I have an assignment for school where I need to do some things with text. One of them being reversing a string.
Now I've got a while-loop that kind of works, but I have some questions about it.
if(drawRev){
int i = textBoxInput.length();
while(i>0){
textRev += textBoxInput.substring(i-1,i);
i--;
if(i==0){
finalReversed = textRev;
drawRev = false;
drawReverse = true;
}
}
}
So first thing I'd like to ask is: Why does the while-loop not stop when i reaches 0?
The boolean drawRev is true when I click a button but I have to manually make it false if i==0.
I shouldn't have to do this right?
Second question I have is: How do I keep the reversed text to display it?
It does in fact reverse the text when I enter it, but it immediately turns into an empty string when it finishes.
I'm a beginning student and pretty new to programming in general, so keep it simple please!
If you'd like to see the whole code it's available here: http://pastebin.com/f1dW8b0Y
I've got it working.
I tried to make it too complex.
Thanks to deamentiaemundi.
This works:
if(drawRev){
int i = textBoxInput.length();
while(i>0){
textRev += textBoxInput.substring(i-1,i);
i--;
}
}
Here's the working code for someone with a similar issue: http://pastebin.com/mQC9AwVD
another way to reverse a string
$(document).ready( function(){
var str = "test";
var revstr = str.split("").reverse().join(""); //"test" to ['t','e','s','t'] to ['t','s','e','t'] to "tset"
$(".test").text(revstr)
});
For reference: How do you reverse a string in place in JavaScript?
Related
I am creating a dynamic list of placeholders, some of the values held in these place holders are decimal numbers that are supposed to represent money.
What I'm wondering is if there is a way I can format them to display as such?
Something like [[+MoneyField:formatmoney]]
I see http://rtfm.modx.com/revolution/2.x/making-sites-with-modx/customizing-content/input-and-output-filters-(output-modifiers) but I do not see a way to do this here.
You most definitely can, under the header "Creating a Custom Output Modifier" on the link you posted it's described how you can place a snippet name as a output modifier. This snippet will recieve the [[+MoneyField]] value in a variable called $input.
So you'd have to create this custom snippet which could be as simple as
return '$'.number_format($input);
Another version of doing this is calling the snippet directly instead of as an output modifier like so:
[[your_custom_money_format_snippet ? input=`[[+MoneyField]]`]]
I'm not sure if theres any difference between the two in this case. Obviously you can pass any value into the number format snippet when calling it as a snippet instead of an output modifier. And i'm sure theres a microsecond of performance difference in the two but i'm afraid i don't know which one would win. ;)
Update:
Actually found the exact example you want to implement on this link;
http://rtfm.modx.com/revolution/2.x/making-sites-with-modx/customizing-content/input-and-output-filters-%28output-modifiers%29/custom-output-filter-examples
Snippet:
<?php
$number = floatval($input);
$optionsXpld = #explode('&', $options);
$optionsArray = array();
foreach ($optionsXpld as $xpld) {
$params = #explode('=', $xpld);
array_walk($params, create_function('&$v', '$v = trim($v);'));
if (isset($params[1])) {
$optionsArray[$params[0]] = $params[1];
} else {
$optionsArray[$params[0]] = '';
}
}
$decimals = isset($optionsArray['decimals']) ? $optionsArray['decimals'] : null;
$dec_point = isset($optionsArray['dec_point']) ? $optionsArray['dec_point'] : null;
$thousands_sep = isset($optionsArray['thousands_sep']) ? $optionsArray['thousands_sep'] : null;
$output = number_format($number, $decimals, $dec_point, $thousands_sep);
return $output;
Used as output modifier:
[[+price:numberformat=`&decimals=2&dec_point=,&thousands_sep=.`]]
I am using MVC 3 and Razor View engine.
What I am trying to do
I am making a blog using MVC 3, I want to remove all HTML formatting tags like <p> <b> <i> etc..
