@lyuboslavlyubenov/node-summary/lib/summary.js

Summarizes text using a naive summarization algorithm

const { convertHTMLToText, getTitle } = require("./helpers/html");
const { isValidUrl } = require("./helpers/urls");
const {
  onlyGetSentences,
  splitContentToSentences,
  splitContentToParagraphs,
  sentencesIntersection,
  formatSentence,
  getBestSentence,
  getSortedSentences,
  getSentencesRanks,
} = require("./helpers/summarizer");

const request = require("request");

exports.summarizeFromUrl = function (url, callback) {
  var summaryToolContext = this;
  if (isValidUrl(url)) {
    request.get(url, function (error, response, body) {
      let title = getTitle(body);
      let text = convertHTMLToText(body);
      let content = onlyGetSentences(text);
      return summaryToolContext.summarize(
        title,
        content,
        (err, result, dict) => {
          if (err) {
            callback(err, result, dict);
          } else {
            callback(err, result, dict);
          }
        }
      );
    });
  } else {
    callback(
      true,
      "Not a valid url. Please try passing a valid url like https://example.com/."
    );
  }
};

exports.summarize = (title, content, callback, sentences_dict) => {
  var summary = [],
    paragraphs = [],
    sentence = "",
    err = false;
  if (arguments.length < 3) {
    if (content.constructor === Function) {
      callback = content;
      content = title;
      title = "";
    }
  }
  getSentencesRanks(
    content,
    (dict) => {
      splitContentToParagraphs(content, (paragraphs) => {
        summary.push(title); // Store the title.

        paragraphs.forEach((p) => {
          getBestSentence(p, dict, (sentence) => {
            if (sentence) summary.push(sentence);
          });
        });

        // If we only have a title, then there is an issue.
        if (sentence.length === 2) err = true;
        callback(err, summary.join("\n"), dict);
      });
    },
    sentences_dict
  );
};

exports.getSortedSentences = (content, n, callback, sentences_dict) => {
  if (typeof n === "function") {
    callback = n;
    n = 0;
  }

  getSentencesRanks(
    content,
    (dict) => {
      getSortedSentences(content, dict, n, (sorted_sentences) => {
        if (sorted_sentences === "") {
          callback(new Error("Too short to summarize."));
        } else {
          callback(null, sorted_sentences, dict);
        }
      });
    },
    sentences_dict
  );
};