I have to write a simple web application using the Java Spring framework as my course project. So I decided to write a simple Stack Overflow clone. My application has the following features:
- Authorization (using Spring Security);
- Posting new questions and answers;
- Voting up/down for questions/answers.
I am very new in Java, Spring, and web-backend world so I think there is much room for improvement.
Some of my thoughts about problems in my Java code:
The
VotesControllerclass consists of several almost identical methods. I know that copy-paste is bad, but I have no idea how to deal with it in this case.I am not sure about naming conventions in Spring. Have I properly named controllers, entities, fields, etc.?
I really hate the way I pass information to the Mustache templates. For example, I need to display a question's creation date in this form:
May 27 '20 at 15:40, but if I just useDate creationDateTimefield from theQuestionentity then Mustache will display it in the form2020-05-27 15:40:49.0.
To solve this problem I have created the String formattedCreationDateTime field in the Question entity and call the Question.formatCreationDateTime method just before passing the question entity to Mustache.
And then I can use formattedCreationDateTime in the template. It is not the only example.
I also do not like the way I store votes for questions/answers. At this time I have four different join tables:
question_vote_up(question_id, user_id) question_vote_down(question_id, user_id) answer_vote_up(answer_id, user_id) answer_vote_down(answer_id, user_id)
I know that it would be better to create only two tables like this:
question_vote(question_id, user_id, vote)
answer_vote(answer_id, user_id, vote)
But I don't know how to implement this database structure in Spring.
I would really appreciate any advice on how to improve my code. I would be glad to see review on my JavaScript and CSS, but it is not a priority.
I've published all the code in the GitHub repository.
Controllers
package com.sstu.StackCanary.controllers;
import java.util.*;
import com.sstu.StackCanary.domain.Answer;
import com.sstu.StackCanary.domain.Question;
import com.sstu.StackCanary.domain.User;
import com.sstu.StackCanary.repositories.AnswerRepository;
import com.sstu.StackCanary.repositories.QuestionRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.annotation.AuthenticationPrincipal;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
@Controller
public class AddAnswerController {
@Autowired
private QuestionRepository questionRepository;
@Autowired
private AnswerRepository answerRepository;
@PostMapping("/q")
public String postQuestion(@AuthenticationPrincipal User user,
@RequestParam Integer questionId,
@RequestParam String body,
Map<String, Object> model) {
// Assuming that the question with given ID always exists.
Question q = questionRepository.findById(questionId).get();
// Add new answer to the database.
answerRepository.save(new Answer(user, q, body));
// Redirect to the question page.
return "redirect:/q?id=" + questionId;
}
}
package com.sstu.StackCanary.controllers;
import java.util.*;
import com.sstu.StackCanary.domain.Question;
import com.sstu.StackCanary.domain.Tag;
import com.sstu.StackCanary.domain.User;
import com.sstu.StackCanary.repositories.QuestionRepository;
import com.sstu.StackCanary.repositories.TagRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.annotation.AuthenticationPrincipal;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
@Controller
public class AskQuestionPageController {
@Autowired
private QuestionRepository questionRepository;
@Autowired
private TagRepository tagRepository;
@GetMapping("/askQuestion")
public String main(@AuthenticationPrincipal User user,
Map<String, Object> model) {
model.put("authorizedUser", user);
return "askQuestion";
}
@PostMapping("/askQuestion")
public String postQuestion(@AuthenticationPrincipal User user,
@RequestParam String title,
@RequestParam String body,
@RequestParam("tag") String [] tagNames,
Map<String, Object> model) {
// Create empty set of tags.
HashSet<Tag> tags = new HashSet<Tag>();
// Fill this set with tags with given name from database.
// If the tag not exist create such new one.
for (String name : tagNames) {
Tag tag = tagRepository.findByName(name);
if (tag == null)
tag = new Tag(name);
tagRepository.save(tag);
tags.add(tag);
}
// Create new question and save it in the database.
