For the following HTML document:

    &lt;html&gt;
      &lt;body&gt;
        &lt;a href=&quot;http://www.example.com&quot;&gt;Example&lt;/a&gt; 
        &lt;a href=&quot;http://www.stackoverflow.com&quot;&gt;SO&lt;/a&gt; 
      &lt;/body&gt;
    &lt;/html&gt;

The xpath query `/html/body//a/@href` (or simply `//a/@href`) will return:
&lt;pre&gt;
    http://www.example.com
    http://www.stackoverflow.com
&lt;/pre&gt;
To select a specific instance use `/html/body//a[N]/@href`, 
&lt;pre&gt;
    $ /html/body//a[2]/@href
    http://www.stackoverflow.com
&lt;/pre&gt;
To test for strings contained in the attribute and return the attribute itself place the check on the tag not on the attribute:
&lt;pre&gt;
    $ /html/body//a[contains(@href,&#39;example&#39;)]/@href
    http://www.example.com
&lt;/pre&gt;

Mixing the two:
&lt;pre&gt;
    $ /html/body//a[contains(@href,&#39;com&#39;)][2]/@href
    http://www.stackoverflow.com
&lt;/pre&gt;

The answer shared by @mockinterface is correct. Although I would like to add my 2 cents to it. 

If someone is using frameworks like `scrapy` the you will have to use `/html/body//a[contains(@href,&#39;com&#39;)][2]/@href` along with get() like this:

```
response.xpath(&#39;//a[contains(@href,&#39;com&#39;)][2]/@href&#39;).get()
```

Am a Scala programmer and understand Akka from a developer point of view. I have not looked into Akka library&#39;s code. Have read about the two types of actors in the Akka model - thread-based and event-based - but not having run Akka at large scale I dont have experience of configuring Akka for production. And am completely new to Vert.x. So, from the choices perspective to build a reactive application stack I want to know -

 1. Is the message-passing model of Akka and Vert.x very different? How?
 2. Are the data-structures behind Akka&#39;s actors and Vert.x&#39;s verticles to buffer messages very different?


Difference in message-passing model of Akka and Vert.x

I need to calculate exact bounding box for every each character (glyph) in NSAttributedString (Core Text).
After putting together some code used to solve similar problems (Core Text selection, etc..), the result is quite good, but only few frames (red) are being calculated properly:

![enter image description here][1]

Most of the frames are misplaces either horizontally or vertically (by tiny bit). What is the cause of that? How can I perfect this code?:

    -(void)recalculate{
        
        // get characters from NSString
        NSUInteger len = [_attributedString.string length];
        UniChar *characters = (UniChar *)malloc(sizeof(UniChar)*len);
        CFStringGetCharacters((__bridge CFStringRef)_attributedString.string, CFRangeMake(0, [_attributedString.string length]), characters);
        
        // allocate glyphs and bounding box arrays for holding the result
        // assuming that each character is only one glyph, which is wrong
        CGGlyph *glyphs = (CGGlyph *)malloc(sizeof(CGGlyph)*len);
        CTFontGetGlyphsForCharacters(_font, characters, glyphs, len);
        
        // get bounding boxes for glyphs
        CTFontGetBoundingRectsForGlyphs(_font, kCTFontDefaultOrientation, glyphs, _characterFrames, len);
        free(characters); free(glyphs);
        
        // Measure how mush specec will be needed for this attributed string
        // So we can find minimun frame needed
        CFRange fitRange;
        CGSize s = CTFramesetterSuggestFrameSizeWithConstraints(_framesetter, rangeAll, NULL, CGSizeMake(W, MAXFLOAT), &amp;fitRange);
        
        _frameRect = CGRectMake(0, 0, s.width, s.height);
        CGPathRef framePath = CGPathCreateWithRect(_frameRect, NULL);
        _ctFrame = CTFramesetterCreateFrame(_framesetter, rangeAll, framePath, NULL);
        CGPathRelease(framePath);
        
        
        // Get the lines in our frame
        NSArray* lines = (NSArray*)CTFrameGetLines(_ctFrame);
        _lineCount = [lines count];
        
        // Allocate memory to hold line frames information:
        if (_lineOrigins != NULL)free(_lineOrigins);
        _lineOrigins = malloc(sizeof(CGPoint) * _lineCount);
        
        if (_lineFrames != NULL)free(_lineFrames);
        _lineFrames = malloc(sizeof(CGRect) * _lineCount);
        
