Tag: CSOM

In this post, I will show you how you can create a widget or web part that show you a list of posts from SharePoint blog site. The element is done purely as client side coding. One thing that is true with SharePoint is the fact that you can do the same things in multiple ways. Same goes here with this example, but my aim here is to demonstrate how you can create plugins, web parts, apps however you want to call them, easily and purely as client side development. I think that a word widget is most descriptive, and that is what we will be using here.

This example is based on real life solution that I made on my last project on top of SharePoint 2013 on-prem. The widget is also tested to be working in SharePoint Online. Technically you could use it any other web platform, and that is the key why I want to present you a framework called Widget Wrangler.

What is Widget Wrangler?

Why try to summarise something when it’s done perfectly in the actual source? “The Widget Wrangler is a lightweight framework for managing the loading of javascript “widgets” on a web page.”. With the framework, you can create isolated widgets and control the loading of each file and dependency you need for the element.

With Widget Wrangler (later ww) you can encapsulate the functionality of the widget so that different, or even multiple of the same kind, elements won’t be interference with the hosting page and other widgets. This way the isolation and creation of truly separated UI and functionality are easier to do. The framework also manages the efficient loading when multiple web parts on a page use the same javascript libraries or CSS files.

<div class="latestPostWP">
 <div posts-element></div>

 <script type="text/javascript" src="/ourfirm/offices/SiteAssets/js/pnp-ww.min.js" 
 ww-appname="LatestPostWPApp" 
 ww-apptype="Angular"
 ww-appcss='[{"src": "/ourfirm/offices/SiteAssets/webparts/LatestPost/latestPost.css", "priority":0}]'
 ww-appScripts='[{"src": "/ourfirm/offices/SiteAssets/js/angular.min.js", "priority":0}}
 ]'>
 </script>
</div> 

You can download Widget Wrangler and find more information from here:
https://github.com/Widget-Wrangler/ww

There’s also more deeply demonstration available in Channel9 PnP Web Cast:
PnP Web Cast – Introducing Widget Wrangler for SharePoint development

Post-Listing Widget

To demonstrate the use of ww, let’s create a simple widget that lists blog post from SharePoint blog site. Actually, I have built this type of functions multiple times before so this is a real world example. I will use my favored framework AngularJS and SharePoint REST API to accomplish the actual functionality. This way we can create a solid client side solution and have a flexible separation of functionality and presentation. And that should be the starting point for every customization IMO.

Requirements

• Get blog post from SharePoint blog site.
• Show three latest post and other through pagination.
• From each post title (link to post) 365 first characters from the blog post.
• Show to order an email alert for new posts.
• Show link to RSS feed.

The whole solution can be found from my GitHub repository https://github.com/MikkoKoskinen/WW-Demo-ListPost

From there you can find four files:

• WWPostsWPHTML.html – File containing the ww implementation that was saved on the script web part.
• listPost.js – The angular application that implements the widget functionality.
• listPost.html – The presentation layer of the widget.
• listPost.css – Styling of the widget.

I’m also using following frameworks and extensions:

• AngularJS
• Pagination Directive
• Angular Truncate

Widget Wrangler Section

<div class="latestPostWP">
 <div posts-element blogSiteURL='' listTitle='Posts' listID='74DF3BE3-5536-45B6-B171-B97C1BCD61D1'></div>

 <script type="text/javascript" src="/ourfirm/offices/SiteAssets/js/pnp-ww.min.js" 
 ww-appname="LatestPostWPApp" 
 ww-apptype="Angular"
 ww-appcss='[{"src": "/ourfirm/offices/SiteAssets/webparts/LatestPost/latestPost.css", "priority":0}]'
 ww-appScripts='[{"src": "/ourfirm/offices/SiteAssets/js/angular.min.js", "priority":0},
 {"src": "/ourfirm/offices/SiteAssets/js/truncate.js", "priority":1},
 {"src": "/ourfirm/offices/SiteAssets/js/dirPagination.js", "priority":1},
 {"src": "/ourfirm/offices/SiteAssets/webparts/LatestPost/latestPost.js", "priority":2}
 ]'>
 </script>
</div> 

Above you can see the WW section of the solution that has to be added to the page. This code will handle the loading of the widget. I’m a fan of script web part, so I have placed that code in the snippet section. You could, of course, use other methods of adding the code of course. As we can see, you can control very well on what you want to load and in which order. Key things in the code are.

