重复使用手柄查找 [英] Using Handlebars lookup with repetition
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问题描述
在这个例子中，我想列出每个大学的学生名单以及每个学生所属部门的信息。
我的代码可以工作，但是嵌套的查询非常有用重复：
{{lookup（lookup ../majors major）'dean'}} $ b $ {{lookup（ lookup ../majors major）'location'}}
我能做些什么吗？我想访问查找的上下文，如下所示：
{{＃lookup ../majors major }}
{{dean}}
{{location}}
{{/ lookup}}
var source = $（＃hb-template）。html（）; var template = Handlebars （html）;
< script src =https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js> ;< / script>< script src =https://cdnjs.cloudflare.com/ajax/libs/handlebars.js/4.0.6/handlebars.min.js>< / script><脚本id =hb-templatetype =text / x-handlebars-template> {{#universities}}< h1> {{name}}< / h1> {{#students}}< h2> {{name}}< / h2> < DL> <峰; dt>主要< / DT> <峰; dd> {{主要}}< / DD> < dt> Department dean< / dt> < dd> {{lookup（lookup ../majors major）'dean'}}< / dd> < dt>部门位置< / dt> < dd> {{lookup（lookup ../majors major）'location'}}< / dd> < / dl的> {/ students}} {{/ universities}}< / script>< div id =hb-html>< / div>< script> var context = {schools：[{name：Example University，students：[{name：Alice，major：Business}，{name ，major：English}]，majors：{English：{dean：Dr. Smith，location：101室}， Dr. Jones，location：房间999}}}，{name：另一所大学，学生：[{名称：鲍勃，主要：商业}} ]，majors：{Business：{dean：Dr. Zimmerman，location：South Campus}}}]};< / script>
解决方案以下是我的解决方案：使用
（lookup ../majors major）}}{{＃with}}helper 并将查找子表达式的结果（一个对象）传递给它。我不确定这是否是最好的方法，或者真的如此，为什么会喜欢评论。
< dt>院系院长< / dt>
< dd> {{dean}}< / dd>
< dt>部门地点< / dt>
< dd> {{location}}< / dd>
{{/ with}}
完整示例：
var source = $（＃hb-template）。html（）; var template = Handlebars.compile （source）; var html = template（context）; $（＃hb-html）。html（html）; < script src =https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js><<< ; / script>< script src =https://cdnjs.cloudflare.com/ajax/libs/handlebars.js/4.0.6/handlebars.min.js>< / script>< script id = hb-templatetype =text / x-handlebars-template> {{#universities}}< h1> {{name}}< / h1> {{#students}}< h2> {{name}}< / h2> < DL> <峰; dt>主要< / DT> <峰; dd> {{主要}}< / DD> {{#with（lookup ../majors major）}}< dt> Department dean< / dt> <峰; dd> {{院长}}< / DD> < dt>部门位置< / dt> <峰; dd> {{位置}}< / DD> {{/ with}}< / dl> {/ students}} {{/ universities}}< / script>< div id =hb-html>< / div>< script> var context = {schools：[{name：Example University，students：[{name：Alice，major：Business}，{name ，major：English}]，majors：{English：{dean：Dr. Smith，location：101室}， Dr. Jones，location：房间999}}}，{name：另一所大学，学生：[{名称：鲍勃，主要：商业}} ]，majors：{Business：{dean：Dr. Zimmerman，location：South Campus}}}]};< / script> pre>
Given an array of objects, I would like to use one property of a nested object to look up various properties in an associated object in Handlebars.
In this example, I would like to show a list of students at each university, and information about the department to which each student belongs.
My code works, but the nested lookups are very repetitive:
{{lookup (lookup ../majors major) 'dean'}}
{{lookup (lookup ../majors major) 'location'}}
Is there anything I can do about this? I'd like to do access the context of the lookup, something like this:
{{#lookup ../majors major}}
{{dean}}
{{location}}
{{/lookup}}
var source = $("#hb-template").html();
var template = Handlebars.compile(source);
var html = template(context);
$("#hb-html").html(html);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/handlebars.js/4.0.6/handlebars.min.js"></script>
<script id="hb-template" type="text/x-handlebars-template">
{{#universities}}
<h1>{{name}}</h1>
{{#students}}
<h2>{{name}}</h2>
<dl>
<dt>Major</dt>
<dd>{{major}}</dd>
<dt>Department dean</dt>
<dd>{{lookup (lookup ../majors major) 'dean'}}</dd>
<dt>Department location</dt>
<dd>{{lookup (lookup ../majors major) 'location'}}</dd>
</dl>
{{/students}}
{{/universities}}
</script>
<div id="hb-html">
</div>
<script>
var context = {
"universities": [{
"name": "Example University",
"students": [{
"name": "Alice",
"major": "Business"
},
{
"name": "John",
"major": "English"
}
],
"majors": {
"English": {
"dean": "Dr. Smith",
"location": "Room 101"
},
"Business": {
"dean": "Dr. Jones",
"location": "Room 999"
}
}
},
{
"name": "Another University",
"students": [{
"name": "Bob",
"major": "Business"
}],
"majors": {
"Business": {
"dean": "Dr. Zimmerman",
"location": "South Campus"
}
}
}
]
};
</script>
解决方案
Here is my solution: use the {{#with}} helper and pass it the result of the lookup subexpression—an object. I'm not sure if this is the best method, or really why this works, so would appreciate comments.
{{#with (lookup ../majors major)}}
<dt>Department dean</dt>
<dd>{{dean}}</dd>
<dt>Department location</dt>
<dd>{{location}}</dd>
{{/with}}
Full example:
var source = $("#hb-template").html();
var template = Handlebars.compile(source);
var html = template(context);
$("#hb-html").html(html);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/handlebars.js/4.0.6/handlebars.min.js"></script>
<script id="hb-template" type="text/x-handlebars-template">
{{#universities}}
<h1>{{name}}</h1>
{{#students}}
<h2>{{name}}</h2>
<dl>
<dt>Major</dt>
<dd>{{major}}</dd>
{{#with (lookup ../majors major)}}
<dt>Department dean</dt>
<dd>{{dean}}</dd>
<dt>Department location</dt>
<dd>{{location}}</dd>
{{/with}}
</dl>
{{/students}}
{{/universities}}
</script>
<div id="hb-html">
</div>
<script>
var context = {
"universities": [{
"name": "Example University",
"students": [{
"name": "Alice",
"major": "Business"
},
{
"name": "John",
"major": "English"
}
],
"majors": {
"English": {
"dean": "Dr. Smith",
"location": "Room 101"
},
"Business": {
"dean": "Dr. Jones",
"location": "Room 999"
}
}
},
{
"name": "Another University",
"students": [{
"name": "Bob",
"major": "Business"
}],
"majors": {
"Business": {
"dean": "Dr. Zimmerman",
"location": "South Campus"
}
}
}
]
};
</script>
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