Develop Reference

how to declare xpath as a string variable? C#

How can I declare the following xpath value as a string variable in C#?
Value: //*[contains(concat( " ", #class, " " ), concat( " ", "lit-movie", " " ))]

You have to use escape characters (use backslash), so " should be replaced by \":
string xpath = "//*[contains(concat( \" \", #class, \" \" ), concat( \" \", \"lit-movie\", \" \" ))]";

Creating SQL Statements from a Text File - C#

Good morning,
I´m trying to create a program to create statements in a .Sql document but i´m having some troubles.
this is my code so far:
string[] filas = File.ReadAllLines("c:\\temp\\Statements.txt");
StreamWriter sw = new StreamWriter("c:\\temp\\Statements.sql");
foreach (string fila in filas)
{
string sql = "INSERT ";
string[] campos = fila.Split(' ');
if (campos[0]== "1A")
{
sql += " INTO TABLE1 (field1) VALUES (" + campos[1] + ");";
}
else
{
sql += " INTO TABLE2 (field1,field2,field3) VALUES (" + campos[1] + "," + campos[2] + "," + campos[3] + ");";
}
sw.WriteLine(sql);
}
sw.Close();
{
the thing is:
I need to read a txt document (the lenght will change), and then transform it to a sql document with all the statements, there are only two tipes of lines starting in "1A" or "2B", example:
1A123456 456,67
2B123456 mr awesome great strt germany
1A123456 456,67
2B123456 mr awesome great strt germany
2B123456 mr awesome great strt germany
1A123456 456,67
1A123456 456,67
then im trying to "transform" that information on "inserts":
INSERT INTO TABLE1 (REF,MONEY) VALUES (A123456,456,67);
INSERT INTO TABLE2 (REF,NAME,ADR) VALUES (B123456,mr awesome,great strt);
INSERT INTO TABLE1 (REF,MONEY) VALUES (A123456,456,67);
INSERT INTO TABLE2 (REF,NAME,ADR) VALUES (B123456,mr awesome,great strt);
INSERT INTO TABLE2 (REF,NAME,ADR) VALUES (B123456,mr awesome,great strt);
INSERT INTO TABLE1 (REF,MONEY) VALUES (A123456,456,67);
INSERT INTO TABLE1 (REF,MONEY) VALUES (A123456,456,67);
my code is not working so well... i hope someone can help me a litte :).
regards.

Firstly I could not see space between 1A and 123456 . So if (campos[0]== "1A") will not work. Use contains method to do this check - if (campos[0].contains("1A"). you can alternately evaluate using startswith
Secondly you need to split 1A123456 to get A123456 .. you can use substring or similar functions for same. (Same for 2B)
Thirdly, you are splitting the string with ' ' - this could result in many more string than your anticipated strings. 2B123456 mr awesome great strt germany - in this case mr awesome great strt are all different. You need to put in logic to concatenate campos[1] & campos[2] and campos[3] & campos[1=4] in the case of 2B ....
Fourthly for the 1A case you need to split campos[1] using , as delimiter to get the two values you want
Hope this provides you enough guidance to solve your issue.

After some research and with the help from anil and Pikoh i found a good solution:
string mydate = DateTime.Now.ToString("yyyyMMdd");
string AÑO = DateTime.Now.ToString("yyyy");
string MES = DateTime.Now.ToString("MM");
string DIA = DateTime.Now.ToString("dd");
string sql = "INSERT ";
string[] campos = fila.Split(' ');
if (campos[0].StartsWith("1H"))
{
sql += "INTO TABLE (VALUES,VALUES,VALUES) VALUES (" + "'" + mydate + "'" + "," + "'" + campos[0].Substring(1, 8) + "'" + "," + "'" + campos[0].Substring(9, 7) + "'" + "," + "'" + campos[8] + "'" + ");";
Inserting data and manipulating strings was good, but now i have the last problem,
what happen if i need to make a "backspace" to an specific string because my logic cant pick the correct information? regards.

weird regex behavior in the tokenization

I am using the following regex to tokenize:
reg = new Regex("([ \\t{}%$^&*():;_–`,\\-\\d!\"?\n])");
The regex is supposed to filter out everything later, however the input string format that i am having problem with is in the following form:
; "string1"; "string2"; "string...n";
the result of the string: ; "social life"; "city life"; "real life" as I know should be like the following:
; White " social White life " ; White " city White life " ; White " real White life "
However there is a problem such that, I get the output in the following form
; empty White empty " social White life " empty ; empty White empty " city White life " empty ; empty White empty " real White life " empty
White: means White-Space,
empty: means empty entry in the split array.
My code for split is as following:
string[] ret = reg.Split(input);
for (int i = 0; i < ret.Length; i++)
{
if (ret[i] == "")
Response.Write("empty<br>");
else
if (ret[i] == " ")
Response.Write("White<br>");
else
Response.Write(ret[i] + "<br>");
}
Why I get these empty entries ? and especially when there is ; followed by space followed by " then the result looks like the following:
; empty White empty "
can I get explanation of why the command adds empty entries ? and how to remove them without any additional O(n) complexity or using another data structure as ret

