javascript - What does the following function writing mean?

Question

A function defined in mutations in vuex calls {code...} {code...} in the component. My question is why there is no need to pass in the state parameter when calling the setCart function. Visually, if it does not If you pass the state parameter, the addCart function will automatically...

伊谢尔伦 · Answer

Just go and look at the source code and you will know.

export const mapMutations = normalizeNamespace((namespace, mutations) => {
  const res = {}
  normalizeMap(mutations).forEach(({ key, val }) => {
    val = namespace + val
    res[key] = function mappedMutation (...args) {
      if (namespace && !getModuleByNamespace(this.$store, 'mapMutations', namespace)) {
        return
      }
      
      // 在这里调用了commit方法
      return this.$store.commit.apply(this.$store, [val].concat(args))
    }
  })
  return res
})

The following is the definition of the commit method

this.commit = function boundCommit (type, payload, options) {
    // store 就是你想要的答案
    return commit.call(store, type, payload, options)
}

扔个三星炸死你 · Answer

this.setCart() is mapped to this.$store.commit('setCart')