Q&A for professional and enthusiast programmers. How can I link two classes in a django query set. For example I have a class Person and a class Department. A person has an attribute salary and a Department has the class. Django로 알파카코믹스 프로젝트를 진행하면서 겪은 몇가지 문제 해결에 대한 간략한 소개입니다. 파이썬 코리아 세미나에서 발표한 자료입니다. Django, 저는 이렇게 씁니다. 1. Django, 저는 이렇게 씁니다. 알파카. Chapter 7: Forms HTML forms are the backbone of interactive Web sites, from the simplicity of Google’s single search box to ubiquitous blog comment-submission forms to complex custom data-entry interfaces. This chapter covers. Hmm. haven't passed a function to jQuery yet, so I'm not sure what that does. Usually I see (function($){.})(jQuery); for when you want $ to be something other than jQuery. Also, in the for (i in provinces) loop I would use $('<option/>').val(provinces[i][0]).text(provinces[i][1]).appendTo($provSelect).
Chapter 9: Advanced Templates. Although most of your interactions with Django’s template language will be in. This chapter delves deep into the guts of Django’s template system. It covers. what you need to know if you plan to extend the system or if you’re just. It also covers the auto- escaping feature, a. Django. If you’re looking to use the Django template system as part of another.
Configuring the Template System in Standalone Mode” section later in the. Template Language Review. First, let’s quickly review a number of terms introduced in Chapter 4: A template is a text document, or a normal Python string, that is. Django template language. A template can contain.
A template tag is a symbol within a template that does something. This. definition is deliberately vague. For example, a template tag can produce. Template tags are surrounded by {% and %}: {% if is_logged_in %}.
Thanks for logging in! Please log in. {% endif %}A variable is a symbol within a template that outputs a value. Variable tags are surrounded by {{ and }}: My first name is {{ first_name }}. My last name is {{ last_name }}. A context is a name - > value mapping (similar to a Python. A template renders a context by replacing the variable “holes” with.
For more details about the basics of these terms, refer back to Chapter 4. The rest of this chapter discusses ways of extending the template engine. First. though, let’s take a quick look at a few internals left out of Chapter 4 for. Request. Context and Context Processors. When rendering a template, you need a context. This can be an instance of.
Context, but Django also comes with a subclass. Request. Context, that acts slightly differently. Request. Context adds a bunch of variables to your template context by. Http. Request object or information about the.
(Note that we’re deliberately not using the render() shortcut in these examples – we’re manually loading the templates, constructing the context objects and rendering the templates. We’re “spelling out” all of the steps for the purpose of. Learn step-by-step to build a 5 Django Web applications and get your project in the real world today. Try Django Tutorial Series (Last Updated: Jan - 6-2016) Three project tutorials to help you launch your project this month. Either.
The render() shortcut creates a Request. Context. unless it is passed a different context instance explicitly. Use Request. Context when you don’t want to have to specify the same set of.
For example, consider these two views: fromdjango. Contextdefview_1(request): # .. Context({'app': 'My app','user': request. META['REMOTE_ADDR'],'message': 'I am view 1.'})returnt. Context({'app': 'My app','user': request. META['REMOTE_ADDR'],'message': 'I am the second view.'})returnt. Note that we’re deliberately not using the render() shortcut.
We’re “spelling out” all of the. Each view passes the same three variables – app, user and. Wouldn’t it be nice if we could remove that. Request. Context and context processors were created to solve this. Context processors let you specify a number of variables that get set. The catch is that you have to use. Request. Context instead of Context when you render a template.
The most low- level way of using context processors is to create some processors. Request. Context. Here’s how the above example could be. Request. Contextdefcustom_proc(request): "A context processor that provides 'app', 'user' and 'ip_address'."return{'app': 'My app','user': request.
META['REMOTE_ADDR']}defview_1(request): # .. Request. Context(request,{'message': 'I am view 1.'},processors=[custom_proc])returnt. Request. Context(request,{'message': 'I am the second view.'},processors=[custom_proc])returnt. Let’s step through this code: First, we define a function custom_proc.
This is a context processor. Http. Request object and returns a dictionary of. That’s all it does. We’ve changed the two view functions to use Request. Context instead. of Context. There are two differences in how the context is. One, Request. Context requires the first argument to be an.
Http. Request object – the one that was passed into the view function. Two, Request. Context takes an.
Here, we pass in custom_proc, the custom. Each view no longer has to include app, user or ip_address in. Each view still has the flexibility to introduce any custom template. In this example, the message template.
In Chapter 4, we introduced the render() shortcut, which saves. Context. then call the render() method on the template. In order to demonstrate the. But it’s possible – and preferable – to use. Do this with the.
