Methods

class XComponent extends HTMLElement {
  constructor() {
    super();
  }
  
  doSomething(){
    console.log('doSomething');
  }
}

let component = document.querySelector('x-component');
component.doSomething();

Attributes & Properties

div.id = 'id-value';
div.hidden = true;

<div id="id-value" hidden>

class XComponent extends HTMLElement {
    constructor() {
        super();
    }

    connectedCallback() {
        this._render();
    }

    get disabled() {
        return this.hasAttribute('disabled');
    }

    set disabled(val) {
        // Reflect the value of `disabled` as an attribute.
        if (val) {
            this.setAttribute('disabled', '');
        } else {
            this.removeAttribute('disabled');
        }

        this._render();
    }

    _render() {
        //... 
    }
}

attributeChangedCallback(name, oldValue, newValue) {
  switch (name) {
    case 'checked':
      // Note the attributeChangedCallback is only handling the *side effects*
      // of setting the attribute.
      this.setAttribute('aria-disabled', !!newValue);
      break;
    ...
  }

attributeChangedCallback(name, oldValue, newValue) {
    // When the component is disabled, update keyboard/screen reader behavior.
    if (this.disabled) {
      this.setAttribute('tabindex', '-1');
      this.setAttribute('aria-disabled', 'true');
    } else {
      this.setAttribute('tabindex', '0');
      this.setAttribute('aria-disabled', 'false');
    }
    // TODO: also react to the other attribute changing.
  }

constructor() {
    super();

    this._data = [];
}

get data() {
    return _data;
}

set data(value) {
    if (this_data === value) return;
    this._data = value;
    this._render();
}

Lazy Properties

<x-component [disabled]="model.disabled"></x-component>

let el = document.querySelector('x-component');
el.disabled = true;

customElements.define("x-component", class extends HTMLElement {
    constructor() {
        super();
    }

    get disabled() {
        return this.hasAttribute('disabled');
    }

    set disabled(val) {
        // Reflect the value of `disabled` as an attribute.
        if (val) {
            this.setAttribute('disabled', '');
        } else {
            this.removeAttribute('disabled');
        }

        this._render();
    }
});

let el = document.querySelector('x-component');
el.disabled = true;

customElements.define("x-component", class extends HTMLElement {
    constructor() {
        super();
    }

    connectedCallback() {
        this._upgradeProp('disabled');
    }

    get disabled() {
        return this.hasAttribute('disabled');
    }

    set disabled(val) {
        // Reflect the value of `disabled` as an attribute.
        if (val) {
            this.setAttribute('disabled', '');
        } else {
            this.removeAttribute('disabled');
        }

        this._render();
    }

    _upgradeProp(prop) {
        if (this.hasOwnProperty(prop)) {
            let value = this[prop];
            delete this[prop]; //delete instance property
            this[prop] = value; // set prototype property
        }
    }
});

connectedCallback() {
  if (!this.hasAttribute('role'))
    this.setAttribute('role', 'checkbox');
  if (!this.hasAttribute('tabindex'))
    this.setAttribute('tabindex', -1); //element is not reachable via sequential keyboard navigation, but could be focused
}

/// <summary>
    /// Represents the lable 
    /// </summary>
    public class Tag
    {
        #region Ctor
        /// <summary>
        /// Create one instance of <see cref="Tag"/>
        /// </summary>
        public Tag()
        {
            Id = SequentialGuidGenerator.NewSequentialGuid();
        }
        #endregion

        #region Properties
        /// <summary>
        /// sets or gets Tag's identifier
        /// </summary>
        public virtual Guid  Id { get; set; }
        /// <summary>
        /// sets or gets Tag's name
        /// </summary>
        public virtual string Name { get; set; }
        #endregion

        #region NavigationProperties
        /// <summary>
        /// sets or gets Tag's posts
        /// </summary>
        public virtual ICollection<BlogPost> BlogPosts { get; set; }
        #endregion
    }

