Search Results

Search found 37598 results on 1504 pages for 'html title'.

Page 438/1504 | < Previous Page | 434 435 436 437 438 439 440 441 442 443 444 445  | Next Page >

  • Help getting MVVM ViewModel to bind to the View

    - by cw
    Okay guys, I'm new to this model and Silverlight in general. I have the following code (changed object names, so syntax/spelling errors ignore). public class ViewModel { ViewModelSource m_vSource; public ViewModel(IViewModelSource source) { m_vSource= source; m_vSource.ItemArrived += new Action<Item>(m_vSource_ItemArrived); } void m_vSource_ItemArrived(Item obj) { Title = obj.Title; Subitems = obj.items; Description = obj.Description; } public void GetFeed(string serviceUrl) { m_vFeedSource.GetFeed(serviceUrl); } public string Title { get; set; } public IEnumerable<Subitems> Subitems { get; set; } public string Description { get; set; } } Here is the code I have in my page's codebehind. ViewModel m_vViewModel; public MainPage() { InitializeComponent(); m_vViewModel = new ViewModel(new ViewModelSource()); this.Loaded += new RoutedEventHandler(MainPage_Loaded); this.DataContext = m_vViewModel; } void MainPage_Loaded(object sender, RoutedEventArgs e) { m_vViewModel.GetItems("http://www.myserviceurl.com"); } Finally, here is a sample of what my xaml looks like. <!--TitleGrid is the name of the application and page title--> <Grid x:Name="TitleGrid" Grid.Row="0"> <TextBlock Text="My Super Title" x:Name="textBlockPageTitle" Style="{StaticResource PhoneTextPageTitle1Style}"/> <TextBlock Text="{Binding Path=Title}" x:Name="textBlockListTitle" Style="{StaticResource PhoneTextPageTitle2Style}"/> </Grid> I know I'm missing something, but I'm just not knowledgable enough which is why I'm asking you guys :) Is there anything I'm doing wrong here? Thanks!

    Read the article

  • Display shift when adding rows to UITableView

    - by Kamchatka
    Hello, I have a UITableView displaying an underlying NSFetchedResultsController. When the fetchedResultsController is updated, - (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath { is called. And the following is executed: case NSFetchedResultsChangeInsert: [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:shiftedIndexPath] withRowAnimation:UITableViewRowAnimationFade]; break; The cellForRowAtIndexPath is only called for the new line (which is logical) The problem is however that all the values displayed in the rows of the table view are shifted down. The first row displays its title. The second rows displays the first row's title. The third row the second row's title etc. If I repeat that, the third row will display the second's row title, the fourth the third row's title etc. I don't understand what can happen, especially because cellForRowAtIndexPath is only called for the new line (which is logical) and not for all these lines. Additionally, if I click on these lines which have the wrong title, it opens the right document (didSelectRowAtIndexPath works correctly with the indexPath) Any clue of what could happen? Thanks!

    Read the article

  • Writing good tests for Django applications

    - by Ludwik Trammer
    I've never written any tests in my life, but I'd like to start writing tests for my Django projects. I've read some articles about tests and decided to try to write some tests for an extremely simple Django app or a start. The app has two views (a list view, and a detail view) and a model with four fields: class News(models.Model): title = models.CharField(max_length=250) content = models.TextField() pub_date = models.DateTimeField(default=datetime.datetime.now) slug = models.SlugField(unique=True) I would like to show you my tests.py file and ask: Does it make sense? Am I even testing for the right things? Are there best practices I'm not following, and you could point me to? my tests.py (it contains 11 tests): # -*- coding: utf-8 -*- from django.test import TestCase from django.test.client import Client from django.core.urlresolvers import reverse import datetime from someproject.myapp.models import News class viewTest(TestCase): def setUp(self): self.test_title = u'Test title: bareksc' self.test_content = u'This is a content 156' self.test_slug = u'test-title-bareksc' self.test_pub_date = datetime.datetime.today() self.test_item = News.objects.create( title=self.test_title, content=self.test_content, slug=self.test_slug, pub_date=self.test_pub_date, ) client = Client() self.response_detail = client.get(self.test_item.get_absolute_url()) self.response_index = client.get(reverse('the-list-view')) def test_detail_status_code(self): """ HTTP status code for the detail view """ self.failUnlessEqual(self.response_detail.status_code, 200) def test_list_status_code(self): """ HTTP status code for the list view """ self.failUnlessEqual(self.response_index.status_code, 200) def test_list_numer_of_items(self): self.failUnlessEqual(len(self.response_index.context['object_list']), 1) def test_detail_title(self): self.failUnlessEqual(self.response_detail.context['object'].title, self.test_title) def test_list_title(self): self.failUnlessEqual(self.response_index.context['object_list'][0].title, self.test_title) def test_detail_content(self): self.failUnlessEqual(self.response_detail.context['object'].content, self.test_content) def test_list_content(self): self.failUnlessEqual(self.response_index.context['object_list'][0].content, self.test_content) def test_detail_slug(self): self.failUnlessEqual(self.response_detail.context['object'].slug, self.test_slug) def test_list_slug(self): self.failUnlessEqual(self.response_index.context['object_list'][0].slug, self.test_slug) def test_detail_template(self): self.assertContains(self.response_detail, self.test_title) self.assertContains(self.response_detail, self.test_content) def test_list_template(self): self.assertContains(self.response_index, self.test_title)

    Read the article

  • Create bookmark into 1st column of MSWord table

    - by MikeD
    Hello All, does anyone have a VBA code to create a bookmark into the first column of an MSWord table? Let's say I have a table looking like this .-----.----------------. . ref . Title . .-----.----------------. . 1 . Title 1 . .-----.----------------. . 2 . Title 2 . .-----.----------------. . foo . Title 3 . .-----.----------------. . bar . Title 4 . .-----.----------------. and I want a VBA code fragment that creates a bookmark named "T1_1" on the string "1" in row 2 / column 1, and bookmarks named "T1_2", "T1_foo" and "T1_bar" on the strings in the other cells of column 1. I don't mind to hardcode the prefix "T1" (and substitute for other tables each time). I don't mind to select tables before running the macro, I don't mind giving those cells a special format, and I don't mind to get a superfluous bookmark "T1_ref" from the first row - so the code doesn't need to distinguish between table title and table row. Thanks a lot in advance

