Blog Elements

Half Sized Blog Element (Single Author Style)

Half Sized Blog Element (Multi Author Style)

Knowledge Base, PowerForms HTML, Web Services

Calling external web services and displaying data

Users can create external web service calls and display the data using a datagrid on the form. NOTE: Other controls can also be connected with a web service call. In that case only the first attribute for the first record will be used and if the value is valid for that control it will be displayed properly. To […]

August 13, 2017/by Konstantinos

Knowledge Base, PowerForms HTML, SQL Queries

SQL Queries in PowerForms

PowerForms HTML supports direct SQL Queries that can be used to provide lookup data for lookup controls (such ComboBoxes). For security reasons, the actual sql query is not defined inside PowerForms designer but another setup model has been adopted : 1. A custom list should be created server-side. 2. The definition should be stored there […]

August 13, 2017/by Konstantinos

Knowledge Base, PowerForms HTML, Web Services

Calling external web services and displaying data

August 13, 2017/by Konstantinos

Knowledge Base, PowerForms HTML, SQL Queries

SQL Queries in PowerForms

August 13, 2017/by Konstantinos

Full Sized Blog Element (Big Preview Pic)

Knowledge Base, PowerForms HTML, Web Services

Calling external web services and displaying data

Users can create external web service calls and display the data using a datagrid on the form.

NOTE: Other controls can also be connected with a web service call. In that case only the first attribute for the first record will be used and if the value is valid for that control it will be displayed properly.

To define a new web service call, all of the followng properties must be defined:

– A custom Name for referencing the web service call.

– The Stored Credentials used to call the web service.

– The external Url of the web service.

– The specific Method to call from the above web service.

– The Xml Namespace used by the Web Service. This is required for a well formed request to the service.

– The Handle Namespace option to allow for simpler xpath queries (see below).

– The Parameters with their respective values. Each parameter is defined as pair of strings (ParameterName];[ParameterValue) and each pair is seperated by a pipeline (|) from the next one. For example, if two parameters exist, FirstName and LastName and their respective values are John Smith then one should input the following: FirstName;John|LastName;Smith. One can also enter the same values or edit them, using the provided pop-up form.

NOTE: As with everything that has to do with XML, the above values are case sensitive.

When all the above fields are filled properly pressing the Test button shows the result that the web service provides, to confirm their validity. If any error occurs while calling the web service the resulting error will be displayed instead.

The second part of a web service call, consists of defing an XPath Query to be used for extracting the needed information. For each element returned a row will be displayed in the DataGrid with all of its attributes (Auto Populate)

If Handle Namespaces is selected simple xpath queries can be used, e.g.: //z:row[@ows__Level=2].
If Handle Namespaces is not selected the xpath cannot contain prefixed elements and one should reside to the use of local-name(), e.g. //*[local-name() = ‘row’][@ows__Level=’1′].

Any element of the form can be referenced inside the XPath Query, by enclosing its name inside brackets. For example: //sales[@customerId={c_customer_id}.
The {c_customer_id} will be replaced with its specific value before Xpath Querying the Web Service Call result.

You can also select specific Attributes to display using their names, seperated by a semicolon (;), e.g. ows_UniqueId;ows_FileLeafRef.

A different name can be used for displaying purposes, other than the name of the Attribute, if a similar list of headers is filled in the Headers textbox. The Headers should match the respective Attributes one-to-one. If fewer Headers are provided the remainng attributes will use the default (the Attribute’s name). If more Headers are provided they will be ignored.

Example :

Once the user has defined a Web Service call, he can then connect it to a WebServiceDataGrid control. In the Advanced tab one has to select a Value Type of Web Service Call, and then pick a specific web service call from the list box Web Service Post Url. The control will display the matching data using the xpath query and the (optionally) defined attributes in a read-only grid.

The same advanced parametrization can be used in all controls but the resulting value might not be valid. For example a checkbox will parse 0 as not checked and 1 as checked but any other value will be ignored and the checkbox will remain not checked.

