Haml: Control whitespace around text - ruby-on-rails

Question

In my Rails template, I'd like to accomplish final HTML to this effect using HAML:
I will first link somewhere, then render this half of the sentence if a condition is met
The template that comes close:
I will first
= link_to 'link somewhere', 'http://example.com'
- if #condition
, then render this half of the sentence if a condition is met
You may, however, note that this produces a space between the link and the comma. Is there any practical way to avoid this whitespace? I know there's syntax to remove whitespace around tags, but can this same syntax be applied to just text? I really don't like the solution of extra markup to accomplish this.

Answer 1

A better way to do this has been introduced via Haml's helpers:
surround
= surround '(', ')' do
%a{:href => "food"} chicken
Produces:
(<a href='food'>chicken</a>)
succeed:
click
= succeed '.' do
%a{:href=>"thing"} here
Produces:
click
<a href='thing'>here</a>.
precede:
= precede '*' do
%span.small Not really
Produces:
*<span class='small'>Not really</span>
To answer the original question:
I will first
= succeed ',' do
= link_to 'link somewhere', 'http://example.com'
- if #condition
then render this half of the sentence if a condition is met
Produces:
I will first
link somewhere,
then render this half of the sentence if a condition is met

Answer 2

You can also do this using Haml's "trim whitespace" modifier. Inserting > after a Haml declaration will prevent whitespace from being added around it:
I will first
%a{:href => 'http://example.com'}> link somewhere
- if #condition
, then render this half of the sentence if a condition is met
produces:
I will first<a href='http://example.com'>link somewhere</a>, then render this half of the sentence if a condition is met
However, as you can see, the > modifier also strips the whitespace in front of the link, removing the desired space between the words and the link. I haven't figured a pretty way around this yet, except to add to the end of "I will first", like so:
I will first
%a{:href => 'http://example.com'}> link somewhere
- if #condition
, then render this half of the sentence if a condition is met
Which finally produces the desired output without lots of hard-to-read interpolation:
I will first <span>link somewhere</span>, then render this half of the sentence if a condition is met

Answer 3

Alright, here's the solution I'm settling on:
Helper
def one_line(&block)
haml_concat capture_haml(&block).gsub("\n", '').gsub('\\n', "\n")
end
View
I will first
- one_line do
= link_to 'link somewhere', 'http://example.com'
- if #condition
, then render this half of the sentence
\\n
if a condition is met
That way, whitespace is excluded by default, but I can still explicitly include it with a "\n" line. (It needs the double-backslash because otherwise HAML interprets it as an actual newline.) Let me know if there's a better option out there!

Answer 4

You can use the 'aligator syntax' of HAML
Whitespace Removal: > and <
and < give you more control over the whitespace near a tag. > will remove all whitespace surrounding a tag, while < will remove all whitespace immediately within a tag. You can think of them as alligators eating the whitespace: > faces out of the tag and eats the whitespace on the outside, and < faces into the tag and eats the whitespace on the inside. They’re placed at the end of a tag definition, after class, id, and attribute declarations but before / or =.
http://haml.info/docs/yardoc/file.REFERENCE.html#whitespace_removal__and_

Answer 5

Once approach I've taken to this sort of thing is to use string interpolation:
I will first #{link_to 'Link somewhere'}#{', then render this half of the sentence if a condition is met' if condition}
I don't like the look of the literal string in the interpolation, but I've used it with previously declared strings or dynamically generated strings before.

Answer 6

You can do this to keep the leading space:
%a{:href => 'http://example.com'}>= ' link somewhere'
The space is in the quotes.

Answer 7

Although not well documented, this is cleanly achieved using HAML whitespace preservation (>) combined with an ASCII space (& #32;), and not with helpers:
%a{:href=>'/home'}> Home link
,
%a{:href=>'/page'} Next link
This will produce what you want:
<a href='/home'>Anchor text</a>,
<a href='/page'>More text</a>
But I agree, HAML needs to come up with a better way of doing this, as it does add unnecessary ASCII characters to the page (but it's still more efficient than using helpers).

Answer 8

There's the angle bracket "whitespace munching" syntax, otherwise write a helper method for it.

Answer 9

I came across a similar problem and found this so I thought I would post another solution which doesn't require a helper method. Use Ruby interpolation #{} to wrap the link and if statements:
I will first
#{link_to 'link somewhere', 'http://example.com'}#{if true : ", then render this half of the sentence if a condition is met" end}
This works in 3.0.18, it may also work in earlier releases.

Answer 10

Yet another option that I've used in the past:
- if #condition
%span> , then some more text after the link.

Answer 11

You could also always do:
= link_to url_path do
= ["part_1", "part_2"].join(", ")

Answer 12

The solution that I got working is:
I will first
= link_to 'link somewhere', 'http://example.com'
- if #condition
= ", then render this half of the sentence if a condition is met"
You can use =, though = is used to output the result of Rails code, but here it will server the purpose.

Answer 13

The preserve function worked for me
.white-space-pre= preserve "TEXT"