Add image function and urlFinder

lib/createComputationContextObject.js

@@ -3,6 +3,7 @@ var ss = require('simple-statistics');
 var evalculist = require('evalculist');
 var isItem = require('./item/isItem');
 var keyToVarName = require('./keyToVarName');
+var urlFinder = require('./urlFinder');
 
 module.exports = function (graph) {
   graph.register('createComputationContextObject', ['isItem','getItemByGuid'], function (isItem, getItemByGuid) {
@@ -377,6 +378,20 @@ module.exports = function (graph) {
       }
     });
 
+    var imageToString = _.constant('[Image]');
+    proto.image = function (url, width, height) {
+      if (!urlFinder.isUrl(url)) return NaN;
+      var html = '<img src="' + url + '"';
+      if (_.isNumber(+width)) html += ' width="' + (+width) + '"';
+      if (_.isNumber(+height)) html += ' height="' + (+height) + '"';
+      html += '/>';
+      return {
+        mediaType: 'image',
+        toString: imageToString,
+        toHTML: _.constant(html),
+      };
+    };
+
     proto.uniq = proto.unique = itemsFirst(function (items) {
       items = _.map(items, proto.valueOf);
       return _.uniq(items);

lib/urlFinder.js

@@ -0,0 +1,44 @@
+// Based on https://gist.github.com/dperini/729294
+var basePatternString = '' +
+  // protocol identifier
+  "(?:(?:https?|ftp)://)" +
+  // user:pass authentication
+  "(?:\\S+(?::\\S*)?@)?" +
+  "(?:" +
+    // IP address exclusion
+    // private & local networks
+    "(?!(?:10|127)(?:\\.\\d{1,3}){3})" +
+    "(?!(?:169\\.254|192\\.168)(?:\\.\\d{1,3}){2})" +
+    "(?!172\\.(?:1[6-9]|2\\d|3[0-1])(?:\\.\\d{1,3}){2})" +
+    // IP address dotted notation octets
+    // excludes loopback network 0.0.0.0
+    // excludes reserved space >= 224.0.0.0
+    // excludes network & broacast addresses
+    // (first & last IP address of each class)
+    "(?:[1-9]\\d?|1\\d\\d|2[01]\\d|22[0-3])" +
+    "(?:\\.(?:1?\\d{1,2}|2[0-4]\\d|25[0-5])){2}" +
+    "(?:\\.(?:[1-9]\\d?|1\\d\\d|2[0-4]\\d|25[0-4]))" +
+  "|" +
+    // host name
+    "(?:(?:[a-z\\u00a1-\\uffff0-9]-*)*[a-z\\u00a1-\\uffff0-9]+)" +
+    // domain name
+    "(?:\\.(?:[a-z\\u00a1-\\uffff0-9]-*)*[a-z\\u00a1-\\uffff0-9]+)*" +
+    // TLD identifier
+    "(?:\\.(?:[a-z\\u00a1-\\uffff]{2,}))" +
+    // TLD may end with dot
+    "\\.?" +
+  ")" +
+  // port number
+  "(?::\\d{2,5})?" +
+  // resource path
+  "(?:[/?#]\\S*)?";
+
+var hasUrlPattern = new RegExp(basePatternString, 'i');
+var allUrlsPattern = new RegExp(basePatternString, 'ig');
+var isUrlPattern = new RegExp('^' + basePatternString + '$', 'i');
+module.exports = {
+  hasUrl: function (string) { return hasUrlPattern.test(string); },
+  isUrl: function (string) { return isUrlPattern.test(string); },
+  replaceUrl: function (string, replacer) { return string.replace(hasUrlPattern, replacer); },
+  getUrls: function (string) { return string.match(allUrlsPattern); }
+}