Use the pretty_generate() function, built into later versions of JSON. For example:
require 'json'
my_object = { :array => [1, 2, 3, { :sample => "hash"} ], :foo => "bar" }
puts JSON.pretty_generate(my_object)
Which gets you:
{
"array": [
1,
2,
3,
{
"sample": "hash"
}
],
"foo": "bar"
}
.nil? can be used on any object and is true if the object is nil.
.empty? can be used on strings, arrays and hashes and returns true if:
- String length == 0
- Array length == 0
- Hash length == 0
Running .empty? on something that is nil will throw a NoMethodError.
That is where .blank? comes in. It is implemented by Rails and will operate on any object as well as work like .empty? on strings, arrays and hashes.
nil.blank? == true
false.blank? == true
[].blank? == true
{}.blank? == true
"".blank? == true
5.blank? == false
0.blank? == false
.blank? also evaluates true on strings which are non-empty but contain only whitespace:
" ".blank? == true
" ".empty? == false
Rails also provides .present?, which returns the negation of .blank?.
Array gotcha: blank? will return false even if all elements of an array are blank. To determine blankness in this case, use all? with blank?, for example:
[ nil, '' ].blank? == false
[ nil, '' ].all? &:blank? == true
Best Answer
To render LaTeX for the web, it looks to me like
mathTeXis the application of choice. There are many other options, all of which seem to build ondvipngas a foundation.MathTeXappears to be the most polished and capable, and it is easy to configure as a CGI service, so your Rails application can generated ordinary HTML<img>tags with rather complexsrcattributes.EDIT: Having installed mathTeX, I can say that the code is inflexible, that it violates the Linux Filesystem Hierarchy standard, and that it is amateur workâin both the good and bad senses of that word. The code is so complex that there are no obvious faults. I will be looking for alternatives.