角度指令创建 - 使用多个模板

Question

I'm fairly new to Angular JS and I'm trying to create a datepicker directive. It will not work like the Angular UI Bootstrap datepicker as it won't use a textbox but a full page calendar which you will be able to swipe through and click a day (which will update ngModel).

My plan was to have a single directive which has a renderMonth() function. This function would accept a month as a parameter and generate all the rows/days in an array which would then be bound to a template for the month.

My problem is that I can specify a template for the datepicker in my directive declaration but I don't know how to specify templates for the rows/days etc and load them in and bind them. I could do it using jQuery and lots of string concetenation, but that seems all wrong.

I have been reading the source code for the Angular UI Datepicker but as a newbie it makes very little sense to me. They have decoupled everything into many sub-directives (month directive, year directive etc.) and they have their own templates, but that's not what I want to do because my Angular skills aren't going to stretch to creating directives which communicate with each other. The Angular UI code is just way too complicated for me.

One thing I do like is that they use existing directives like ng-repeat in their templates and bind them to the array or rows/days. For me to do that I'd need to load the template in each time the renderMonth() is called and compile the template because it has existing directives in it.

So, basically my question is, does anybody have any examples of how I could write a import a template into my render function, compile it and ten bind it to the row/day data which is in my directives scope.

I'll be honest. I have no idea if I'm even speaking any sense. I'm just typing words which sound vaguely right.

ALl I need is for somebody to point me in the right direction. Thanks.

Answer 1

As discussed in the comments, I personally wouldn't worry too much about importing templates, the $compile function, or anything that complex for what is relatively simple markup.

I've created a (very) basic barebones plunker here , to demonstrate what my approach would be. I've used moment.js to deal with dates, because I am terrible with vanilla javascript date manipulation and find it very clumsy.

This is the template:

<div class="controls">
  <button ng-click="prevMonth()"><-</button>
  <span>{{selected.format('MMMM')}}</span>
  <button ng-click="nextMonth()">-></button>
</div>
<div class="month">
  <span class="day" ng-repeat="day in selected.days">
    {{day.number}}
  </span>
</div>

The template relies on the scope having a selected property which is a moment object. All it does is creates some buttons change the month and displays the month name at the top, then creates a span for each day in that month.

A tiny bit of CSS puts the days in rows of 7:

span.day{
  float: left;
  width: 25px;
}
span.day:nth-child(7n+1){
  clear:left;
}

This is the directive's link function:

link: function(scope, element, attributes){
  // Set the selection to now initially.
  scope.selected = moment();

  generateDaysArray = function(){
    // -- REMOVED FOR BREVITY -- //
    return days;
  }
  // Watch the month for changes and update the days array
  scope.$watch(
    function(){
      return scope.selected.month();
    },
    function(newVal, oldVal){
      scope.selected.days = generateDaysArray();
    }
  )
  // Control button actions
  scope.nextMonth = function(){
    scope.selected.add('month', 1)
  }
  scope.prevMonth = function(){
    scope.selected.subtract('month', 1)
  }
}

There is really nothing special there, but do note that the $watch command used takes advantage of the fact that you can pass a function instead of a string (though looking at it now you could just use 'selected.month()' as a string).

Generating the days array is slightly more complex if you want to align the dates with days of the week, which I started to do, but didn't finish. My plan was for each object in the array to have a isPreviousMonth property which would conditionally apply a different style using ng-class , and would look up the correct number as well, rather than just using a ~ for the offset days!

There is a lot more to do to finish this off - not least making the dates selectable and integrating with ngModel , but hopefully this example has given you an idea of one way to approach the problem of templating. There are many other ways you could do this, but I find this the most intuitive.

Extension

To address your question regarding having multiple months, I've expanded the plunker a bit.

I added an attribute to the directive:

<date-picker num-months="3"></date-picker>

And modified the template to ng-repeat certain parts depending on the number of months you specify in the attribute:

<div class="controls">
  <button ng-click="prevMonth()"><-</button>
  <span ng-repeat="month in months" class="month-title">
    {{month.moment.format('MMMM')}}
  </span>
  <button ng-click="nextMonth()">-></button>
</div>
<div class="month" ng-repeat="month in months">
  <span class="day" ng-repeat="day in month.days">
    {{day.number}}
  </span>
</div>

So this instead requires an array of months, each with 2 properties: a moment, and an array of days. I added some quick and dirty javascript to generate that, but I won't paste it here as there are almost certainly much neater ways of doing it!

Note that at present we're still watching scope.selected for changes in the month, which would lead to the (probably unwanted) behaviour that if you selected a date not in the first month, the calendar would rearrange itself. I think instead of using a $watch in this case, I'd just add to the click events to handle redrawing the calendar properly.

PS This addresses the cloning part but not the scrolling part. For scrolling, I would recommend adding one extra month on either end of the months array, then having an ng-show condition that means only the middle month(s) is shown. You can then take advantage of angular's inbuilt animations ( this is a good reference ) to scroll them in/out using css. If you want more info about that contact me through the chat I opened for this question.