├── Code.gs
└── README.md


/Code.gs:
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  1 | // source: https://github.com/qoomon/gmail-rss-feed
  2 | // Version: 1.0.1
  3 | 
  4 | const {doGet} = (() => {
  5 |   // --------------- config ---------------------
  6 |   const rssFeedGmailRootLabel = 'RSS Feed'
  7 |   const rssFeedMaxItems = 50
  8 |   
  9 |   // --------------- entrypoint ---------------------
 10 |   function doGet(event) {
 11 |     Logger.log("[EVENT]")
 12 |     Logger.log('Parameters:', event.parameter)
 13 |     const response = doGetRssFeedXml(event)
 14 |     Logger.log('[RESPONSE]')
 15 |     Logger.log('MimeType:', response.getMimeType())
 16 |     Logger.log('Content...')
 17 |     Logger.log(response.getContent())
 18 |     return response
 19 |   }
 20 |   
 21 |   function doGetRssFeedXml(event) {
 22 |     // --------------- input parameters---------------------
 23 |   
 24 |     const rssFeedName = event.parameter['gmail-rss-feed']
 25 |     if (!rssFeedName) {
 26 |       return ContentService.createTextOutput("400 - 'feed' parameter missing")
 27 |     }
 28 |     
 29 |     const rssFeedTitle = event.parameter['title']
 30 |     
 31 |     const isMultiAuthor = isAnyOf(event.parameter['multi-author'], ['', 'true'])
 32 |   
 33 |     // --------------- gather rss mails---------------------
 34 |   
 35 |     const gmailFeedLabel = GmailApp.getUserLabelByName(`${rssFeedGmailRootLabel}/${rssFeedName}`)
 36 |     if (!gmailFeedLabel) {
 37 |       return ContentService.createTextOutput(`400 - '${rssFeedName}' feed not found`)
 38 |     }
 39 |   
 40 |     const gmailFeedMessages = gmailFeedLabel.getThreads(0, rssFeedMaxItems)
 41 |       .map(thread => thread.getMessages()[0])
 42 |   
 43 |     // --------------- create rss feed ---------------------
 44 |   
 45 |     const rssFeed = {
 46 |       title: rssFeedTitle || `${rssFeedName} - Gmail RSS Feed`,
 47 |       description: `${rssFeedName} - Gmail RSS Feed`,
 48 |       link: `https://mail.google.com/#label/${gmailFeedLabel.getName()}`,
 49 |       image: 'https://ssl.gstatic.com/ui/v1/icons/mail/favicon.ico',
 50 |       atomLink: ScriptApp.getService().getUrl(),
 51 |       items: gmailFeedMessages.map(gmailMessage => ({
 52 |           guid: gmailMessage.getId(),
 53 |           author: gmailMessage.getFrom(),
 54 |           title: (isMultiAuthor ? `${getSenderDisplayName(gmailMessage.getFrom())} - `: "")
 55 |             + gmailMessage.getSubject(),
 56 |           link: `https://mail.google.com/mail/u/0/#label/${gmailFeedLabel.getName()}/${gmailMessage.getId()}`,
 57 |           description: gmailMessage.getBody(),
 58 |           pubDate: gmailMessage.getDate()
 59 |         }))
 60 |     }
 61 |   
 62 |     const rssFeedXmlElement = createRssFeedXmlElement(rssFeed)
 63 |     const rssFeedXmlDocument = XmlService.createDocument(rssFeedXmlElement)
 64 |     const rssFeedXmlText = XmlService.getPrettyFormat().format(rssFeedXmlDocument)
 65 |     return ContentService.createTextOutput(rssFeedXmlText)
 66 |       .setMimeType(ContentService.MimeType.RSS)
 67 |   }
 68 |   
 69 |   function createRssFeedXmlElement(rssObject) {
 70 |     const rss = XmlService.parse("<rss xmlns:atom='http://www.w3.org/2005/Atom' version='2.0'/>").detachRootElement()
 71 |     return rss.addContent(xmlElement('channel', channel => {
 72 |       channel.addContent(xmlElement('title').setText(rssObject.title))
 73 |       channel.addContent(xmlElement('description').setText(rssObject.description))
 74 |       channel.addContent(xmlElement('link').setText(rssObject.link))
 75 |       if (rssObject.image) {
 76 |         channel.addContent(xmlElement('image')
 77 |           .addContent(xmlElement('url').setText(rssObject.image))
 78 |           .addContent(xmlElement('title').setText(rssObject.title))
 79 |           .addContent(xmlElement('link').setText(rssObject.link)))
 80 |       }
 81 |       if (rssObject.atomLink) {
 82 |         channel.addContent(XmlService.createElement('link')
 83 |           .setNamespace(rss.getNamespace('atom'))
 84 |           .setAttribute('href', rssObject.atomLink)
 85 |           .setAttribute('rel', 'self')
 86 |           .setAttribute('type', 'application/rss+xml'))
 87 |       }
 88 |       rssObject.items.forEach(itemObject => {
 89 |         channel.addContent(createRssFeedItemXmlElement(itemObject))
 90 |       })
 91 |     }))
 92 |   }
 93 |   
 94 |   function createRssFeedItemXmlElement(itemObject) {
 95 |     return xmlElement('item', item => {
 96 |       item.addContent(xmlElement('title').setText(itemObject.title))
 97 |       item.addContent(xmlElement('link').setText(itemObject.link))
 98 |       item.addContent(xmlElement('description')
 99 |         .addContent(XmlService.createCdata(itemObject.description)))
100 |       if (itemObject.pubDate) {
101 |         item.addContent(xmlElement('pubDate')
102 |           .setText(Utilities.formatDate(itemObject.pubDate, 'UTC', "EEE, dd MMM yyyy HH:mm:ss Z")))
103 |       }
104 |       if (itemObject.guid) {
105 |         item.addContent(xmlElement('guid').setText(itemObject.guid))
106 |       }
107 |       if (itemObject.author) {
108 |         item.addContent(xmlElement('author').setText(itemObject.author))
109 |       }
110 |     })
111 |   }
112 |   
113 |   function xmlElement(name, modifier) {
114 |     const element = XmlService.createElement(name)
115 |     if (modifier) {
116 |       modifier(element)
117 |     }
118 |     return element
119 |   }
120 |   
121 |   function isAnyOf(value, ...validValues) {
122 |      validValues.includes(value)
123 |   }
124 |   
125 |   function getSenderDisplayName(sender) {
126 |     return sender.trim().match(/^(?<name>[^<]+)<.*>/)?.groups?.name?.trim()
127 |       ?? sender.trim().match(/^<(?<name>[^>]*)>/)?.groups?.name?.trim()
128 |       ?? sender.trim()
129 |   }
130 |   
131 |   return {doGet}
132 | })();
133 | 
134 | // --------------- test ---------------------
135 | 
136 | function doGet_sample_event() {
137 |   doGet({
138 |     parameter: {
139 |       'gmail-rss-feed': 'Newsletter',
140 |       'multi-account': 'true'
141 |     }
142 |   })
143 | }
144 | 