    Read the article

  • Enabling new admin action(button sales_order/view) in ACL

    - by latvian
    Hi, We created new action similar to 'hold', 'ship' and others in the 'sales_order/view' admin section that can be triggered by clicking at the button. Afterward, we added our new action to the ACL with the following code in config.xml: <acl> <resources> <admin> <children> <sales> <children> <order> <children> <actions translate="title"> <title>Actions</title> <children> <shipNew translate="title"><title>Ship Ups</title></shipNew> </children> </actions> </children> <sort_order>10</sort_order> </order> </children> </sales> </children> </admin> </resources> </acl> ACL functionality works, however, in the 'Resources Tree'(System/Permissions/Roles/Role Resources) our new action does never show up as selected(checked) even thou it is allowed for particular Role. I can see that from table 'admin_rule' with resource id for our new action that it is allowed, so it needs to be selected, but it is not. When trying to solve this issue i looked into the template(permissions/rolesedit.phtml) and I found that the 'resource tree' is draw with Javascript...thats where i got stock due to my limited knowledge in Javascript. Why the resource tree does not display our new ACL entry correctly, that is the check box is never checked? Thank You for helping margots

    Read the article

  • WordPress plugin to output a certain category on content page tweak help

    - by talkingD0G
    I'm using WordPress plugin Category Page to display the most recent 5 posts from a certain category on a regular content page (not the blog page) of a website. Right now the plugin is limited to display the post title linked to the post page. This is a video blog type site and I need the plugin to display the post title (as it does now) with the video as well. Probably just telling the script to show the content would work but I don't know how to tweak it. This is the section of the script that is outputting the post title: function page2cat_content_catlist($content){ global $post; if ( stristr( $content, '[catlist' )) { $search = "@(?:<p>)*\s*\[catlist\s*=\s*(\w+|^\+)\]\s*(?:</p>)*@i"; if (preg_match_all($search, $content, $matches)) { if (is_array($matches)) { $title = get_option('p2c_catlist_title'); if($title != "") $output = "<h4>".$title."</h4>"; else $output = ""; $output .= "<ul class='p2c_catlist'>"; $limit = get_option('p2c_catlist_limit'); foreach ($matches[1] as $key =>$v0) { $catposts = get_posts('category='.$v0."&numberposts=".$limit); foreach($catposts as $single): $output .= "<li><a href='".get_permalink($single->ID)." '>".$single->post_title."</a></li>"; endforeach; $search = $matches[0][$key]; $replace= $output; $content= str_replace ($search, $replace, $content); } $output .= "</ul>"; } } } return $content; } If anyone has any advice or knows how to help thanks in advance!

    Read the article

  • Exclude children based on content in XML with PHP (simplexml)

    - by Hakan
    Another question about PHP and XML... Is it posible to exclude children based on there childrens content. See the example below: If "title" contains the word "XTRA:" I don't want this "movie" to be listed. This is my PHP code: <? $xml = simplexml_load_file("movies.xml"); foreach ($xml->movie as $movie){ ?> <h2><? echo $movie->title ?></h2> <p>Year: <? echo $movie->year ?></p> <? } ?> This is mys XML file: <?xml version="1.0" encoding="UTF-8"?> <movies> <movie> <title>Little Fockers</title> <year>2010</year> </movie> <movie> <title>Little Fockers XTRA: teaser 3</title> <year>2010</year> </movie> </movies> The outcome of the code above is: <h2>Little Fockers</h2> <p>Year: 2010</p> <h2>Little Fockers XTRA: teaser 3</h2> <p>Year: 2010</p> I want it to be only: <h2>Little Fockers</h2> <p>Year: 2010</p>

