In haml, how do I render the following incredibly basic HTML:
<p>Results found for <strong>search term</strong>
where 'search term' is actually a Ruby variable called #query?
I'm trying the following,
%p results found for <strong>= #query</strong>
But that renders = #query literally. If I try:
%p results found for <strong>
= #query
</strong>
then the query term renders correctly, but is on a new line.
Also, I'm wondering if there's a better way to render <strong> in haml, while keeping everything on the same line.
I'm aware of the haml documentation, but as far as I can see there isn't an example of using a simple inline Ruby variable.
-----UPDATE-------
The following code works, and shows how to use a variable that's not within tags:
%p
= #trials_found_count
results found for
%strong= #query
But I find it really unreadable - it's hard to tell that it renders as just one line of HTML without adding a comment above.
Is there a way I can put all this code on a single line? Or is this just how haml works?
HAML is whitespace delimited. Nested tags go on the line below and one level in from the tag above. Embedded Ruby from which you want to display output is opened with an '='. Embedded Ruby which you don't want to display such as the start of loops uses '-' These are equivalent to <%= %> and <% %> respectively in erb.
What you want would look like this:
%p
results found for
%strong= #query
Which would produce the html:
<p>results found for <strong>#query</strong></p>
It should be noted that the '=' to start Ruby evaluation can only come at the beginning of the line or after a tag declaration and that only one tag declaration can occur per line.
The Ruby Evaluation section of the reference you linked covers embedded Ruby in detail and the haml tutorial which covers embedded ruby and many other haml basics is here:
http://haml-lang.com/tutorial.html
Here's how I'd do it:
%p No results found for <strong>#{h #query}</strong>
I'm not sure, but you might need a non-breaking space to preserve the space between the for and the <strong>
%p results found for
%strong= #query
Related
I have created a blog in rails. I'm a beginner and got quite far, but now I'm stuck with a seemingly minor detail: I can't seem to format the posts (articles).
Here's the relevant part of my show.html.erb:
<p>
<strong>Content:</strong>
<%= simple_format (#article.content) %>
</p>
When I write something and insert html-tags, they are not recognized as such. What am I doing wrong?
Rails will automatically remove html tags to prevent someone from injecting code into your webpage (e.g. malicious javascript)
If your users cannot enter data into #article.content and it's always safe then you can flag it as safe usng the html_safe method.
<%= (simple_format (#article.content)).html_safe %>
Can you post the article content for reference? If I had to guess, I'd imagine Rails is escaping the html tags and inserting them as plain text (so the output looks like: Article content !
Take a look at Rails' helper methods like content_tag (http://apidock.com/rails/ActionView/Helpers/TagHelper/content_tag) and concat (http://apidock.com/rails/ActionView/Helpers/TextHelper/concat) and consider using those to help with generating the appropriate html tags.
An issue to be concerned with is who's going to be supplying the content. For example, if you're writing an application that other people will use, you want to make sure any html give you is escaped to avoid XSS attacks. In that case, you'll want to spend some time reading about how to properly sanitize user input.
You can now specify the tag it gets wrapped in (defaults to p) like so:
<%= simple_format (#article.content, {}, wrapper_tag: "div") %>
or
add white-space: pre-line style.
It will display \r or \n (enter) in user input as a new line.
for more info:
http://apidock.com/rails/v4.0.2/ActionView/Helpers/TextHelper/simple_format
If I have a line in a Rails template that evaluates to nil, is there a way to have Haml not bother to generate output for that line rather than create an empty tag? For instance given this:
%h4= #my_hash[:optional]
...imagine that there's no data for that hash-key. I don't want to end up with:
<h4></h4>
I'd like no output at all from that line because empty tags can still affect page layout, particularly if you're using something CSS-heavy like Bootstrap.
I can write this everywhere:
-if #my_hash[:optional]
%h4= #my_hash[:optional]
but it's long-winded and ugly.
(It seems like lots of people would want to do this, but I couldn't find any mention of either a way to do it in the Haml docs, or people on SO or elsewhere asking how it could be done. So clearly everybody already knows how to do it except me, right?)
Update: Thanks for the suggestions. The thing is, it doesn't seem to matter what you put after the equals sign here:
%h4= amazing_intelligent_helper_method_but_sadly_too_late()
because Haml has already decided to output a tag at that point, the only question is what goes in the tag? If the expression after the equals sign evaluates to nil, Haml doesn't put any content in the tag - but it still outputs the tag itself.