Question q = new Question(user, title, body, tags);
questionRepository.save(q);
// Redirect to the new question's page.
return "redirect:/q?id=" + q.getId();
}
}
package com.sstu.StackCanary.controllers;
import java.util.Map;
import com.sstu.StackCanary.domain.Question;
import com.sstu.StackCanary.domain.User;
import com.sstu.StackCanary.repositories.QuestionRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.annotation.AuthenticationPrincipal;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
@Controller
public class IndexController {
@Autowired
private QuestionRepository questionRepository;
@GetMapping
public String main(@AuthenticationPrincipal User user,
Map<String, Object> model) {
Iterable<Question> questions = questionRepository.findAll();
// Prepare transient fields
//
// — formattedCreationDateTime
// — votes
//
// that will be used in the template.
questions.forEach(Question::calculateVotes);
questions.forEach(Question::formatCreationDateTime);
model.put("questions", questions);
model.put("authorized", (user != null));
return "index";
}
}
package com.sstu.StackCanary.controllers;
import java.util.Map;
import com.sstu.StackCanary.domain.Answer;
import com.sstu.StackCanary.domain.Question;
import com.sstu.StackCanary.domain.User;
import com.sstu.StackCanary.repositories.QuestionRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.annotation.AuthenticationPrincipal;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
@Controller
public class QuestionPageController {
@Autowired
private QuestionRepository questionRepository;
@GetMapping("/q")
public String main(@AuthenticationPrincipal User user,
@RequestParam Integer id,
Map<String, Object> model) {
// Assuming that the question with
// given ID always exists.
Question q = questionRepository.findById(id).get();
// Prepare transient fields
//
// — formattedCreationDateTime
// — votes
// — answersCount
// — bodyInHTML
//
// that will be used in the template.
q.calculateVotes();
q.calculateAnswersCount();
q.formatCreationDateTime();
q.convertBodyFromMarkdownToHTML();
q.setVotedByActiveUser(user);
// Prepare transient fields of the each answer as well
// as we have done with the question.
q.answers.forEach(Answer::formatCreationDateTime);
q.answers.forEach(Answer::calculateVotes);
q.answers.forEach(Answer::convertBodyFromMarkdownToHTML);
q.answers.forEach(a -> a.setVotedByActiveUser(user));
model.put("question", q);
model.put("authorized", (user != null));
return "question";
}
}
package com.sstu.StackCanary.controllers;
import com.sstu.StackCanary.domain.Role;
import com.sstu.StackCanary.domain.User;
import com.sstu.StackCanary.repositories.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import java.util.Collections;
import java.util.Map;
@Controller
public class RegistrationController {
@Autowired
private UserRepository userRepository;
@GetMapping("/registration")
public String main(Map<String, Object> model) {
return "registration";
}
@PostMapping("/registration")
public String registerUser(User user, Map<String, Object> model) {
if (userWithThisUsernameAlreadyExists(user)) {
model.put("userWithThisUsernameAlreadyExistsMessage", "User with this username already exists.");
return "registration";
}
user.setActive(true);
user.setRoles(Collections.singleton(Role.USER));
userRepository.save(user);
return "redirect:/login";
}
private boolean userWithThisUsernameAlreadyExists(User u) {
return userRepository.findByUsername(u.getUsername()) != null;
}
}
package com.sstu.StackCanary.controllers;
import com.sstu.StackCanary.domain.Answer;
import com.sstu.StackCanary.domain.Question;
import com.sstu.StackCanary.domain.User;
import com.sstu.StackCanary.repositories.AnswerRepository;
import com.sstu.StackCanary.repositories.QuestionRepository;
import com.sstu.StackCanary.repositories.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.annotation.AuthenticationPrincipal;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import java.util.Map;
@Controller
public class VotesController {
@Autowired
private AnswerRepository answerRepository;
@Autowired
private QuestionRepository questionRepository;
@Autowired
private UserRepository userRepository;
@PostMapping("/voteUpForAnswer")
public String voteUpForAnswer(@AuthenticationPrincipal User user,
@RequestParam Integer questionId,
@RequestParam Integer answerId,
Map<String, Object> model) {
Answer answer = answerRepository.findById(answerId).get();
answer.votedUpByUsers.add(user);
answer.votedDownByUsers.remove(user);
user.voteUpForAnswer(answer);
answerRepository.save(answer);