        // Get the origin point of each of the lines
        CTFrameGetLineOrigins(_ctFrame, CFRangeMake(0, 0), _lineOrigins);
        
        // Solution borrowew from (but simplified):
        // https://github.com/twitter/twui/blob/master/lib/Support/CoreText%2BAdditions.m
       
    
        // Loop throught the lines
    	for(CFIndex i = 0; i &lt; _lineCount; ++i) {
            
    		CTLineRef line = (__bridge CTLineRef)[lines objectAtIndex:i];
    		
    		CFRange lineRange = CTLineGetStringRange(line);
    		CFIndex lineStartIndex = lineRange.location;
    		CFIndex lineEndIndex = lineStartIndex + lineRange.length;
            
    		CGPoint lineOrigin = _lineOrigins[i];
    		CGFloat ascent, descent, leading;
    		CGFloat lineWidth = CTLineGetTypographicBounds(line, &amp;ascent, &amp;descent, &amp;leading);
    		
            
            // If we have more than 1 line, we want to find the real height of the line by measuring the distance between the current line and previous line. If it&#39;s only 1 line, then we&#39;ll guess the line&#39;s height.
    		BOOL useRealHeight = i &lt; _lineCount - 1;
    		CGFloat neighborLineY = i &gt; 0 ? _lineOrigins[i - 1].y : (_lineCount - 1 &gt; i ? _lineOrigins[i + 1].y : 0.0f);
    		CGFloat lineHeight = ceil(useRealHeight ? abs(neighborLineY - lineOrigin.y) : ascent + descent + leading);
    		
            _lineFrames[i].origin = lineOrigin;
            _lineFrames[i].size = CGSizeMake(lineWidth, lineHeight);
            
            for (int ic = lineStartIndex; ic &lt; lineEndIndex; ic++) {
                
                CGFloat startOffset = CTLineGetOffsetForStringIndex(line, ic, NULL);
                _characterFrames[ic].origin = CGPointMake(startOffset, lineOrigin.y);
            }
        }
    }
    
    
    #pragma mark - Rendering Text:
    
    -(void)renderInContext:(CGContextRef)context contextSize:(CGSize)size{
    	
    	CGContextSaveGState(context);
        
        // Draw Core Text attributes string:
    	CGContextSetTextMatrix(context, CGAffineTransformIdentity);
    	CGContextTranslateCTM(context, 0, CGRectGetHeight(_frameRect));
    	CGContextScaleCTM(context, 1.0, -1.0);
    
    	CTFrameDraw(_ctFrame, context);
        
        // Draw line and letter frames:
        CGContextSetStrokeColorWithColor(context, [UIColor colorWithRed:0.0 green:0.0 blue:1.0 alpha:0.5].CGColor);
        CGContextSetLineWidth(context, 1.0);
        
        CGContextBeginPath(context);
        CGContextAddRects(context, _lineFrames, _lineCount);
        CGContextClosePath(context);
        CGContextStrokePath(context);
        
        CGContextSetStrokeColorWithColor(context, [UIColor colorWithRed:1.0 green:0.0 blue:0.0 alpha:0.5].CGColor);
        CGContextBeginPath(context);
        CGContextAddRects(context, _characterFrames, _attributedString.string.length);
        CGContextClosePath(context);
        CGContextStrokePath(context);
        
        CGContextRestoreGState(context);
    
    }


  [1]: http://i.stack.imgur.com/Jxd2T.jpg

Core Text calculate letter frame in iOS

I want to use XPath to get the `href` attribute from an `a`-tag, but it has two occurrences within the same file. How am I getting along?
I need to check IF there is an `href` attribute with value $street/object, I have got this code and it does not work:

    $product_photo     = $xpath-&gt;query(&quot;//a[contains(@href,&#39;{$object_street}fotos/&#39;)][1]&quot;);
            $product_360       = $xpath-&gt;query(&quot;//a[contains(@href,&#39;{$object_street}360-fotos/&#39;)][1]&quot;);
            $product_blueprint = $xpath-&gt;query(&quot;//a[contains(@href,&#39;{$object_street}plattegrond/&#39;)][1]&quot;);
            $product_video     = $xpath-&gt;query(&quot;//a[contains(@href,&#39;{$object_street}video/&#39;)][1]&quot;);

It does not return anything at all. Who can help me out?

