Rails 3 - Make text field accept only numeric values - ruby-on-rails-3

How do I make a text field accept only numeric values? If I press a letter or a symbol, the text field should not be filled, it should only allow numbers.
Is there a rails way to do this?

Use number_field_tag, this will generate a HTML5 number field
http://apidock.com/rails/ActionView/Helpers/FormTagHelper/number_field_tag

On the server side validate numericality:
class SomeModel
validates :some_column, :numericality => {:only_integer => true}
end
and on the client side, add an input mask via javascript https://github.com/ruoso/jquery-regex-mask-plugin
$('#some_input').regexMask(/^\d+$/);

#clyfe's answer is good, but that plugin doesn't work with HTML5 type=number elements. Here's some quick jQuery code that only allows integers:
$("input[type=number]").keypress(function(event) {
if (!event.charCode) return true;
ch = String.fromCharCode(event.charCode);
return (/[\d]/.test(ch));
});
to allow decimals or commas, make the regex look more like those in the plugin, e.g. https://github.com/ruoso/jquery-regex-mask-plugin/blob/master/regex-mask-plugin.js#L8 :
/^((\d{1,3}(\,\d{3})*(((\,\d{0,2}))|((\.\d*)?)))|(\d+(\.\d*)?))$/
(Note that different locales have different conventions for decimals and commas, so it's probably safer to just allow digits :-)
Note also that this is a workaround for the Chrome bugs mentioned here:
https://code.google.com/p/chromium/issues/detail?id=304455
https://github.com/angular/angular.js/issues/2144

Related

Display markdown safely as HTML in Vue3

So I have a set of strings, with some "custom markdown" that I have created. My intention is to render these strings as HTML in the frontend. Let's say, I have this string:
This is a string <color>that I need</color> to\nrender <caution>safely in the browser</caution>. This is some trailing text
I would be expecting to get something like:
This is a string <span class="primaryColor">that I need</span> to<br>render <div class="caution">safely in the browser</div>. This is some trailing text
And the way I do it right now is with some basic Regex:
toHtml = text
.replace(/<color>(.*)<\/color>/gim, "<span class='primaryColor'>$1</span>")
.replace(/\\n/g, "<br>")
.replace(/<caution>(.*)<\/caution>/gims, "<div class='caution'>$1</div>")
This works fine and returns the correct string. And then for printing, in the template I just:
<div id="container" v-html="result"></div>
My problem is that at some point I expect users to be able to enter this strings themselves, and that would be displayed to other users too. So for sure, I am gonna be vulnerable to XSS attacks.
Is there any alternative I can use to avoid this? I have been looking at https://github.com/Vannsl/vue-3-sanitize which looks like a good way of just allowing the div, span and br tags that I am using, and set the allowed attributes to be only class for all the tags. Would this be safe enough? Is there something else I should do?
In that case, I believe it will not be necessary to sanitize it in the backend too, right? Meaning, there will be no way for the web browser to execut malicious code, even if the string in the server contains <script>malicious code</script>, right?
My problem is that at some point I expect users to be able to enter this strings themselves
So, Do we have a form input for the users to enter the string which you mentioned in the post ? If Yes, My suggestion is that you can sanitize the user input at first place before passing to the backend. So that in backend itself no malicious code should be stored.
Hence, By using string.replace() method. You can first replace the malicious tags for ex. <script>, <a, etc. from the input string and then store that in a database.
Steps you can follow :
Create a blacklist variable which will contain the regex of non-allowed characters/strings.
By using string.replace(), replace all the occurrence of the characters available in the string as per the blacklist regex with the empty string.
Store the sanitized string in database.
So that, You will not get worried about the string coming from backend and you can bind that via v-html without any harm.

Email validation passes without domain extension

I am using Aurelia-Validation in my project and trying to validate email address. When I add an email example#g, it passes the validation. Shouldn't email validation have .com, .net, etc extension at the end to pass the validation? See the plunker link as an example.
Here is the screenshot to show what I mean:
This is a bit nit-picky, but like emix already pointed out in comments, the validation regex used by aurelia-validation is currently the widely accepted standard as specified by WHATWG. This is the same regex as documented on MDN and w3.org.
Mozilla seems to follow this specification for validating input type="email" at least. I couldn't find any official sources on chrome or edge though.
The JavaScript version of that regex is:
/^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+#[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/
In simple terms this translates to:
(required) before the # symbol, any number of alphanumeric characters and (certain) symbols
(required) after the # symbol, between 1 and 63 alphanumeric characters or hyphens (and cannot start or end with a hyphen)
(optional) same as 2 (but starting with a period), repeated for any number of times
If you want to restrict this validation to emails which are routable in the internet, simply change the asterisk * at the end of the regex to a plus +. That keeps the regex identical except there must now be at least one segment starting with a period.
/^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+#[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)+$/
Made change to my validation rule with below code:
Original code:
ValidationRules.ensure('setEmail')
.displayName('Email')
.required()
.email()
.on(this);
Modified code with matches pattern:
ValidationRules.ensure('setEmail')
.displayName('Email')
.required()
.email()
.matches(/^[a-zA-Z0-9._-]+#[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/)
.on(this);
See the screenshot:
Invalid:
Valid:
In the latest versions I think we can use Validators.pattern(REGEX_VALID_EMAIL) instead of Validators.email in the formControl validator.
and REGEX_VALID_EMAIL can be the following.
const REGEX_VALID_EMAIL = /^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+#[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)+$/
;