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/README.md:
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 1 | # Gmail RSS Feed
 2 | A [Google Scripts](https://script.google.com) Web App to dynamicaly generate an RSS feed based on labeled emails (`RSS Feed/<RSS_FEED_NAME>`)
 3 | 
 4 | ### Installation
 5 | * Create a blank project on https://script.google.com/
 6 | * Copy content of [`Code.gs`](Code.gs) into your new project
 7 | * Run the script once by clicking Menu `Run > doGet` 
 8 |   * You will be asked to grant this script access to your Gmail account
 9 |   * Accept the request
10 | * Create a first version by clicking Menu `File > Manage Versions`
11 | * Deploy this script by clicking Menu `Publish > Deploy as web app`
12 |   * Select `Execute the app as : me`
13 |   * Select `Who has access to the app : Anonyone, even anonymous`
14 |   * Copy `Current web app URL` e.g. `https://script.google.com/macros/s/<SCRIPT_ID>/exec`
15 |   * ⚠️ Everyone with this URL is potentialy able to read all mails labled with `RSS Feed/<RSS_FEED_NAME>`
16 | * Label your first emails with a nested `RSS` label (`RSS Feed/<RSS_FEED_NAME>`) e.g. `RSS Feed/Newsletter`
17 | * Create your feed URL by add following query parameters to `Current web app URL`
18 |   * `gmail-rss-feed=<RSS_FEED_NAME>` selects rss feed name of coresponding Gmail label (`RSS Feed/<RSS_FEED_NAME>`)
19 |   * `multi-author` enables author name to be prepand to feed item titles
20 |   * Example URL `https://script.google.com/macros/s/<SCRIPT_ID>/exec?gmail-rss-feed=Newsletter&multi-author`
21 | 


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