Question

Technologies:

javascript

typescript

Tolerim

20 hours ago

How can I combine an Angular modal dialog with an HTTP request?

As a web developer, you may wonder whether it's best to send an HTTP request to a web API inside a modal dialog box or to close the dialog and return the name before sending the request. In this scenario, my web API has endpoints for both creating new directories and renaming existing ones. Within a modal dialog box in Angular, I can input the desired directory name. If any validation errors occur or the HTTP request is unsuccessful, the dialog box can be reopened to display the error message. Here's an example:

I hope this solution works for you! Feel free to let me know if you have any further questions.

Answers(1)

Accepted Answer

It is generally better to send the HTTP request to the web API after closing the modal dialog and validating the input, instead of sending the request inside the modal dialog. This approach allows for better separation of concerns and follows the principles of the Single Responsibility and Open/Closed SOLID principles. Here is an example of how you can implement this approach: 1. Define a function in your Angular component that handles the creation or renaming of the directory. This function should take the directory name as a parameter and return an observable that emits the results of the HTTP request.

createDirectory(directoryName: string): Observable<any> {
    return this.http.post('/api/directory', { name: directoryName });
}

renameDirectory(oldName: string, newName: string): Observable<any> {
    return this.http.put(`/api/directory/${oldName}`, { name: newName });
}

2. In your component, define a function that opens the modal dialog and returns a promise that resolves with the directory name when the user confirms their input.

openModal(): Promise<string> {
    return new Promise((resolve, reject) => {
        const dialogRef = this.dialog.open(DirectoryModalComponent);

        dialogRef.afterClosed().subscribe(result => {
            if (result) {
                resolve(result);
            } else {
                reject();
            }
        });
    });
}

3. When the user wants to create or rename the directory, first call the openModal() function to get the directory name from the user. Then, validate the input and call the appropriate function to create or rename the directory, handling any errors that may occur.

async createDirectoryHandler() {
    try {
        const directoryName = await this.openModal();

        if (directoryName) {
            // Validate directory name
            if (!/^[a-zA-Z0-9_-]+$/.test(directoryName)) {
                throw new Error('Invalid directory name');
            }

            // Send HTTP request to create the directory
            await this.createDirectory(directoryName).toPromise();

            // Display success message
            this.snackbar.open('Directory created', 'Close', { duration: 3000 });
        }
    } catch (error) {
        // Display error message
        this.snackbar.open(error.message, 'Close', { duration: 3000 });
    }
}

async renameDirectoryHandler() {
    try {
        const oldName = this.currentDirectory;
        const newName = await this.openModal();

        if (newName) {
            // Validate new directory name
            if (!/^[a-zA-Z0-9_-]+$/.test(newName)) {
                throw new Error('Invalid directory name');
            }

            // Send HTTP request to rename the directory
            await this.renameDirectory(oldName, newName).toPromise();

            // Display success message
            this.snackbar.open('Directory renamed', 'Close', { duration: 3000 });
        }
    } catch (error) {
        // Display error message
        this.snackbar.open(error.message, 'Close', { duration: 3000 });
    }
}

With this approach, the modal dialog is responsible only for getting the directory name from the user, and the actual creation or renaming of the directory is handled separately in the component's functions. This makes the code easier to read, test, and maintain, and allows for better error handling and feedback to the user.