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Getting external values using web posts

You can retrieve information from web posts and use them inside your form. For example, as soon as you select a customer from a combobox, you want to display the balance of the selected customer in a label next to the customer. In order to achieve this, you must declare a new unbound control (you […]

August 15, 2017/by Konstantinos

General, Knowledge Base, PowerForms Siverlight

Building Custom Controls

Power Forms is designed with extensibility in mind. There are some cases where you need some special customization for your form. For these cases, developers can build and register their custom controls (using Visual Studio & Silverlight). Since any Silverlight control can be registerer inside Power Forms, the possibilities are endless. For this example, we will use MS Visual […]

August 15, 2017/by Konstantinos

Knowledge Base, PowerForms Siverlight, Web Services and Web Posts

Getting external values using web posts

August 15, 2017/by Konstantinos

General, Knowledge Base, PowerForms Siverlight

Building Custom Controls

August 15, 2017/by Konstantinos

Full Sized Blog Element (Big Preview Pic)

Knowledge Base, PowerForms Siverlight, Web Services and Web Posts

Getting external values using web posts

You can retrieve information from web posts and use them inside your form.

For example, as soon as you select a customer from a combobox, you want to display the balance of the selected customer in a label next to the customer.

In order to achieve this, you must declare a new unbound control (you do now set the Target Field Name property) and place it inside the form.

Next, go to the Post Info tab and select Value Type=”Url” Post.

Finally inside the Web Post Url property type the url you want to use to retrieve the required information.

For example :
http://servername/balance.aspx?id={c_Customer}

Where balance.aspx is a web page hosted inside a web site. The parameter {c_Customer}, will retrieve the selected value from the c_Customer combobox and use it to create the final uri for the web post.

The web post is asynchronus, so it may take some time from the user selection until the result appears on the form.

Note : In order to get the value, you should first allow the target web site to accept calls from the silverlight form.

To do that, you have to add a file called clientaccesspolicy.xml at the root of the site.

This file should look something like this:

<?xml version=”1.0″ encoding=”utf-8″?>

<access-policy>

<cross-domain-access>

<allow-from http-request-headers=”*”>

</allow-from>

<grant-to>

</grant-to>

</policy>

</cross-domain-access>

</access-policy>

IMPORTANT : The above file provides unlimited access to silverlight components trying to access the site. You have to setup the parameters inside the file according to your needs. See full documentantion for clientaccesspolicy.xml file Here.

August 15, 2017/by Konstantinos

General, Knowledge Base, PowerForms Siverlight

Building Custom Controls

Power Forms is designed with extensibility in mind.

There are some cases where you need some special customization for your form. For these cases, developers can build and register their custom controls (using Visual Studio & Silverlight). Since any Silverlight control can be registerer inside Power Forms, the possibilities are endless.

For this example, we will use MS Visual Studio 2010 to implement an alternative control for boolean fields. Instead of the default checkbox control, we will create a control that will display radio buttons for TRUE and FALSE boolean values.

In order to develop your own custom controls, you will have to build a Silverlight Control that implements the IInputControl interface (BPC.PowerForms.Core.IInputControl). Some of the interface methods are only required for lookup controls.

Note: This procedure requires a reference to the BPC.PowerForms.Core.dll library that contains the required interfaces. Please contact us to request for the SDK containing the dll.

The interface definition follows:

public interface IInputControl

{

/// <summary>

/// The event should be raised whenever the

/// value of the control changes

/// </summary>

event EventHandler InputControlValueChanged;

/// <summary>

/// In case of Lookup controls, this event should be raised

/// at the end of the data-loading procedure.

/// The dynamic form will then take control

/// and set the control value

/// </summary>

event EventHandler LookupLoaded;

/// <summary>

/// In case of choice controls containing static values,

/// the datasource (a string array) will be provided

/// </summary>

/// <param name=”datasource”></param>

void SetDataSource(IEnumerable datasource);

/// <summary>

/// This method is called to set the value to the control.

/// The value provided has the format provided by Sharepoint.

/// </summary>

/// <param name=”value”></param>

void SetValue(object value);

/// <summary>

/// This method should be implemented to provide values back to the form

/// </summary>

/// <returns></returns>

string GetValue();

/// <summary>

/// This function should return a human friendly representation of the control value.

/// You should implement this method because there is a system function

/// (FDV = FieldDisplayValue) that may be used during calculation

/// for formulas that retrieves the display value of the control

/// For example, you may have a combo loookup, persisting the ID and displaying

/// the title of countries and another one for cities

/// If want to create a new calculated field containing a friendly representation

/// of the address, you could use the following formula:

/// FV(“c_Address”) & ” ” & FDV(“c_City”) & ” ” & FDV(“c_Country”)

/// </summary>

/// <returns></returns>

string GetDisplayValue();

/// <summary>

/// This method should be implemented to clear the value of the control

/// </summary>

void ClearValue();

/// <summary>

/// This method should only be implemented for lookup controls and

/// should query the undelying datasource to fill its data

/// Filter criteria are provided

/// </summary>

/// <param name=”queryFieldName”></param>

/// <param name=”queryFieldValue”></param>

void LoadLookupData(string queryFieldName, string queryFieldValue);

/// <summary>

/// This method should only be implemented for lookup controls and

/// should query the undelying datasource to fill its data

/// Filter criteria are provided

/// </summary>

/// <param name=”queryFieldName”></param>

/// <param name=”queryFieldValue”></param>

/// <param name=”queryType”></param>

/// <param name=”op”></param>

void LoadLookupData(string queryFieldName, string queryFieldValue, string queryType, SearchOperators op);

/// <summary>

/// Implement to enable or disable the control

/// </summary>

/// <param name=”enable”></param>

void SetEnable(bool enable);

/// <summary>

/// Implement to show or hide the control

/// </summary>

/// <param name=”visible”></param>

void SetVisible(bool visible);

/// <summary>

/// Implement to set or clear the readonly status of the control

/// </summary>

/// <param name=”readOnly”></param>

void SetReadOnly(bool readOnly);

/// <summary>