You can find a video describing how to integrate Web Service calls with your form here.

August 13, 2017/by Konstantinos

Knowledge Base, PowerForms HTML, SQL Queries

SQL Queries in PowerForms

PowerForms HTML supports direct SQL Queries that can be used to provide lookup data for lookup controls (such ComboBoxes).

For security reasons, the actual sql query is not defined inside PowerForms designer but another setup model has been adopted :

1. A custom list should be created server-side.
2. The definition should be stored there (including ConnectionString, SQL Command and parameters) in XML format
3. Inside the PowerForms designer, the user references the sql-query entry of that list and binds parameter values using static data or dynamic control values

1. Create a new custom list in your site collection (for example name : PowerForms SQL Queries)
2. Add a new column called “QueryXML: (multiple lines of text, PlainText)
3. Setup security for your list as you may want to restrict users from viewing query details (query is executed using elevated permissions)

Add a new item inside the list. Set the title of the item.

Inside the QueryXML field, you should use the following xml schema to define the query.

Code

<Query Elevated=”true”>
<ConnectionString>Provider=SQLOLEDB;Data Source=.;Initial Catalog=WSS_Content;Integrated Security=SSPI;</ConnectionString>
<SQL>select ID, Title, Priority, Type, StartDate from Customers where ID=?</SQL>
<Parameters>
<Parameter Name=”ID” Type=”Number” />
</Parameters>
</Query>

The Elevated=”true” parameter forces the execution of the query to be done under the application pool account. This is needed in case you need to access your database using windows authentication. If you are using SQL/native database authentication then this is not needed.

Note that the schema contains 3 main properties :

ConnectionString

This contains the OLEDB connectionstring to the database

SQL

Contains the sql command of your query. If a stored procedure is to be called, you should add the attribute Type=”SP” to the Query element. For example : <Query Type=”SP”>

Parameters

You can define unlimited number of parameters in your query. Values for these parameters are provided by the form during query execution.

Parameter types supported : “Text”, “Number”, “DateTime”.

A new section inside the designer has been added to configure SQL Queries.

There you must reference the Query List URL and Query List Name, set the Query Name (which corresponds to the Title column) and setup parameters (that should be already defined in the query xml)

In our example, we want to set the parameter with the value ({value:c_Customer}) of a form control.

Add a combobox control on your form.

Inside the Looup Details section, you should select that the lookup values come from a SQL query, select the query from the provided list and set the Display and Value fields of the control.

If a single field is required (i.e. Title) use that field for both properties (Display and Value members)/

NOTE : PowerForms provide automatic refresh to the lookup control every time a control value that affects the query parameter, is changed by the users.

We assume we have a table (named Products) containing our product list.

Columns : ID (int), NAME (nvarchar), DESCRIPTION (nvarchar)

We create a stored procedure to retrieve products :

Code

CREATE PROCEDURE P_GetProducts
@ID int = null
AS
BEGIN
SET NOCOUNT ON;
SELECT ID, NAME, DESCRIPTION FROM Products
WHERE (@ID IS NULL OR @ID=ID)
END

As you may notice, we have provided an optional parameter in order to retrieve a single record if necessary.

Now to define the query xml we would have to provide something like the following :

Code

<Query Type=”SP”>
<ConnectionString>Provider=SQLOLEDB;Data Source=.;Initial Catalog=TestDB;Integrated Security=SSPI;</ConnectionString>
<SQL>P_GetProducts</SQL>
<Parameters>
<Parameter Name=”ID” Type=”Number” />
</Parameters>
</Query>

Notice the Type=”SP” attribute of the query xml element. It is important to use this attribute in order to call a stored procedure.

Now we setup the query inside the PowerForms designer and test the results:

Test the optional parameter by setting “ID;1” inside the Parameters propery.

Now we bind the query to a ComboBox control to examine the results :

The combobox in action :

Instead of a ComboBox control, RadioButtons can be used to display SQL Query results :

August 13, 2017/by Konstantinos