    Read the article

  • webscraper grabbing images, but not entering info into database

    - by Jason
    Hello, again. I'm having more issues with my script entering info into my database. The script below grabs a page, strips down the necessary info, then downloads the related image file. After that, it is supposed to enter the information gleaned from the URL into the database. For some reason, the script seems to iterate through the URLs, as I get downloaded images for each URL, but each URL's product is not entered into the database. The script will insert the first product's categories and product info, and then it just stops, and continues to download images. Any suggestions? <?php define('IN_PHPBB', true); $phpbb_root_path = (defined('PHPBB_ROOT_PATH')) ? PHPBB_ROOT_PATH : './'; $phpEx = substr(strrchr(__FILE__, '.'), 1); include($phpbb_root_path . 'common.' . $phpEx); include($phpbb_root_path . 'includes/simple_html_dom.' . $phpEx); // Start session management $user->session_begin(); $auth->acl($user->data); $user->setup(); set_time_limit(259200); function save($in, $out) { $ch = curl_init ($in); curl_setopt($ch, CURLOPT_HEADER, 0); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); curl_setopt($ch, CURLOPT_BINARYTRANSFER,1); $rawdata=curl_exec($ch); curl_close ($ch); if(file_exists($out)) { unlink($out); } $fp = fopen($out,'x'); fwrite($fp, $rawdata); fclose($fp); } function scrape($i) { $url = 'http:/xxxxxxxx/index.php?main_page=product_info&products_id='.$i.'&zenid=e4b7dde8de02e1df005d4549e2e3e529'; echo "$url -- "; $exists = file_get_contents($url); if ($exists != false) { $html = file_get_html($url); foreach($html->find('body') as $html) { $test = $html->find('#productName', 0); if ($test) { $item['title'] = trim($html->find('#productName', 0)->plaintext); $item['price'] = trim($html->find('#productPrices', 0)->plaintext); $item['cat'] = $html->find('#navBreadCrumb', 0)->plaintext; list($home, $item['cat'], $item['subcat'], $title) = explode("::", $item['cat']); $item['cat'] = str_replace("&nbsp;", "", $item['cat']); $item['subcat'] = str_replace("\n", "", str_replace("&nbsp;", "", $item['subcat'])); $item['desc'] = trim($html->find('#productDescription', 0)->plaintext); $item['model'] = $html->find('ul#productDetailsList', 0)->find('li', 0)->plaintext; $item['model'] = explode(":", $item['model']); $item['model'] = trim($item['model'][1]); $item['manufacturer'] = $html->find('ul#productDetailsList', 0)->find('li', 1)->plaintext; $item['manufacturer'] = explode(":", $item['manufacturer']); $item['manufacturer'] = trim($item['manufacturer'][1]); foreach($html->find('img') as $img) { if($img->alt == $item['title']) { $item['img_sm'] = $img->src; } } $ret[] = $item; } } $html->clear(); unset($html); unset($item); return $ret; } else { echo "Could not find page<br />"; } unset($exists); } $i = 1; $end = 9999999; while($i < $end) { $ret = scrape($i); if(isset($ret)) { foreach($ret as $v) { $item['title'] = $v['title']; $item['price'] = $v['price']; $item['desc'] = $v['desc']; $item['model'] = $v['model']; $item['manufacturer'] = $v['manufacturer']; $item['image'] = $v['image']; $item['cat'] = $v['cat']; $item['subcat'] = $v['subcat']; $item['img_sm'] = $v['img_sm']; } unset($ret); unset($v); $sm_img_src = "http://xxxxxx/".$item['img_sm']; $ext = strrchr($item['img_sm'], '.'); $filename = $item['model'] . $ext; $lg_img_src = "http://xxxxx/images/STC/".$filename; $new_sm = "./rip_images/small/{$filename}"; $new_lg = "./rip_images/large/{$filename}"; $item['image'] = $filename; save($lg_img_src,$new_lg); save($sm_img_src,$new_sm); //see if parent cat exists $sql = 'SELECT cat_id FROM ' . SHOP_CAT_TABLE . ' WHERE cat_name = "'.$db->sql_escape($item['cat']).'"'; $result = $db->sql_query($sql); $parent = $db->sql_fetchrow($result); $db->sql_freeresult($result); // if not exists if($parent['cat_id'] == '') { //add the parent cat to the db $sql_ary = array( 'cat_name' => $item['cat'], 'cat_parent' => 0 ); $sql = 'INSERT INTO '.SHOP_CAT_TABLE.' '.$db->sql_build_array('INSERT', $sql_ary); $db->sql_query($sql); $cat_id = $db->sql_nextid(); //see if subcat exists $sql = 'SELECT cat_id FROM ' . SHOP_CAT_TABLE . ' WHERE cat_name = "'.$db->sql_escape($item['subcat']).'"'; $result = $db->sql_query($sql); $row = $db->sql_fetchrow($result); $db->sql_freeresult($result); // if not exists if($row['cat_id'] == '') { //add subcat to db $sql_ary = array( 'cat_name' => $db->sql_escape($item['subcat']), 'cat_parent' => $cat_id ); $sql = 'INSERT INTO '.SHOP_CAT_TABLE.' '.$db->sql_build_array('INSERT', $sql_ary); $db->sql_query($sql); $item_cat = $db->sql_nextid(); } else //if exists { $item_cat = $row['cat_id']; } } else //if parent cat exists { //see if subcat exists $sql = 'SELECT cat_id FROM ' . SHOP_CAT_TABLE . ' WHERE cat_name = "'.$db->sql_escape($item['subcat']).'"'; $result = $db->sql_query($sql); $row = $db->sql_fetchrow($result); $db->sql_freeresult($result); // if not exists if($row['cat_id'] == '') { //add the subcat to the db $sql_ary = array( 'cat_name' => $db->sql_escape($item['subcat']), 'cat_parent' => $parent['cat_id'] ); $sql = 'INSERT INTO '.SHOP_CAT_TABLE.' '.$db->sql_build_array('INSERT', $sql_ary); $db->sql_query($sql); $item_cat = $db->sql_nextid(); } else //if exists { $item_cat = $row['cat_id']; } } $sql_ary = array( 'item_title' => $db->sql_escape($item['title']), 'item_price' => $db->sql_escape($item['price']), 'item_desc' => $db->sql_escape($item['desc']), 'item_model' => $db->sql_escape($item['model']), 'item_manufacturer' => $db->sql_escape($item['manufacturer']), 'item_image' => $db->sql_escape($item['image']), 'item_cat' => $db->sql_escape($item_cat) ); $sql = 'INSERT INTO ' . SHOP_ITEM_TABLE . ' ' . $db->sql_build_array('INSERT', $sql_ary); $db->sql_query($sql); garbage_collection(); echo 'Done<br />'; } $i++; unset($item); } ?>

    Read the article

  • Help with an RSS Feed

    - by Pete Herbert Penito
    Hi Everyone! I've spent ages on this, all I'm trying to do is extract the "title" contents from an rss feed, everything else can be ignored. I've looked into simplepie, magpie and all that stuff, but I feel its kind of overkill for what I need to do. I realise there are google gadgets that are made that can do this, but I didn't want all the google logo stuff, and I wanted to personally make this. theres a whole bunch of unneeded tags thats coming in from the rss feed all I need is the title tag, it looks like this <title> My Title 3.0 </title> My server has PHP 5+ so I know I can use some of these simple xml functions which look promising. so far I've got <?php $blogfeed = file_get_contents("http://myblog.blogspot.com/feeds/posts/default?alt=rss"); echo $blogfeed; ?> And it gives me all the data, I was thinking of running through it with strpos and searching for <title> but is there any easier way to do this?? Thanks alot!

    Read the article

  • Using a join with three tables when a field might be null

    - by John
    Hello, The code below works great. It combines data from two MySQL tables. I would like to modify it by pulling in some data from a third MySQL table called "comment." In the HTML table below, "title" is a field in the MySQL table "submission." Every "title" has a corresponding "submissionid" field. The field "submissionid" is also found in the "comment" MySQL table. In the HTML table below, I would like "countComments" to equal the number of times a field called "commentid" appears in the MySQL table "comment" for any given "submissionid," where the "submissionid" is the same in both the "submission" and "comment" tables, and where the "submissionid" corresponds to the "title" being used. Here's the catch: if there is no row in the MySQL table "comment" that corresponds with the "submissionid" being used for "table", I would like "countComments" to equal to zero. How can I do this? Thanks in advance, John $sqlStr = "SELECT s.loginid, s.title, s.url, s.displayurl, l.username FROM submission AS s, login AS l WHERE s.loginid = l.loginid ORDER BY s.datesubmitted DESC LIMIT 10"; $result = mysql_query($sqlStr); $arr = array(); echo "<table class=\"samplesrec\">"; while ($row = mysql_fetch_array($result)) { echo '<tr>'; echo '<td class="sitename1"><a href="http://www.'.$row["url"].'">'.$row["title"].'</a></td>'; echo '</tr>'; echo '<tr>'; echo '<td class="sitename2"><a href="http://www...com/sandbox/members/index.php?profile='.$row["username"].'">'.$row["username"].'</a><a href="http://www...com/sandbox/comments/index.php?submission='.$row["title"].'">'.$row["countComments"].'</a></td>'; echo '</tr>'; } echo "</table>";

