Question

我在代码中使用块帮助程序来比较值，但是每次运行此代码时都会出现问题我在我的网页视图中得到了这个错误按摩

Error: Missing helper: "compare"
    at Object.<anonymous> (/opt/lampp/htdocs/x/chessMult/regtest/using-passport-with-sequelize-and-mysql-master/node_modules/handlebars/dist/cjs/handlebars/helpers/helper-missing.js:19:13)
    at Object.eval (eval at createFunctionContext (/opt/lampp/htdocs/x/chessMult/regtest/using-passport-with-sequelize-and-mysql-master/node_modules/handlebars/dist/cjs/handlebars/compiler/javascript-compiler.js:254:23),
    <anonymous>:8:91)
    at main (/opt/lampp/htdocs/x/chessMult/regtest/using-passport-with-sequelize-and-mysql-master/node_modules/handlebars/dist/cjs/handlebars/runtime.js:175:32)
    at ret (/opt/lampp/htdocs/x/chessMult/regtest/using-passport-with-sequelize-and-mysql-master/node_modules/handlebars/dist/cjs/handlebars/runtime.js:178:12)
    at ret (/opt/lampp/htdocs/x/chessMult/regtest/using-passport-with-sequelize-and-mysql-master/node_modules/handlebars/dist/cjs/handlebars/compiler/compiler.js:525:21)
    at ExpressHandlebars._renderTemplate (/opt/lampp/htdocs/x/chessMult/regtest/using-passport-with-sequelize-and-mysql-master/node_modules/express-handlebars/lib/express-handlebars.js:247:12)
    at ExpressHandlebars.<anonymous> (/opt/lampp/htdocs/x/chessMult/regtest/using-passport-with-sequelize-and-mysql-master/node_modules/express-handlebars/lib/express-handlebars.js:173:21)

我的index.hbs文件

{{#compare pageCount ">" 1 }}
  <ul class="pagination"></ul>
    {{#compare  currentPage ">" 1  }}

       <li><a href="/?page=1"> &laquo;</a></li>
    {{/compare}}

{{/compare}}

我的auth.js文件

res.render('index', {x:"1888", "personList": personList,data: data, pageSize: pageSize, pageCount: pageCount,currentPage: currentPage});

我的app.js文件

const exphbs     = require('express-handlebars');
const hbs = exphbs.create({
  // Specify helpers which are only registered on this instance.
  helpers: {
    foo: function () { return 'FOO!'; },
    extname: ".hbs",
    compare: function(lvalue, rvalue, options) {

      if (arguments.length < 3)
        throw new Error("Handlerbars Helper 'compare' needs 2 parameters");

      var operator = options.hash.operator || "==";

      var operators = {
        '==':       function(l,r) { return l == r; },
        '===':      function(l,r) { return l === r; },
        '!=':       function(l,r) { return l != r; },
        '<':        function(l,r) { return l < r; },
        '>':        function(l,r) { return l > r; },
        '<=':       function(l,r) { return l <= r; },
        '>=':       function(l,r) { return l >= r; },
        'typeof':   function(l,r) { return typeof l == r; }
      }

      if (!operators[operator])
        throw new Error("Handlerbars Helper 'compare' doesn't know the operator "+operator);

      var result = operators[operator](lvalue,rvalue);

      if( result ) {
        return options.fn(this);
      } else {
        return options.inverse(this);
      }

    }

  }
});


//For Handlebars
app.set('views', './app/views')
app.engine('.hbs', exphbs({extname: '.hbs'}));
app.set('view engine', '.hbs');

哪里错了？

Answer 1

app.js档

有一个小错误

const exphbs     = require('express-handlebars');
const hbs = exphbs.create({
//...
});

//For Handlebars
app.set('views', './app/views');
app.engine('.hbs', hbs.engine); // <===== Use `hbs.engine`
app.set('view engine', '.hbs');

比较块手柄的助手

1 个答案: