一、样式：
django-haystack在utils模块中封装了HighHighlighter用于配置搜索结果的样式展示。想要更改结果的样式，可以写个子类重写相应的方法达到效果
1.关键字高亮：
HighHighlighter为模版文件提供了搜索关键字相关的配置信息，只需在模版文件search.html中使用即可
1 # 关键字高亮分为三步：
2 # 1.模版引用
3 {% load highlight %}
4
5 # 2.改变模版变量的填充方式
6 # 改变写法后，higtlight会为原结果中的关键字部分添一个span标签，并设置class为highlighted
7 # 改变前
8 {{ item.object.title }}
9 # 改变后
10 {% highlight item.object.title with query %}
11
12 # 3.给关键字设置样式
13 <style>
14 span.highlighted {
15 color: red;
16 }
17 </style>
效果如下：
注：我这里改了关键字显示位置，原生的django-haystack的搜索结果是会以 ... 开头，然后拼接关键字以及后面部分的。
2.关键字显示位置：
通过改变HighHighlighter类的find_window方法可改变关键字显示位置，具体实现如下：
1 # 1.定义子类继承，并重写find_window方法
2 class MyHighlighter(Highlighter):
3 """自定义Highlighter，改变高亮部分前面文本长度"""
4 def find_window(self, highlight_locations):
5 best_start = 0
6 best_end = self.max_length
7
8 # First, make sure we have words.
9 if not len(highlight_locations):
10 return (best_start, best_end)
11
12 words_found = []
13
14 # Next, make sure we found any words at all.
15 for word, offset_list in highlight_locations.items():
16 if len(offset_list):
17 # Add all of the locations to the list.
18 words_found.extend(offset_list)
19
20 if not len(words_found):
21 return (best_start, best_end)
22
23 if len(words_found) == 1:
24 # 查找内容中只找到一个query
25 best_start = words_found[0]
26 best_end = words_found[0] + self.max_length
27
28 if best_end > len(self.text_block):
29 move_forward_steps = best_end - len(self.text_block)
30 best_start -= move_forward_steps
31
32 if best_start < 0:
33 best_start = 0
34
35 return (best_start, best_end)
36
37 # 2.django的settings文件中自定义Highlighter类
38 HAYSTACK_CUSTOM_HIGHLIGHTER = 'utils.haystack_custom.MyHighlighter'
效果如上图
二、搜索频率限制：
跟踪haystack.urls可以知道，Django-haystack的视图定义在SearchView这个类中
1 # haystack.urls.py
2
3 urlpatterns = [
4 url(r'^$', SearchView(), name='haystack_search'),
5 ]
urls.py中将SearchView的类对象直接作为视图函数，当搜索请求来的时候，将会执行SearchView类的__call__方法，__call__方法源码如下：
1 def __call__(self, request):
2 """
3 Generates the actual response to the search.
4
5 Relies on internal, overridable methods to construct the response.
6 """
7 # 获取request对象
8 self.request = request
9
10 # 获取form中的参数
11 self.form = self.build_form()
12 # 校验form参数
13 self.query = self.get_query()
14 # 生成搜索结果
15 self.results = self.get_results()
16
17 # 返回视图
18 return self.create_response()
那么，可以写个子类继承SearchView类，在SearchView类的__call__方法执行之前，从request对象中获取到用户ip，然后对ip做频率限制即可实现我们的需求，实现如下：
1 # 1.写个子类继承SearchView类，重写__call__方法
2
3 # 导入这里就不说了
4 class MySearchView(SearchView):
5 """自定义search视图函数，添加IP搜索频率限制"""
6 def __call__(self, request):
7 # 获取用户IP
8 ip = request.META.get("REMOTE_ADDR", "")
9 if ip == "":
10 return super(MySearchView, self).__call__(request)
11
12 try:
13 has_search_flag = cache.get("has_search_%s" % ip)
14 except Exception as e:
15 settings.LOGGER.error(e)
16 return super(MySearchView, self).__call__(request)
17 else:
18 if has_search_flag is None:
19 cache.set("has_search_%s" % ip, 1, settings.SEARCH_FREQUENCY_FORBID_TIME)
20 return super(MySearchView, self).__call__(request)
21
22 return render(request, 'search/search.html', {"errmsg":"您的操作过于频繁，请稍后再试"})
23
24 # 2.修改路由匹配
25
26 # 导入这里就不说了
27 urlpatterns = [
28 # path('search', include('haystack.urls')), # 全文检索框架
29 path('search', MySearchView(), name="haystack_search"), # 全文检索框架
30 ]
------------------------------
更新：当搜索结果分页后，用户点击下一页或上一页，是会改变page参数重新发起请求的，这里也会视为频繁操作，那就有问题了。
于是逻辑修改如下：将缓存中的从固定的1改成存关键字，下次搜索关键字变更了的情况下才加以限制，实现如下：
1 class MySearchView(SearchView):
2 """自定义search视图函数，添加IP搜索频率限制"""
3 def __call__(self, request):
4 # 获取用户IP
5 search_q = request.GET.get("q", None)
6 if search_q is None:
7 return render(request, 'search/search.html', {"errmsg":"参数有误"})
8
9 ip = request.META.get("REMOTE_ADDR", "")
10 if ip == "":
11 return super(MySearchView, self).__call__(request)
12
13 try:
14 has_search_flag = cache.get("has_search_%s" % ip)
15 except Exception as e:
16 settings.LOGGER.error(e)
17 return super(MySearchView, self).__call__(request)
18 else:
19 if has_search_flag:
20 if has_search_flag != search_q:
21 return render(request, 'search/search.html', {"errmsg":"您的操作过于频繁，请稍后再试"})
22 else:
23 return super(MySearchView, self).__call__(request)
24 else:
25 cache.set("has_search_%s" % ip, search_q, settings.SEARCH_FREQUENCY_FORBID_TIME)
26 return super(MySearchView, self).__call__(request)