    Read the article

  • Display all feeds using simplexml_load() using PHP

    - by Jean
    Hello, I want to loop to get all feeds, but displaying only one $url = "http://localhost/feeds/feeds.rss"; $xml = simplexml_load_file($url); foreach($xml->item as $result){ echo $result->description."<br>"; } RSS Feed is - <channel> <title>/</title> <link>/</link> <atom:link type="application/rss+xml" href="/" rel="self"/> <description>/</description> <language>/</language> <ttl>/</ttl> <item> <title>/</title> <description>/</description> <pubDate>/</pubDate> <guid>/</guid> <link>/</link> </item> <item> <title>/</title> <description>/</description> <pubDate>/</pubDate> <guid>/</guid> <link>/</link> </item> </channel> Thanks Jean

    Read the article

  • Json get a parameter can't access on it iOS

    - by Usi Usi
    That's an example { "updated":1350213484, "id":"http://www.google.com/reader/api/0/feed-finder?q\u003dProva\u0026output\u003djson", "title":"Risultati di feed per \"Prova\"", "self":[ { "href":"http://www.google.com/reader/api/0/feed-finder?q\u003dProva\u0026output\u003djson" } ], "items":[ { "title":"Home Page - La prova del cuoco", "id":"http://www.laprovadelcuoco.rai.it/", "updated":1350213485, "feed":[ { "href":"http://www.laprovadelcuoco.rai.it/dl/portali/site/page/Page-ffb545b4-9e72-41e5-866f-a465588c43fa-rss.html" } ], "alternate":[ { "href":"http://www.laprovadelcuoco.rai.it/", "type":"text/html" } ], "content":{ "direction":"ltr", "content":"Diventa un cuoco provetto con “La Prova del Cuoco”: le videoricette in un' applicazione di facile e veloce consultazione per il tuo Iphone. Scopri come acquistare ..." } }, { "title":"Le prove Invalsi di matematica e italiano", "id":"http://online.scuola.zanichelli.it/quartaprova/", "updated":1350213486, "feed":[ { "href":"http://online.scuola.zanichelli.it/quartaprova/feed/" } ], "alternate":[ { "href":"http://online.scuola.zanichelli.it/quartaprova/", "type":"text/html" } ], "content":{ "direction":"ltr", "content":"Un sito Zanichelli dedicato alle prove Invalsi di italiano e matematica: esercitazioni, consigli, informazioni utili, novità, aggiornamenti e blog d'autore sulle prove ..." } }, How can I get the feed URL? That's what I do NSString *daParsare=[reader searchFeed:searchText]; NSArray *items = [[daParsare JSONValue] objectForKey:@"items"]; for (NSDictionary *item in items) { NSString *title = [item objectForKey:@"title"]; NSString *feed = [item valueForKeyPath:@"feed.href"]; } [tab reloadData]; With the title everything is ok but when I try to access to the feed paramater I get the error...

    Read the article

  • problem in creating a php tree menu

    - by Mac Taylor
    hi mates im writing a tree menu for my categories in php and i wonder how can i code it correctly ! this is my table in database " |----topicid------topicname--------parent | |---- 1 ------ News -------- 0 | |---- 2 ------ sport -------- 1 | |---- 3 ------ games -------- 1 | |---- 4 ------ PES -------- 3 | so now for showing it like a tree i did try but not worked : $result = mysql_query("SELECT * FROM Topics ORDER BY topicid"); while ($row = mysql_fetchrow($result)) { $id = intval($row['topicid']); $title = filter($row['topicname'], "nohtml"); $parent = $row['parent'] ; if ($parent==0) { $menu_item .= "<li><span class='folder'><a title = \"$alt\" href=\"modules.php?name=News&amp;new_topic=$id\">$title</a></span></li>"; }else { $result = mysql_query("SELECT * FROM ".$prefix."_Topics where parent='$id' ORDER BY topicid"); while ($row = mysql_fetchrow($result)) { $id = intval($row['topicid']); $title = filter($row['topicname'], "nohtml"); $parent = $row['parent'] ; $menu_item .= " <ul><li><span class='file'><a title = \"$alt\" href=\"modules.php?name=News&amp;new_topic=$id\">$title</a></span></li></ul>"; } } i dont know how to solve this

    Read the article

  • Outstanding issues with jQuery.ajax() in IE8?

    - by RyanV
    I am loading feed-items into a ul using this jQuery .ajax() call, which I basically lifted from http://www.makemineatriple.com/2007/10/bbcnewsticker/ var timestamp = true; //set whether timestamp is displayed in $.ajax({ type: "GET", url: "sample-feed.xml", dataType: "xml", success: function(xml) { $(xml).find('item').each(function(){ var title = $(this).find('title').text(); var link = $(this).find('link').text(); if(title.length >=57){ title = title.substring(0,54) + "..."; } var addItem = '<li class="tickerTitle"><a href="'+link+'">'+title+'</a>'; if (Boolean(timestamp)== true){ var time = new Date(Date.parse($(this).find('pubDate').text())); addItem +='<span class="timestamp">' + makestamp(time) +'</span></li>'; } $('ul#news').append(addItem); }); It works in Chrome 4 and Firefox 3.6, but I load it up in IE8 and somehow the ajax call fails. I have tried to use IE8's Developer tools to see where exactly it fails, but I haven't been successful yet. So two questions Is there anything blatantly wrong with my ajax call here that could be preventing me from seeing it in IE where it works in FF/Chrome? Are there any special considerations I have to make for the Internet Explorer family of browsers with regards to this particular jQuery method? I've done some googling on this but nothing obvious is coming up. One other note: I am currently using jQuery 1.3.2 due to some legacy scripts on the same site. I did try loading 1.4.2 and it had the same results on IE8

    Read the article

  • Appending a function to an existing onclick event at page load

    - by tonsils
    Hi, I have the following html code that is pre written by the app I am using, which I do not have access to, i.e. <td align="center" class="shuttleControl"> <img src="/i/mydb/icons/shuttle_reload.png" onclick="g_Shuttlep_v61.reset();" alt="Reset" title="Reset"/> <img src="/i/mydb/icons/shuttle_last.png" onclick="g_Shuttlep_v61.move_all();" alt="Move All" title="Move All"/> <img src="/i/mydb/icons/shuttle_right.png" onclick="g_Shuttlep_v61.move();" alt="Move" title="Move" /> <img src="/i/mydb/icons/shuttle_left.png" onclick="g_Shuttlep_v61.remove();" alt="Remove" title="Remove" /> <img src="/i/mydb/icons/shuttle_first.png" onclick="g_Shuttlep_v61.remove_all();" alt="Remove All" title="Remove All" /> </td> Based on the above code, using jQuery, would it be possible that when the page finishes loading, search for the img src "shuttle_last.png" and append to it's onclick call, my own function get_Count(); ? That is, I would then see the following code when I do a view page source for this particular line, i.e.: <img src="/i/mydb/icons/shuttle_last.png" onclick="g_Shuttlep_v61.move_all();get_Count();" alt="Move All" title="Move All"/> Is this possible - if so, would really appreciate a code sample? Thanks.