#Dblookup and formatting on web

I have been developing a web application using domino, therein I have dblookup-ing the field from notes client; Now, this is working fine but the format of value is missing while using on web.
For example in lotus notes client the field value format is as above
I am one, I am two, I am one , I am two, labbblallalalalalalalalalalalalalalalalalalaallllal
Labbbaalalalallalalalalalaalallaal
Hello there, labblalalallalalalllaalalalalalalalalalalalalalalalalalalalalalalala
Now when I retrieve the value of the field on web it seems it takes 2 immediate after 1. and so forth, I was expecting line feed here which is not happening.
The field above is multi valued field. Also on web I have used computed text which does db lookup from notes client.
Please help me what else could/alternate solution for this case.
Thanks
HD
Your multi-valued field has display options associated with it and the Notes client honors those. Obviously, your options are set up to display entries separated by newlines.
The computed text that you are using for the web does not have options like that and the field options are irrelevant because you aren't displaying the field. Your code has to insert the #Newlines. That's pretty easy because #DbLookup returns a list, and if you concatenate a list and a scalar, the scalar will be appended to each element of the list. (Look at the third example under "concatenation, pairwise" here to see what I mean.
The way you've worded your question is a little unclear to me, but what you need in your computed text formula is either something like this:
list := #DbLookup(etc,. etc.);
list + #Newline;
Or something like this:
multiValueFieldContainingListWithDbLookupResult + #NewLine;
I used #implode(Dblookupreturnedvalue;"");
thanks All :)

rails user input with <script>, stored, and displayed

I have an application that collect user input and store to DB and show back to user.
One user entered "alert(1)" into the name field and saved it into DB.
Whenever the name is displayed, the page will be broken.
I know how to fix that input only with validation for input, and h() for output.
However, I have so many input fields and so many outputs that accept users' text.
Is there any simple way to prevent this happening(i.e. overriding params method, etc)?
I also want to know how you expert guys are dealing with this problem?
As of Rails 3, my understanding was that embedded ruby code was html escaped by default. You don't need to use h() to make it that way. That is, if you use <%= "<script>a=1/0;</script>" %> in a view, the string is going to be made html safe, and so the script doesn't execute. You would have to specifically use raw() or something similar to avoid it - which you should naturally not do unless you're really confident about the contents.
For output, Rails 3 automatically html-encode all text unless I use raw() method.
For input, How about making a common validator and apply to all fields that are text or string? Is it desirable?
http://api.rubyonrails.org/classes/ActiveModel/Validator.html
class MyValidator < ActiveModel::Validator
def validate(record)
record.class.columns.each do |c|
if c.type==:text || c.type == :string
record.errors.add c.type, "script tag is not allowed" if c[/<script[^>]*>/]
end
end
end
end

Can you remove the _snowman in Rails 3?

I'm building an app on Rails 3 RC. I understand the point behind the _snowman param (http://railssnowman.info/)...however, I have a search form which makes a GET request to the index. Therefore, submitting the form is creating the following query string:
?_snowman=☃&search=Box
I don't know that supporting UTF encoding is as important as a clean query string for this particular form. (Perhaps I'm just too much of a perfectionist...hehe) Is there some way to remove the _snowman param for just this form? I'd rather not convert the form to a POST request to hide the snowman, but I'd also prefer it not be in my query string. Any thoughts?
You can avoid the snowman (now a checkmark) in Rails 3 by.... not using Rails for the search form. Instead of using form_tag, write your own as outlined in:
Rails 3 UTF-8 query string showing up in URL?
Rails helpers are great unless they're not helping. Do-it-yourself is good as long as you understand the consequences, and are willing to maintain it in the future.
I believe the snowman has to be sent over the wire to ensure your data is being encoded properly, which means you can't really remove the snowman input from forms. Since, it's being sent in your GET request, it will have to be appended to the URL.
I suppose you could write some javascript to clean up the URL once the search page loads, or you could setup a redirect to the equivalent URL minus the snowman. Both options don't really feel right to me.
Also, it doesn't seem there is any way to configure Rails to not output it. If you really wanted to get rid of it, you could comment out those lines in Rails' source (the committed patches at the bottom of railssnowman.info should lead you to the files and line numbers). This adds some maintenance chores for you when you upgrade Rails. Perhaps you can submit a patch to be able to turn this off?
EDIT: Looks like they just switched it to what looks like a checkmark instead of a snowman.
EDIT: Oops, back to a snowman.
In Rails 4.1 you can use the option :enforce_utf8 => false to disable utf8 input tag.
However I want to use this in Rails 3, so I monkey-patched my Rails. I put the following in the config/initializers directory.
# allow removing utf8 using enforce_utf8, remove after Rails 4.1
module ActionView
module Helpers
module FormTagHelper
def extra_tags_for_form(html_options)
authenticity_token = html_options.delete("authenticity_token")
method = html_options.delete("method").to_s
method_tag = case method
when /^get$/i # must be case-insensitive, but can't use downcase as might be nil
html_options["method"] = "get"
''
when /^post$/i, "", nil
html_options["method"] = "post"
token_tag(authenticity_token)
else
html_options["method"] = "post"
tag(:input, :type => "hidden", :name => "_method", :value => method) + token_tag(authenticity_token)
end
enforce_utf8 = html_options.delete("enforce_utf8") { true }
tags = (enforce_utf8 ? utf8_enforcer_tag : ''.html_safe) << method_tag
content_tag(:div, tags, :style => 'margin:0;padding:0;display:inline')
end
end
end
end