#Frontend

The following class contains 1 class method "test" that creates a Zen Application and Page:

This code snippet provides a ZEN page that downloads a stream from its database directly:

/// We assume that you have stored your data within this schema:
/// MyApp.Model.Storage: Filename,FileSize,Content,ContentType
Class zen.downloadStream Extends (%ZEN.Component.page,%CSP.StreamServer)
{
 
    /// Wrapper to get the id of the download, we assume that the id is passed to this zen page
    /// as a URI parameter, i.e.: MyApp.Downloads.cls?OID=1234
    ClassMethod GetId()
    {
        Quit $Get(%request.Data("OID",1))
    }
     
    /// Set the appropriate header for the file.
    ClassMethod OnPreHTTP() As %Boolean
    {
        Set tId = ..GetId()
     
        If ##Class(MyApp.Model.Storage).%ExistsId(tId) {
            Set tStream = ##Class(MyApp.Model.Storage).%OpenId(tId)
            // You could "guess" the content type by its file extension
            // or you can store it (before) in the database separately (like in this example).
            // Set Extension = $Piece(tStream.Filename,".",$Length(tStream.Filename,"."))
            // Set ContentType = ..FileClassify(Extension)
     
            Set %response.ContentType = tStream.ContentType
            Do %response.SetHeader("content-disposition","attachment; filename="_tStream.Filename)
            Do %response.SetHeader("Content-Length",tStream.FileSize)
        }
        Else {
            Set %response.Status="404 File Not Found"
            Quit 0
        }
        Quit $$$OK
    }
     
    ClassMethod OnPage() As %Status
    {
        Set Download = ##Class(MyApp.Model.Storage).%OpenId(..GetId())
        Do Download.Content.OutputToDevice()
        Quit $$$OK
    }
 
}

Link to code on GitHub

In this article I would like to present the RESTForms project - generic REST API backend for modern web applications.

The idea behind the project is simple -after I wrote several REST APIs I realized that generally, REST API consists of two parts:

• Work with persistent classes
• Custom business logic

And, while you'll have to write your own custom business logic, RESTForms provides all things related to working with persistent classes right out of the box.
Use cases

• You already have a data model in Caché and you want to expose some (or all) of the information in a form of REST API
• You are developing a new Caché application and you want to provide a REST API

This series of articles aims to address the following topics:

• Creation of a web application based on REST pages;
• Overview of some tools for tracing (debugging) HTTP requests;
• Switching from hyperevents to... hyperevents;
• Integration with jQuery File Upload;
• Conversion of JSON from the {id:1,parentId:1} format to the {id:1,children:[{}]} format for tree visualization;
• Integration with jQuery EasyUI (using datagrid and tree as examples);
• Other topics.

Let’s continue our series of articles about creating a web application using REST only.

Integration with jQuery EasyUI (using datagrid and tree components as examples)

Hi, Community!

In the second part about DeepSee Web, I’ll describe what customization options you have with DSW.

There are two types of customizations: widget customization and dashboard panel customization.

Example of dashboard customization on Developer Community analytics.

Sometimes you can face the situation when you did update the web app on Caché server but you cannot get the newest version of the app in a browser.

Here are couple recipes which help me to solve it. From simplest to more sophisticated and not obvious.

1. Refresh page in a browser

In Chrome it is Ctrl+R or 'Refresh' button. Obvious, but helpful.

2. Hard reset in a browser

If you are in Chrome, open Developer tools

a.k.a.. "The World of Widgets Returns!" or "Paternity leave damages Instructional Series momentum"

In our last lesson, we combined 2 separate classes to appear as the same property. We now have the ability to Update our Widget catalog, but what if we want to Create a Widget? Thankfully, we've already done 90% of what we need, just by implementing Edits

If you read my previous post that introduced QEWD Micro-Services, you're hopefully eager to learn how to use them. So in this post I'll explain what you need to know in order to get started.

If you look in the QEWD repository, you'll find the folder:

https://github.com/robtweed/qewd/blob/master/example/jwt

In our last lesson, we implemented a linkage to our WidgetAccessory class, and debugged some errors we encountered along the way. We now have our data being returned by REST, but what if we want to update or add new data to our application?

About the Ontodia library

In our last lesson, we added a form to Edit our existing Widgets, and save them back to the server. However, our Form was not well structured and our Save button had no intelligence, and was not fully visible. So today, we will apply some Material components and Angular style to make the form more useful

At the end of our last lesson, we ended with our page displaying a nice (but garish) Angular Material Toolbar, and our Widget data displaying in a list of Material cards. Our page feels a bit static, and we already know that the large number of Widgets that we will be dealing with will not be especially usable on a static list. What can we do to help?