    Read the article

  • ZendX Jquery Decorator

    - by iJD
    How use partial decorator in Jquery Element I use this code for Form Element: $title = new Zend_Form_Element_Text('title'); $title->setRequired(true) ->setAttrib('class', 'inputbox') ->setLabel('Title'); $title->viewScript = 'RegElement.phtml'; $title->setDecorators( array( array('ViewScript', array('class' => 'RegElement')) ) ); But when i use Jquery Element i dont know how implement it: $datePicker = new ZendX_JQuery_Form_Element_DatePicker( "datePicker1", array("label" => "Date:") ); $datePicker->viewScript = 'RegElement.phtml'; $datePicker->setDecorators( array( array('ViewScript', array('class' => 'RegElement')) ) ); //views/scripts/RegElement.phtml <li class="row <?php echo $this->class ?>"> <div class="cont-error"> <?php echo $this->formErrors($this->element->getMessages()); ?> </div> <div class="rowfields"> <?php echo $this->formLabel($this->element->getName(), $this->element->getLabel()) ?> <?php echo $this->{$this->element->helper}( $this->element->getName(), $this->element->getValue(), $this->element->getAttribs() ) ?> </div> <div class="hint"><?php echo $this->element->getDescription() ?></div> </li> And display this error: Warning: Exception caught by form: Cannot render jQuery form element without at least one decorator implementing the 'ZendX_JQuery_Form_Decorator_UiWidgetElementMarker' interface. I need display datePicker with same format. but idk how implement this interface. thx for your help.

    Read the article

  • linq to xml selection/update

    - by gleasonomicon
    If I have the following xml, how would I use linq to xml blank out the date fields in each video node? I wanted to do it for the purpose of a comparison in a unit test. <?xml version="1.0" encoding="utf-8" standalone="yes" ?> <main> <videos> <video> <id>00000000-0000-0000-0000-000000000000</id> <title>Video Title</title> <videourl>http://sample.com</videourl> <thumbnail>http://sample.com</thumbnail> <dateCreated>2011-01-12T18:54:56.7318386-05:00</dateCreated> <dateModified>2011-02-12T18:54:56.7318386-05:00</dateModified> <Numbers> <Number>28</Number> <Number>78</Number> </Numbers> </video> <video> <id>00000000-0000-0000-0000-000000000000</id> <title>Video Title</title> <videourl>http://sample.com</videourl> <thumbnail>http://sample.com</thumbnail> <dateCreated>2011-01-12T18:54:56.7318386-05:00</dateCreated> <dateModified>2011-02-12T18:54:56.7318386-05:00</dateModified> <Numbers> <Number>28</Number> <Number>78</Number> </Numbers> </video> </videos>

    Read the article

  • How to search within an xml data set?

    - by user187580
    Hi, I have some xml data and I am trying to keyword search data. For example, if I search "some" for the following data it returns me the <id> and <title>. <resource> <id>101</id> <title>Test Environment</title> <description><b>Some</b> description. </description> <type>classroom</type> </resource> <resource> <id>102</id> <title>ABC Test Environment</title> <description><b>Some</b> another description. </description> <type>classroom</type> </resource> ... I had a look on on xpath e.g. $xml->xpath('//title') but looks for elements only. Basically what I need to do is to create a functionality where users can keyword search within the above data set which I receive from third party api in the above format. Any ideas how I can achieve this? using PHP/ Javascript etc. Thanks.

    Read the article

  • Rails : can't write unknown attribute `url'

    - by user2954789
    I am new to ruby on rails,and I am learning by creating a blog. I am not able to save to my blogs table and I get this error "can't write unknown attribute url" Blogs migration :db/migrate/ class CreateBlogs < ActiveRecord::Migration --def change --- create_table :blogs do |t| ---- t.string :title ---- t.text :description ---- t.string :slug ---- t.timestamps --- end --end end Blogs Model :/app/models/blogs.rb class Blogs < ActiveRecord::Base --acts_as_url :title --def to_param ---url --end --validates :title, presence:true end Blogs Controller : /app/controllers/blogs_controller.rb class BlogsController < ApplicationController before_action :require_login --def new --- @blogs = Blogs.new --end --def show ---@blogs = Blogs.find(params[:id]) --end --def create ---@blogs = Blogs.new(blogs_params) --if @blogs.save ---flash[:success] = "Your Blog has been created." ---redirect_to home_path --else ---render 'new' --end -end --def blogs_params ---params.require(:blogs).permit(:title,:description) --end private --def require_login ---unless signed_in? ----flash[:error] = "You must be logged in to create a new Blog" ----redirect_to signin_path ---end --end end Blogs Form:/app/views/blogs/new.html.erb Blockquote <%= form_for @blogs, url: blogs_path do |f| %><br/> <%= render 'shared/error_messages_blogs' %><br/> <%= f.label :title %><br/> <%= f.text_field :title %><br/> <%= f.label :description %><br/> <%= f.text_area :description %><br/> <%= f.submit "Submit Blog", class: "btn btn-large btn-primary" %><br/> <% end %><br/> and I have also added "resources :blogs" to my routes.rb file. I get this error in controller at if @blogs.save

    Read the article

  • Stop Rewrite htaccess create random pages

    - by Vistol
    Recently I saw in my Webmaster tools that some random sites are linking to my site. Actually this is not an big issue. The issue comes when the pages that are linked are not real pages because of my httaccess file. This is the htaccess code that Im running: <pre> #Options +FollowSymLinks RewriteEngine on RewriteRule ^([^/\.]+)/?$ index.php?id=$1 [L] RewriteRule ^([0-9]+)/(.*)$ index.php?id=$1 [L] </pre> So the real URLs would be: mysite.com/folder/999/TITLE-OR-NAME But cecause I only check the 1st folder ($1) which is an I numberD, this htaccess file is allowing hackers linking to my site with random URLs like: mysite.com/folder/999/TITLE-OR-NAME1 mysite.com/folder/999/TITLE-OR-NAME2 mysite.com/folder/999/TITLE-OR-NAME3 mysite.com/folder/999/TITLE-OR-NAME4 mysite.com/folder/999/TITLE-OR-NAME5 The worst part comes when google tells me that I am duplicating content!!! Actually I am not duplicating content, the htaccess is duplicating it for me. And yes I know, Im a bad newbie programmer but Id really appreciate your help with this cause Im struggling to find a solution but it never. Thank you very much for all your support to this newbie :)

