Tersus: Forex

ForexDate: Jun 2, 2019Tags:XMLThis is a mobile version of the Load view of Web Services - Forex (from the Examples project)It allows you to convert amounts to/from NIS (Israeli New Shekel). Forex Screenshot 2019-06-02

This app was developed during a live demo during the Mobility2011 conference, and here are the instructions for modeling it in a few minutes:

New->Tersus Project ("Forex", Native Mobile Application).

Zoom into "<Mobile View>" and rename "Page 1" to "Exchange Rates". Zoom into the page's "Header" and delete "Button". Save the changes.

Start your browser and go to the web site of Bank of Israel - http://www.boi.org.il/en .

At the right side of the page, right click the Exchange Rates XML link, and save the file (currency.xml) on your desktop.

In the Repository Explorer: Select the package "Forex/Exchange Rates", and then File->Import...->Import XML Data Structure by Example (select the saved currency.xml file).

In the "Content" element of the page:

Add a grid "List";
Add a row "Currency Row" (make it repetitive);
Add display elements "Unit" (Number), "Symbol" (Text), "Country" (Text) and "Rate" (Number).

Zoom out to "<Mobile View>" and add an action "Init Rates":

Add a service "Get Rates":
1. Add "Read Resource";
2. Add a text constant "Rates URL" (with value "https://www.boi.org.il/currency.xml");
3. Add "Parse XML";
4. Drag "CURRENCIES";
5. Connect all the above by flows
6. Add a repetitive exit (gets the value of the repetitive "CURRENCY" element of "CURRENCIES").
Add an ancestor reference to "<Mobile View>".
Add a repetitive action "Create Currency Item":
1. The input comes from "Get Rates", the output goes to <Mobile View>/Exchange Rates/Content/List/Currency Row
2. Add the input and output data structures;
3. Add transformation flows

Save the changes and launch the app. We see the data, but the display can be improved through some CSS changes:

Add to the grid html.style=font-weight:bold and html.width=100%
Add to "Rate" html.style=color:blue
Launch the app again

Add a second page "Convert" (zoom into "Header" and delete the button).

Model "Convert/Content":

Add a selection field "Currency";
Add a number field "Amount";
Add a second number field "Amount in NIS".

Zoom back to "<Mobile View>" and then to "Init Rates", and add a flow from the exit of "Get Rates" to "<Mobile View>/Convert/Content/Currency/<Options>" (relaunch the app to show how the page and the currency selection field look like)

Zoom into "Create Currency Item" and move the "CURRENCYCODE" element to be the first in the "CURRENCY" data structure (so it is displayed in the "Currency" selection field).

Return to "Convert" and complete its modeling:

Zoom into "Content/Amount";
Add element "<On Change>";
Add an ancestor reference to "Content";
Add the "CURRENCY" data structure and create a flow to it from "Content/Currency/<Value>";
Add "Multiply" ("Content/Amount/<Value>" and "CURRENCY/RATE") and "Divide" ("Multiply/<Product>" by "CURRENCY/UNIT");
The output goes to "Content/Amount in NIS/<Value>".

Reuse "<On Change>" in "Currency".

Add a similar calculation in "<On Change>" of "Amount in NIS".

Set the html.decimalPlaces of "Amount" and "Amount in NIS" to 2.