  /// <summary>
    /// Represents the Post's Draft
    /// </summary>
    public  class BlogDraft
    {
        #region Ctor
        /// <summary>
        /// create one instance of <see cref="BlogDraft"/>
        /// </summary>
        public  BlogDraft()
        {
            Id = SequentialGuidGenerator.NewSequentialGuid();
        }
        #endregion

        #region Properties
        /// <summary>
        /// gets or sets Id of post's draft
        /// </summary>
        public virtual  Guid Id { get; set; }
        /// <summary>
        /// gets or sets body of post's draft
        /// </summary>
        public virtual  string Body { get; set; }
        /// <summary>
        /// gets or set title of post's draft
        /// </summary>
        public virtual  string Title { get; set; }
        /// <summary>
        /// gets or sets tags of post's draft that seperated using ','
        /// </summary>
        public virtual  string TagNames { get; set; }
        /// <summary>
        /// gets or sets value indicating whether this draft is ready to publish
        /// </summary>
        public virtual  bool IsReadyForPublish { get; set; }
        /// <summary>
        /// ges ro sets DateTime that this draft added
        /// </summary>
        public virtual  DateTime CreatedOn { get; set; }
        /// <summary>
        /// gets or sets information of User-Agent
        /// </summary>
        public virtual string Agent { get; set; }
        /// <summary>
        /// gets or sets date that this draft publish as ready
        /// </summary>
        public virtual DateTime? ReadyForPublishOn { get; set; }
        #endregion

        #region NavigationProperties
        /// <summary>
        /// gets or sets Id of user that he is owner of this draft
        /// </summary>
        public virtual  long OwnerId { get; set; }
        /// <summary>
        /// gets or sets user that he is owner of this draft
        /// </summary>
        public virtual  User Owner { get; set; }
        #endregion
    }

/// <summary>
    /// Represents a base class for every content in system
    /// </summary>
    public abstract class BaseContent
    {
        #region Properties