XPath Query: get attribute href from a tag

I want to use XPath to get the <code>href</code> attribute from an <code>a</code>-tag, but it has two occurrences within the same file. How am I getting along?
I need to check IF there is an <code>href</code> attribute with value $street/object, I have got this code and it does not work:
<pre><code class="hljs language-ini">$product_photo = $xpath->query("//a[contains(@href,'{$object_street}fotos/')][1]");
 $product_360 = $xpath->query("//a[contains(@href,'{$object_street}360-fotos/')][1]");
 $product_blueprint = $xpath->query("//a[contains(@href,'{$object_street}plattegrond/')][1]");
 $product_video = $xpath->query("//a[contains(@href,'{$object_street}video/')][1]");
</code></pre>
It does not return anything at all. Who can help me out?

In a project recently when I loaded a sound with 

    var myAudio = new Audio(&quot;myAudio.mp3&quot;);
    myAudio.play();

It played fine unless a dialogue was opened (ie alert, confirm). However when I instead tried adding an audio tag in my html

    &lt;audio id=&quot;audio1&quot;&gt;
    	&lt;source src=&quot;alarm.mp3&quot; type=&quot;audio/mpeg&quot; /&gt;
    &lt;/audio&gt;

and using

    var myAudio1 = document.getElementById(&quot;audio1&quot;);
    myAudio1.play()

it continued to play after a dialogue was opened. Does anyone know why this is? Also more generally what are the differences between the two ways to play sounds?

javascript Audio object vs. HTML5 Audio tag

All,

I would like to be able to use calc() with transform:translateX in my CSS.

E.g.,

    


&lt;!-- language: lang-css --&gt;

    #myDiv {
      -webkit-transform: translateX(calc(100% - 50px));
      -moz-transform: translateX(calc(100% - 50px));
      transform: translateX(calc(100% - 50px));
    }


While this works perfectly in Chrome, Safari, and Firefox - it does not work in IE10 or IE11.

You can see a simple example here: http://jsfiddle.net/SL2mk/9/

Is this impossible? Is it a bug in IE, or is `calc()` not supposed to work in this context?

For what it&#39;s worth - I read [here][1] that you can &quot;stack&quot; `translateX` to acheive the same effect, and my testing seems to confirm this. I.e.,

&lt;!-- language: lang-css --&gt;

    #div {
      transform: translateX(calc(100% - 50px));
    }

is the same as:

&lt;!-- language: lang-css --&gt;

    #div {
      transform: translateX(100%) translateX(-50px);
    }

But I don&#39;t know if this is the best, most reliable, and future-proof way to do this.

I also know that it&#39;s possible to use `left` instead of `translateX`, but the latter is much smoother when used with transitions, since, as I understand it, it forces the use of the GPU to handle the animation.

Thanks in advance for your advice and insight!

  [1]: https://stackoverflow.com/a/21381301/49383 &quot;here&quot;

Not possible to use CSS calc() with transform:translateX in IE

I have following html in email template.

I am getting different view in MS Outlook and in gmail for the same.

    &lt;tr&gt;
    	&lt;td bgcolor=&quot;#7d9aaa&quot; style=&quot;color: #fff; font-size:15px; font-family:Arial, Helvetica, sans-serif; padding: 12px 2px 12px 0px; &quot;&gt;
    	&lt;span style=&quot;font-weight: bold;padding-right:150px;padding-left: 35px;&quot;&gt;Order Confirmation &lt;/span&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;
    	&lt;span style=&quot;font-weight: bold;width:400px;&quot;&gt; Your Confirmation number is {{var order.increment_id}} &lt;/span&gt;&lt;/td&gt;
    &lt;/tr&gt;

![In gmail][1]


![In outlook][2]


  [1]: http://i.stack.imgur.com/ZLuwg.png
  [2]: http://i.stack.imgur.com/mwS74.png


How to fix this?

css padding is not working in outlook

I&#39;m trying to make an animated &quot;scroll to top&quot; effect without using jQuery.

