Client

This contains methods and classes providing functionality for interacting with app's client-side and divided into two categories:

Client alerts

Classes and methods intended to help in communicating with client side by sending alerts and messages ti be displayed in UI

ClientAlert

ClientAlert class itself represents an alert of specified type with message. This is a main class of alerts infrastructure.

It has two properties:

Property name
Property type
Description

Type

string

Type of alert. E.g. Success, Warning or Error.

Message

string

Message sending with alert.

ClientAlertProvider

ClientAlertProvider allows to perform alert-related operations, provides methods for assisting in transferring alerts from server side to client.

Method name
Return type
Description

AddClientAlert

void

Adds alert to be transferred to client.

GetAllClientAlerts

IEnumerable<ClientAlert>

Gets all alerts transferred to client.

Action result

ClientAlertResult - represents an alert to be send along with action result.

Extension method for IActionResult:

Method name
Return type
Description

AddClientAlert

void

Appends specified alert to IActionResult

Sample usage

Create IActionResult extensions:

public static class ActionResultExtensions
{
    public static IActionResult Info(this IActionResult result, string message)
        => result.AddClientAlert(new JavaScriptAlert("info", message));

    public static IActionResult Success(this IActionResult result, string message)
        => result.AddClientAlert(new JavaScriptAlert("success", message));

    public static IActionResult Warning(this IActionResult result, string message)
        => result.AddClientAlert(new JavaScriptAlert("warning", message));

    public static IActionResult Error(this IActionResult result, string message)
        => result.AddClientAlert(new JavaScriptAlert("error", message));
}

Generate ClientAlert in server side:

public class UsersController : Controller
{
    [HttpPost]
    public async Task<IActionResult> Edit(int id)
    {
        if (ModelState.IsValid)
        {
            /* Some logic here */
            return RedirectToAction(nameof(Index))
                .Success("Successfully edited.");
        }

        return View(editVm);
    }
}

Handle alerts in TagHelper:

[HtmlTargetElement("client-alerts", TagStructure = TagStructure.NormalOrSelfClosing)]
public class ClientAlertsTagHelper : TagHelper
{
    private readonly IClientAlertProvider _alertProvider;

    public ClientAlertsTagHelper(IClientAlertProvider alertProvider)
        => _alertProvider = alertProvider;

    public override void Process(TagHelperContext context, TagHelperOutput output)
    {
        IEnumerable<ClientAlert> alerts = _alertProvider.GetAllClientAlerts();

        if (alerts.Any() == false)
        {
            output.SuppressOutput();
        }
        else
        {
            output.TagName = "script";
            output.Attributes.SetAttribute("type", "text/javascript");
            output.TagMode = TagMode.StartTagAndEndTag;

            output.Content.AppendHtml(";(function(){");
            foreach (var alert in alerts)
            {
                var type = alert.Type.ToString().ToLower();
                var message = alert.Message.Replace("'", "\'");
                output.Content.AppendHtml($"app.alert('{type}', '{message}');");
            }
            output.Content.AppendHtml("})();");
        }
    }
}

Use ClientAlertsTagHelper in _Layout.cshtml to send ClientAlert to client side:

<!DOCTYPE html>
<html>
<head>
    <!-- Some HTML here -->
    <client-alerts/>
</body>
</html>

Client options

This is a group of methods and classes assisting in passing data represented by dictionary via HttpContext.Items.

ClientOptionProvider

It provides methods assisting in passing data represented by dictionary via HttpContext.Items:

Method name
Return type
Description

AddClientOptions

void

Places set of options with specified key into current HttpContext.

GetClientOptions

IReadOnlyDictionary<string, object>

Gets all options with specified key stored in current HttpContext.

GetAllClientOptions

IReadOnlyDictionary<string, IReadOnlyDictionary<string, object>>

Gets all options stored in current HttpContext.

BuildClientOptionsKey

string

Builds a key for options using routeData and taking into account current area, controller and action methods. In such way all options will be related to their corresponding pages (urls).

Controller extensions

This controller extensions are helping in manipulating with options:

Method name
Return type
Description

AddClientOptions

void

Adds client options to context associated with controller. There are different versions taking options as object with some public properties or options dictionary.

Sample usage

Generate ClientOption in server side:

public class UsersController
{
    public async Task<IActionResult> Index()
    {
        /* Some logic here */

        this.AddClientOptions(new
        {
            urlEdit = Url.Action(nameof(Edit))
        });

        return View();
    }
}

Handle alerts in TagHelper:

[HtmlTargetElement("client-options", TagStructure = TagStructure.NormalOrSelfClosing)]
public class ClientOptionsTagHelper : TagHelper
{
    private readonly IClientOptionProvider _optionProvider;

    public ClientOptionsTagHelper(IClientOptionProvider optionProvider)
        => _optionProvider = optionProvider;

    public override void Process(TagHelperContext context, TagHelperOutput output)
    {
        var options = _optionProvider.GetAllClientOptions();

        if (options.Any() == false)
        {
            output.SuppressOutput();
        }
        else
        {
            output.TagName = "script";
            output.Attributes.SetAttribute("type", "text/javascript");
            output.TagMode = TagMode.StartTagAndEndTag;

            var serializer = new JsonSerializer()
            {
                ContractResolver = new CamelCasePropertyNamesContractResolver()
            };

            output.Content.AppendHtml(";(function(){");
            foreach (var option in options)
            {
                var key = option.Key;
                var keyOptions = JObject.FromObject(option.Value, serializer).ToString(Formatting.None);
                output.Content.AppendHtml($"app.options('{key}', {keyOptions});");
            }
            output.Content.AppendHtml("})();");
        }
    }
}

Use ClientOptionsTagHelper in _Layout.cshtml to send ClientOption to client side:

<!DOCTYPE html>
<html>
<head>
    <!-- Some HTML here -->
    <client-options/>
</body>
</html>
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