I'm fairly new to Angular. I have a form where the user need to assign port numbers to 9 different port input fields (context: it's a form for a server environment configuration). The validation requirement is that no port number can be assigned twice, so each of the 9 port numbers needs to be unique.
For that, I have a custom validation directive called "srb-unique-port", which I assign to my input fields.
Directive:
(function () {
'use strict';
angular
.module('account')
.directive('srbUniquePort', [srbUniquePort]);
function srbUniquePort() {
return {
restrict: 'A',
require: 'ngModel',
scope: true,
link: function (scope, element, attrs, ngModel) {
ngModel.$validators.srbUniquePort = function (val) {
if (val == null || val == undefined || val == "" || val==0) return true;
var fieldName = attrs.name;
var configuration = scope.$eval(attrs.srbUniquePort);
var portFieldsToCheck = [
"myRestServicePort",
"myRestServicePortSSL",
"alfrescoPortHttp",
"alfrescoPortHttps",
"alfrescoPortTomcatShutdown",
"alfrescoPortAJP",
"alfrescoPortMySql",
"alfrescoPortJOD",
"alfrescoPortVti"
];
for (var i = 0; i < portFieldsToCheck.length; i++) {
if (fieldName!=portFieldsToCheck[i] && configuration[portFieldsToCheck[i]] == val) {
return false;
}
}
return true;
}
}
}
}
})();
HTML form (excerpt, just showing 2 of the 9 fields):
...
<md-input-container>
<label for="company" translate>COMPANY.CONFIGURATION.DBLIB_WEB_SRVC_PORT</label>
<input ng-model="vm.configuration.dblibWebSrvcPort" name="dblibWebSrvcPort" srb-unique-port="vm.configuration">
<div ng-messages="configurationForm.dblibWebSrvcPort.$error">
<div ng-message when="srbUniquePort">
<span translate>COMPANY.CONFIGURATION.VALIDATION.PORT_NOT_UNIQUE</span>
</div>
</div>
</md-input-container>
<md-input-container>
<label for="company" translate>COMPANY.CONFIGURATION.DBLIB_WEB_SRVC_PORT_SSL</label>
<input ng-model="vm.configuration.dblibWebSrvcPortSLL" name="dblibWebSrvcPortSLL" srb-unique-port="vm.configuration">
<div ng-messages="configurationForm.dblibWebSrvcPortSLL.$error">
<div ng-message when="srbUniquePort">
<span translate>COMPANY.CONFIGURATION.VALIDATION.PORT_NOT_UNIQUE</span>
</div>
</div>
</md-input-container>
...
It basically works for the field that I am current entering a value into. But the problem is that when I change the value of one input field, I need to re-validate all other depending fields as well. But I am not sure what the best way is in order to not run into an endless loop here, since all fields have the "srb-unique-port" assigned.
I already looked on StackOverflow and found this very similar question:
Angular directive with scope.$watch to force validation of other fields
with this plunker sample code: http://plnkr.co/edit/YnxDDAUCS2K7KyXT1AXP?p=preview
but the example provided there is different: it's only about a password and a password repeat field, where only one field has the validation directive assigned. So it differs from my case.
I tried to add this in my above code:
scope.$watch(ngModel, function (newValue, oldValue) {
ngModel.$validate();
});
but this causes endless loops (why does the ngModel frequently change here without any further action other than a validation which should always result to the same?).
This is the solution I ended up with. Looks a bit hacked to me, but it works.
(function () {
'use strict';
angular
.module('account')
.directive('srbUniquePort', [srbUniquePort]);
function srbUniquePort() {
return {
restrict: 'A',
require: 'ngModel',
scope: true,
link: function (scope, element, attrs, ngModel) {
function hasAValue(field) {
return !!field;
}
ngModel.$validators.srbUniquePort = function (val) {
var fieldName = attrs.name;
var configuration = scope.$eval(attrs.srbUniquePort);
var portFieldsToCheck = [
"dblibWebSrvcPort",
"dblibWebSrvcPortSLL",
"myRestServicePort",
"myRestServicePortSSL",
"alfrescoPortHttp",
"alfrescoPortHttps",
"alfrescoPortTomcatShutdown",
"alfrescoPortAJP",
"alfrescoPortMySql",
"alfrescoPortJOD",
"alfrescoPortVti"
];
configuration[fieldName] = val;
if (scope.$parent.configuration == undefined) {
scope.$parent.configuration = JSON.parse(JSON.stringify(configuration));
}
scope.$parent.configuration[fieldName] = val;
// compare each port field with each other and in case if equality,
// remember it by putting a "false" into the validityMap helper variable
var validityMap = [];
for (var i = 0; i < portFieldsToCheck.length; i++) {
for (var j = 0; j < portFieldsToCheck.length; j++) {
if (portFieldsToCheck[i] != portFieldsToCheck[j]) {
var iFieldHasAValue = hasAValue(scope.$parent.configuration[portFieldsToCheck[i]]);
var jFieldHasAValue = hasAValue(scope.$parent.configuration[portFieldsToCheck[j]]);
var valHasAValue = hasAValue(val);
if (iFieldHasAValue && jFieldHasAValue
&& scope.$parent.configuration[portFieldsToCheck[i]] == scope.$parent.configuration[portFieldsToCheck[j]]
) {
validityMap[portFieldsToCheck[i]] = false;
validityMap[portFieldsToCheck[j]] = false;
}
}
}
}
// in the end, loop through all port fields and set
// the validity here manually
for (var i = 0; i < portFieldsToCheck.length; i++) {
var valid = validityMap[portFieldsToCheck[i]];
if (valid == undefined) valid = true;
ngModel.$$parentForm[portFieldsToCheck[i]].$setValidity("srbUniquePort", valid);
}
// ending with the standard validation for the current field
for (var i = 0; i < portFieldsToCheck.length; i++) {
if (fieldName != portFieldsToCheck[i] && configuration[portFieldsToCheck[i]] == val) {
return false;
}
}
return true;
}
}
}
}
})();
来源：https://stackoverflow.com/questions/34850124/how-to-revalidate-a-form-with-multiple-dependent-fields