In jQuery, I usually use this code:

    $(&#39;#go-to-top&#39;).click(function(){ 
          $(&#39;html,body&#39;).animate({ scrollTop: 0 }, 400);
          return false; 
    });

How do I animate scrollTop without using jQuery?

scrollTop animation without jquery

I am trying to call my JS function that I added in the header. 
Please find below code that shows my problem scenario. 
Note: I don&#39;t have access to the body in my application. 
Everytime I click on the element with `id=&quot;Save&quot;` it only calls `f1()` but not `fun()`. How can I make it call even my `fun()`?
Please help.


      &lt;!DOCTYPE html&gt;
      &lt;html&gt;
      &lt;head&gt;
    
      &lt;script&gt;
	
	   document.getElementById(&quot;Save&quot;).onclick = function fun()
        {
         alert(&quot;hello&quot;);
         //validation code to see State field is mandatory.  
        }	

        function f1()
        {
           alert(&quot;f1 called&quot;);
	       //form validation that recalls the page showing with supplied inputs. 	
        }
	
      &lt;/script&gt;
      &lt;/head&gt;
      &lt;body&gt;
      &lt;form name=&quot;form1&quot; id=&quot;form1&quot; method=&quot;post&quot;&gt;
                State: 
                &lt;select id=&quot;state ID&quot;&gt;
                   &lt;option&gt;&lt;/option&gt;
                   &lt;option value=&quot;ap&quot;&gt;ap&lt;/option&gt;
                   &lt;option value=&quot;bp&quot;&gt;bp&lt;/option&gt;
                &lt;/select&gt;
       &lt;/form&gt;
   
       &lt;table&gt;&lt;tr&gt;&lt;td id=&quot;Save&quot; onclick=&quot;f1()&quot;&gt;click&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;

       &lt;/body&gt;
       &lt;/html&gt;


How to Call a JS function using OnClick event

I am trying to find an input element with dynamic id name always ending with &quot;register&quot;. So far I tried this 

    &quot;//input[@id[ends-with(.,&#39;register&#39;)]]&quot;

and this

    &quot;//input[ends-with(@id,&#39;register&#39;)]&quot;

none of these result in an element. What am I doing wrong? At the same time this works:

    &quot;//input[@id[contains(.,&#39;register&#39;)]]&quot;

Here&#39;s the part of source:

    &lt;td class=&quot;input&quot;&gt;
    &lt;input id=&quot;m.f0.menu.f2.volumeTabs.BLOCK_COMMON.tcw.form.register&quot; name=&quot;m.f0.menu.f2.volumeTabs.BLOCK_COMMON.tcw.form.register&quot; class=&quot;aranea-checkbox&quot; type=&quot;checkbox&quot;&gt; &lt;/td&gt;

Xpath &quot;ends-with&quot; does not work

How can I verify my XPath?

I am using Chrome Developers tool to inspect the elements and form my XPath. I verify it using the Chrome plugin XPath Checker, however it does not always give me the result. What is a better way to verify my XPath.

I have also tried using Firebug to inspect the bug and also using the FirePath to verify. But does Firepath also verify the XPath.

My last option would be to use the Selenium WebDriver to confirm my XPath. 

How to verify an XPath expression in Chrome Developers tool or Firefox&#39;s Firebug?

I am writing tests for my site using Selenium IDE and I am having trouble with having selenium click on a button using preceding-sibling

    &lt;td&gt;
    &lt;div class=&quot;btn-group&quot;&gt;
    &lt;button class=&quot;btn btn btn-danger block&quot; title=&quot;Warning, Delete&quot; name=&quot;delete&quot; type=&quot;button&quot;&gt;
    &lt;button class=&quot;btn btn btn-default block&quot; title=&quot;View History&quot; name=&quot;history&quot; type=&quot;button&quot;&gt;
    &lt;button class=&quot;btn btn btn-default block&quot; title=&quot;View Settings&quot; name=&quot;settings&quot; type=&quot;button&quot;&gt;
    &lt;button class=&quot;btn btn btn-default block&quot; name=&quot;device&quot; type=&quot;button&quot;&gt;
    &lt;span class=&quot;glyphicon glyphicon-pencil&quot;/&gt;
     Arcade Reader
    &lt;/button&gt;
    &lt;/div&gt;
    &lt;/td&gt;
My path

    xpath=//button[contains(.,&#39;Arcade Reader&#39;)]/../preceding-sibling::button[@name=&#39;settings&#39;]

How to use XPath preceding-sibling correctly

I need get the parent node for child node `title 50`

At the moment I am using only

    //*[title=&quot;50&quot;]

How could I get its parent?
Result should be the `store` node.