For which I am using the following code. (it does work)
#{
post.PostContent = post.PostContent.Replace("<p>", " ");
post.PostContent = post.PostContent.Replace("</p>", " ");
post.PostContent = post.PostContent.Replace("<b>", " ");
post.PostContent = post.PostContent.Replace("</b>", " ");
post.PostContent = post.PostContent.Replace("<i>", " ");
post.PostContent = post.PostContent.Replace("</i>", " ");
}
I feel that there definitely has to be a better way to do this. Can anyone please guide me on this.
Thanks Alex Yaroshevich,
Here is what I use now..
post.PostContent = Regex.Replace(post.PostContent, #"<[^>]*>", String.Empty);
The regular expression is slow. use this, it's faster:
public static string StripHtmlTagByCharArray(string htmlString)
{
char[] array = new char[htmlString.Length];
int arrayIndex = 0;
bool inside = false;
for (int i = 0; i < htmlString.Length; i++)
{
char let = htmlString[i];
if (let == '<')
{
inside = true;
continue;
}
if (let == '>')
{
inside = false;
continue;
}
if (!inside)
{
array[arrayIndex] = let;
arrayIndex++;
}
}
return new string(array, 0, arrayIndex);
}
You can take a look at http://www.dotnetperls.com/remove-html-tags
Just in case you want to use regex in .NET to strip the HTML tags, the following seems to work pretty well on the source code for this very page. It's better than some of the other answers on this page because it looks for actual HTML tags instead of blindly removing everything between < and >. Back in the BBS days, we typed <grin> a lot instead of :), so removing <grin> is not an option. :)
This solution only removes the tags. It does not remove the contents of those tags in situations where that might be important -- a script tag, for example. You'd see the script, but the script wouldn't execute because the script tag itself gets removed. Removing the contents of an HTML tag is VERY tricky, and practically requires that the HTML fragment be well formed...
Also note the RegexOption.Singleline option. That's very important for any block of HTML. as there's nothing wrong with opening an HTML tag on one line and closing it in another.
string strRegex = #"</{0,1}(!DOCTYPE|a|abbr|acronym|address|applet|area|article|aside|audio|b|base|basefont|bdi|bdo|big|blockquote|body|br|button|canvas|caption|center|cite|code|col|colgroup|datalist|dd|del|details|dfn|dialog|dir|div|dl|dt|em|embed|fieldset|figcaption|figure|font|footer|form|frame|frameset|h1|h2|h3|h4|h5|h6|head|header|hr|html|i|iframe|img|input|ins|kbd|keygen|label|legend|li|link|main|map|mark|menu|menuitem|meta|meter|nav|noframes|noscript|object|ol|optgroup|option|output|p|param|pre|progress|q|rp|rt|ruby|s|samp|script|section|select|small|source|span|strike|strong|style|sub|summary|sup|table|tbody|td|textarea|tfoot|th|thead|time|title|tr|track|tt|u|ul|var|video|wbr){1}(\s*/{0,1}>|\s+.*?/{0,1}>)";
Regex myRegex = new Regex(strRegex, RegexOptions.Singleline);
string strTargetString = #"<p>Hello, World</p>";
string strReplace = #"";
return myRegex.Replace(strTargetString, strReplace);
I'm not saying this is the best answer. It's just an option and it worked great for me.
I'm using T4 to generate some class definitions and find that I'm getting an underscore in front of my field names.
I have set
code.CamelCaseFields = true;
just to be safe (even though I understand that's the default) but still end up with _myField rather than myField.
How can I generate a field name without the '_' character?
Also, where is the documentation for T4? I'm finding plenty of resources such as
Code Generation and Text Templates and numerous blogs, but I have not found the class-by-class, property-by-property documentation.
You're probably talking about EF4 Self Tracking Entities. The CodeGenerationTools class is included via the <## include file="EF.Utility.CS.ttinclude"#> directive, which you can find at "[VSInstallDir]\Common7\IDE\Extensions\Microsoft\Entity Framework Tools\Templates\Includes\EF.Utility.CS.ttinclude".