1. Everything has to be wrapped inside a div. Div with class ‘latestPostWP’ in our case.
   1. This is an important thing to remember because ww won’t work without it.
2. Ww implementation is done inside the script tag that is calling the library on the source attribute. After that, you can give the necessary settings.
3. ww-appname = The name of your widget application. In Angular implementation, this has to match with the module name.
4. ww-apptype = Type of the framework used on the widget. On the time of writing this, only Angular is supported.
5. ww-appcss = List of CSS style sheet you want to be loaded for the widget. You can give multiple files and control the loading order with the parameter.
6. ww-appScripts = List of script files sh you want to be loaded for the widget. You can give multiple files and control the loading order with the parameter.

And that’s it. It’s just that simple.

Now, if look at the browser console after page load, you can see that ww has initialized a widget on the page. As you can see our widget has an index number 0. If there were multiple of these elements on the page, all of them would have them own number. This is the power of ww and encapsulating of the widgets.

Presentation

<div class="resultItem announcementItem" dir-paginate="post in posts | itemsPerPage: 2" pagination-id="posts"> 
 <div class="resultTitle"> 
 <a class="" href="{{viewItemURL}}{{post.ID}}">{{post.Title}}</a> 
 </div> 
 <div class="resultContent"> 
 <span class="resultDate" ng-bind="post.PublishedDate | date:'LLLL dd, yyyy'"></span> 
 <br>
 <div class="resultDetail">{{ post.Body | htmlToPlaintext | characters:350 :true}}</div> 
 <div class="resultMore"><a href="{{viewItemURL}}{{post.ID}}">More≫</a></div> 
 </div> 
</div>
<div class="blogActions">
 <div class="action">
 <a class="ms-calloutLink" target="_blank" href="{{listRSSURL}}">
 <span style="height:16px;width:16px;position:relative;display:inline-block;overflow:hidden;" class="s4-clust ms-blog-linkCommandImage">
 <img src="/ourfirm/offices/_catalogs/theme/Themed/4D8112E7/spcommon-B35BB0A9.themedpng?ctag=3" style="position:absolute;left:-236px !important;top:-66px !important;border-width:0px;"></span>&nbsp;<span class="ms-splinkbutton-text">RSS Feed</span></a>
 </div>
 <div class="action">
 <a class="ms-calloutLink" href="{{postAlertURL}}">
 <span style="height:16px;width:16px;position:relative;display:inline-block;overflow:hidden;" class="s4-clust ms-blog-linkCommandImage"><img src="/ourfirm/offices/_catalogs/theme/Themed/4D8112E7/spcommon-B35BB0A9.themedpng?ctag=3" style="position:absolute;left:-236px !important;top:-30px !important;border-width:0px;"></span>&nbsp;<span class="ms-splinkbutton-text">Alert Me</span>
 </a>
 </div>
 <div class="ms-clear"></div>
</div>
<dir-pagination-controls pagination-id="posts"></dir-pagination-controls>

Here you can see the presentation layer. Technically it’s just plain HTML with some Angular code. But I would like to highlight few relevant things, though.

I’m not using the default repeater to show a list of fetched post. The code is using pagination extension for that. This will provide us an easy way to divide the result to a different section. Pagination is done in the first div element “dir-paginate=”post in posts | itemsPerPage: 2″ pagination-id=”posts””. The first setting is the same than in default repeater telling to loop through all the post in posts variable. Next, we will give the amount of visible items per page. Finally, we give a unique id for the pagination element. This way we can connect the repeater, and the pagination action element added as the last element on the widget (dir-pagination-controls div). The extension is also handling all the necessary functions like showing the page count and back and forward links.

Next thing to notice here is that we are modifying the date format for better visibility with ng-bind element.

 ng-bind="post.PublishedDate | date:'LLLL dd, yyyy'"
{{ post.Body | htmlToPlaintext | characters:350 :true}}

Lastly, we are showing a short teaser from post body with element above. We can truncate the text with Angular Truncate filter and give the amount of character shown to the user. True settings tell that also complete words can be cut. htmlToPlaintext is our custom filter that takes out any HTML elements form the body text. More about this soon.

