Add model for search engines

profiles/models.py

@@ -1,6 +1,18 @@
 from django.db import models
 
 
+class InvalidData(Exception):
+    ''' Thrown when the DB contains invalid data, and cannot perform
+    something '''
+
+    def __init__(self, what):
+        self.what = what
+        super(InvalidData, self).__init__()
+
+    def __str__(self):
+        return self.what
+
+
 class BrowserFingerprint(models.Model):
     ''' A browser fingerprint, containing things like a user agent '''
 
@@ -22,3 +34,24 @@ class BrowserFingerprint(models.Model):
 
     def __str__(self):
         return self.description
+
+
+class SearchEngine(models.Model):
+    ''' A search engine, and all the data needed to use it '''
+
+    name = models.CharField(max_length=256)
+    url = models.URLField()
+    query_pattern = models.CharField(max_length=256)  # This field is the
+    # query pattern. It should contain a `{}`, which, when substituted with a
+    # search term (using `.format()`), must yield a URL that can be resolved to
+    # perform the search
+
+    def __str__(self):
+        return self.name
+
+    def search_url(self, search_term):
+        ''' Obtain a url to search `search_term` with this search engine '''
+        pattern = str(self.query_pattern)
+        if '{}' not in pattern:
+            raise InvalidData("Search engine {}: bad pattern".format(self))
+        return str(self.query_pattern).format(search_term)