userRepository.save(user);
return "redirect:/q?id=" + questionId;
}
@PostMapping("/undoVoteUpForAnswer")
public String undoVoteUpForAnswer(@AuthenticationPrincipal User user,
@RequestParam Integer answerId,
Map<String, Object> model) {
Answer answer = answerRepository.findById(answerId).get();
answer.votedUpByUsers.remove(user);
user.getVotedUpAnswers().remove(answer);
answerRepository.save(answer);
userRepository.save(user);
return "redirect:/q?id=" + answerId;
}
@PostMapping("/voteDownForAnswer")
public String voteDownForAnswer(@AuthenticationPrincipal User user,
@RequestParam Integer questionId,
@RequestParam Integer answerId,
Map<String, Object> model) {
Answer answer = answerRepository.findById(answerId).get();
answer.votedDownByUsers.add(user);
answer.votedUpByUsers.remove(user);
user.voteDownForAnswer(answer);
answerRepository.save(answer);
userRepository.save(user);
return "redirect:/q?id=" + questionId;
}
@PostMapping("/undoVoteDownForAnswer")
public String undoVoteDownForAnswer(@AuthenticationPrincipal User user,
@RequestParam Integer answerId,
Map<String, Object> model) {
Answer answer = answerRepository.findById(answerId).get();
answer.votedDownByUsers.remove(user);
user.getVotedDownAnswers().remove(answer);
answerRepository.save(answer);
userRepository.save(user);
return "redirect:/q?id=" + answerId;
}
@PostMapping("/voteUpForQuestion")
public String voteUpForQuestion(@AuthenticationPrincipal User user,
@RequestParam Integer questionId,
Map<String, Object> model) {
Question question = questionRepository.findById(questionId).get();
question.votedUpByUsers.add(user);
question.votedDownByUsers.remove(user);
user.voteUpForQuestion(question);
questionRepository.save(question);
userRepository.save(user);
return "redirect:/q?id=" + questionId;
}
@PostMapping("/undoVoteUpForQuestion")
public String undoVoteUpForQuestion(@AuthenticationPrincipal User user,
@RequestParam Integer questionId,
Map<String, Object> model) {
Question question = questionRepository.findById(questionId).get();
question.votedUpByUsers.remove(user);
user.getVotedUpQuestions().remove(question);
questionRepository.save(question);
userRepository.save(user);
return "redirect:/q?id=" + questionId;
}
@PostMapping("/voteDownForQuestion")
public String voteDownForQuestion(@AuthenticationPrincipal User user,
@RequestParam Integer questionId,
Map<String, Object> model) {
Question question = questionRepository.findById(questionId).get();
question.votedDownByUsers.add(user);
question.votedUpByUsers.remove(user);
user.voteDownForQuestion(question);
questionRepository.save(question);
userRepository.save(user);
return "redirect:/q?id=" + questionId;
}
@PostMapping("/undoVoteDownForQuestion")
public String undoVoteDownForQuestion(@AuthenticationPrincipal User user,
@RequestParam Integer questionId,
Map<String, Object> model) {
Question question = questionRepository.findById(questionId).get();
question.votedDownByUsers.remove(user);
user.getVotedDownQuestions().remove(question);
questionRepository.save(question);
userRepository.save(user);
return "redirect:/q?id=" + questionId;
}
}
Entities
package com.sstu.StackCanary.domain;
import org.commonmark.node.Node;
import org.commonmark.parser.Parser;
import org.commonmark.renderer.html.HtmlRenderer;
import javax.persistence.*;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Set;
@Entity
public class Answer {
//==========================================
//
// Database Columns
//
//==========================================
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
@Column(columnDefinition = "LONGTEXT")
private String body;
@Column(name = "creationDateTime", columnDefinition = "DATETIME")
@Temporal(TemporalType.TIMESTAMP)
private Date creationDateTime;
//==========================================
//
// Relations
//
//==========================================
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "author")
private User author;
@ManyToOne
@JoinColumn(name = "question", nullable = false)
private Question question;
@ManyToMany
@JoinTable(
name = "answer_vote_up",
joinColumns = @JoinColumn(name = "answer_id"),
inverseJoinColumns = @JoinColumn(name = "user_id")
)
public Set<User> votedUpByUsers;
@ManyToMany
@JoinTable(
name = "answer_vote_down",
joinColumns = @JoinColumn(name = "answer_id"),
inverseJoinColumns = @JoinColumn(name = "user_id")
)
public Set<User> votedDownByUsers;
//==========================================
//
// Transient Fields
//
// This fields must be initialized manually by
// calling the corresponding entity's method.
