GetImagesForInchisInGoogleDocs.js

// This script will insert images for all the inchis it finds
// in a google document

//How to use this scipt: 
// Go to a google document where you want this script to work
// Choose from the Menu: Tools -> Script editor
// Delete everything in the editor that opens
// Paste in this entire script
// Save it and close the window
//
// Now close the document
// Reopen the document and wait a little
// You should see a new Menu called "Douglas Connect Tools"
// Go there and click "Get Images for Inchis"
// Wait a little and you will get images for all found inchis
// appended at the end of the document

function onOpen() {
  var ui = DocumentApp.getUi();
  // Or DocumentApp or FormApp.
  ui.createMenu('Douglas Connect Tools')
      .addItem('Get Images for Inchis', 'getImageForInchi')
      .addToUi();
}


function searchInchi(body, nextSearchStart) {
  
  var inchiRegex = "(InChI=)[^\s]{6,}"
  if (nextSearchStart != undefined)
    return body.findText(inchiRegex, nextSearchStart);
  else 
    return body.findText(inchiRegex);
}

function getImageForInchi() {
  Logger.log("Getting document, starting search for inchi")
  var document = DocumentApp.getActiveDocument()
  var body = document.getBody()
  var errors = ""
  
  var searchResult = searchInchi(body);
  
  while (searchResult != null) {
    Logger.log("Found inchi")
    var matchedparagraph = searchResult.getElement().asText().getText();
    
    var text = matchedparagraph
          .substring(searchResult.getStartOffset(), searchResult.getEndOffsetInclusive()+1);
    
    
    var nextSearchStart = searchResult
    
    Logger.log(text);
    // Download a file now (GET), so we can upload it in the HTTP POST below.
    Logger.log("https://cactus.nci.nih.gov/chemical/structure/" + text + "/image");
    
    var response = UrlFetchApp.fetch("https://cactus.nci.nih.gov/chemical/structure/" + text + "/image", { escaping: true });
    
    if (response.getResponseCode() == 200) {
      Logger.log("Download successful");
      var fileBlob = response.getAs('image/png');
      try {
        body.appendImage(fileBlob);
      }
      catch (err) {
        Logger.log("Error appending file, image was probably invalid")
        errors = errors + "Could not get valid image for inchi: " + text + "\n"
      }
    }
    else
      Logger.log("Download failed with code " + response.getResponseCode());
    
    if (nextSearchStart != null && nextSearchStart != undefined)
      searchResult = searchInchi(body, nextSearchStart);
    else
      searchResult = null
  }
  
  if (errors != "")
    body.appendParagraph("The following errors occured:\n" + errors)
}