Explicit way to check whether a function was called from within the Window
7
Is there a more explicit way of checking whether a function was called from within Window than if (typeof this.value == "undefined")
in the code below?
So that it is apparent that I am checking against Window, something like: if this.name === "Window".
function get_caller() {
if (typeof this.value == "undefined") {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>javascript
asked Feb 24 at 8:20
barciewiczbarciewicz
672313
add a comment |
7
Is there a more explicit way of checking whether a function was called from within Window than if (typeof this.value == "undefined")
in the code below?
So that it is apparent that I am checking against Window, something like: if this.name === "Window".
function get_caller() {
if (typeof this.value == "undefined") {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>javascript
asked Feb 24 at 8:20
barciewiczbarciewicz
672313
3
What happens when somebody callsget_caller.call({value: "I am not in window"})?
– VLAZ
Feb 24 at 8:23
add a comment |
7
7
7
Is there a more explicit way of checking whether a function was called from within Window than if (typeof this.value == "undefined")
in the code below?
So that it is apparent that I am checking against Window, something like: if this.name === "Window".
function get_caller() {
if (typeof this.value == "undefined") {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>javascript
asked Feb 24 at 8:20
barciewiczbarciewicz
672313
Is there a more explicit way of checking whether a function was called from within Window than if (typeof this.value == "undefined")
in the code below?
So that it is apparent that I am checking against Window, something like: if this.name === "Window".
function get_caller() {
if (typeof this.value == "undefined") {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>function get_caller() {
if (typeof this.value == "undefined") {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>function get_caller() {
if (typeof this.value == "undefined") {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>javascript
javascript
asked Feb 24 at 8:20
barciewiczbarciewicz
672313
asked Feb 24 at 8:20
barciewiczbarciewicz
672313
edited Feb 24 at 10:03
barciewicz
asked Feb 24 at 8:20
barciewiczbarciewicz
672313
asked Feb 24 at 8:20
barciewiczbarciewicz
672313
asked Feb 24 at 8:20
barciewiczbarciewicz
672313
672313
3
What happens when somebody callsget_caller.call({value: "I am not in window"})?
– VLAZ
Feb 24 at 8:23
add a comment |
3
What happens when somebody callsget_caller.call({value: "I am not in window"})?
– VLAZ
Feb 24 at 8:23
3
3
What happens when somebody calls
get_caller.call({value: "I am not in window"})?– VLAZ
Feb 24 at 8:23
What happens when somebody calls
get_caller.call({value: "I am not in window"})?– VLAZ
Feb 24 at 8:23
add a comment |
2 Answers
2
active
oldest
votes
7
Just check if this is window:
function get_caller() {
if (this === window) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>answered Feb 24 at 8:22
SnowSnow
41112
1
Orundefined, in strict mode, which is the more common case today with webpack/modules.
– Madara Uchiha♦
Feb 24 at 10:17
add a comment |
1
You can check if this==window or if strict mode is on check if this is undefined,
function get_caller() {
"use strict"; // !this is used for strict mode check
if (this == window || !this) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>answered Feb 24 at 8:51
Code_ModeCode_Mode
1,152714
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
draft saved
draft discarded
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f54850048%2fexplicit-way-to-check-whether-a-function-was-called-from-within-the-window%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
7
Just check if this is window:
function get_caller() {
if (this === window) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>answered Feb 24 at 8:22
SnowSnow
41112
1
Orundefined, in strict mode, which is the more common case today with webpack/modules.
– Madara Uchiha♦
Feb 24 at 10:17
add a comment |
7
Just check if this is window:
function get_caller() {
if (this === window) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>answered Feb 24 at 8:22
SnowSnow
41112
1
Orundefined, in strict mode, which is the more common case today with webpack/modules.
– Madara Uchiha♦
Feb 24 at 10:17
add a comment |
7
7
7
Just check if this is window:
function get_caller() {
if (this === window) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>answered Feb 24 at 8:22
SnowSnow
41112
Just check if this is window:
function get_caller() {
if (this === window) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>function get_caller() {
if (this === window) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>function get_caller() {
if (this === window) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>answered Feb 24 at 8:22
SnowSnow
41112
answered Feb 24 at 8:22
SnowSnow
41112
answered Feb 24 at 8:22
SnowSnow
41112
answered Feb 24 at 8:22
SnowSnow
41112
41112
1
Orundefined, in strict mode, which is the more common case today with webpack/modules.
– Madara Uchiha♦
Feb 24 at 10:17
add a comment |
1
Orundefined, in strict mode, which is the more common case today with webpack/modules.
– Madara Uchiha♦
Feb 24 at 10:17
1
1
Or
undefined, in strict mode, which is the more common case today with webpack/modules.– Madara Uchiha♦
Feb 24 at 10:17
Or
undefined, in strict mode, which is the more common case today with webpack/modules.– Madara Uchiha♦
Feb 24 at 10:17
add a comment |
1
You can check if this==window or if strict mode is on check if this is undefined,
function get_caller() {
"use strict"; // !this is used for strict mode check
if (this == window || !this) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>answered Feb 24 at 8:51
Code_ModeCode_Mode
1,152714
add a comment |
1
You can check if this==window or if strict mode is on check if this is undefined,
function get_caller() {
"use strict"; // !this is used for strict mode check
if (this == window || !this) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>answered Feb 24 at 8:51
Code_ModeCode_Mode
1,152714
add a comment |
1
1
1
You can check if this==window or if strict mode is on check if this is undefined,
function get_caller() {
"use strict"; // !this is used for strict mode check
if (this == window || !this) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>answered Feb 24 at 8:51
Code_ModeCode_Mode
1,152714
You can check if this==window or if strict mode is on check if this is undefined,
function get_caller() {
"use strict"; // !this is used for strict mode check
if (this == window || !this) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>function get_caller() {
"use strict"; // !this is used for strict mode check
if (this == window || !this) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>function get_caller() {
"use strict"; // !this is used for strict mode check
if (this == window || !this) {
console.log('function get_caller called from window')
}
else {
console.log('function get_caller called by button press')
}
}
btn.addEventListener('click', get_caller)
get_caller()<button id="btn">Get caller</button>answered Feb 24 at 8:51
Code_ModeCode_Mode
1,152714
answered Feb 24 at 8:51
Code_ModeCode_Mode
1,152714
answered Feb 24 at 8:51
Code_ModeCode_Mode
1,152714
answered Feb 24 at 8:51
Code_ModeCode_Mode
1,152714
1,152714
add a comment |
add a comment |
draft saved
draft discarded
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
draft saved
draft discarded
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f54850048%2fexplicit-way-to-check-whether-a-function-was-called-from-within-the-window%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
3
What happens when somebody calls
get_caller.call({value: "I am not in window"})?– VLAZ
Feb 24 at 8:23