Events

The following events can be used as extension points to intervene and manipulate data:

Event	Description
`preFileProcessing`	Execute custom logic before processing the spreadsheet file starts
`checkBeforeRead`	Check data before it is uploaded to the UI5
`changeBeforeCreate`	Change data before it is sent to the backend
`requestCompleted`	Event when the request is completed
`uploadButtonPress`	Fired when the `Upload` button is pressed, possible to prevent data from being sent to the backend

You can attach async functions to the events by wrapping the function in a Promise. See Attach async functions to events for more information.

Execute custom logic before processing the spreadsheet file starts¶

When the file is uploaded to the app, the preFileProcessing event is fired. Use this event to execute custom logic before processing the spreadsheet file starts. The file is available in the event and can be manipulated. If you want to prevent the processing of the file, call the preventDefault method of the event. If you want to change the file that will be processed, return the new file.

Example¶

this.spreadsheetUpload.attachPreFileProcessing(function (event) {
// example
let file = event.getParameter("file");
if (file.name.endsWith(".txt")) {
    // prevent processing of file
    event.preventDefault();
    // show custom ui5 error message
    new MessageToast.show("File with .txt extension is not allowed");
    // change the file that will be processed
    // Create a Blob with some text content
    const blob = new Blob(["This is some dummy text content"], { type: "text/plain" });
    // Create a File object from the Blob
    const file2 = new File([blob], "TEXT.txt", { type: "text/plain" });
    return file2;
}
});

Check data before upload to app¶

When the file is uploaded to the app, the checkBeforeRead event is fired.

Example¶

This sample is from the sample app. It checks whether the price is over 100.

this.spreadsheetUpload.attachCheckBeforeRead(function(event) {
    // example
    const sheetdata = event.getParameter("sheetData");
    let errorArray = [];
    for (const [index, row] of sheetData.entries()) {
        // Check for invalid price
        for (const key in row) {
            if (key.endsWith("[price]") && row[key].rawValue > 100) {
                const error = {
                    title: "Price too high (max 100)",
                    row: index + 2,
                    group: true,
                    rawValue: row[key].rawValue,
                    ui5type: "Error"
                };
                errorArray.push(error);
            }
        }
    }
    event.getSource().addArrayToMessages(errorArray);
}, this);

You can add errors to the messages property of the SpreadsheetUpload control. After the event, the upload is canceled and the errors are displayed in the error dialog. Use the addArrayToMessages method to add errors to the messages property. It expects an array of objects with the following properties:

title - the title of the error
row - the row number of the error
group - set to true or false to group the errors by title
rawValue - the raw value of the data from the spreadsheet
ui5type - the type of the error, can be Error, Warning, Success, Information or None from the `MessageType enum

Errors with the same title will be grouped.

Error Dialog

Manipulate data before it is sent to the backend¶

When the Upload button is pressed, the changeBeforeCreate event is fired. Use this event to manipulate the data before it is sent to the backend. The event expects a payload object to be returned.
Make sure only one handler is attached to this event. If multiple handlers are attached, only the first payload will be used.

Example¶

This sample is from the sample app. It overwrites the payload.

this.spreadsheetUpload.attachChangeBeforeCreate(function (event) {
    let payload = event.getParameter("payload");
    // round number from 12,56 to 12,6
    if (payload.price) {
        payload.price = Number(payload.price.toFixed(1));
    }
    return payload;
}, this);

Event when the request is completed¶

When the request is completed, the requestCompleted event is fired. Use the success parameter to check if the request was successful.

Example¶

this.spreadsheetUpload.attachRequestCompleted(function (event) {
    const success = event.getParameter("success");
    if (success) {
        console.log("Request Completed");
    } else {
        console.log("Request Failed");
    }
}, this);

Event when the upload button is pressed¶

When the Upload button is pressed, the uploadButtonPress event is fired. The event is fired before the changeBeforeCreate event. Prevent the data from being sent to the backend by calling the preventDefault method of the event.

Example 1¶

this.spreadsheetUpload.attachUploadButtonPress(function (event) {
    // Prevent data from being sent to the backend
    event.preventDefault();
    // Get payload
    const payload = event.getParameter("payload");
}, this);

Example 2¶

You can also use this event to sent the data to the backend and add possible errors to the component. Use the addArrayToMessages method to add errors. It will display the errors in the error dialog after the execution of the event.

this.spreadsheetUpload.attachUploadButtonPress(async function (event) {
    event.preventDefault();

    event.getSource().addArrayToMessages([{
        title: "Error on creating",
        group: false,
        ui5type: "Error"
    }]);

    // simulate async call
    await new Promise((resolve) => {
        // Wait for 2 seconds
        setTimeout(() => {
            resolve();
        }, 2000);
    });

    // Code here will execute after the 2-second wait
}, this);

Attach async functions to events¶

You can attach async functions to the events by wrapping the function in a Promise. This allows you to send a request to the backend for checks that are not possible in the frontend, for example with a function import.

// Init spreadsheet upload
this.spreadsheetUpload = await this.editFlow.getView()
        .getController()
        .getAppComponent()
        .createComponent({
            usage: "spreadsheetImporter",
            async: true,
            componentData: {
                context: this,
                activateDraft: true
            }
        });

// Event to check before uploading to app
this.spreadsheetUpload.attachCheckBeforeRead(async function (event) {
    return new Promise(async (resolve, reject) => {
        // Example
        console.log("Start async wait");
        await new Promise((resolve) => setTimeout(resolve, 5000));
        console.log("End async wait");
        // Don't forget to resolve the promise
        resolve();
    });
}, this);