Add parsing library.

lib/search-query-parser.js

@@ -0,0 +1,138 @@
+/*!
+ * search-query-parser.js
+ * Copyright(c) 2014 Julien Buty <julien@nepsilon.net>
+ * MIT Licensed
+ */
+
+exports.parse = function (string, options) {
+
+  // Set an empty options object when none provided
+  if (!options) {
+    options = {};
+  }
+
+  // Regularize white spacing
+  // Make in-between white spaces a unique space
+  string = string.trim().replace(/\s+/g, ' ');
+
+  // When a simple string, return it
+  if (-1 === string.indexOf(':')) {
+    return string;
+  }
+  // When no keywords or ranges set, treat as a simple string
+  else if (!options.keywords && !options.ranges){
+    return string;
+  }
+  // Otherwise parse the advanced query syntax
+  else {
+    // Our object to store the query object
+    var query = {text: []};
+    // Get a list of search term. Reverse to ensure proper order when pop()'ing.
+    var terms = string.split(' ').reverse();
+    // For each search term
+    while (term = terms.pop()) {
+      // Advanced search terms syntax has key and value
+      // separated with a colon
+      var sepIdx = term.indexOf(':');
+      // When just a simple term
+      if (-1 === sepIdx) {
+        // We add it as pure text
+        query.text.push(term);
+      }
+      // We got an advanced search syntax
+      else {
+        var key = term.slice(0, sepIdx);
+        // Check if the key is a registered keyword
+        options.keywords = options.keywords || [];
+        var isKeyword = !(-1 === options.keywords.indexOf(key));
+        // Check if the key is a registered range
+        options.ranges = options.ranges || [];
+        var isRange = !(-1 === options.ranges.indexOf(key));
+        // When the key matches a keyword
+        if (isKeyword) {
+          var value = term.slice(sepIdx + 1);
+          // When value is a thing
+          if (value.length) {
+            // Get an array of values when several are there
+            var values = value.split(',');
+            // If we already have seen that keyword...
+            if (query[key]) {
+              // ...many times...
+              if (query[key] instanceof Array) {
+                // ...and got several values this time...
+                if (values.length > 1) {
+                  // ... concatenate both arrays.
+                  query[key] = query[key].concat(values);
+                }
+                else {
+                  // ... append the current single value.
+                  query[key].push(value);
+                }
+              }
+              // We saw that keyword only once before
+              else {
+                // Put both the current value and the new
+                // value in an array
+                query[key] = [query[key]]
+                query[key].push(value);
+              }
+            }
+            // First time we see that keyword
+            else {
+              // ...and got several values this time...
+              if (values.length > 1) {
+                // ...add all values seen.
+                query[key] = values;
+              }
+              // Got only a single value this time
+              else {
+                // Record its value as a string
+                query[key] = value;
+              }
+            }
+           }
+        }
+        // The key allows a range
+        else if (isRange) {
+          var value = term.slice(sepIdx + 1);
+          // Range are separated with a dash
+          var rangeValues = value.split('-');
+          // When both end of the range are specified
+          // keyword:XXXX-YYYY
+          query[key] = {};
+          if (2 === rangeValues.length) {
+            query[key].from = rangeValues[0];
+            query[key].to = rangeValues[1];
+          }
+          // When pairs of ranges are specified
+          // keyword:XXXX-YYYY,AAAA-BBBB
+          else if (!rangeValues.length % 2) {
+          }
+          // When only getting a single value,
+          // or an odd number of values
+          else {
+            query[key].from = value;
+          }
+        }
+        else {
+          // We add it as pure text
+          query.text.push(term);
+        }
+      }
+    }
+
+    // Concatenate all text terms if any
+    if (query.text.length) {
+      query.text = query.text.join(' ').trim();
+    }
+    // Just remove the attribute text when it's empty
+    else {
+      delete query.text;
+    }
+
+    // Return forged query object
+    return query;
+
+  }
+
+};