        /// <summary>
        /// get or set identifier of record
        /// </summary>
        public virtual long Id { get; set; }
        /// <summary>
        /// gets or sets date of publishing content
        /// </summary>
        public virtual DateTime PublishedOn { get; set; }
        /// <summary>
        /// gets or sets Last Update's Date
        /// </summary>
        public virtual DateTime ModifiedOn { get; set; }
        /// <summary>
        /// gets or sets the blog pot body
        /// </summary>
        public virtual string Body { get; set; }
        /// <summary>
        /// gets or sets the content title
        /// </summary>
        public virtual string Title { get; set; }
        /// <summary>
        /// gets or sets value  indicating Custom Slug
        /// </summary>
        public virtual string SlugUrl { get; set; }
        /// <summary>
        /// gets or sets meta title for seo
        /// </summary>
        public virtual string MetaTitle { get; set; }
        /// <summary>
        /// gets or sets meta keywords for seo
        /// </summary>
        public virtual string MetaKeywords { get; set; }
        /// <summary>
        /// gets or sets meta description of the content
        /// </summary>
        public virtual string MetaDescription { get; set; }
        /// <summary>
        /// gets or sets 
        /// </summary>
        public virtual string FocusKeyword { get; set; }
        /// <summary>
        /// gets or sets value indicating whether the content use CanonicalUrl
        /// </summary>
        public virtual bool UseCanonicalUrl { get; set; }
        /// <summary>
        /// gets or sets CanonicalUrl That the Post Point to it
        /// </summary>
        public virtual string CanonicalUrl { get; set; }
        /// <summary>
        /// gets or sets value indicating whether the content user no Follow for Seo
        /// </summary>
        public virtual bool UseNoFollow { get; set; }
        /// <summary>
        /// gets or sets value indicating whether the content user no Index for Seo
        /// </summary>
        public virtual bool UseNoIndex { get; set; }
        /// <summary>
        /// gets or sets value indicating whether the content in sitemap
        /// </summary>
        public virtual bool IsInSitemap { get; set; }
        /// <summary>
        /// gets or sets a value indicating whether the content comments are allowed 
        /// </summary>
        public virtual bool AllowComments { get; set; }
        /// <summary>
        /// gets or sets a value indicating whether the content comments are allowed for anonymouses 
        /// </summary>
        public virtual bool AllowCommentForAnonymous { get; set; }
        /// <summary>
        /// gets or sets  viewed count by rss
        /// </summary>
        public virtual long ViewCountByRss { get; set; }
        /// <summary>
        /// gets or sets viewed count 
        /// </summary>
        public virtual long ViewCount { get; set; }
        /// <summary>
        /// Gets or sets the total number of  comments
        /// <remarks>The same as if we run Item.Comments.where(a=>a.Status==Status.Approved).Count()
        /// We use this property for performance optimization (no SQL command executed)
        /// </remarks>
        /// </summary>
        public virtual int ApprovedCommentsCount { get; set; }
        /// <summary>
        /// Gets or sets the total number of  comments
        /// <remarks>The same as if we run Item.Comments.where(a=>a.Status==Status.UnApproved).Count()
        /// We use this property for performance optimization (no SQL command executed)</remarks></summary>
        public virtual int UnApprovedCommentsCount { get; set; }
        /// <summary>
        /// gets or sets value  indicating whether the content is logical deleted or hidden
        /// </summary>
        public virtual bool IsDeleted { get; set; }
        /// <summary>
        /// gets or sets rating complex instance
        /// </summary>
        public virtual Rating Rating { get; set; }
        /// <summary>
        /// gets or sets value indicating whether the content show with rssFeed
        /// </summary>
        public virtual bool ShowWithRss { get; set; }
        /// <summary>
        /// gets or sets value indicating maximum days count that users can send comment
        /// </summary>
        public virtual int DaysCountForSupportComment { get; set; }
        /// <summary>
        /// gets or sets information of User-Agent
        /// </summary>
        public virtual string Agent { get; set; }
        /// <summary>
        /// gets or sets icon name with size 200*200 px for snippet 
        /// </summary>
        public virtual string SocialSnippetIconName { get; set; }
        /// <summary>
        /// gets or sets title for snippet
        /// </summary>
        public virtual string SocialSnippetTitle { get; set; }
        /// <summary>
        /// gets or sets description for snippet
        /// </summary>
        public virtual string SocialSnippetDescription { get; set; }
        /// <summary>
        /// gets or sets body of content's comment
        /// </summary>
        public virtual byte[] RowVersion { get; set; }
        /// <summary>
        /// gets or sets name of tags seperated by comma that assosiated with this content fo increase performance
        /// </summary>
        public virtual string TagNames { get; set; }
        /// <summary>
        /// gets or sets counter for Content's report
        /// </summary>
        public virtual int ReportsCount { get; set; }
        #endregion

        #region NavigationProperties

        /// <summary>
        /// get or set user that create this record
        /// </summary>
        public virtual User Author { get; set; }

        /// <summary>
        /// gets or sets Id of user that create this record
        /// </summary>
        public virtual long AuthorId { get; set; }
        /// <summary>
        /// get or set  the tags integrated with content
        /// </summary>
        public virtual ICollection<Tag> Tags { get; set; }
        #endregion

    }

 /// <summary>
    /// Represents link for implemention linkback
    /// </summary>
    public class LinkBack
    {

        #region Ctor
        /// <summary>
        /// create one instance of <see cref="LinkBack"/>
        /// </summary>
        public LinkBack()
        {
            CreatedOn = DateTime.Now;
            Id = SequentialGuidGenerator.NewSequentialGuid();
        }
        #endregion

        #region Properties
        /// <summary>
        /// gets or sets link's Id
        /// </summary>
        public virtual Guid Id { get; set; }
        /// <summary>
        /// gets or sets text for show Link
        /// </summary>
        public virtual string Title { get; set; }
        /// <summary>
        /// gets or sets link's address 
        /// </summary>
        public virtual string Url { get; set; }
        /// <summary>
        /// gets or set value indicating whether this link is internal o external
        /// </summary>
        public virtual LinkBackType Type { get; set; }
        /// <summary>
        /// gets or sets date that this record is added
        /// </summary>
        public virtual DateTime CreatedOn { get; set; }
        #endregion

