Source code
Revision control
Copy as Markdown
Other Tools
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/**
* A factory to generate FormLike objects that represent a set of related fields
* which aren't necessarily marked up with a <form> element. FormLike's emulate
* the properties of an HTMLFormElement which are relevant to form tasks.
*/
export let FormLikeFactory = {
_propsFromForm: ["action", "autocomplete", "ownerDocument"],
/**
* Create a FormLike object from a <form>.
*
* @param {HTMLFormElement} aForm
* @return {FormLike}
* @throws Error if aForm isn't an HTMLFormElement
*/
createFromForm(aForm) {
if (!HTMLFormElement.isInstance(aForm)) {
throw new Error("createFromForm: aForm must be a HTMLFormElement");
}
let formLike = {
elements: [...aForm.elements],
rootElement: aForm,
};
for (let prop of this._propsFromForm) {
formLike[prop] = aForm[prop];
}
this._addToJSONProperty(formLike);
return formLike;
},
/**
* Create a FormLike object from an <input>/<select> in a document.
*
* If the field is in a <form>, construct the FormLike from the form.
* Otherwise, create a FormLike with a rootElement (wrapper) according to
* heuristics. Currently all <input>/<select> not in a <form> are one FormLike
* but this shouldn't be relied upon as the heuristics may change to detect
* multiple "forms" (e.g. registration and login) on one page with a <form>.
*
* Note that two FormLikes created from the same field won't return the same FormLike object.
* Use the `rootElement` property on the FormLike as a key instead.
*
* @param {HTMLInputElement|HTMLSelectElement} aField - an <input> or <select> field in a document
* @return {FormLike}
* @throws Error if aField isn't a password or username field in a document
*/
createFromField(aField) {
if (
(!HTMLInputElement.isInstance(aField) &&
!HTMLSelectElement.isInstance(aField)) ||
!aField.ownerDocument
) {
throw new Error("createFromField requires a field in a document");
}
let rootElement = this.findRootForField(aField);
if (HTMLFormElement.isInstance(rootElement)) {
return this.createFromForm(rootElement);
}
let doc = aField.ownerDocument;
let formLike = {
action: doc.baseURI,
autocomplete: "on",
ownerDocument: doc,
rootElement,
};
// FormLikes can be created when fields are inserted into the DOM. When
// many, many fields are inserted one after the other, we create many
// FormLikes, and computing the elements list becomes more and more
// expensive. Making the elements list lazy means that it'll only
// be computed when it's eventually needed (if ever).
ChromeUtils.defineLazyGetter(formLike, "elements", function () {
let elements = [];
for (let el of this.rootElement.querySelectorAll("input, select")) {
// Exclude elements inside the rootElement that are already in a <form> as
// they will be handled by their own FormLike.
if (!el.form) {
elements.push(el);
}
}
return elements;
});
this._addToJSONProperty(formLike);
return formLike;
},
/**
* Find the closest <form> if any when aField is inside a ShadowRoot.
*
* @param {HTMLInputElement} aField - a password or username field in a document
* @return {HTMLFormElement|null}
*/
closestFormIgnoringShadowRoots(aField) {
let form = aField.closest("form");
let current = aField;
while (!form) {
let shadowRoot = current.getRootNode();
if (!ShadowRoot.isInstance(shadowRoot)) {
break;
}
let host = shadowRoot.host;
form = host.closest("form");
current = host;
}
return form;
},
/**
* Determine the Element that encapsulates the related fields. For example, if
* a page contains a login form and a checkout form which are "submitted"
* separately, and the username field is passed in, ideally this would return
* an ancestor Element of the username and password fields which doesn't
* include any of the checkout fields.
*
* @param {HTMLInputElement|HTMLSelectElement} aField - a field in a document
* @return {HTMLElement} - the root element surrounding related fields
*/
findRootForField(aField) {
let form = aField.form || this.closestFormIgnoringShadowRoots(aField);
if (form) {
return form;
}
return aField.ownerDocument.documentElement;
},
/**
* Add a `toJSON` property to a FormLike so logging which ends up going
* through dump doesn't include usless garbage from DOM objects.
*/
_addToJSONProperty(aFormLike) {
function prettyElementOutput(aElement) {
let idText = aElement.id ? "#" + aElement.id : "";
let classText = "";
for (let className of aElement.classList) {
classText += "." + className;
}
return `<${aElement.nodeName + idText + classText}>`;
}
Object.defineProperty(aFormLike, "toJSON", {
value: () => {
let cleansed = {};
for (let key of Object.keys(aFormLike)) {
let value = aFormLike[key];
let cleansedValue = value;
switch (key) {
case "elements": {
cleansedValue = [];
for (let element of value) {
cleansedValue.push(prettyElementOutput(element));
}
break;
}
case "ownerDocument": {
cleansedValue = {
location: {
href: value.location.href,
},
};
break;
}
case "rootElement": {
cleansedValue = prettyElementOutput(value);
break;
}
}
cleansed[key] = cleansedValue;
}
return cleansed;
},
});
},
};