//==========================================
@Transient
private String formattedCreationDateTime;
@Transient
public Integer votes;
@Transient
public String bodyInHTML;
@Transient
public boolean votedUpByActiveUser;
@Transient
public boolean votedDownByActiveUser;
//==========================================
//
// Constructors
//
//==========================================
protected Answer() {}
public Answer(User author, Question question, String body) {
this.author = author;
this.question = question;
this.body = body;
// Assign current date and time.
this.creationDateTime = new Date();
}
//==========================================
//
// Methods
//
//==========================================
public void formatCreationDateTime() {
DateFormat d = new SimpleDateFormat("MMM d ''yy 'at' HH:mm");
formattedCreationDateTime = d.format(creationDateTime);
}
public void calculateVotes() {
votes = votedUpByUsers.size() - votedDownByUsers.size();
}
public void convertBodyFromMarkdownToHTML() {
Node document = Parser.builder().build().parse(body);
HtmlRenderer renderer = HtmlRenderer.builder().escapeHtml(true).build();
bodyInHTML = renderer.render(document);
}
public void setVotedByActiveUser(User user) {
if (user == null) {
this.votedUpByActiveUser = false;
this.votedDownByActiveUser = false;
} else if (user.getVotedUpAnswers().contains(this)) {
this.votedUpByActiveUser = true;
this.votedDownByActiveUser = false;
} else if (user.getVotedDownAnswers().contains(this)) {
this.votedUpByActiveUser = false;
this.votedDownByActiveUser = true;
} else {
this.votedUpByActiveUser = false;
this.votedDownByActiveUser = false;
}
}
@Override
public boolean equals(Object that) {
if (this == that)
return true;
if (!(that instanceof Answer))
return false;
Answer thatAnswer = (Answer) that;
return this.id.equals(thatAnswer.id);
}
@Override
public int hashCode() {
final int PRIME = 37;
return PRIME * id.hashCode();
}
}
package com.sstu.StackCanary.domain;
import org.commonmark.node.Node;
import org.commonmark.parser.Parser;
import org.commonmark.renderer.html.HtmlRenderer;
import javax.persistence.*;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Set;
@Entity
public class Question {
//==========================================
//
// Database Columns
//
//==========================================
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String title;
@Column(columnDefinition = "LONGTEXT")
private String body;
@Column(name = "creationDateTime", columnDefinition = "DATETIME")
@Temporal(TemporalType.TIMESTAMP)
private Date creationDateTime;
//==========================================
//
// Relations
//
//==========================================
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "author")
private User author;
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(
name = "question_tag",
joinColumns = @JoinColumn(name = "question_id"),
inverseJoinColumns = @JoinColumn(name = "tag_id")
)
private Set<Tag> tags;
@OneToMany(mappedBy = "question", fetch = FetchType.EAGER)
public Set<Answer> answers;
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(
name = "question_vote_up",
joinColumns = @JoinColumn(name = "question_id"),
inverseJoinColumns = @JoinColumn(name = "user_id")
)
public Set<User> votedUpByUsers;
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(
name = "question_vote_down",
joinColumns = @JoinColumn(name = "question_id"),
inverseJoinColumns = @JoinColumn(name = "user_id")
)
public Set<User> votedDownByUsers;
//==========================================
//
// Transient Fields
//
// This fields must be initialized manually by
// calling the corresponding entity's method.
//==========================================
@Transient
public String formattedCreationDateTime;
@Transient
public Integer votes;
@Transient
public Integer answersCount;
@Transient
public String bodyInHTML;
@Transient
public boolean votedUpByActiveUser;
@Transient
public boolean votedDownByActiveUser;
//==========================================
//
// Constructors
//
//==========================================
protected Question() {}
public Question(User author, String title, String body, Set<Tag> tags) {
this.author = author;
this.title = title;
this.body = body;
this.tags = tags;
// Assign current date and time.
