Kerangka pesan¶

Backend Penyimpanan¶

Kerangka kerja pesan-pesan dapat menggunakan backend berbeda untuk menyimpan pesan-pesan sementara.

Django menyediakan kelas-kelas penyimpanan siap-pakai di django.contrib.messages:

class storage.session.SessionStorage¶

This class stores all messages inside of the request’s session. Therefore it requires Django’s contrib.sessions application.

class storage.cookie.CookieStorage¶

Kelas ini menyimpan data pesan dalam sebuah kue (ditandai dengan campuran rahasia untuk mencegah perubahan) untuk bertahan pemberitahuan terhadap permintaan. Pesan-pesan lama dibuang jika ukuran data kue akan melebihi 2048 byte.

class storage.fallback.FallbackStorage¶

This class first uses CookieStorage, and falls back to using SessionStorage for the messages that could not fit in a single cookie. It also requires Django’s contrib.sessions application.

Perilaku ini menghindari menulis ke sesi bilamana memungkinkan. Itu harus menyediakan penampilan terbaik di kasus umum.

FallbackStorage adalah kelas penyimpanan awalan. Jika itu tidak cocok pada kebutuhan anda, anda dapat memilih kelas penyimpanan lain dengan mengatur MESSAGE_STORAGE ke jalur impor penuhnya, sebagai contoh:

MESSAGE_STORAGE = 'django.contrib.messages.storage.cookie.CookieStorage'

class storage.base.BaseStorage¶

Untuk menulis kelas penyimpanan sendiri, subkelas kelas BaseStorage di django.contrib.messages.storage.base dan menerapkan metode _get dan _store.

Tingkatan pesan¶

The messages framework is based on a configurable level architecture similar to that of the Python logging module. Message levels allow you to group messages by type so they can be filtered or displayed differently in views and templates.

Tingkat siap-pakai, yang dapat diimpor dari django.contrib.messages secar langsung, adalah:

The MESSAGE_LEVEL setting can be used to change the minimum recorded level (or it can be changed per request). Attempts to add messages of a level less than this will be ignored.

Etiket pesan¶

Message tags are a string representation of the message level plus any extra tags that were added directly in the view (see Adding extra message tags below for more details). Tags are stored in a string and are separated by spaces. Typically, message tags are used as CSS classes to customize message style based on message type. By default, each level has a single tag that’s a lowercase version of its own constant:

To change the default tags for a message level (either built-in or custom), set the MESSAGE_TAGS setting to a dictionary containing the levels you wish to change. As this extends the default tags, you only need to provide tags for the levels you wish to override:

from django.contrib.messages import constants as messages
MESSAGE_TAGS = {
    messages.INFO: '',
    50: 'critical',
}

Menambahkan pesan¶

Untuk menambahkan pesan, panggil:

from django.contrib import messages
messages.add_message(request, messages.INFO, 'Hello world.')

Some shortcut methods provide a standard way to add messages with commonly used tags (which are usually represented as HTML classes for the message):

messages.debug(request, '%s SQL statements were executed.' % count)
messages.info(request, 'Three credits remain in your account.')
messages.success(request, 'Profile details updated.')
messages.warning(request, 'Your account expires in three days.')
messages.error(request, 'Document deleted.')

Menampilkan pesan¶

get_messages(request)[sumber]¶

Di cetakan anda, gunakan sesuatu seperti:

{% if messages %}
<ul class="messages">
    {% for message in messages %}
    <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>{{ message }}</li>
    {% endfor %}
</ul>
{% endif %}

If you’re using the context processor, your template should be rendered with a RequestContext. Otherwise, ensure messages is available to the template context.

Even if you know there is only just one message, you should still iterate over the messages sequence, because otherwise the message storage will not be cleared for the next request.

The context processor also provides a DEFAULT_MESSAGE_LEVELS variable which is a mapping of the message level names to their numeric value:

{% if messages %}
<ul class="messages">
    {% for message in messages %}
    <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>
        {% if message.level == DEFAULT_MESSAGE_LEVELS.ERROR %}Important: {% endif %}
        {{ message }}
    </li>
    {% endfor %}
</ul>
{% endif %}

Diluar Cetakan, anda dapat menggunakan get_messages():

from django.contrib.messages import get_messages

storage = get_messages(request)
for message in storage:
    do_something_with_the_message(message)

For instance, you can fetch all the messages to return them in a JSONResponseMixin instead of a TemplateResponseMixin.

get_messages() akan mengembalikan sebuah instance dari backend penyimpanan dikonfigurasi

Kelas Message¶

class storage.base.Message¶

When you loop over the list of messages in a template, what you get are instances of the Message class. It’s quite a simple object, with only a few attributes:

• message: Teks sebenarnya dari pesan.

