Pagination Elasticsearch in Django - django

Question

I am a newbie in Elasticsearch, I just try to create a search engine using it in Django. Overall, the engine shows good results. Unfortunately, it loads a large number of the results. Then, I try to paginate it by regular pagination in Django, after that, the page load error object of type 'Search' has no len().
These are my codes:
view.py
from django.shortcuts import render, redirect
from elasticsearch import Elasticsearch
from elasticsearch_dsl import Search
from django.core.paginator import Paginator
def search_es(request):
return render(request,'search/search.html')
def results(request):
s = Search(using=Elasticsearch())
keyword = request.GET.get('q') # keyword that want to be found
print(keyword)
if keyword:
# posts = s.query('match_phrase_prefix',head_title=keyword)
# if posts.count() == 0:
posts = s.query(
"multi_match",
query=keyword,
fields=['head_title^5', 'description^5', 'description.ngram'],
# type="phrase_prefix",
)
posts = posts[0: 100]
else:
posts = ''
page = request.GET.get('page', 1)
paginator = Paginator(posts, 10)
try:
users = paginator.page(page)
except PageNotAnInteger:
users = paginator.page(1)
except EmptyPage:
users = paginator.page(paginator.num_pages)
context = {
'page_title': keyword,
'posts': users,
'count': posts.count(),
'keyword': keyword,
}
return render(request,'search/results.html',context)
results.html
{% if posts.has_other_pages %}
<ul class="pagination">
{% if posts.has_previous %}
<li>«</li>
{% else %}
<li class="disabled"><span>«</span></li>
{% endif %}
{% for i in posts.paginator.page_range %}
{% if posts.number == i %}
<li class="active"><span>{{ i }} <span class="sr-only">(current)</span></span></li>
{% else %}
<li>{{ i }}</li>
{% endif %}
{% endfor %}
{% if posts.has_next %}
<li>»</li>
{% else %}
<li class="disabled"><span>»</span></li>
{% endif %}
</ul>
{% endif %}
Hope for every possible solution.
Thank you very much.

Answer 1

ElasticSearch provided two parameters you can use for pagination: from and size. You can refer to https://elasticsearch-dsl.readthedocs.io/en/latest/search_dsl.html#pagination
for example:
posts = s[0:20].query(
"multi_match",
query=keyword,
fields=['head_title^5', 'description^5', 'description.ngram'],
# type="phrase_prefix",
)
to get first page, and page size is 20.