If the el-dialog has not opened before,elements under el-dialog cannot be retrieved using this.$refs
as elements has not rendered.
I want to know how to render el-dialog but not show it because I need to initialize something in el-dialog.
You can use vm.$nextTick( [callback] )
Example
in methods
OpenDialog() {
this.dialogFormVisible = true; // your dialog toggle variable
this.$nextTick(() => {
// some action or your this.$refs will here
});
},
Reference https://v2.vuejs.org/v2/api/#vm-nextTick