BaseDocumentLoader {
+    constructor(public filePathOrBlob: string | Blob) {
+        super()
+    }
+
+    protected async parse(raw: string): Promise<{ pageContent: string; metadata: ICommonObject }[]> {
+        return [{ pageContent: raw, metadata: {} }]
+    }
+
+    public async load(): Promise<Document[]> {
+        let text: string
+        let metadata: Record<string, string>
+        if (typeof this.filePathOrBlob === 'string') {
+            const { readFile } = await TextLoader.imports()
+            text = await readFile(this.filePathOrBlob, 'utf8')
+            metadata = { source: this.filePathOrBlob }
+        } else {
+            text = await this.filePathOrBlob.text()
+            metadata = { source: 'blob', blobType: this.filePathOrBlob.type }
+        }
+        const parsed = await this.parse(text)
+        parsed.forEach((parsedData, i) => {
+            const { pageContent } = parsedData
+            if (typeof pageContent !== 'string') {
+                throw new Error(`Expected string, at position ${i} got ${typeof pageContent}`)
+            }
+        })
+        return parsed.map((parsedData, i) => {
+            const { pageContent, metadata: additionalMetadata } = parsedData
+            return new Document({
+                pageContent,
+                metadata:
+                    parsed.length === 1
+                        ? { ...metadata, ...additionalMetadata }
+                        : {
+                              ...metadata,
+                              line: i + 1,
+                              ...additionalMetadata
+                          }
+            })
+        })
+    }
+
+    static async imports(): Promise<{
+        readFile: typeof ReadFileT
+    }> {
+        try {
+            const { readFile } = await import('node:fs/promises')
+            return { readFile }
+        } catch (e) {
+            console.error(e)
+            throw new Error(`Failed to load fs/promises. Make sure you are running in Node.js environment.`)
+        }
+    }
+}
+
+class JSONLinesLoader extends TextLoader {
+    metadata?: ICommonObject
+    additionalMetadata: ICommonObject[] = []
+
+    constructor(filePathOrBlob: string | Blob, public pointer: string, metadata?: any) {
+        super(filePathOrBlob)
+        if (metadata) {
+            this.metadata = typeof metadata === 'object' ? metadata : JSON.parse(metadata)
+        }
+    }
+
+    async getAdditionalMetadata(): Promise<ICommonObject[]> {
+        return this.additionalMetadata
+    }
+
+    protected async parse(raw: string): Promise<{ pageContent: string; metadata: ICommonObject }[]> {
+        const lines = raw.split('\n')
+        const jsons = lines
+            .map((line) => line.trim())
+            .filter(Boolean)
+            .map((line) => JSON.parse(line))
+        const pointer = jsonpointer.compile(this.pointer)
+        if (this.metadata) {
+            const values = Object.values(this.metadata).filter((value) => typeof value === 'string' && value.startsWith('/'))
+            let newJsons = []
+            for (const json of jsons) {
+                let metadata = {}
+                for (const value of values) {
+                    if (value) {
+                        const key = Object.keys(this.metadata).find((key) => this.metadata?.[key] === value)
+                        if (key) {
+                            metadata = {
+                                ...metadata,
+                                [key]: jsonpointer.get(json, value)
+                            }
+                        }
+                    }
+                }
+                newJsons.push({ pageContent: pointer.get(json), metadata })
+            }
+            return newJsons
+        }
+        return jsons.map((json) => {
+            return { pageContent: pointer.get(json), metadata: {} }
+        })
+    }
+}
+
 module.exports = { nodeClass: Jsonlines_DocumentLoaders }