The FieldName function is defined as such:
private string FieldName(string name)
{
if (CamelCaseFields)
{
return "_" + CamelCase(name);
}
else
{
return "_" + name;
}
}
The "_" is hardcoded in the function. Coding your own shouldn't be difficult. Note that the CodeGenerationTools class is specific to this ttinclude file and isn't a generic and embedded way to generate code in T4.
I've written the following method to make first character upper case, remove spaces/underscores and make next character upper case. See samples below. Feel free to use.
private string CodeName(string name)
{
name = name.ToLowerInvariant();
string result = name;
bool upperCase = false;
result = string.Empty;
for (int i = 0; i < name.Length; i++)
{
if (name[i] == ' ' || name[i] == '_')
{
upperCase = true;
}
else
{
if (i == 0 || upperCase)
{
result += name[i].ToString().ToUpperInvariant();
upperCase = false;
}
else
{
result += name[i];
}
}
}
return result;
}
input/output samples:
first_name = FirstName,
id = Id,
status message = StatusMessage
This is good advice however it doesn't help you in knowing WHERE the right place to put such a function is...
Is there any guidance on DECOMPOSING the EF .tt files or stepping through the output generation to see how it builds the output?
I was able to use the above function successfully by plugging it into a function called
(Ef4.3)
public string Property(EdmProperty edmProperty)
Which appears to be used to output the lines like "public int fieldname { get; set; }"
and changed the 3rd (index {2}) param to the formating to wrap with the function to modify the name, like this:
_typeMapper.GetTypeName(edmProperty.TypeUsage), //unchanged
UnderScoreToPascalCase(_code.Escape(edmProperty)), //wrapped "name"
_code.SpaceAfter(Accessibility.ForGetter(edmProperty)), // unchanged
This is not perfect, eg: it doesn't keep existing "Ucasing" and doesn't care about things like this:
customerIP
outputs: Customerip
which IMO is not very readable...
but its better than what I WAS looking at which was a nightmare because the database was intermingled mess of camelCase, PascalCase and underscore separation, so pretty horrific.
anyway hope this helps someone...
Using the HTMLAgilityPack to write out a new image node, it seems to remove the closing tag of an image, e.g. should be but when you check outer html, has .
string strIMG = "<img src='" + imgPath + "' height='" + pubImg.Height + "px' width='" + pubImg.Width + "px' />";
HtmlNode newNode = HtmlNode.Create(strIMG);
This breaks xhtml.
Telling it to output XML as Micky suggests works, but if you have other reasons not to want XML, try this:
doc.OptionWriteEmptyNodes = true;
Edit 1:Here is how to fix an HTML Agilty Pack document to correctly display image (img) tags:
if (HtmlNode.ElementsFlags.ContainsKey("img"))
{ HtmlNode.ElementsFlags["img"] = HtmlElementFlag.Closed;}
else
{ HtmlNode.ElementsFlags.Add("img", HtmlElementFlag.Closed);}
replace "img" for any other tag to fix them as well (input, select, and option come up frequently). Repeat as needed. Keep in mind that this will produce rather than , because of the HAP bug preventing the "closed" and "empty" flags from being set simultaneously.
Source: Mike Bridge
Original answer:
Having just labored over solutions to this issue, and not finding any sufficient answers (doctype set properly, using Output as XML, Check Syntax, AutoCloseOnEnd, and Write Empty Node options), I was able to solve this with a dirty hack.
This will certainly not solve the issue outright for everyone, but for anyone returning their generated html/xml as a string (EG via a web service), the simple solution is to use fake tags that the agility pack doesn't know to break.
Once you have finished doing everything you need to do on your document, call the following method once for each tag giving you a headache (notable examples being option, input, and img). Immediately after, render your final string and do a simple replace for each tag prefixed with some string (in this case "Fix_", and return your string.
