Chapter 5

Working with extensions

Overview

In this chapter we will install a few extensions to enhance our application. The Servoy platform is highly extensible and it's easy add capabilities to your project.

Key Concepts Covered

Servoy Extensions
Servoy Package Manager (SPM)
Modules
Form Variables
Search Module Extension
Scopes
Chart Component Extension

Add Search Capability

In this section, we will install a special extension to enable text-based searching of our database. Then we will bind it to a TextBox component and process user input to find records in our example database.

Install a Search Module

Let's install the SvySearch module using the Servoy Package Manger (SPM).

At the top of your pallet, click "Get more components". This opens the SPM.
Click "Modules" and scroll down to locate "SvySearch" Click the + button to install it.

The Servoy Package Manager

Also known as the SPM, it makes it easy to manage the extensions in your project.

The SvySearch module will be installed in your workspace and will be referenced as one of your solution's modules. You will find it located under the Modules mode in the Solution Explorer.

Modules

Servoy is modular by design. Any Solution can be reused as a "Module" and it's easy to include modules in your application via the SPM. However, you can also create your own modules to simplify larger applications, reuse code and standardize development.

Create a Form Variable

Because we will search based on user input, we will use a Form Variable to capture and reference the input.

From the Solution Explorer, expand your orders form and locate the variables node.
Right-click and select "Create Variable" to open the Form Variable Editor.
Give your variable a name searchText, the Type as TEXT and the default null value.
This also opens the orders.js, showing your variable declaration in source.

/**
 * @type {String}
 *
 * @properties={typeid:35,uuid:"02248C57-9D99-427A-99FB-748B405F2022"}
 */
var searchText = null;

Form Variables work like any other Data Provider, such as database columns, except that they are not stored to a database. They hold session state, such as user input. You can also manually type the variable declaration into your form.js file.

Add a Search Field

Let's add a field to the form and bind it to our form variable to capture the user input.

From the pallet, drag the TextBox component to the form, placing it above your orders grid. (You can use the cssPosition property 10,75%,-1,10,140,30)
Double-click the dataProvider property to open the Data Provider Chooser. Select the searchText form variable that you just created.
Edit the placeholderText property to be "Enter Search Criteria" This text will be displayed when the field is empty.

Handle Input Event

To run the search, we'll need to bind an event handler to call the search module that we added. This time, we'll use the onAction event, which we've seen for buttons. However, for an input field, this will be triggered when the user hits the ENTER key.

Double-click the onAction event of the TextBox component that you just added. This opens the Method Selection Wizard.
Choose "Create method in Form". Name your method onSearch and select "Create Private". Click "OK and Show" to finish. The new method stub is opened in the orders.js file.
Let's add a few lines to the method. Don't be shy, you will get help from code completion based on the installed module.

function onSearch(event) {
	var search = scopes.svySearch.createSimpleSearch(foundset);
	search.setSearchAllColumns();
	search.setSearchText(searchText);
	search.loadRecords(foundset);
}

Line 2 we access the SvySearch module and create a new search object based on this form's DataSource or FoundSet.
Line3 we indicate that the search will look across all TEXT columns in the data source.
Line 4 we indicate that the search object should use the user input, captured in our form variable searchText.
Line 5 we bring it home by applying the search object to this form's FoundSet. This will run the search and load records in our form.

Scopes

You'll notice a new keyword scopes in this example. So far, we've only looked at form-level script files. Scopes are another kind of script file used to reference top-level packages of code in your solution and other modules. Enter "scopes." to get code completion on all available scopes.

Save your editors and preview the change in the NG Client. Enter some text in your search input field and hit ENTER.

Here you can see that the search module is able to match on all orders where the shipcountry column = Germany. Try it out! What happens when you enter a string fragment, such as "germ" or part of a city name instead?

This is nice, but let's try something a little more...."advanced". Suppose we wanted to search on a customer name or a product in and order? Fortunately the SvySearch module is quite powerful and this can be done by adding just a little code.

function onSearch(event) {
	var search = scopes.svySearch.createSimpleSearch(foundset);
	search.setSearchAllColumns();
	search.setSearchText(searchText);
	search.addSearchProvider('orders_to_customers.companyname');
	search.addSearchProvider('orders_to_order_details.order_details_to_products.productname');
	search.loadRecords(foundset);
}

Let's examine the two lines of code added to enable a related search.

Line 5 we add the related data provider for the company name
Line 6 we add the order detail records and the related product name.

Save your editor and preview the results in the NG Client.

Enter "big" and you will match on the orders of the customer "The Big Cheese". Enter "coffee Germany" and you will match on all orders shipped to Germany having coffee as one of the products.

Robust Searching Well done. You added a robust user text search to your application in just a few lines of code. The Servoy platform handles all the parsing of terms, caching and querying. This approach works equally well on very large databases.

Add a Chart Component

Let's finish the chapter by adding a simple chart to our orders form to help visualize the breakdown of the products. It takes just a few clicks and demonstrates how to add extend your pallet of components.

Install the ChartJS Component

In the previous example, we added a module, which included some code libraries we took advantage of. In this example, we'll add a new component package.

Open the Servoy Package Manager (SPM) as you did in the previous example. In the list of components, scroll to find the ChartJS package and click the + button to install.
After the package installs, the component is available drag a chart component from the pallet onto your form.
You may position the component right of your input fields, by setting the cssProperty to 86,-1,-1,calc(25% + 390px),200,170
Next, we'll set the data binding for the component. Double-click the foundset property to open the Foundset Chooser. Select your orders_to_order_details relation and click OK.
Expand the dataproviders sub-property and double-click the label property to open the Data Provider Chooser. Select order_details_to_products.productname. This will be the display value for the chart.
Do the same for the value sub-property and choose the subtotal calculation that you made in a previous chapter.
Just for fun, let's switch the chart type. Edit the type property and select DOUGHNUT.

Save your editors and preview the changes in the NG Client.

You can see that the chart labels match the product name and the values match the subtotal. When the selected order record changes, the chart is redrawn. Moreover, when the input values to the subtotal calculation change (i.e. unit price), the chart is redrawn.

Data-Bound Components Nice work! In only a few clicks (and zero lines of code) you have a working chart. Most UI Components in Servoy are data-bound by default, meaning they always reflect the real-time values in the connected data source....automatically.

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Last updated 8 months ago