In my experience, splitting at regex matches is almost always not the best idea. You'll get much better results through plain matching.
And regexes are very well suited for tokenization purposes, as they let you implement a state machine really easily, just take a look at that:
\G(?:
(?<string> "(?>[^"\\]+|\\.)*" )
| (?<separator> ; )
| (?<whitespace> \s+ )
| (?<invalid> . )
)
Demo - use this with RegexOptions.IgnorePatternWhitespace of course.
Here, each match will have the following properties:
It will start at the end of the previous match, so there will be no unmatched text
It will contain exactly one matching group
The name of the group tells you the token type
You can ignore the whitespace group, and you should raise an error if you ever encounter a matching invalid group.
The string group will match an entire quoted string, it can handle escapes such as \" inside the string.
The invalid group should always be last in the pattern. You may add rules for other other types.
Some example code:
var regex = new Regex(#"
\G(?:
(?<string> ""(?>[^""\\]+|\\.)*"" )
| (?<separator> ; )
| (?<whitespace> \s+ )
| (?<invalid> . )
)
", RegexOptions.IgnorePatternWhitespace);
var input = "; \"social life\"; \"city life\"; \"real life\"";
var groupNames = regex.GetGroupNames().Skip(1).ToList();
foreach (Match match in regex.Matches(input))
{
var groupName = groupNames.Single(name => match.Groups[name].Success);
var group = match.Groups[groupName];
Console.WriteLine("{0}: {1}", groupName, group.Value);
}
This produces the following:
separator: ;
whitespace:
string: "social life"
separator: ;
whitespace:
string: "city life"
separator: ;
whitespace:
string: "real life"
See how much easier it is to deal with these results rather than using split?

How to covert shortened html string into actual html link in label

Hey guys I am trying to print a list of responses from an API into labels and one issue I have is that the response (from JSON) is a string with a shortened link in it. When I put that string into a label the link is not recognized as a link the browser just think it is HTML so there is no underline or pointer. How can I solve this? I have already tried to HtmlEncode it and that did not help.
Here is what I am trying to do.
lblResponse.InnerHtml += "<strong>created_at:</strong> " + item.created_at
+ "<strong>&nbsp text:</strong> " + HttpUtility.HtmlEncode(item.text) + "<br />";
Which returns this into the label. Though in my browser the shortened link is not recognized as a link. Advice?
created_at: Tue Apr 16 20:30:32 +0000 2013 text: Here is some social media news for the week... http://t.co/RR5DKvqUjd
Thanks in advance for the help.

var date = "Tue Apr 16 20:30:32 +0000 2013";
var text = "Here is some social media news for the week... http://t.co/RR5DKvqUjd";
var textwithanchor = Regex.Replace(text, #"\(?\bhttp://[-A-Za-z0-9+&##/%?=~_()|!:,.;]*[-A-Za-z0-9+&##/%=~_()|]", delegate(Match match)
{
return string.Format("<a href='{0}'>{0}</a>", match.ToString());
});
var html = "<strong>created_at:</strong> " + date + "<strong>&nbsp text:</strong> " + textwithanchor + "<br />";
Regex gracefully borrowed from here: http://www.codinghorror.com/blog/2008/10/the-problem-with-urls.html but please take note of the caveats.

Try something like this:
lblResponse.InnerHtml += "<strong>created_at:</strong> " +
item.created_at +
"<strong>&nbsp text:</strong> " +
"<a href=\"" + item.text + "\"" +
HttpUtility.HtmlEncode(item.text) +
"</a><br />";

Can I write this regex in one step?

This is the input string "23x +y-34 x + y+21x - 3y2-3x-y+2". I want to surround every '+' and '-' character with whitespaces but only if they are not allready sourrounded from left or right side. So my input string would look like this "23x + y - 34 x + y + 21x - 3y2 - 3x - y + 2". I wrote this code that does the job:
Regex reg1 = new Regex(#"\+(?! )|\-(?! )");
input = reg1.Replace(input, delegate(Match m) { return m.Value + " "; });
Regex reg2 = new Regex(#"(?<! )\+|(?<! )\-");
input = reg2.Replace(input, delegate(Match m) { return " " + m.Value; });
explanation:
reg1 // Match '+' followed by any character not ' ' (whitespace) or same thing for '-'
reg2 // Same thing only that I match '+' or '-' not preceding by ' '(whitespace)
delegate 1 and 2 just insert " " before and after m.Value ( match value )
Question is, is there a way to create just one regex and just one delegate? i.e. do this job in one step? I am a new to regex and I want to learn efficient way.

I don't see the need of lookarounds or delegates here. Just replace
\s*([-+])\s*
with
" $1 "
(See http://ideone.com/r3Oog.)

I'd try
Regex.Replace(input, #"\s*[+-]\s*", m => " " + m.ToString().Trim() + " ");