This is only marginally better in my opinion than the regex solution proposed in another question I cannot locate at the moment (something along the lines of )
private void fixHAPUnclosedTags(ref HtmlDocument doc, string tagName, bool hasInnerText = false)
{
HtmlNode tagReplacement = null;
foreach(var tag in doc.DocumentNode.SelectNodes("//"+tagName))
{
tagReplacement = HtmlTextNode.CreateNode("<fix_"+tagName+"></fix_"+tagName+">");
foreach(var attr in tag.Attributes)
{
tagReplacement.SetAttributeValue(attr.Name, attr.Value);
}
if(hasInnerText)//for option tags and other non-empty nodes, the next (text) node will be its inner HTML
{
tagReplacement.InnerHtml = tag.InnerHtml + tag.NextSibling.InnerHtml;
tag.NextSibling.Remove();
}
tag.ParentNode.ReplaceChild(tagReplacement, tag);
}
}
As a note, if I were a betting man I would guess that MikeBridge's answer above inadvertently identifies the source of this bug in the pack - something is causing the closed and empty flags to be mutually exclusive
Additionally, after a bit more digging, I don't appear to be the only one who has taken this approach:
HtmlAgilityPack Drops Option End Tags
Furthermore, in cases where you ONLY need non-empty elements, there is a very simple fix listed in that same question, as well as the HAP codeplex discussion here: This essentially sets the empty flag option listed in Mike Bridge's answer above permanently everywhere.
There is an option to turn on XML output that makes this issue go away.
var htmlDoc = new HtmlDocument();
htmlDoc.OptionOutputAsXml = true;
htmlDoc.LoadHtml(rawHtml);
This seems to be a bug with HtmlAgilityPack. There are many ways to reproduce this, for example:
Debug.WriteLine(HtmlNode.CreateNode("<img id=\"bla\"></img>").OuterHtml);
Outputs malformed HTML. Using the suggested fixes in the other answers does nothing.
HtmlDocument doc = new HtmlDocument();
doc.OptionOutputAsXml = true;
HtmlNode node = doc.CreateElement("x");
node.InnerHtml = "<img id=\"bla\"></img>";
doc.DocumentNode.AppendChild(node);
Debug.WriteLine(doc.DocumentNode.OuterHtml);
Produces malformed XML / XHTML like <x><img id="bla"></x>
I have created a issue in CodePlex for this.
I have read a number of posts about this but none with any solid answer. Here is my code:
// button creation
onew = document.createElement('input');
onew.setAttribute("type", "button");
onew.setAttribute("value", "hosts");
onew.onclick = function(){fnDisplay_Computers("'" + alines[i] + "'"); }; // ie
onew.setAttribute("onclick", "fnDisplay_Computers('" + alines[i] + "')"); // mozilla
odiv.appendChild(onew);
Now, the setAttribute() method (with the mozilla comment) works fine in mozilla but only if it comes AFTER the line above it. So in other words it seems to just default to whichever gets set last. The .onclick method (with the ie comment) does not work in either case, am I using it incorrectly?
Either way I can't find a way to make this work at all in IE, let alone in both. I did change the function call when using the .onclick method and it worked fine using just a simple call to an alert function which is why I believe my syntax is incorrect.
Long story short, I can't get the onclick parameter to work consistently between IE/Mozilla.
-- Nicholas
onew.setAttribute("type", "button");
Never use setAttribute on HTML documents. IE gets it badly wrong in many cases, and the DOM-HTML properties are shorter, faster and easier to read:
onew.type= 'button';
onew.onclick = function(){fnDisplay_Computers("'" + alines[i] + "'"); }; // ie
What is ‘alines’? Why are you converting it to a string and surrounding it with single quotes? It looks like you are trying to do something heinous involving evaluating code in a string (which is what you're doing below in the ‘onew.setAttribute’ version). Evaluating JavaScript code in strings is almost always the Wrong Thing; avoid it like the plague. In the above case, IE should do the same as Firefox: it shouldn't work.
