In this article we reveal some theory and show clever, practical way to setup filtering for external data sources in SharePoint 2013 through query string parameters to achieve significant performance improvement.<\/p>\n\n\n\n
Introducing BDC<\/h2>\n\n\n\n
First of all let us explain what BDC actually is and what are its main goals and foundations. The core function of BDC is to provide connectivity to external systems of different kinds with very little effort. BDC has built-in support for connecting to most common data providers:<\/p>\n\n\n\n There is also a possibility to develop a custom connector plugin through Connector Framework (so in theory BDC service can connect to any<\/strong> data source).<\/p>\n\n\n\n The following diagram presents general concept of BDC:<\/p>\n\n\n\n At the foundation of Business Data Connectivity we have an object called BDC model<\/strong>, which is a bridge between SharePoint and external data source, describing how the connection is handled and what data is transferred between the two ends. In general, BDC model comprises of an entity<\/strong> and its methods<\/strong>:<\/p>\n\n\n\n Full interface defining possible data operations for BDC model contains the following method types:<\/p>\n\n\n\n While complete two-directional communication between SharePoint and external data source will require implementing all methods, for simple one-way communication we will concentrate on Finder method, which returns list of all entities from external data source. We will configure this method to support filtering and to return only the subset of data we are interested in.<\/p>\n\n\n\n Visual Studio will make lots of work for us, so we can quickly setup a project and add model based on Business Data Connectivity Model<\/strong> template.<\/p>\n\n\n\n We make couple of quick changes in naming \u2013 feature name, Entity1 and Entity1Service should get more meaningful names (one thing to note \u2013 Visual Studio has already created Farm-scoped feature for us that will be used to deploy BDC model).<\/p>\n\n\n\n ExternalEntity class should be further changed to define set of metadata to be retrieved from external data source and to be presented to end users.<\/p>\n\n\n\n We will also provide a code to return a list of dummy external entities in ReadList method instance.<\/p>\n\n\n\n Now we can deploy our solution to SharePoint and test our BDC model. If you don\u2019t see your model in External Content Type Picker, most probably you\u2019ve made a mistake in model configuration (ULS will help you to track down the problem). If everything is configured correctly, we should see data pulled from external data source with possibility to filter and sort as in normal SharePoint list view (this kind of filtering however happens on SharePoint side, so no matter what filter we choose in a list view, a whole list of entities is retrieved from external data source).<\/p>\n\n\n\n Now we will enable BDC model to be dynamically filtered on Category column. We give the filter descriptor a name (in our case it will be called categoryFilter<\/strong>). In Filter Field property we should say which property from ExternalEntity will be filtered (in our case it is called Category<\/strong>). We have different type of filters, but since we have a text property, we will use Wildcard<\/strong> filter.<\/p>\n\n\n\n The second step is to add input parameter to our ReadList method.<\/p>\n\n\n\n It is crucial here to bind type descriptor for parameter to filter descriptor created in previous step through Associated Filter<\/strong> property.<\/p>\n\n\n\n One last step is to adjust ReadList method to actually filter the results (note that category<\/strong> parameter has been added automatically to reflect changes made to the model).<\/p>\n\n\n\n Once we have the latest version of our model deployed to the server, we can make additional setup on our page to actually enable filtering with the use of value provided in query string. To achieve that, we should put Query String (URL) Filter<\/strong> web part on the page and edit its properties.<\/p>\n\n\n\n Filter Name<\/strong> is the name of our choice, it is used only for identification. Query String Parameter Name<\/strong> is more important, because it says what key we will use in URL query string to provide value for filtering (for example http:\/\/pageUrl?category<\/strong>=Cat1<\/a>).<\/p>\n\n\n\n Now we will connect Query String (URL) Filter<\/strong> web part to our Business Data List<\/strong> web part following these steps:<\/p>\n\n\n\n
Business Data Connectivity (often referred as BDC) is a service built into Microsoft SharePoint that enables to declaratively model external systems and to expose external data as a list in SharePoint sites.<\/em><\/p>\n\n\n\n\n
![\"concept](\"https:\/\/sii.pl\/blog\/wp-content\/uploads\/2017\/05\/bdc2.png\")
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Method types<\/h2>\n\n\n\n
<\/a><\/figure>\n\n\n\nCreating sample BDC model<\/h2>\n\n\n\n
<\/a><\/figure>\n\n\n\n<\/a><\/figure>\n\n\n\n<\/a><\/figure>\n\n\n\n<\/a><\/figure>\n\n\n\nTesting BDC model<\/h2>\n\n\n\n
To see the results we need to put Business Data List web part on the page and browse for our BDC model in web part settings.<\/p>\n\n\n\n<\/a><\/figure>\n\n\n\n<\/a><\/figure>\n\n\n\nMaking BDC model filterable<\/h2>\n\n\n\n
First step is to define filter description for Category column (we can use Visual Studio designer to do that).<\/p>\n\n\n\n<\/a><\/figure>\n\n\n\n<\/a><\/figure>\n\n\n\n<\/a><\/figure>\n\n\n\nSetting up filtering on the page<\/h2>\n\n\n\n
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