Template inheritance with extends in Flask - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to extend the base template in Flask.

Flask

{% [1] 'base.html' %}

Drag options to blanks, or click blank then click option'

Aextends

Binclude

Cimport

Dblock

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'include' instead of 'extends' will insert the template but not inherit.

Using 'block' or 'import' are incorrect for extending templates.

The {% extends %} tag is used to inherit from a base template in Flask.

2fill in blank

medium

Complete the code to define a block named 'content' in a Flask template.

Flask

{% block [1] %}{% endblock %}

Drag options to blanks, or click blank then click option'

Aheader

Bfooter

Ctitle

Dcontent

Attempts:

3 left

💡 Hint

Common Mistakes

Using unrelated block names like 'header' or 'footer' when the main content block is 'content'.

Blocks define sections that child templates can override. 'content' is a common block name.

3fill in blank

hard

Fix the error in the code to correctly extend the base template and define a block.

Flask

{% [1] 'base.html' %}
{% block content %}
<p>Hello!</p>
{% endblock %}

Drag options to blanks, or click blank then click option'

Aextends

Binclude

Cimport

Dblock

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'include' instead of 'extends' causes the template not to inherit.

The correct tag to inherit a template is 'extends'.

4fill in blank

hard

Fill both blanks to create a child template that extends 'layout.html' and overrides the 'title' block.

Flask

{% [1] 'layout.html' %}
{% block [2] %}My Page Title{% endblock %}

Drag options to blanks, or click blank then click option'

Aextends

Bcontent

Ctitle

Dinclude

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'include' instead of 'extends' for inheritance.

Overriding the wrong block name like 'content' instead of 'title'.

Use 'extends' to inherit and 'title' to override the title block.

5fill in blank

hard

Fill all three blanks to extend 'base.html', override 'content' block, and add a paragraph inside.

Flask

{% [1] 'base.html' %}
{% block [2] %}
<p>[3]</p>
{% endblock %}

Drag options to blanks, or click blank then click option'

Aextends

Bcontent

CWelcome to my site!

Dfooter

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong block names or missing the extends tag.

Putting text outside the block tags.

Use 'extends' to inherit, 'content' block to override main content, and add the paragraph text.

Practice

1. What is the main purpose of using {% extends %} in Flask templates?

easy

A. To inherit the layout from a base template and reuse it

B. To include JavaScript files in the template

C. To define a new CSS style inside the template

D. To create a new Flask route

Solution

1. Step 1: Understand the role of {% extends %}

   This tag is used to inherit from a base template, allowing reuse of common layout parts.

2. Step 2: Differentiate from other template tags

   Other options like including scripts or defining CSS are done differently, not with {% extends %}.

3. Final Answer:

   To inherit the layout from a base template and reuse it -> Option A

4. Quick Check:

   Template inheritance = reuse layout [OK]

Hint: Remember: extends means reuse base layout [OK]

Common Mistakes:

• Confusing extends with including scripts
• Thinking extends creates new routes
• Using extends to add CSS styles

2. Which of the following is the correct syntax to inherit from a base template named base.html?

easy

A. {% include 'base.html' %}

B. {% import 'base.html' %}

C. {% extends 'base.html' %}

D. {% block 'base.html' %}

Solution

1. Step 1: Recall the syntax for template inheritance

   The correct tag to inherit a template is {% extends 'filename' %}.

2. Step 2: Identify incorrect tags

   {% include %} inserts content but does not inherit; {% import %} is for macros; {% block %} defines sections, not inheritance.

3. Final Answer:

   {% extends 'base.html' %} -> Option C

4. Quick Check:

   Extends = inherit base template [OK]

Hint: Use extends, not include, to inherit templates [OK]

Common Mistakes:

• Using include instead of extends
• Confusing import with extends
• Misusing block tag for inheritance

3. Given the base template base.html with a block named content and a child template that extends it and overrides content, what will be displayed when rendering the child template?

medium

A. An error because blocks cannot be overridden

B. The content defined inside the child's content block

C. The content defined inside the base template's content block

D. Both base and child content concatenated automatically

Solution

1. Step 1: Understand block overriding in template inheritance

   The child template replaces the base template's block content with its own block content.

2. Step 2: Clarify behavior of blocks

   Blocks are placeholders in the base template; child templates override them. No automatic concatenation occurs unless explicitly coded.

3. Final Answer:

   The content defined inside the child's content block -> Option B

4. Quick Check:

   Child block overrides base block content [OK]

Hint: Child block content replaces base block content [OK]

Common Mistakes:

• Thinking base block content shows instead
• Expecting automatic concatenation of blocks
• Believing block override causes errors

4. Consider this child template code snippet:

{% extends 'base.html' %}
{% block content %}
Hello World

What is the error in this template?

medium

A. The closing tag should be {% endblock %} instead of

B. The extends tag is missing quotes around the filename

C. The block name should be main not content

D. The p tag cannot be used inside blocks

Solution

1. Step 1: Check block syntax correctness

   Blocks must be closed with {% endblock %}, not with HTML-like closing tags.

2. Step 2: Verify other parts

   The extends tag is correctly quoted; block name can be any valid name; p tags are allowed inside blocks.

3. Final Answer:

   The closing tag should be {% endblock %} instead of -> Option A

4. Quick Check:

   Block ends with endblock tag [OK]

Hint: Close blocks with {% endblock %}, not HTML tags [OK]

Common Mistakes:

• Using HTML closing tags for blocks
• Forgetting quotes in extends (not here though)
• Assuming block names are fixed keywords

5. You have a base template base.html with two blocks: header and content. You want a child template to reuse the base layout but only change the content block, keeping the base header as is. Which is the correct approach?

hard

A. In the child template, extend base.html and redefine only the header block

B. In the child template, extend base.html and redefine both header and content blocks

C. In the child template, do not use extends; copy all base content and change content

D. In the child template, extend base.html and define only the content block; omit the header block

Solution

1. Step 1: Understand block overriding behavior

   If a block is not redefined in the child, the base template's block content is used automatically.

2. Step 2: Apply this to the problem

   To keep the base header, do not redefine the header block in the child; only override content.

3. Final Answer:

   In the child template, extend base.html and define only the content block; omit the header block -> Option D

4. Quick Check:

   Omit block to keep base content [OK]

Hint: Override only blocks you want to change [OK]

Common Mistakes:

• Redefining all blocks unnecessarily
• Copying base template instead of extending
• Overriding wrong block by mistake