-----------------------
    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;d:data xmlns:d=&quot;defiant-namespace&quot; d:mi=&quot;23&quot;&gt;
        &lt;store d:mi=&quot;22&quot;&gt;
            &lt;book price=&quot;12.99&quot; d:price=&quot;Number&quot; d:mi=&quot;4&quot;&gt;
                &lt;title d:constr=&quot;String&quot; d:mi=&quot;1&quot;&gt;Sword of Honour&lt;/title&gt;
                &lt;category d:constr=&quot;String&quot; d:mi=&quot;2&quot;&gt;fiction&lt;/category&gt;
                &lt;author d:constr=&quot;String&quot; d:mi=&quot;3&quot;&gt;Evelyn Waugh&lt;/author&gt;
            &lt;/book&gt;
            &lt;book price=&quot;8.99&quot; d:price=&quot;Number&quot; d:mi=&quot;9&quot;&gt;
                &lt;title d:constr=&quot;String&quot; d:mi=&quot;5&quot;&gt;Moby Dick&lt;/title&gt;
                &lt;category d:constr=&quot;String&quot; d:mi=&quot;6&quot;&gt;fiction&lt;/category&gt;
                &lt;author d:constr=&quot;String&quot; d:mi=&quot;7&quot;&gt;Herman Melville&lt;/author&gt;
                &lt;isbn d:constr=&quot;String&quot; d:mi=&quot;8&quot;&gt;0-553-21311-3&lt;/isbn&gt;
            &lt;/book&gt;
            &lt;book price=&quot;8.95&quot; d:price=&quot;Number&quot; d:mi=&quot;13&quot;&gt;
                &lt;title d:constr=&quot;String&quot; d:mi=&quot;10&quot;&gt;50&lt;/title&gt;
                &lt;category d:constr=&quot;String&quot; d:mi=&quot;11&quot;&gt;reference&lt;/category&gt;
                &lt;author d:constr=&quot;String&quot; d:mi=&quot;12&quot;&gt;Nigel Rees&lt;/author&gt;
            &lt;/book&gt;
            &lt;book price=&quot;22.99&quot; d:price=&quot;Number&quot; d:mi=&quot;18&quot;&gt;
                &lt;title d:constr=&quot;String&quot; d:mi=&quot;14&quot;&gt;The Lord of the Rings&lt;/title&gt;
                &lt;category d:constr=&quot;String&quot; d:mi=&quot;15&quot;&gt;fiction&lt;/category&gt;
                &lt;author d:constr=&quot;String&quot; d:mi=&quot;16&quot;&gt;J. R. R. Tolkien&lt;/author&gt;
                &lt;isbn d:constr=&quot;String&quot; d:mi=&quot;17&quot;&gt;0-395-19395-8&lt;/isbn&gt;
            &lt;/book&gt;
            &lt;bicycle price=&quot;19.95&quot; d:price=&quot;Number&quot; d:mi=&quot;21&quot;&gt;
                &lt;brand d:constr=&quot;String&quot; d:mi=&quot;19&quot;&gt;Cannondale&lt;/brand&gt;
                &lt;color d:constr=&quot;String&quot; d:mi=&quot;20&quot;&gt;red&lt;/color&gt;
            &lt;/bicycle&gt;
        &lt;/store&gt;
    &lt;/d:data&gt;

XPath: Get parent node from child node

My question is about specifics of using dot and `text()` in `XPath`. For example, following `find_element` lines returns same element:

    driver.get(&#39;http://stackoverflow.com/&#39;)

    driver.find_element_by_xpath(&#39;//a[text()=&quot;Ask Question&quot;]&#39;)
    driver.find_element_by_xpath(&#39;//a[.=&quot;Ask Question&quot;]&#39;)

So what is the difference? What are the benefits and drawbacks of using `.` and `text()`?

Content Type	Original Author	Original Content on Stackoverflow
Question	user3239713	View Question on Stackoverflow
Solution 1 - Html	mockinterface	View Answer on Stackoverflow
Solution 2 - Html	Rahul Saxena	View Answer on Stackoverflow

XPath Query: get attribute href from a tag

Html Problem Overview

Html Solutions

Solution 1 - Html

Solution 2 - Html

Core Text calculate letter frame in iOS

Difference in message-passing model of Akka and Vert.x

Attributions