the idea is to separate the business logic from presentation logic,
(here is a nice article
http://www.paragoncorporation.com/ArticleDetail.aspx?ArticleID=21)
not necessarily make everything in a template be xml, which can
sometimes make things more complicated.
You have to introduce namespaces(designer says "name what?").
Putting an xml tag as an attribute of an html tag can make things
nasty, such as:
<div class="<gae:if="field.required" /><gae:string
name="required_class" /></gae:if>"></div>
vs.
<div class="{% if field.required %}{{ required_class }}{% endif %}"></
div>
the first is, I believe, ironically, invalid xml, and the second is
valid xml.
django's template language has relatively simple logic. Just present
the data that is passed to the template.
In presentation logic, there are many times you have to decide what
html to display depending on the data passed to you.
If each time that was encountered by the designer, they would have to
think about the logic anyway and then ask a programmer to write a
function to return one piece of html if a certain piece of data was
true and another if false, and then pass that to the template. Then
they would have to learn the new xml tag to insert to get that piece
of html. very complicated.
On Jan 2, 11:40 am, Kelly A <kelly.j.ander...@gmail.com> wrote:
> I have this problem with most templating systems, they talk about
> separating code from HTML but then they define all these programming
> constructs like if, while, for, etc.. For instance given the example
> from the getting started guide:
>
> <html>
> <body>
> {% for greeting in greetings %}
> {% if greeting.author %}
> <b>{{ greeting.author.nickname }}</b> wrote:
> {% else %}
> An anonymous person wrote:
> {% endif %}
> <blockquote>{{ greeting.content|escape }}</blockquote>
> {% endfor %}
>
> In the above "HTML" there are five lines of code, this is not
> separation of code from HTML in my book. There is no ifs, ands or
> buts about it, that is code, if a designer looked at that they would
> say that is code. If this were HTML separated from code it would look
> more like this:
>
> <html>
> <body>
> <gae:list of="greetings">
> <gae:listItem >
> <div class="name"><gae:field name="author.nickname" /></
> div>
> <blockquote><gae:field name="content" /></blockquote>
> </gae:listitem>
> </gae:list>
>
> The developer/programmer would handle the case statement and the
> iteration back in the code where it belongs. All the designer needs
> to know is that this will display a list and the list item allows the
> designer to layout and style each element in the list.
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