Request. Contextdefcustom_proc(request): "A context processor that provides 'app', 'user' and 'ip_address'."return{'app': 'My app','user': request. META['REMOTE_ADDR']}defview_1(request): # .. I am view 1.'},context_instance=Request. Context(request,processors=[custom_proc]))defview_2(request): # .. I am the second view.'},context_instance=Request. Context(request,processors=[custom_proc]))Here, we’ve trimmed down each view’s template rendering code to a single.
This is an improvement, but, evaluating the conciseness of this code, we have. We’ve. removed redundancy in data (our template variables) at the cost of adding. Using context processors. For that reason, Django provides support for global context processors. The. TEMPLATE_CONTEXT_PROCESSORS setting (in your settings.
Request. Context. This. removes the need to specify processors each time you use. Request. Context.
By default, TEMPLATE_CONTEXT_PROCESSORS is set to the following: TEMPLATE_CONTEXT_PROCESSORS=('django. This setting is a tuple of callables that use the same interface as our. Note. that the values in TEMPLATE_CONTEXT_PROCESSORS are specified as strings. Python path. (so you can refer to them from the setting).
Each processor is applied in order. That is, if one processor adds a variable.
Django provides a number of simple context processors, including the ones that. If TEMPLATE_CONTEXT_PROCESSORS contains this processor, every. Request. Context will contain these variables: user: A django. User instance representing the. Anonymous. User instance, if the client. A list of messages (as strings) for the current logged- in. Behind the scenes, this variable calls.
That method. collects the user’s messages and deletes them from the database. An instance of django.
Perm. Wrapper. which represents the permissions the current logged- in user has. See Chapter 1. 4 for more information on users, permissions, and messages. This processor pushes debugging information down to the template layer.
If. TEMPLATE_CONTEXT_PROCESSORS contains this processor, every. Request. Context will contain these variables: debug: The value of your DEBUG setting (either True or. False). You can use this variable in templates to test whether you’re. A list of {'sql'..,'time'..} dictionaries. SQL query that has happened so far during the request. The list is in the order in which the queries were. Because debugging information is sensitive, this context processor will only.
The DEBUG setting is True. The request came from an IP address in the INTERNAL_IPS setting. Astute readers will notice that the debug template variable will never have. False because, if DEBUG is False, then the debug. If this processor is enabled, every Request. Context will contain these. LANGUAGES: The value of the LANGUAGES setting.
LANGUAGE_CODE: request. LANGUAGE_CODE if it exists; otherwise, the. LANGUAGE_CODE setting. Appendix D provides more information about these two settings. If this processor is enabled, every Request. Context will contain a variable. Http. Request object.
Note that this. processor is not enabled by default; you have to activate it. You might want to use this if you find your templates needing to access. Http. Request such as the IP address: Guidelines for Writing Your Own Context Processors. Here are a few tips for rolling your own: Make each context processor responsible for the smallest subset of. It’s easy to use multiple processors, so you.
Keep in mind that any context processor in TEMPLATE_CONTEXT_PROCESSORS. As variable names are.
It doesn’t matter where on the filesystem they live, as long as they’re. Python path so you can point to them from the. TEMPLATE_CONTEXT_PROCESSORS setting.
With that said, the convention. Automatic HTML Escaping. When generating HTML from templates, there’s always a risk that a variable will. HTML. For example, consider this. At first, this seems like a harmless way to display a user’s name, but consider. With this name value, the template would be rendered as: Hello, < script> alert('hello')< /script>..
Java. Script alert box! Similarly, what if the name contained a '< ' symbol, like this? That would result in a rendered template like this..
Web page being bolded! Clearly, user- submitted data shouldn’t be trusted blindly and inserted directly. Web pages, because a malicious user could use this kind of hole to. This type of security exploit is called a. Cross Site Scripting (XSS) attack. For more on security, see Chapter 2. To avoid this problem, you have two options: One, you can make sure to run each untrusted variable through the.
HTML characters to. This was the default solution in Django for its first few.
It’s easy to forget. Two, you can take advantage of Django’s automatic HTML escaping. The. remainder of this section describes how auto- escaping works. By default in Django, every template automatically escapes the output. Specifically, these five characters are.
Again, we stress that this behavior is on by default. If you’re using Django’s.
How to Turn it Off. If you don’t want data to be auto- escaped, on a per- site, per- template level or. Why would you want to turn it off?
Because sometimes, template variables. HTML, in which case you. For example, you might store a blob of. HTML in your database and want to embed that directly into your. Or, you might be using Django’s template system to produce text that. HTML – like an e- mail message, for instance. For Individual Variables.
To disable auto- escaping for an individual variable, use the safe filter: This will be escaped: {{ data }}. This will not be escaped: {{ data|safe }}Think of safe as shorthand for safe from further escaping or can be. HTML. In this example, if data contains '< b> '. This will be escaped: & lt; b& gt. This will not be escaped: < b> For Template Blocks. To control auto- escaping for a template, wrap the template (or just a. Hello {{ name }}.
The autoescape tag takes either on or off as its argument.