    Read the article

  • simplexml object node iteration

    - by MorbidWrath
    I have an xml file that I'm parsing with php's simplexml, but I'm having an issue with an iteration through nodes. the xml: <channel> <item> <title>Title1</title> <category>Cat1</category> </item> <item> <title>Title2</title> <category>Cat1</category> </item> <item> <title>Title3</title> <category>Cat2</category> </item> </channel> my counting function: public function cat_count($cat){ $count = 0; $items = $this->xml->channel->item; $size = count($size); for($i=0;$i<$size;$i++){ if($items[$i]->category == $cat){ $count++; } } return $count; } Am I overlooking an error in my code, or is there another preferred method for iterating through the nodes? I've also used a foreach and while statement with no luck, so I'm at a loss. Any suggestions?

    Read the article

  • Getting rejected value null spring validation

    - by Shabarinath
    Hi in my project when I am trying to validate my form its not showing any error messages even if validation fails (Event Form is not submitted and enters into validation fail block) Here is my code /****************** Post Method *************/ @RequestMapping(value="/property", method = RequestMethod.POST) public String saveOrUpdateProperty(@ModelAttribute("property") Property property, BindingResult result, Model model, HttpServletRequest request) throws Exception { try { if(validateFormData(property, result)) { model.addAttribute("property", new Property()); return "property/postProperty"; } } /********* Validate Block *************/ private boolean validateFormData(Property property, BindingResult result) throws DaoException { if (property.getPropertyType() == null || property.getPropertyType().equals("")) { result.rejectValue("propertyType", "Cannot Be Empty !", "Cannot Be Empty !"); } if (property.getTitle() == null || property.getTitle().equals("")) { result.rejectValue("title", "Cannot Be Empty !", "Cannot Be Empty !"); } return (result.hasFieldErrors() || result.hasErrors()); } But when i debug i can see below one org.springframework.validation.BeanPropertyBindingResult: 1 errors Field error in object 'property' on field 'title': rejected value [null]; codes [Cannot Be Empty !.property.title,Cannot Be Empty !.title,Cannot Be Empty !.java.lang.String,Cannot Be Empty !]; arguments []; default message [Cannot Be Empty !] and this is how i am displaying in jsp file <div class="control-group"> <div class="controls"> <label class="control-label"><span class="required">* </span>Property Type</label> <div class="controls"> <form:input path="title" placeholder="Pin Code" cssClass="form-control border-radius-4 textField"/> <form:errors path="title" style="color:red;"/> </div> </div> </div> Event though when i see the below one when i debug (1 Error its correct) org.springframework.validation.BeanPropertyBindingResult: 1 errors Why it is not displayed in jsp can any one hep me?

    Read the article

  • str_replace between two numerical strings

    - by user330840
    Another problem with str_replace, I would like to change the following $title data into URL by taking the $string between number in the beginning and after dash (-) Chicago's Public Schools - $10.3M New Jersey - $3M Michigan: Public Health - $1M The desire output is: chicago-public-school new-jersey michigan-public-health PHP code I am using $title = ucwords(strtolower(strip_tags(str_replace("1: ","",$title)))); $x=1; while($x <= 10) { $title = ucwords(strtolower(strip_tags(str_replace("$x: ","",$title)))); $x++; } $link = preg_replace('/[<>()!#?:.$%\^&=+~`*&#233;"\']/', '',$title); $money = str_replace(" ","-",$link); $link = explode(" - ",$link); $link = preg_replace(" (\(.*?\))", "", $link[0]); $amount = preg_replace(" (\(.*?\))", "", $link[1]); $code_entities_match = array( '&#39;s' ,'&quot;' ,'!' ,'@' ,'#' ,'$' ,'%' ,'^' ,'&' ,'*' ,'(' ,')' ,'+' ,'{' ,'}' ,'|' ,':' ,'"' ,'<' ,'>' ,'?' ,'[' ,']' ,'' ,';' ,"'" ,',' ,'.' ,'_' ,'/' ,'*' ,'+' ,'~' ,'`' ,'=' ,' ' ,'---' ,'--','--'); $code_entities_replace = array('' ,'-' ,'-' ,'' ,'' ,'' ,'-' ,'-' ,'' ,'' ,'' ,'' ,'' ,'' ,'' ,'-' ,'' ,'' ,'' ,'' ,'' ,'' ,'' ,'' ,'' ,'-' ,'' ,'-' ,'-' ,'' ,'' ,'' ,'' ,'' ,'-' ,'-' ,'-','-'); $link = str_replace($code_entities_match, $code_entities_replace, $link); $link = strtolower($link); Unfortunately the result I got: -chicagoamp9s-public-school 2-new-jersey 3-michigan-public-health Anyone has a better solution for this? Thanks guys! (the &#39; changed into amp9 - wonder why?)

    Read the article

  • Why can I not echo out the value from an input text?

    - by user3684783
    I am using Wordpress to do an auction website. Here is what the code looks like <form method="post" action="<?php echo ProjectTheme_post_new_with_pid_stuff_thg($pid, '1');?>"> <?php do_action('ProjectTheme_step1_before_title'); ?> <!--////////// Project Title /////////////--> <li> <h2><?php echo __('Your Project Title', 'ProjectTheme'); ?>: <img src="../../images/help-icon.png" width="16" height="16" id="showhelp1"/></h2> <div id="help1">Your Project Title should be informative and brief.</div> <p><input type="text" style="width:90%;" class="do_input" name="project_title" value="Enter an informative & brief title..." onfocus="this.value = this.value=='Enter an informative & brief title...'?'':this.value;" onblur="this.value = this.value==''?'Enter an informative & brief title...':this.value;" /></p> <input type="submit" class="post-button" name="project_submit1" value="<?php _e("Next Step", 'ProjectTheme'); ?> &raquo;" /> </form> I am using a step by step form for users to fill in and I wanted to do a preview page, however I tried to use: if(isset($_POST['project_submit1'])){ $Name = $_POST['project_title']; echo "$Name"; } It shows up nothing.

