init the awkward code

static/js/api/0.js

@@ -0,0 +1,147 @@
+class Win32 {
+
+    constructor() {
+        if(window != null){
+            this.setup();
+        }
+    }
+
+    setup() {
+        let url = new URL(window.location.href);
+        this.program_id = url.searchParams.get('program_id');
+        this.parent_origin = url.searchParams.get('parent_origin');
+    }
+
+    send(data){
+        if(this.program_id == null || this.parent_origin == null){
+            this.setup();
+        }
+        window.parent.postMessage(data, this.parent_origin);
+    }
+    /**
+     * Check for whether or not your webapp is running on win32.run
+     * @returns {Bool}
+     */
+    is_it() {
+        if(this.program_id == null || this.parent_origin == null){
+            this.setup();
+        }
+        return this.parent_origin != null;
+    }
+
+    /**
+     * @description Let the user pick files through win32.run Files Picker dialog.
+     * @param {string} desc Description of the file type you want.
+     * e.g. Image Files
+     * @param {[string]} exts Acceptable file extensions, case-insensitive. Each extension starts with the dot character.
+     * ```
+     * e.g. ['.jpg','.jpeg','.png','.avif']
+     * ```
+     * Specify an empty array [] to accept any extension
+     * @param {boolean} multiple Whether to accept multiple or single file. Default to true.
+     * @returns {Promise<[Object]>} an array of win32 files. See {@link https://docs.win32.run/3rd-party-apps/pick-files#returns Docs}
+     */
+    async pick_files(desc = '', exts = [], multiple = true) {
+        console.log(this.parent_origin)
+        this.send({
+            desc,
+            exts,
+            multiple,
+            program_id: this.program_id,
+            type: 'pick_files'
+        });
+
+        let promise = new Promise(resolve => {
+            window.onmessage = ({ data }) => {
+                if (data == null || typeof data !== 'object') return;
+                let { type, files } = data;
+                if (type == 'files_picked' && Array.isArray(files)) {
+                    resolve(files)
+                }
+            }
+        })
+        return promise;
+    }
+    /**
+     * Save content to a file without File Saving Dialog. Need to have a win32 file id first, which could obtain when you first save the file using or win32.pick_files win32.save_file_as
+     * @param {File} file File object. See {@link https://developer.mozilla.org/en-US/docs/Web/API/File Mozilla Docs}
+     * @param {String} id file id on win32.run
+     * @returns {Promise<Void>}
+     */
+    async save_file(file, id) {
+        this.send({
+            file,
+            fs_id: id,
+            program_id: this.program_id,
+            type: 'save_file'
+        })
+
+        let promise = new Promise(resolve => {
+            window.onmessage = ({ data }) => {
+                if (data == null || typeof data !== 'object') return;
+                let { type, success } = data;
+                if (type == 'file_saved') {
+                    resolve()
+                }
+            }
+        })
+        return promise;
+    }
+
+    /**
+     * Save a file to win32.run through File Saving Dialog
+     * @param {File} file File object. See {@link https://developer.mozilla.org/en-US/docs/Web/API/File Mozilla Docs}
+     * @param {[Object]} types list of saving formats. E.g.
+     * ```
+     * types = [
+     *  {desc: 'Photos', mime: 'image/png', ext: '.png'},
+     *  {desc: 'Bitmap', mime: 'image/bmp', ext: '.bmp'},
+     * ]
+     * ```
+     * See {@link https://docs.win32.run Docs} for more details.
+     * @returns {Promise<String>} id of the saved file, which later can be used to retrieve said file info with this.get_file(id)
+     */
+    async save_file_as(file, types) {
+        this.send({
+            file,
+            types,
+            program_id: this.program_id,
+            type: 'save_file_as',
+        })
+
+        let promise = new Promise(resolve => {
+            window.onmessage = ({ data }) => {
+                if (data == null || typeof data !== 'object') return;
+                let { type, fs_id } = data;
+                if (type == 'file_saved_as') {
+                    resolve(fs_id)
+                }
+            }
+        })
+        return promise;
+    }
+
+    /**
+     * @description Get a file on win32.run by its id.
+     * @param {String} id id of the file
+     * @returns {Promise<Object>} a win32 file object. See {@link https://docs.win32.run/3rd-party-apps/pick-files#returns Docs}
+     */
+    async get_file(id) {
+        this.send({
+            fs_id: id,
+            program_id: this.program_id,
+            type: 'get_file'
+        });
+
+        let promise = new Promise(resolve => {
+            window.onmessage = ({ data }) => {
+                if (data == null || typeof data !== 'object') return;
+                let { type, file } = data;
+                if (type == 'file') {
+                    resolve(file)
+                }
+            }
+        })
+        return promise;
+    }
+}