5 files changed, 116 insertions, 5 deletions
diff --git a/Pages/Component/AboutDialog.razor b/Pages/Component/AboutDialog.razor
index 9823761..9ffbad4 100644
--- a/Pages/Component/AboutDialog.razor
+++ b/Pages/Component/AboutDialog.razor
@@ -1,6 +1,7 @@
 @using System.Reflection
 @using Microsoft.AspNetCore.Hosting
 @inject IHostingEnvironment hostingEnvironment
+@implements IDialog
 
 <Dialog @ref=dialog>
     <p id="title">@Title</p>
diff --git a/Pages/Component/Dialog.razor b/Pages/Component/Dialog.razor
index ded2d2d..f479368 100644
--- a/Pages/Component/Dialog.razor
+++ b/Pages/Component/Dialog.razor
@@ -1,4 +1,6 @@
-<div style="@(heightStyle + visiblilityStyle)">
+@implements IDialog
+
+<div style="@(heightStyle + visiblilityStyle)">
     @if(Title is not null) {
         <p>@Title</p>
         <hr/>
diff --git a/Pages/Component/TagEditDialog.razor b/Pages/Component/TagEditDialog.razor
new file mode 100644
index 0000000..2e443d4
--- /dev/null
+++ b/Pages/Component/TagEditDialog.razor
@@ -0,0 +1,96 @@
+@inject IDbContextFactory<HBContext> dbFactory;
+@inject ITagService tagService
+@implements IDialog
+
+<Dialog Title=@Title @ref=dialog>
+    <label>
+        Name
+        @if(nameExists) {
+            <p class="error">Tag with that name already exists!</p>
+        }
+    </label>
+    <input type="text" @bind=tagName required/>
+    <label>Namespace</label>
+    <input type="text" @bind=tagNamespace/>
+    <label>
+        Alias
+        @if(aliasExists) {
+            <p class="error">Tag with that alias already exists!</p>
+        }
+    </label>
+    <input type="text" @bind=tagAlias/>
+    <ButtonContainer>
+        <button @onclick=Hide class="secondary">Cancel</button>
+        <button @onclick=Submit>@(TagDefinition is null ? "Create" : "Apply")</button>
+    </ButtonContainer>
+</Dialog>
+
+@code {
+    [Parameter]
+    public TagDefinition? TagDefinition { get; set; }
+
+    [Parameter]
+    public EventHandler OnTagUpdate { get; set; }
+
+    public bool Visible {
+        get => visible;
+        set {
+            if(value)
+                Load();
+            visible = dialog.Visible = value;
+        }
+    }
+
+    private string Title =>
+        TagDefinition is null ? "Create a new tag definition" : "Edit tag definition";
+
+    private Dialog dialog;
+
+    private string? tagName;
+    private string? tagNamespace;
+    private string? tagAlias;
+
+    private bool nameExists  = false;
+    private bool aliasExists = false;
+
+    private bool visible = false;
+
+    public void Show() => Visible = true;
+    public void Hide() => Visible = false;
+
+    public void Show(TagDefinition? toEdit) {
+        TagDefinition = toEdit;
+        Visible       = true;
+    }
+
+    public void Show(string? @namespace) {
+        TagDefinition = null;
+        Visible       = true;
+        tagNamespace  = @namespace;
+    }
+
+    private void Load() {
+        tagName      = TagDefinition?.Name;
+        tagNamespace = TagDefinition?.Namespace;
+        tagAlias     = TagDefinition?.Alias;
+        nameExists   = false;
+        aliasExists  = false;
+    }
+
+    private void Submit() {
+        try {
+            if(TagDefinition is null) {
+                tagService.CreateTagDefinition(tagName, tagNamespace, tagAlias);
+            } else {
+                tagService.UpdateTagDefinition(TagDefinition, tagName, tagNamespace, tagAlias);
+            }
+        } catch(TagDuplicateException e) {
+            nameExists  = e.NameExists;
+            aliasExists = e.AliasExists;
+            return;
+        }
+
+        OnTagUpdate.Invoke(this, new EventArgs());
+        Hide();
+    }
+}
diff --git a/Pages/Component/TagEditDialog.razor.css b/Pages/Component/TagEditDialog.razor.css
new file mode 100644
index 0000000..02781c0
--- /dev/null
+++ b/Pages/Component/TagEditDialog.razor.css
@@ -0,0 +1,11 @@
+p.error {
+    color:          var(--col-error-pri);
+    display:        inline;
+    font-size:      8pt;
+    margin-left:    5px;
+    vertical-align: middle;
+}
+
+input {
+    width: 100%;
+}
diff --git a/Pages/Component/TagSelectDialog.razor b/Pages/Component/TagSelectDialog.razor
index 916a070..88e1471 100644
--- a/Pages/Component/TagSelectDialog.razor
+++ b/Pages/Component/TagSelectDialog.razor
@@ -2,6 +2,7 @@
 @inject ITagService tagService
 @inject IUserService userService
 @implements IDisposable
+@implements IDialog
 
 <link rel="stylesheet" href="@(nameof(HyperBooru)).styles.css"/>
 
@@ -36,11 +37,11 @@
 </Dialog>
 
 @code {
-        [Parameter]
-        public string? Title { get; set; }
+    [Parameter]
+    public string? Title { get; set; }
 
-        [Parameter]
-        public EventCallback<TagDefinition[]> OnSubmit { get; set; }
+    [Parameter]
+    public EventCallback<TagDefinition[]> OnSubmit { get; set; }
 
     public TagDefinition[] SelectedTags { get; set; } =
     Array.Empty<TagDefinition>();