Print in ERB without <%=?

Question

Sometimes it's more convenient to print in <%%>. How to do it in Rails?

@JohnTopley A loop which only calls many other partials. – lulalala Oct 03 '13 at 03:57 — lulalala, Oct 03 '13 at 03:57

score 50 · Accepted Answer · edited Jul 30 '15 at 05:38

50

http://api.rubyonrails.org/classes/ActionView/Helpers/TextHelper.html#method-i-concat

Should be what you are looking for.

E.g. the following statement using concat:

<% concat "Output" %>

is equivalent to:

<%= "Output" %>

edited Jul 30 '15 at 05:38

rodamn

2,191
19
24

answered Nov 15 '09 at 14:28

Omar Qureshi

8,963
3
33
35

2

Why doesn't it work with `puts` like `echo` works in PHP? – Chloe Dec 06 '15 at 05:32
2

STDOUT goes somewhere else with Rails, you probably *could* do something nasty so that all STDOUT goes to your erb template, but, don't. – Omar Qureshi Dec 07 '15 at 11:18
1

@Chloe, be grateful for that. :) – floer32 Oct 11 '16 at 06:06
1

@Chloe - STDOUT goes to the log. I've found this default behaviour very handy when running Passenger (for example) where a quick print can help debug. – Nathan Crause Oct 04 '17 at 16:01
To print HTML, use for e.g. `<% concat "
".html_safe %>` – FloatingRock Nov 12 '18 at 13:13

Evolve · Answer 2 · 2014-06-05T07:05:45.550

In ERB: The <% %> signify that there is Ruby code here to be interpreted. The <%= %> says output the ruby code, ie display/print the result.

So it seems you need to use the extra = sign if you want to output in a standard ERB file.

Otherwise, you could look at alternatives to ERB which require less syntax,.. maybe try something like HAML. http://haml-lang.com/tutorial.html

Example:

# ERB
<strong><%= item.title %></strong>

# HAML
%strong= item.title

Is that more convenient?

brianegge · Answer 3 · 2009-11-16T01:40:13.333

erb has two method to evaluate inline ruby expressions. The <% which evaluates the expression and the <%= which evaluates and prints. There is no global object to print to within the binding context.

As mentioned by Omar, there is a concat method, which is part of ActionView. This will do what you want.

Unlike a scripting language escape, there is no default output for erb. Since erb is simply a function, and given a template and binding will return a variable, it returns the values of text and functions recursively.

There is hot debate as to how much logic should be allowed in a view, but as little as possible is what most people aim for. If you are putting more code than text in the view, you may want to consider refactoring your code.

Print in ERB without <%=?

3 Answers3

Linked

Related