this.creationDateTime = new Date();
}
//==========================================
//
// Getters and Setters
//
//==========================================
public Integer getId() {
return id;
}
//==========================================
//
// Methods
//
//==========================================
public void formatCreationDateTime() {
DateFormat d = new SimpleDateFormat("MMM d ''yy 'at' HH:mm");
formattedCreationDateTime = d.format(creationDateTime);
}
public void calculateVotes() {
votes = votedUpByUsers.size() - votedDownByUsers.size();
}
public void calculateAnswersCount() {
answersCount = this.answers.size();
}
public void convertBodyFromMarkdownToHTML() {
Node document = Parser.builder().build().parse(body);
HtmlRenderer renderer = HtmlRenderer.builder().escapeHtml(true).build();
bodyInHTML = renderer.render(document);
}
public void setVotedByActiveUser(User user) {
if (user == null) {
this.votedUpByActiveUser = false;
this.votedDownByActiveUser = false;
} else if (user.getVotedUpQuestions().contains(this)) {
this.votedUpByActiveUser = true;
this.votedDownByActiveUser = false;
} else if (user.getVotedDownQuestions().contains(this)) {
this.votedUpByActiveUser = false;
this.votedDownByActiveUser = true;
} else {
this.votedUpByActiveUser = false;
this.votedDownByActiveUser = false;
}
}
@Override
public boolean equals(Object that) {
if (this == that)
return true;
if (!(that instanceof Question))
return false;
Question thatQuestion = (Question) that;
return this.id.equals(thatQuestion.id);
}
@Override
public int hashCode() {
final int PRIME = 37;
return PRIME * id.hashCode();
}
}
package com.sstu.StackCanary.domain;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;
import javax.persistence.*;
import java.util.Collection;
import java.util.Set;
@Entity
public class User implements UserDetails {
//==========================================
//
// Database Columns
//
//==========================================
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String username;
private String password;
private Boolean active;
@ElementCollection(targetClass = Role.class, fetch = FetchType.EAGER)
@CollectionTable(name = "user_role", joinColumns = @JoinColumn(name = "user_id"))
@Enumerated(EnumType.STRING)
@Column(name = "role")
private Set<Role> roles;
//==========================================
//
// Relations
//
//==========================================
@ManyToMany(mappedBy = "votedUpByUsers", fetch = FetchType.EAGER)
private Set<Question> votedUpQuestions;
@ManyToMany(mappedBy = "votedDownByUsers", fetch = FetchType.EAGER)
private Set<Question> votedDownQuestions;
@ManyToMany(mappedBy = "votedUpByUsers", fetch = FetchType.EAGER)
private Set<Answer> votedUpAnswers;
@ManyToMany(mappedBy = "votedDownByUsers", fetch = FetchType.EAGER)
private Set<Answer> votedDownAnswers;
//==========================================
//
// Constructors
//
//==========================================
protected User() {}
//==========================================
//
// Getters and Setters
//
//==========================================
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public Boolean getActive() {
return active;
}
public void setActive(Boolean active) {
this.active = active;
}
public Set<Role> getRoles() {
return roles;
}
public void setRoles(Set<Role> roles) {
this.roles = roles;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public Set<Question> getVotedUpQuestions() {
return votedUpQuestions;
}
public void setVotedUpQuestions(Set<Question> votedUpQuestions) {
this.votedUpQuestions = votedUpQuestions;
}
public Set<Question> getVotedDownQuestions() {
return votedDownQuestions;
}
public void setVotedDownQuestions(Set<Question> votedDownQuestions) {
this.votedDownQuestions = votedDownQuestions;
}
public Set<Answer> getVotedUpAnswers() {
return votedUpAnswers;
}
public void setVotedUpAnswers(Set<Answer> votedUpAnswers) {
this.votedUpAnswers = votedUpAnswers;
}
public Set<Answer> getVotedDownAnswers() {
return votedDownAnswers;
}
public void setVotedDownAnswers(Set<Answer> votedDownAnswers) {
this.votedDownAnswers = votedDownAnswers;
}
@Override
public boolean equals(Object that) {
if (this == that)
return true;
if (!(that instanceof User))
return false;
User thatUser = (User) that;
return this.id.equals(thatUser.id);
}
@Override
public int hashCode() {
final int PRIME = 37;
return PRIME * id.hashCode();
}
public void voteUpForQuestion(Question q) {
votedUpQuestions.add(q);
votedDownQuestions.remove(q);
}
public void voteDownForQuestion(Question q) {
votedDownQuestions.add(q);
votedUpQuestions.remove(q);
}
public void voteUpForAnswer(Answer q) {
votedUpAnswers.add(q);
votedDownAnswers.remove(q);
}
public void voteDownForAnswer(Answer q) {
votedDownAnswers.add(q);
votedUpAnswers.remove(q);
}
//==========================================
//
// UserDetails abstract methods implementation
//
//==========================================
@Override
public Collection<? extends GrantedAuthority> getAuthorities() {
return getRoles();
}
@Override
public boolean isAccountNonExpired() {
return true;
}
@Override
public boolean isAccountNonLocked() {
return true;
}
@Override
public boolean isCredentialsNonExpired() {
return true;
}
@Override
public boolean isEnabled() {
return getActive();
}
}
JS scripts:
questionAndAnswersBodyRendering.js:
"use strict";
function renderQuestionAndAnswersBodies() {
convertQuestionBodyToHTML();
convertAnswersBodiesToHTML();
highlightCodeInQuestion();
highlightCodeInAnswers();
}
function convertQuestionBodyToHTML() {
let questionBody = document.getElementById("questionBody");
questionBody.innerHTML = replaceHTMLEntitiesWithRealCharacters(questionBody.innerHTML);
// Add support for HTML tags inside Markdown code
// that comes from the server.
