URL encoding special characters

i had a weird bug yesterday that consumed a bit of my time.
we have that we have an email that is sent to the user of one of our sites, with a link leading him back to his session (we add some key of the user to the link for that purpose). anyway.. we use a mail template.. a jsf page... all we need to do is to read that page (html generated for that jsf page) and replace some keywork with that parameter value
i had the link in the following format
http://server/servlet?target={user.key}
and i should replace that "{user.key}" with the actual value of the generated key.
this approach have been working fine for quite a while for that feature in several of our sites.
However, recently i was reported that the link was broken and leading to the error page.. as i investigated the matter i found that the link in the emails is
http://server/servlet?targetKKKKKK such that (KKKKKK is the key value)... the equal for some reason was missing.. pretty odd.

i checked the content of my template file.. the equal was there.. mmm..
after a lot of trials and debugging.. i was able to isolate the part where this problem was generated.
in reading the template we read it as an html resource on the web. not as a file. that's how to get the generated HTML and not the jsf code.

i tried http://server/templateURL.faces and voila... the problem was there..
for some reason the server dropped the equal character when generating the link. going little deeper i realized it is not the equal.. is it is the letter directly before the curly brace "{"... whatever u put there is being eliminated.

"Some systems can possibly modify these characters" that's was mentioned in some site describing a set of unsafe characters in URL encoding. maybe our system just decided to interpret the left curly brace as a back space..

my proposed solutions was either to use another stable character.. or to add another space and handle that when reading and parsing the template. (using "target=={" and when parsing the template i reverse it back if it is still there..)
it is a silly quick fix.. but it is the one that makes me backward compatible specially that i'm changing a code that is used by several of the sites.

Comments

Post a Comment

Popular posts from this blog

Success of Startups

Entrepreneurship has become one of the one of the most interesting topic in the business side in any country in the world. While it is digging its way in the middle east, there is some sort of confusion and a lot of aspects related to that topic. A Startup can act and advance to tackle business opportunities in a way that competes with large enterprises. and most of the times, they need to be supported by Investors to back them up. One of the things that started to really bother me in the culture is the definition of success of a startup. No one denies that a decent revenue generating startup is a successful one. However, some people believe that just raising an investment is a success.... umm, debatable. I believe we can make some kind of analogy with some entities that showed up in the past decade like biznas and skybiz (I'm sure some of you will remember those names).   they used an invalid scheme summarized as: People can register and join the network for a fee (as an i...
Read more

Prime Numbers Generator

Image
did u know that 34136029 is a prime number?!! well.. that's what i recently realized :) I thought of writing a piece of code for that purpose.. wondering how far i can get. The idea of the code is simple We know that 2 and 3 are prime numbers the code checks every following odd numbers to be prime or not. To verify a prime number, the number divisibility by the prime numbers generated so far is checked. (29 is a prime number.. because it id not divisible by 2, 3, 5, 7, 11, 13, 17, 19 nor 23) We only need to verify divisibility against the numbers smaller than or equal to the root of the number in hand. (We needn't check the divisibility of 33 with 11, as we already must have found out it is divisible by 3).. I did not want to go with the mathematical root evaluation as i am not sure about its load. I used bits handling instead. the root of a number uses at most half of the number of bits that the original number uses. i only made a naive java implementation so far. downloa...
Read more

Converting a batch of files of csv format to xls or xlsx

While working with data, we tend to deal a lot with CSV files. It is more efficient and trivial to manipulate csv data either through command line tools or through programming languages like ruby. However, occasionally we need to convert files to MS Excel format before sending them to 3rd party. Gnumeric is a wonderful opensource spreadsheet program.  It contains a command line convertion tool called ssconvert that can be used to perform direct conversion among lots of supported formats easily from the command line. For example, conversion from csv to xlsx can be done via ssconvert  file.csv file.xlsx OR ssconvert  file.csv --export-type=Gnumeric_Excel:xlsx It can be installed in ubuntu via apt-get install gnumeric In order to convert lots of files, I wrote a simple bash script that will process all csv files in the current directory and generate the corresponding xlsx files.  The script came pretty handy in data preparation. I believe i can be h...
Read more