I have a encrypted string which would be passed from the server side, now I want to test to convert it into readable language by some conventional decoding method.
but I found I totally cannot use the string:
The error shows: invalid escape sequence in literal.
There exists some conversions in swift string like "\(variable)" or "\b".
Is there a way for me to use pure String?
For example. in python, I can declare a = """content""" to represent pure String
It's the backslash (\), just before the character the up-arrow is pointing to in the error message. In a literal, this needs to be represented by a double backslash (\\).
This issue won't arise once you're no longer testing and you're doing this all with actual values; it's a feature only of literal strings.
I recently fount a quick solution:
Use ' content ' instead of " content ", then Xcode would give you a warning.
Press Fix-it, Xcode would automatically add \ at right places to avoid literal convention.
I would suggest you save the string in a file in you app and read it from there, to avoid having to modify the string (it's a rather ugly string and you will have to escape a bunch of stuff).
You can use NSBundle.pathForResource and NSString.initWithContentsOfFile to get the string into memory from the file.
Related
Hello I am constructing a URI from two different strings coming from a source.
String1 = 12345&67890
String2 = 78326832
URI = /api?invoice=String1&supplier=String2
After using concat function available in studio, this is the final URI.
/api?invoice=12345&67890&supplier=78326832
(Get request fails because 67890 is taken as query)
Expected output is
/api?invoice=12345&67890&supplier=78326832
how do I achieve this, Can i use xslt to convert symbols to its HTML entity characters
Your expected output /api?invoice=12345&67890&supplier=78326832 is rather bizarre: there's no context where it makes sense to escape some ampersands (at the XML/HTML level) and leave others unescaped.
I think that what you really want is to use URI escaping (not XML escaping) for the first ampersand, that is you want /api?invoice=12345%2667890&supplier=78326832. If you're building the URI using XSLT 2.0 you can achieve this by passing the strings through encode-for-uri() before you concatenate them into the URI.
But you've given so little information about the context of your processing that it's hard to be sure exactly what you want.
in this gist
https://gist.github.com/greedo/957ba26575b3f5e445dc
there is a comments.coffee file.
in that it says
#accessor 'quote', ->
"“#{#get('current_comment')?.body}”"
The alternate type of double quotes is used. Is that on purpose? What are those called, and what is it doing there? Or is this just some character set conversion error. Tried to search but i have no idea what backwards double quotes are called.
Check out #mudasobwa's answer on this question How do I declare a string with both single and double quotes in YAML?
The main purpose of those quotes is so that it doesn't collide with the standard double quotes if dealing with a string that needs to output one. The coder can get away with having to remember to add a \ if he makes sure that every string that needs a double quote uses “ instead of ".
The code may be changed to the following without any effect.
#accessor 'quote', -> "\"#{#get('current_comment')?.body}\""
My Rails application stores strings containing html entity codes, e.g. "Θ", which display Greeks and other characters on browser pages. To display these same characters in Prawn documents, I need to convert "Θ" to "\u0398". Using a regexp I can extract the bare codepoint, "0398", from the original string. But I'm unable to use this to create a new string variable containing "\u0398".
I've tried many variations of string concatenation, interpolation and even array operations, but no joy. Anything that looks like
new_string_var = "\u" + my_codepoint
generates an "invalid Unicode escape" error at "\u".
Anything that looks like
new_string_var = "\\u" + my_codepoint
runs without error but inserts the literal string "\u0398" in the Prawn document.
Is it possible in Ruby to construct a string like this? Is there a better approach?
Actually, you don't need \uxxxx notation - this is for display purposes in Ruby. Try CGI.unescapeHTML(string_with_entities) from built-in CGI module.
I am getting text from a feed that has alot of characters like:
Insignia™ 2.0 Stereo Computer Speaker System (2-Piece) - Black
4th-Generation Apple® iPod® touch
Is there an easy way to get rid of these, or do I have to anticipate which characters I want to delete and use the delete method to remove them? Also, when I try to remove
&
with
str.delete("&")
It leaves behind "amp;" Is there a better way to delete this type of character? Do I need to re-encode the text?
String#delete is certainly not what you want, as it works on characters, not the string as a whole.
Try
str.gsub /&/, ""
You may also want to try replacing the & with a literal ampersand, such as:
str.gsub /&/, "&"
If this is closer to what you really want, you may get the best results unescaping the HTML string. If so try this:
CGI::unescapeHTML(str)
Details of the unescapeHTML method are here.
If you are getting data from a 'feed', aka RSS XML, then you should be using an XML parser like Nokogiri to process the XML. This will automatically unescape HTML entities and allow you to get the proper string representation directly.
For removing try to use gsub method, something like this:
text = "foo&bar"
text.gsub /\b&\b/, "" #=> foobar
I'm using Url.Encode within a view and it's replacing spaces with + so instead of:
/production/cats-the-musical I'm getting .../cats+the+musical.
I'm sure this is an easy one, but where do you go to configuring which characters are used for this?
I'll be doing this:
public static string EncodeForSEO(this UrlHelper helper, string unencodedUrl)
{
return helper.Encode(unencodedUrl.Replace(' ', '-'));
}
Until I get a better answer from you guys.
Edit: Thanks Guffa for pointing out my hasty coding.
I want to draw attention to Path versus Query String encoding differences
MVC allows / encourages us to write paths (routes) that can be easier to remember than query strings. e.g. /Products.aspx?id=1 could, in MVC, be /Products/View/1
Building on that, it also encourages, for SEO friendliness, other data that may or may not be necessary like /Products/View/1/Coffee
If the name has space characters, or a necessary parameter is a string containing space characters, and you are including it in the Url path, one of 2 things must happen because a ' ' cannot be left in a Url Path or Query string parameter without being encoded.
You must UrlPathEncode() the string
first you transform the spaces in the string,
then call UrlPathEncode() as you may have other characters requiring encoding.
Note: there is a big difference between Url Encoding (meant for query strings) and Url Path Encoding (meant for path portions of Urls)
cats the musical -> UrlEncode -> cats+the+musical
-- this is not valid in a url path
cats the musical -> UrlPathEncode -> cats%20the%20musical
If you're following along; going back to Web Forms vs MVC - /Products.aspx?name=Coffee+Beans would be rewritten as /Products/View/Coffee%20Beans
So that leaves us where OP's question starts. Q: How do you get SEO and human Friendly Urls? Q: Use #Guffas code to replace the " " with "-" in your own code before UrlPathEncoding the rest.
In sites I've worked on, when we have a user-entered value used only for SEO (like a blog title or similar) we go a step further normalizing the string output by collapsing successive spaces into a single "-" e.g.
cats the musical which would otherwise be cats-----the-----musical becomes cats-the-musical
You can't change which characters the UrlEncode method uses, the use of "+" for spaces is defined in the standards for how an URL is encoded, using "-" instead would mean that the method would change the value and not just encoding it. As the "-" character is not encoded, there would be no way to decode the string back to the original value.
In your method, there is no need to check for the character before doing the replacement. If the Replace method doesn't find anything to replace, it just returns the original string reference.
public static string EncodeForSEO(this UrlHelper helper, string unencodedUrl) {
return helper.Encode(unencodedUrl.Replace(' ', '-'));
}