Functionality

(function() {
  angular
    .module('LatestPostWPApp', ['truncate','angularUtils.directives.dirPagination'])
    .filter('htmlToPlaintext', function () {
        return function(text) {
            return  text ? String(text).replace(/<[^>]+>/gm, '') : '';
        };
    })
    .directive('postsElement', function() {
        return {
            restrict : 'EA',
            transclude : false,
            templateUrl: '/ourfirm/offices/SiteAssets/webparts/LatestPost/latestPost.html',
            controller: function ($scope, $log, $q, $http, $attrs) {

                $scope.getEvents = function getEvents() {
                    return $http({
                        method : "GET",
                        url: _spPageContextInfo.webAbsoluteUrl + "/" + $attrs.blogsiteurl + "/_api/web/lists/GetByTitle('" + $attrs.listtitle + "')/items?$orderby=PublishedDate desc",
                        headers: { "Accept": "application/json;odata=verbose" }
                    })
                    .then(function sendResponseData(response) {
                        // Success
                        return {
                            Items: response.data.d
                        }

                    }).catch(function(response) {
                        $log.error('HTTP request error: ' + response.status)
                        return $q.reject('Error: ' + response.status);
                    });
                };

                $scope.getEvents()
                .then(function(data) {
					//Get list items
					$scope.posts = data.Items.results;

					if ($scope.posts.length > 0) {
                        $scope.viewItemURL = _spPageContextInfo.webAbsoluteUrl + "/" + $attrs.blogsiteurl + "/Lists/" + $attrs.listtitle + "/Post.aspx?ID=";
                        $scope.listRSSURL = _spPageContextInfo.webAbsoluteUrl + "/" + $attrs.blogsiteurl + "/_layouts/15/listfeed.aspx?List={" + $attrs.listid + "}";
                        $scope.postAlertURL = _spPageContextInfo.webAbsoluteUrl + "/" + $attrs.blogsiteurl + "/_layouts/15/SubNew.aspx?List={" + $attrs.listid + "}&Source=" + _spPageContextInfo.serverRequestPath + "";
                    }
					else {

					    $scope.noItemsFound = true;
					}
				});
            }
        };
    }); // End directive()
}()); // End IFFE

The functionality of the widget is done as an Angular application. On the first rows of the code, we are giving a name for the application and loading the necessary extension. First thing on the code is a custom filter called htmlToPlaintext. You may call this function with a parameter holding some text content. The function will strip out all HTML elements with a regular expression and return a pure text content. This is used in the presentation layer.

 .directive('postsElement', function() {
 return {
 restrict : 'EA',
 transclude : false,
 templateUrl: '/ourfirm/offices/SiteAssets/webparts/LatestPost/latestPost.html',
 controller: function ($scope, $log, $q, $http, $attrs) {

After this, we have created a directive element named ‘postsElement’ that is will be called on the script web part.

Important things for the directive are to give the right path to the template file and pass-through the variables with $attrs parameter. As we can see from the directive element, we are passing a couple of parameters to be used during the functionality.

• blogSiteURL = If the widget is placed on another web than in blog site, you can give the URL with this parameter. URL is used during the REST call to get the post. URL should be given as relative against site collection root.
• listTitle = Title of the list where posts are read. The title is used during the REST call to get the post.
• listID = Id of the list where posts are saved. This is used in email alert and RSS functions.

In the first section of the code, we are creating a function called ‘getEvents’ that makes and REST API call against SharePoint and gets all the posts from a given list. The call is using the parameters mentioned above to do the call. If the call is successful, the found data items will be returned.

Next, the code will construct a deferred object from the function above. We are catching the promise and saving the found data items to the ‘posts’ variable. Also if some items were found, we would construct few parameters for view item, RSS and alert links. These parameters are used in the template during the construction of the widget.

<div class="resultMore"><a href="{{viewItemURL}}{{post.ID}}">More≫</a></div>

And that’s it. Here you have a relative simple POC of client-side widget that is reading information from SharePoint and using Widget Wrangler framework for better maintenance.