    Read the article

  • Design by Contract with Microsoft .Net Code Contract

    - by Fredrik N
    I have done some talks on different events and summits about Defensive Programming and Design by Contract, last time was at Cornerstone’s Developer Summit 2010. Next time will be at SweNug (Sweden .Net User Group). I decided to write a blog post about of some stuffs I was talking about. Users are a terrible thing! Protect your self from them ”Human users have a gift for doing the worst possible thing at the worst possible time.” – Michael T. Nygard, Release It! The kind of users Michael T. Nygard are talking about is the users of a system. We also have users that uses our code, the users I’m going to focus on is the users of our code. Me and you and another developers. “Any fool can write code that a computer can understand. Good programmers write code that humans can understand.” – Martin Fowler Good programmers also writes code that humans know how to use, good programmers also make sure software behave in a predictable manner despise inputs or user actions. Design by Contract   Design by Contract (DbC) is a way for us to make a contract between us (the code writer) and the users of our code. It’s about “If you give me this, I promise to give you this”. It’s not about business validations, that is something completely different that should be part of the domain model. DbC is to make sure the users of our code uses it in a correct way, and that we can rely on the contract and write code in a way where we know that the users will follow the contract. It will make it much easier for us to write code with a contract specified. Something like the following code is something we may see often: public void DoSomething(Object value) { value.DoIKnowThatICanDoThis(); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Where “value” can be uses directly or passed to other methods and later be used. What some of us can easily forget here is that the “value” can be “null”. We will probably not passing a null value, but someone else that uses our code maybe will do it. I think most of you (including me) have passed “null” into a method because you don’t know if the argument need to be specified to a valid value etc. I bet most of you also have got the “Null reference exception”. Sometimes this “Null reference exception” can be hard and take time to fix, because we need to search among our code to see where the “null” value was passed in etc. Wouldn’t it be much better if we can as early as possible specify that the value can’t not be null, so the users of our code also know it when the users starts to use our code, and before run time execution of the code? This is where DbC comes into the picture. We can use DbC to specify what we need, and by doing so we can rely on the contract when we write our code. So the code above can actually use the DoIKnowThatICanDoThis() method on the value object without being worried that the “value” can be null. The contract between the users of the code and us writing the code, says that the “value” can’t be null.   Pre- and Postconditions   When working with DbC we are specifying pre- and postconditions.  Precondition is a condition that should be met before a query or command is executed. An example of a precondition is: “The Value argument of the method can’t be null”, and we make sure the “value” isn’t null before the method is called. Postcondition is a condition that should be met when a command or query is completed, a postcondition will make sure the result is correct. An example of a postconditon is “The method will return a list with at least 1 item”. Commands an Quires When using DbC, we need to know what a Command and a Query is, because some principles that can be good to follow are based on commands and queries. A Command is something that will not return anything, like the SQL’s CREATE, UPDATE and DELETE. There are two kinds of Commands when using DbC, the Creation commands (for example a Constructor), and Others. Others can for example be a Command to add a value to a list, remove or update a value etc. //Creation commands public Stack(int size) //Other commands public void Push(object value); public void Remove(); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   A Query, is something that will return something, for example an Attribute, Property or a Function, like the SQL’s SELECT.   There are two kinds of Queries, the Basic Queries  (Quires that aren’t based on another queries), and the Derived Queries, queries that is based on another queries. Here is an example of queries of a Stack: //Basic Queries public int Count; public object this[int index] { get; } //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } To understand about some principles that are good to follow when using DbC, we need to know about the Commands and different Queries. The 6 Principles When working with DbC, it’s advisable to follow some principles to make it easier to define and use contracts. The following DbC principles are: Separate commands and queries. Separate basic queries from derived queries. For each derived query, write a postcondition that specifies what result will be returned, in terms of one or more basic queries. For each command, write a postcondition that specifies the value of every basic query. For every query and command, decide on a suitable precondition. Write invariants to define unchanging properties of objects. Before I will write about each of them I want you to now that I’m going to use .Net 4.0 Code Contract. I will in the rest of the post uses a simple Stack (Yes I know, .Net already have a Stack class) to give you the basic understanding about using DbC. A Stack is a data structure where the first item in, will be the first item out. Here is a basic implementation of a Stack where not contract is specified yet: public class Stack { private object[] _array; //Basic Queries public uint Count; public object this[uint index] { get { return _array[index]; } set { _array[index] = value; } } //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } //Is related to Count and this[] Query public object Top() { return this[Count]; } //Creation commands public Stack(uint size) { Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { this[++Count] = value; } public void Remove() { this[Count] = null; Count--; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Note: The Stack is implemented in a way to demonstrate the use of Code Contract in a simple way, the implementation may not look like how you would implement it, so don’t think this is the perfect Stack implementation, only used for demonstration.   Before I will go deeper into the principles I will simply mention how we can use the .Net Code Contract. I mention before about pre- and postcondition, is about “Require” something and to “Ensure” something. When using Code Contract, we will use a static class called “Contract” and is located in he “System.Diagnostics.Contracts” namespace. The contract must be specified at the top or our member statement block. To specify a precondition with Code Contract we uses the Contract.Requires method, and to specify a postcondition, we uses the Contract.Ensure method. Here is an example where both a pre- and postcondition are used: public object Top() { Contract.Requires(Count > 0, "Stack is empty"); Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The contract above requires that the Count is greater than 0, if not we can’t get the item at the Top of a Stack. We also Ensures that the results (By using the Contract.Result method, we can specify a postcondition that will check if the value returned from a method is correct) of the Top query is equal to this[Count].   1. Separate Commands and Queries   When working with DbC, it’s important to separate Command and Quires. A method should either be a command that performs an Action, or returning information to the caller, not both. By asking a question the answer shouldn’t be changed. The following is an example of a Command and a Query of a Stack: public void Push(object value) public object Top() .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The Push is a command and will not return anything, just add a value to the Stack, the Top is a query to get the item at the top of the stack.   2. Separate basic queries from derived queries There are two different kinds of queries,  the basic queries that doesn’t rely on another queries, and derived queries that uses a basic query. The “Separate basic queries from derived queries” principle is about about that derived queries can be specified in terms of basic queries. So this principles is more about recognizing that a query is a derived query or a basic query. It will then make is much easier to follow the other principles. The following code shows a basic query and a derived query: //Basic Queries public uint Count; //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   We can see that IsEmpty will use the Count query, and that makes the IsEmpty a Derived query.   