Utilities

flask-peewee ships with several useful utilities. If you’re coming from the django world, some of these functions may look familiar to you.

Getting objects

get_object_or_404()

Provides a handy way of getting an object or 404ing if not found, useful for urls that match based on ID.

@app.route('/blog/<title>/')
def blog_detail(title):
    blog = get_object_or_404(Blog.select().where(Blog.active==True), Blog.title==title)
    return render_template('blog/detail.html', blog=blog)

object_list()

Wraps the given query and handles pagination automatically. Pagination defaults to 20 but can be changed by passing in paginate_by=XX.

@app.route('/blog/')
def blog_list():
    active = Blog.select().where(Blog.active==True)
    return object_list('blog/index.html', active)

<!-- template -->
{% for blog in object_list %}
  {# render the blog here #}
{% endfor %}

{% if page > 1 %}
  <a href="./?page={{ page - 1 }}">Prev</a>
{% endif %}
{% if page < pagination.get_pages() %}
  <a href="./?page={{ page + 1 }}">Next</a>
{% endif %}

PaginatedQuery

A wrapper around a query (or model class) that handles pagination.

Example:

query = Blog.select().where(Blog.active==True)
pq = PaginatedQuery(query, 20)  # 20 items per page

# assume url was /?page=3
obj_list = pq.get_list()  # returns 3rd page of results

pq.get_page() # returns "3"

pq.get_pages() # returns total objects / objects-per-page

pq.get_count() # total number of matching rows

# a windowed list of page numbers for pagination controls; None marks a
# gap to render as an ellipsis. On page 10 of 20 it returns:
pq.get_page_range()  # [1, None, 7, 8, 9, 10, 11, 12, 13, None, 20]

get_page_range(window=N) controls how many pages are shown on either side of the current page (the default is 3).

Misc

slugify(string)

Convert a string into something suitable for use as part of a URL, e.g. “This is a url” becomes “this-is-a-url”

from flask_peewee.utils import slugify


class Blog(db.Model):
    title = CharField()
    slug = CharField()

    def save(self, *args, **kwargs):
        self.slug = slugify(self.title)
        super(Blog, self).save(*args, **kwargs)

make_password(raw_password)

Create a salted hash for the given plain-text password

check_password(raw_password, enc_password)

Compare a plain-text password against a salted/hashed password

PASSWORD_HASH_METHOD

The hashing method make_password() hands to werkzeug’s generate_password_hash ('scrypt' by default). Override it before hashing to change the algorithm or work factor, for instance to pick a cheaper method that speeds up your test suite:

import flask_peewee.utils

flask_peewee.utils.PASSWORD_HASH_METHOD = 'pbkdf2:sha256:1'

See werkzeug.security.generate_password_hash for the accepted values.