        #region NavigationProperties
        /// <summary>
        /// gets or sets Post that associated
        /// </summary>
        public virtual BlogPost Post { get; set; }
        /// <summary>
        /// gets or sets id of Post that associated
        /// </summary>
        public virtual long PostId { get; set; }
        #endregion
    }


 /// <summary>
    /// represents Type of ReferrerLinks
    /// </summary>
    public enum LinkBackType
    {
        /// <summary>
        /// Internal link
        /// </summary>
        Internal,
        /// <summary>
        /// External Link
        /// </summary>
        External
    }

  /// <summary>
    /// Represents a base class for every comment in system 
    /// </summary>

    public abstract class BaseComment
    {
        #region Properties
        /// <summary>
        /// get or set identifier of record
        /// </summary>
        public virtual long Id { get; set; }
        /// <summary>
        /// gets or sets date of creation 
        /// </summary>
        public virtual DateTime CreatedOn { get; set; }
        /// <summary>
        /// gets or sets displayName of this comment's Creator if  he/she is Anonymous
        /// </summary>
        public virtual string CreatorDisplayName { get; set; }
        /// <summary>
        /// gets or sets body of blog post's comment
        /// </summary>
        public virtual string Body { get; set; }
        /// <summary>
        /// gets or sets body of blog post's comment
        /// </summary>
        public virtual Rating Rating { get; set; }
        /// <summary>
        /// gets or sets informations of agent
        /// </summary>
        public virtual string UserAgent { get; set; }
        /// <summary>
        /// gets or sets siteUrl of Creator if he/she is Anonymous
        /// </summary>
        public virtual string SiteUrl { get; set; }
        /// <summary>
        /// gets or sets Email of Creator if he/she is anonymous
        /// </summary>
        public virtual string Email { get; set; }
        /// <summary>
        /// gets or sets status of comment
        /// </summary>
        public virtual CommentStatus Status { get; set; }
        /// <summary>
        /// gets or sets Ip Address of Creator
        /// </summary>
        public virtual string CreatorIp { get; set; }
        /// <summary>
        /// gets or sets datetime that is modified
        /// </summary>
        public virtual DateTime? ModifiedOn { get; set; }
        /// <summary>
        /// gets or sets counter for report this comment
        /// </summary>
        public virtual int ReportsCount { get; set; }
        #endregion

        #region NavigationProperties

        /// <summary>
        /// get or set user that create this record
        /// </summary>
        public virtual User Creator { get; set; }

        /// <summary>
        /// get or set Id of user that create this record
        /// </summary>
        public virtual long? CreatorId { get; set; }
        #endregion
    }

public enum CommentStatus
    {
        /* 0 - approved, 1 - pending, 2 - spam, -1 - trash */
        [Display(Name = "تأیید شده")]
        Approved = 0,
        [Display(Name = "در انتظار بررسی")]
        Pending = 1,
        [Display(Name = "جفنگ")]
        Spam = 2,
        [Display(Name = "زباله دان")]
        Trash = -1
    }

/// <summary>
    /// Represents a blog post's comment
    /// </summary>
    public class BlogComment : BaseComment
    {
        #region Ctor
        /// <summary>
        /// Create One Instance for <see cref="BlogComment"/>
        /// </summary>
        public BlogComment()
        {
            Rating = new Rating();
            CreatedOn = DateTime.Now;
        }
        #endregion

        #region NavigationProperties
        /// <summary>
        /// gets or sets BlogComment's identifier for Replying and impelemention self referencing
        /// </summary>
        public virtual long? ReplyId { get; set; }
        /// <summary>
        /// gets or sets blog's comment for Replying and impelemention self referencing
        /// </summary>
        public virtual BlogComment Reply { get; set; }
        /// <summary>
        /// get or set collection of blog's comment for Replying and impelemention self referencing
        /// </summary>
        public virtual ICollection<BlogComment> Children { get; set; }
        /// <summary>
        /// gets or sets post that this comment sent to it
        /// </summary>
        public virtual BlogPost Post { get; set; }
        /// <summary>
        /// gets or sets post'Id that this comment sent to it
        /// </summary>
        public virtual long PostId { get; set; }
        #endregion
    }