3. For each derived query, write a postcondition that specifies what result will be returned, in terms of one or more basic queries.   When the derived query is recognize we can follow the 3ed principle. For each derived query, we can create a postcondition that specifies what result our derived query will return in terms of one or more basic queries. Remember that DbC is about contracts between the users of the code and us writing the code. So we can’t use demand that the users will pass in a valid value, we must also ensure that we will give the users what the users wants, when the user is following our contract. The IsEmpty query of the Stack will use a Count query and that will make the IsEmpty a Derived query, so we should now write a postcondition that specified what results will be returned, in terms of using a basic query and in this case the Count query, //Basic Queries public uint Count; //Derived Queries public bool IsEmpty() { Contract.Ensures(Contract.Result<bool>() == (Count == 0)); return Count == 0; } The Contract.Ensures is used to create a postcondition. The above code will make sure that the results of the IsEmpty (by using the Contract.Result to get the result of the IsEmpty method) is correct, that will say that the IsEmpty will be either true or false based on Count is equal to 0 or not. The postcondition are using a basic query, so the IsEmpty is now following the 3ed principle. We also have another Derived Query, the Top query, it will also need a postcondition and it uses all basic queries. The Result of the Top method must be the same value as the this[] query returns. //Basic Queries public uint Count; public object this[uint index] { get { return _array[index]; } set { _array[index] = value; } } //Derived Queries //Is related to Count and this[] Query public object Top() { Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   4. For each command, write a postcondition that specifies the value of every basic query.   For each command we will create a postconditon that specifies the value of basic queries. If we look at the Stack implementation we will have three Commands, one Creation command, the Constructor, and two others commands, Push and Remove. Those commands need a postcondition and they should include basic query to follow the 4th principle. //Creation commands public Stack(uint size) { Contract.Ensures(Count == 0); Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { Contract.Ensures(Count == Contract.OldValue<uint>(Count) + 1); Contract.Ensures(this[Count] == value); this[++Count] = value; } public void Remove() { Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   As you can see the Create command will Ensures that Count will be 0 when the Stack is created, when a Stack is created there shouldn’t be any items in the stack. The Push command will take a value and put it into the Stack, when an item is pushed into the Stack, the Count need to be increased to know the number of items added to the Stack, and we must also make sure the item is really added to the Stack. The postconditon of the Push method will make sure the that old value of the Count (by using the Contract.OldValue we can get the value a Query has before the method is called)  plus 1 will be equal to the Count query, this is the way we can ensure that the Push will increase the Count with one. We also make sure the this[] query will now contain the item we pushed into the Stack. The Remove method must make sure the Count is decreased by one when the top item is removed from the Stack. The Commands is now following the 4th principle, where each command now have a postcondition that used the value of basic queries. Note: The principle says every basic Query, the Remove only used one Query the Count, it’s because this command can’t use the this[] query because an item is removed, so the only way to make sure an item is removed is to just use the Count query, so the Remove will still follow the principle.   5. For every query and command, decide on a suitable precondition.   We have now focused only on postcondition, now time for some preconditons. The 5th principle is about deciding a suitable preconditon for every query and command. If we starts to look at one of our basic queries (will not go through all Queries and commands here, just some of them) the this[] query, we can’t pass an index that is lower then 1 (.Net arrays and list are zero based, but not the stack in this blog post ;)) and the index can’t be lesser than the number of items in the stack. So here we will need a preconditon. public object this[uint index] { get { Contract.Requires(index >= 1); Contract.Requires(index <= Count); return _array[index]; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Think about the Contract as an documentation about how to use the code in a correct way, so if the contract could be specified elsewhere (not part of the method body), we could simply write “return _array[index]” and there is no need to check if index is greater or lesser than Count, because that is specified in a “contract”. The implementation of Code Contract, requires that the contract is specified in the code. As a developer I would rather have this contract elsewhere (Like Spec#) or implemented in a way Eiffel uses it as part of the language. Now when we have looked at one Query, we can also look at one command, the Remove command (You can see the whole implementation of the Stack at the end of this blog post, where precondition is added to more queries and commands then what I’m going to show in this section). We can only Remove an item if the Count is greater than 0. So we can write a precondition that will require that Count must be greater than 0. public void Remove() { Contract.Requires(Count > 0); Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   6. Write invariants to define unchanging properties of objects.   The last principle is about making sure the object are feeling great! This is done by using invariants. When using Code Contract we can specify invariants by adding a method with the attribute ContractInvariantMethod, the method must be private or public and can only contains calls to Contract.Invariant. To make sure the Stack feels great, the Stack must have 0 or more items, the Count can’t never be a negative value to make sure each command and queries can be used of the Stack. Here is our invariant for the Stack object: [ContractInvariantMethod] private void ObjectInvariant() { Contract.Invariant(Count >= 0); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Note: The ObjectInvariant method will be called every time after a Query or Commands is called. Here is the full example using Code Contract:   public class Stack { private object[] _array; //Basic Queries public uint Count; public object this[uint index] { get { Contract.Requires(index >= 1); Contract.Requires(index <= Count); return _array[index]; } set { Contract.Requires(index >= 1); Contract.Requires(index <= Count); _array[index] = value; } } //Derived Queries //Is related to Count Query public bool IsEmpty() { Contract.Ensures(Contract.Result<bool>() == (Count == 0)); return Count == 0; } //Is related to Count and this[] Query public object Top() { Contract.Requires(Count > 0, "Stack is empty"); Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } //Creation commands public Stack(uint size) { Contract.Requires(size > 0); Contract.Ensures(Count == 0); Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { Contract.Requires(value != null); Contract.Ensures(Count == Contract.OldValue<uint>(Count) + 1); Contract.Ensures(this[Count] == value); this[++Count] = value; } public void Remove() { Contract.Requires(Count > 0); Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } [ContractInvariantMethod] private void ObjectInvariant() { Contract.Invariant(Count >= 0); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Summary By using Design By Contract we can make sure the users are using our code in a correct way, and we must also make sure the users will get the expected results when they uses our code. This can be done by specifying contracts. To make it easy to use Design By Contract, some principles may be good to follow like the separation of commands an queries. With .Net 4.0 we can use the Code Contract feature to specify contracts.

    Read the article

< Previous Page | 434 435 436 437 438 439 440 441 442 443 444 445  | Next Page >