• level: An integer describing the type of the message (see the message levels section above).
• tags: A string combining all the message’s tags (extra_tags and level_tag) separated by spaces.
• extra_tags: A string containing custom tags for this message, separated by spaces. It’s empty by default.
• level_tag: The string representation of the level. By default, it’s the lowercase version of the name of the associated constant, but this can be changed if you need by using the MESSAGE_TAGS setting.

Membuat penyesuaian tingkatan pesan¶

Messages levels are nothing more than integers, so you can define your own level constants and use them to create more customized user feedback, e.g.:

CRITICAL = 50

def my_view(request):
    messages.add_message(request, CRITICAL, 'A serious error occurred.')

When creating custom message levels you should be careful to avoid overloading existing levels. The values for the built-in levels are:

If you need to identify the custom levels in your HTML or CSS, you need to provide a mapping via the MESSAGE_TAGS setting.

Merubah tingkat terekam minimal per-permintaan¶

Tingkat terekam minimal dapat disetel per permintaan melalui metode set_level:

from django.contrib import messages

# Change the messages level to ensure the debug message is added.
messages.set_level(request, messages.DEBUG)
messages.debug(request, 'Test message...')

# In another request, record only messages with a level of WARNING and higher
messages.set_level(request, messages.WARNING)
messages.success(request, 'Your profile was updated.') # ignored
messages.warning(request, 'Your account is about to expire.') # recorded

# Set the messages level back to default.
messages.set_level(request, None)

Mirip, tingkat efektif saat ini dapat diambil dengan get_level:

from django.contrib import messages
current_level = messages.get_level(request)

Untuk informasi lebih pada bagaimana fungsi tingkat terekam minimal, lihat Message levels diatas.

Menambahkan etiket pesan tambahan¶

Untuk lebih kendali langsung melalui etiket pesan, anda dapat secara pilihan menyediakan string mengandung etiket tambahan ke apapun dari metode tambah:

messages.add_message(request, messages.INFO, 'Over 9000!', extra_tags='dragonball')
messages.error(request, 'Email box full', extra_tags='email')

Etiket tambahan ditambahkan sebelum etiket awalan untuk tingkat itu dan ruang terpisah.

Failing silently when the message framework is disabled¶

If you’re writing a reusable app (or other piece of code) and want to include messaging functionality, but don’t want to require your users to enable it if they don’t want to, you may pass an additional keyword argument fail_silently=True to any of the add_message family of methods. For example:

messages.add_message(
    request, messages.SUCCESS, 'Profile details updated.',
    fail_silently=True,
)
messages.info(request, 'Hello world.', fail_silently=True)

Menambahkan pesan-pesan di tampilan berdasarkan-kelas¶

class views.SuccessMessageMixin¶

Menambah sebuah atribut pesan berhasil pada FormView berdasarkan kelas-kelas

get_success_message(cleaned_data)¶

cleaned_data adalah data dibersihkan dari formulir yang digunakan untuk pembentukan string

Contoh views.py:

from django.contrib.messages.views import SuccessMessageMixin
from django.views.generic.edit import CreateView
from myapp.models import Author

class AuthorCreate(SuccessMessageMixin, CreateView):
    model = Author
    success_url = '/success/'
    success_message = "%(name)s was created successfully"

The cleaned data from the form is available for string interpolation using the %(field_name)s syntax. For ModelForms, if you need access to fields from the saved object override the get_success_message() method.

Contoh views.py untuk ModelForms:

from django.contrib.messages.views import SuccessMessageMixin
from django.views.generic.edit import CreateView
from myapp.models import ComplicatedModel

class ComplicatedCreate(SuccessMessageMixin, CreateView):
    model = ComplicatedModel
    success_url = '/success/'
    success_message = "%(calculated_field)s was created successfully"

    def get_success_message(self, cleaned_data):
        return self.success_message % dict(
            cleaned_data,
            calculated_field=self.object.calculated_field,
        )