%h4= nil #output: <h4></h4>
%h4= '' #output: <h4></h4>
%h4= false #unexpected output: <h4>false</h4>
%h4= #Haml::SyntaxError 'There's no Ruby code for = to evaluate.'
So at the moment, I don't have a one-line way of omitting empty tags. But surely I'm not the only one who wants to do this? When you look at some of the esoteric options Haml supports, I'd have really expected this feature to already be in there somewhere.
Just append the condition to the line ala Ruby statement modifiers:
%h4= #my_hash[:optional] if #my_hash[:optional]
Still long winded but at least its on one line now.
Here are some other techniques that were discussed but they're not any shorter or prettier: HAML: Create container/wrapper element only if condition is true
Try this code
%h4= #my_hash[:optional] unless #my_hash[:optional].blank?
Even though this is my question I thought I'd suggest a semi-OK-ish answer I've just thought of in the hope that someone will look at it and say 'Aha! I can do better than that.'
I could put this in the view
!= h4_if #my_hash[:options]
and I throw this in my helper file:
TAGS_TO_DELETE_WHEN_EMPTY = ['h1', 'h2', 'h3', 'h4', 'p', 'span']
TAGS_TO_DELETE_WHEN_EMPTY.each do |tag|
new_method_name = (tag + '_if').to_sym
define_method new_method_name do |content = nil|
"<#{tag}>#{content}</#{tag}" if content
end
end
then I only get an h4 tag if there's content for it. I can use these little conditional helper methods, coupled with Haml's unescaped ruby evaluator '!=', to get what I'm looking for. Downsides include: even though it's very concise in the view, and easy to extend, it doesn't look much like regular Haml. Also, I'm not 100% sure it won't upset Haml in some way if I use much of it.
Plus I'm still hoping someone will tell me there's an option in Haml to not output empty tags, because then I don't need to write any additional code at all (which is my favourite solution to problems).
I'm trying to use haml on RoR.
I faced some problems in haml.
My sample code is below.
ERB:
<p> <div class="hello"> <%= #sample.val %> <%= #hogehoge.val %> </div> </p>
HAML:
%p
.hello
= #sample.val
= #hogehoge.val
I can write one line in erb file.
But, I have to write 4 lines in haml.
Haml is so smart and beautiful syntacx structure, isn't it?
But I think writing so many lines is not smart.
How do I write in one line in haml in this case.
If you don't like the way haml work, why do you use it? that's how haml work. If you want something different you need something different, there are more template languages.
You complain about the amount of line but think about the amount of characters and readability, maintainability. The amout of line is one of the less important things on your code, or do you write all your html code in one line when you use erb or plain html?
You could save a few line though doing:
%p
.hello= "#{#sample.val} #{#hogehoge.val}"
but is it really THAT important? Well, now you have 2 lines instead of 1, is it "smart" enough? I don't think you can have that in one line using haml.
But, I have to write 4 lines in haml.
Yes, but you've saved a lot of characters and now have compile-time errors if you don't get your nesting right. Don't focus on the lines used, but the clarity.
I think you can do this:
%p %div.hello
= #sample.val + " " + #hogehoge.val
.hello
= #sample.val
= #hogehoge.val
If you're using <p> for styling, you'd be better putting a margin property in your .hello css
You're missing the point of haml - it's less verbose than erb
I use ruby on rails to get some variables and suppose to send them in email format to some email address.
%div
- #msg.each do |line|
%p = "#{line}"
%br
The msg is the string array I passed in and would like to get each element in separate line. How can I achieve that. The above code won't work.
One of the key things of coding HAML is you really are only going to have one item per line, plus you automatically get a div tag as the default tag. So you might as well add a class to your div to differentiate it. Additionally, make sure your indentation is correct:
.messages
- #msg.each do |line|
%p= line
You don't really need a br because the p will break for you, and following a tag with '=' will automatically give you the interpolation.
I read the Haml docs where they talk about the pre tag and "preserving whitespace". According to the docs, pre "preserves whitespace" by default and you need to use the ~ operator to output the contents of the tag to get it to render correctly. Following the recommended practice, I have this:
%pre
~ #calendar.main_template
The output in the browser:
(This may be a little confusing -- the app is letting the user manipulate Haml code, so I'm actually displaying Haml code here in the UI.)
%div
= events
What output want:
%div
= events
I also tried using = instead of ~. Also tried %pre>, %pre<, and %pre>< all with identical results.
You want preserve.
%pre
= preserve "I like\n Cheese"