If ‘alines[i]’ is a string, I guess what you're trying to do is make it remember that string by constructing a code string that will evaluate in JavaScript to the original string. But:
"'" + alines[i] + "'"
is insufficient. What happens if ‘alines[i]’ has an apostrophe in, or a backslash?
'O'Reilly'
you've got a syntax error and possible security hole. Now, you could do something laborious and annoying like:
"'" + alines[i].split('\\').join('\\\\').split("'").join("\\'") + "'"
to try to escape the string, but it's ugly and won't work for other datatypes. You could even ask JavaScript to do it for you:
uneval(alines[i])
But not all objects can even be converted to evaluatable JavaScript source strings; basically the entire approach is doomed to failure.
The normal thing to do if you just want to have the onclick callback call a function with a parameter is to write the code in the straightforward way:
onew.onclick= function() {
fnDisplay_Computers(alines[i]);
};
Generally this will work and is what you want. There is, however, a slight wrinkle which you may have hit here, which could be what is confusing you into considering the wacky approach with the strings.
Namely, if ‘i’ in this case is the variable of an enclosing ‘for’ loop, the reference to ‘alines[i]’ won't do what you think it does. The ‘i’ will be accessed by the callback function when the click happens — which is after the loop has finished. At this point the ‘i’ variable will be left with whatever value it had at the end of the loop, so ‘alines[i]’ will always be the last element of ‘alines’, regardless of which ‘onew’ was clicked.
(See eg. How to fix closure problem in ActionScript 3 (AS3) for some discussion of this. It's one of the biggest causes of confusion with closures in both JavaScript and Python, and should really be fixed at a language level some day.)
You can get around the loop problem by encapsulating the closure in its own function, like this:
function callbackWithArgs(f, args) {
return function() { f.apply(window, args); }
}
// ...
onew.onclick= callbackWithArgs(fnDisplay_Computers, [alines[i]]);
And in a later version of JavaScript, you'll be able to say simply:
onew.onclick= fnDisplay_Computers.bind(window, alines[i]);
If you would like to be able to use ‘Function.bind()’ in browsers today, you can get an implementation from the Prototype framework, or just use:
if (!('bind' in Function.prototype)) {
Function.prototype.bind= function(owner) {
var that= this;
var args= Array.prototype.slice.call(arguments, 1);
return function() {
return that.apply(owner,
args.length===0? arguments : arguments.length===0? args :
args.concat(Array.prototype.slice.call(arguments, 0))
);
};
};
}
I usually use something like:
onew.onclick = new Function("fnDisplay_Computers('" + alines[i] + "')");
this should work both in IE e Firefox.
Use the addEventListener() function with "click" for the type argument for Mozilla-based browsers, and attachEvent() function with "onclick" as the sEvent argument for IE; I find it best to use a try/catch statement, for example:
try {
onew.attachEvent("onclick", //For IE
function(){fnDisplay_Computers("'" + alines[i] + "'"); });
}
catch(e) {
onew.addEventListener("click", //For Mozilla-based browsers
function(){fnDisplay_Computers("'" + alines[i] + "'"); },
false);
}
I think #3 protesteth too much. In a lot of situations I'm building a table dynamically and need to pass parameters to the callback function. It isn't a typesafe issue since my variable parm is an integer index to the table row in question. Here's code with both a variable and fixed parameter that seems to be cross-browser compliant:
for (i = 0; i < arrTableData.length; i++) {
eleTR = objTable.insertRow(i + 1);
cell = eleTR.insertCell(0);
cell.width = "21";
var myElement = document.createElement('img');
myElement.setAttribute('src', 'images/button_down.gif');
myElement.setAttribute('alt', 'Move item down');
myElement.onclick = new Function('moveItem(' + i + ',0)');
cell.appendChild(myElement);
}