Respect whitespace about marko

[patrick-steele-idem]

Hi @mattfysh, Marko will remove unnecessary whitespace based on some builtin rules, by default. These rules are partially based on the rules that browser's use to normalize whitespace and partially based on the goal of allowing nicely indented markup. These rules are as follows:

• For whitespace before the first child element: text = text.replace(/^\n\s*/g, '')
• For whitespace after the last child element: text = text.replace(/\n\s*$/g, '')
• For whitespace between child elements: text = text.replace(/^\n\s*$/g, '')
• Any contiguous sequence of whitespace characters is collapsed into a single whitespace character

FYI, the whitespace removal happens in the following code:
marko/compiler/TextNode.js:112

It's possible to disable whitespace removal on a per-element basis using a special attribute applied to a parent element. It's also possible to disable all whitespace removal by changing an option for the compiler. Unfortunately the docs are currently lacking for both these options so I'll describe them below for now:

Option 1) Disable whitespace removal using the c-whitespace attribute:

<div c-whitespace="preserve">
    <my-first-tag>
    <my-second-tag>
</div>

Option 2) Disable all whitespace removal by changing a compiler option

require('marko/compiler').defaultOptions.preserveWhitespace = true;

Also, you can avoid whitespace removal by avoiding the new line character. For example, the following whitespace between the elements will be preserved:

<my-first-tag> <my-second-tag>

I'll work on adding some formal documentation on the whitespace removal rules. Do these options meet your needs or are you looking for a different solution?

[patrick-steele-idem]

@mattfysh, I added some documentation to clarify how Marko deals with whitespace:
https://github.com/raptorjs/marko#whitespace

Please let me know what you think.

Thanks,
Patrick

[philidem]

Perhaps we should add a tag that can be used to enable preservation of whitespace.

For example, something like this:

<preserve-whitespace>
<my-first-tag>
<my-second-tag>
</preserve-whitespace>

Sometimes there isn't a convenient parent tag to add the c-whitespace="preserve" attribute

[patrick-steele-idem]

I agree regarding introducing a <preserve-whitespace> tag. I have added Issue #11 to the backlog.

[patrick-steele-idem]

Marking issue as closed since additional docs were added clarifying the whitespace rules for Marko. If there are still issues please let us know. Thanks.

[ivanfilhoz]

require('marko/compiler').defaultOptions.preserveWhitespace = true;

Sorry to reopen an old issue, but how to set this option with marko/express?