Secondary processing of template data

watch、computed

because watch and computed Very similar So put it together and say

        watch:

                 Monitor the corresponding data changes , Execute the corresponding logical callback .

                 No cache data , Must be data Data in

                 Unwanted return

                 If you need to load and execute, you need to add immediate:true attribute

                 Applicable to a data change , When affecting multiple pieces of data , Execute the corresponding data logical callback

 

 

        computed

                 Monitor multiple data changes , The calculation produces a result .

                 There is cached data , data Data that does not exist in

                 need return One result is the result of calculation

                 The default load will be executed

                 Applicable to multiple data changes , When the calculation produces a result , Execute the corresponding data logical callback

 
 

filters filter

         single | The vertical line is the pipe symbol Inject the front data into the rear registration filter function, and then return

                <div>{ { data | format }}</div>

         Is equivalent to data Import format(data) perform

                <div>{ { data | format(val, 'type') }}</div>

        At this time data Will be used as the first parameter val Pass in fromat Subsequent parameters can be customized, and arbitrary parameters can be passed in for execution

         Single component registration :

                filters: {

                        format (val) {

                                return 99 ? 99 || val

                        }

                }

         Global registration

                Vue.filter('format', function (val) {

                        return 99 ? 99 || val

                })

         Use :

                <div>{ { data | format }}</div>

Reference resources ： API — Vue.js