for (let e of questionBody.getElementsByTagName("*"))
if (e.tagName !== "CODE" && e.tagName !== "PRE")
e.innerHTML = replaceHTMLEntitiesWithRealCharacters(e.innerHTML);
}
function convertAnswersBodiesToHTML() {
let answersBodies = document.getElementsByClassName("answerBody");
for (let a of answersBodies) {
a.innerHTML = replaceHTMLEntitiesWithRealCharacters(a.innerHTML);
// Add support for HTML tags inside Markdown code
// that comes from the server.
for (let e of a.getElementsByTagName("*"))
if (e.tagName !== "CODE")
e.innerHTML = replaceHTMLEntitiesWithRealCharacters(e.innerHTML);
}
}
function replaceHTMLEntitiesWithRealCharacters(string) {
function replaceAll(string, search, replace) {
return string.split(search).join(replace);
}
string = replaceAll(string, "<", "<");
string = replaceAll(string, ">", ">");
// This HTML entity should be the last since
// it can affect on the other entities.
string = replaceAll(string, "&", "&");
return string;
}
function highlightCodeInQuestion() {
let questionBody = document.getElementById("questionBody");
highlightCodeInsideElement(questionBody);
}
function highlightCodeInAnswers() {
let answersBodies = document.getElementsByClassName("answerBody");
for (let a of answersBodies)
highlightCodeInsideElement(a);
}
function highlightCodeInsideElement(element) {
let children = element.getElementsByTagName("*");
for (let c of children)
if (c.tagName === "CODE" && c.parentElement.tagName === "PRE")
hljs.highlightBlock(c);
}
"use strict";
let tagsList = [];
const MAX_TAGS_COUNT = 5;
function tagEditorInputOnInput() {
var tagEditorInput = document.getElementById("tagEditorInput");
function clearInput() {
tagEditorInput.value = "";
}
let value = tagEditorInput.value;
let length = value.length;
const firstCharacter = getStringFirstCharacter(value);
const lastCharacter = getStringLastCharacter(value);
if (tagsList.length >= MAX_TAGS_COUNT) {
clearInput();
} else if (length < 2 && firstCharacter === " ") {
clearInput();
} else if (lastCharacter === " ") {
const tagName = value.toLowerCase().trim();
tagsList.push(tagName);
clearInput();
renderTags();
updateTagInputs();
}
}
function renderTags() {
removeAllRenderedTags();
let renderedTags = document.getElementById("renderedTags");
for (let t of tagsList)
renderedTags.appendChild(createRendererTagElement(t));
}
function createRendererTagElement(tagName) {
let tag = document.createElement("span");
addClass(tag, "renderedTag");
tag.innerHTML = '<span class="tagName">' + tagName + '</span>';
tag.innerHTML += '<svg onmouseup="removeRenderedTag(this.parentElement.firstChild);" class="removeTagButton" width="14" height="14" viewBox="0 0 14 14"><path d="M12 3.41L10.59 2 7 5.59 3.41 2 2 3.41 5.59 7 2 10.59 3.41 12 7 8.41 10.59 12 12 10.59 8.41 7z"></path></svg>';
return tag;
}
function removeAllRenderedTags() {
let renderedTags = document.getElementById("renderedTags");
renderedTags.innerHTML = "";
}
function removeRenderedTag(element) {
const tagName = getFirstWordInString(element.innerHTML);
const tagIndex = tagsList.indexOf(tagName);
removeItemFromArray(tagsList, tagIndex);
renderTags();
}
function updateTagInputs() {
for (let i = 0; i < 5; ++i) {
let tag = document.getElementById("tag" + i);
if (tagsList[i] === undefined)
tag.name = "emptyTag";
else
tag.name = "tag";
tag.value = tagsList[i];
}
}
function removeLastCharacterInString(s) {
return s.substring(0, s.length - 1);
}
function getStringLastCharacter(s) {
return s.slice(s.length - 1);
}
function getStringFirstCharacter(s) {
return s[0];
}
function getFirstWordInString(s) {
const spaceIndex = s.indexOf(" ");
if (spaceIndex === -1)
return s;
else
return s.substr(0, spaceIndex);
};
function removeItemFromArray(array, index) {
array.splice(index, 1);
}
function addClass(element, className) {
element.classList.add(className);
}
function removeClass(element, className) {
if (element.classList.contains(className))
element.classList.remove(className);
}
