Django Basic Template Tags

Label

The following sections provide an overview of common Django tags.

If/else

The {%if%} tag tests for a variable value, and if the result is true, the system will display everything between {%if%} and {%endif%}, see example:

If Today_is_weekend%}    <p>welcome to the weekend!</p>{% endif%} is    if today_is _weekend%} <p>welcome to the weekend!</p>else%} <p>get back to work.</p>{% endif%}        

{%if%} tags accept and,or,not to test for multivariable, refer to the following example:

{%If Athlete_listand coach_list%} Both AthletesandCoaches is available. {% ENDIF%}{%IfNot athlete_list%} There is no athletes. {% ENDIF%}{%if athlete_list or coach_list%  There is some athletes or  some coaches. {% endif%}{% if not Athlete_list or coach_list%} There is no athletes or there is some coaches.{ % endif%}{% if athlete_list and not coach_list%and absolutely no coaches.{ % endif%}                

{%if%} tags do not accept and and or are present in a label statement, because this can cause ambiguity. For example:

or Cheerleader_list%}

Parentheses are not supported here, and if you need to, consider putting logic in the outer layer of the template and passing the specified template variable as a result. or nested {%if%} tags:

If athlete_list%}    or cheerleader_list%}    or cheerleaders! {% ENDIF%}{% endif%}     

It is possible to use the same operator multiple times, but it is not possible to use multiple different operators at the same time. The following statement is valid:

or Teacher_list%}

Without the {%elif%} tag, the same thing is done with a nested {%if%} tag:

If athlete_list%}    <p>here is the athletes: {{athlete_list}}.</p>else%}    <p> No athletes is available.</p>if coach_list%} <p>here is the coaches: {{coach_list}}.</p>< c15> {% endif%}{% endif%}     

Make sure that each {%if%} corresponds to a {%endif%}, or Django throws a Templatesyntaxerror exception.

For

{%for%} allows you to loop through each item in a sequence, in the form of a for x in Y,y is the set to traverse, and X is the variable name. For Each loop, the template system will display the contents of {%for%} and {%endfor%}.

For example:

<ul> in    athlete_list%}    <li>{{athlete.name}}</li>    {% ENDFOR% }</ul>   

You can also reverse-traverse a collection:

In athlete_list reversed%} ... {% ENDFOR%}

You can also nest:

In athlete_list%}        athlete.sports_ Played%} <li>{{sport}}</li> {% endfor%} </ul>{% endfor%}   

A common pattern is to check the size of the list before iterating, and to output some special text if the list is empty

If athlete_list% inathlete_list%}<p>{{athlete.name}}</p>{% endfor%Else%}& Lt;p>there is no athletes. Only computer programmers.</p>{% endif%}     

Because this method is too common, the for tag supports an optional {%empty%} option that lets you define the output custom text. For example:

In athlete_list%}<p>{{athlete.name}}</p>{% empty%}<p>there is no athletes. Only computer programmers.</p>{% endfor%}   

Note that the for label does not support Break,countinue.

In the {%for%} tab, you can access the Forloop variable, which has several common properties:

1.forloop.counter: How many times are used to record loops

2.forloop.counter0: Similar to Forloop.counter0, just starting from 0.

3.forloop.revcounter: Number of items used to record an item that has not been traversed

4.forloop.revcounter0: Similar to Revcounter, but counting is starting from 0

5.forloop.first: A Boolean value that identifies whether the first item

6.forloop.last: Boolean value to indicate whether the last item

Ifequal/ifnotequal

The {%ifequal%} tag compares two values and displays all the code between {%ifequal%} and {%endifequal%} if they are equal.

{% ifequal user CurrentUser%}{% endifequal%} 

The arguments can be hard-coded, so the following examples are valid:

'sitenews'%}{% endifequal%}   

{% ifequal section "community"%}
{% endifequal%}

Similar to {%if%}, the {%ifequal%} tag also supports option {%else%}

'sitenews'%}Else%}{% Endifequal%}     

Only template variables, characters, integers, and floating-point types can be used as comparison parameters, here are some valid examples:

{% ifequal variable 1%}{% ifequal variable 1.23%'foo'%"foo"%}
          

Other types, such as list, dictionary, and Boolean types, are not allowed as parameters of {%ifequal%}.

{% ifequal variable True%}{% ifequal variable [1, 2, 3]%}{% ifequal variable {'key'value'}% }

These are invalid parameters. If you want to test if something is true or false, use {%ifequal%}

Comments

Use {# #}, multi-line comments using {%comment%} and {%endcoomment%}

Filter filters

Template filtering is the simplest way to change the value of a variable before displaying them. For example: {{name|lower}}, this will first change the value of name to lowercase and then display it again.

Filters can be used in multiple successive uses:

{{My_list|first|upper}}

Django Basic Template Tags