zulip/web/src/upload_widget.ts

import {$t} from "./i18n";

const default_max_file_size = 5;

const supported_types = ["image/jpeg", "image/png", "image/gif", "image/tiff"];

function is_image_format(file: File): boolean {
    const type = file.type;
    if (!type) {
        return false;
    }
    return supported_types.includes(type);
}

export function build_widget(
    // function returns a jQuery file input object
    get_file_input: () => JQuery<HTMLInputElement>,
    // jQuery object to show file name
    $file_name_field: JQuery,
    // jQuery object for error text
    $input_error: JQuery,
    // jQuery button to clear last upload choice
    $clear_button: JQuery,
    // jQuery button to open file dialog
    $upload_button: JQuery,
    $preview_text?: JQuery,
    $preview_image?: JQuery,
    max_file_upload_size = default_max_file_size,
): {clear(): void; close(): void} {
    function accept(file: File): void {
        $file_name_field.text(file.name);
        $input_error.hide();
        $clear_button.show();
        $upload_button.hide();
        if ($preview_text !== undefined && $preview_image !== undefined) {
            const image_blob = URL.createObjectURL(file);
            $preview_image.attr("src", image_blob);
            $preview_image.addClass("upload_widget_image_preview");
            $preview_text.show();
        }
    }

    function clear(): void {
        const $control = get_file_input();
        $control.val("");
        $file_name_field.text("");
        $clear_button.hide();
        $upload_button.show();
        if ($preview_text !== undefined) {
            $preview_text.hide();
        }
    }

    $clear_button.on("click", (e) => {
        clear();
        e.preventDefault();
    });

    $upload_button.on("drop", (e) => {
        const files = e.originalEvent?.dataTransfer?.files;
        if (files === null || files === undefined || files.length === 0) {
            return false;
        }
        get_file_input()[0].files = files;
        e.preventDefault();
        return false;
    });

    get_file_input().attr("accept", supported_types.toString());
    get_file_input().on("change", (e) => {
        if (e.target.files?.length === 0) {
            $input_error.hide();
        } else if (e.target.files?.length === 1) {
            const file = e.target.files[0];
            if (file.size > max_file_upload_size * 1024 * 1024) {
                $input_error.text(
                    $t(
                        {defaultMessage: "File size must be at most {max_file_size} MiB."},
                        {max_file_size: max_file_upload_size},
                    ),
                );
                $input_error.show();
                clear();
            } else if (!is_image_format(file)) {
                $input_error.text($t({defaultMessage: "File type is not supported."}));
                $input_error.show();
                clear();
            } else {
                accept(file);
            }
        } else {
            $input_error.text($t({defaultMessage: "Please just upload one file."}));
        }
    });

    $upload_button.on("click", (e) => {
        get_file_input().trigger("click");
        e.preventDefault();
    });

    function close(): void {
        clear();
        $clear_button.off("click");
        $upload_button.off("drop");
        get_file_input().off("change");
        $upload_button.off("click");
    }

    return {
        // Call back to clear() in situations like adding bots, when
        // we want to use the same widget over and over again.
        clear,
        // Call back to close() when you are truly done with the widget,
        // so you can release handlers.
        close,
    };
}

export function build_direct_upload_widget(
    // function returns a jQuery file input object
    get_file_input: () => JQuery<HTMLInputElement>,
    // jQuery object for error text
    $input_error: JQuery,
    // jQuery button to open file dialog
    $upload_button: JQuery,
    upload_function: (
        $file_input: JQuery<HTMLInputElement>,
        night: boolean | null,
        icon: boolean,
    ) => void,
    max_file_upload_size = default_max_file_size,
): void {
    // default value of max uploaded file size
    function accept(): void {
        $input_error.hide();
        const $realm_logo_section = $upload_button.closest(".image_upload_widget");
        if ($realm_logo_section.attr("id") === "realm-night-logo-upload-widget") {
            upload_function(get_file_input(), true, false);
        } else if ($realm_logo_section.attr("id") === "realm-day-logo-upload-widget") {
            upload_function(get_file_input(), false, false);
        } else {
            upload_function(get_file_input(), null, true);
        }
    }

    function clear(): void {
        const $control = get_file_input();
        $control.val("");
    }

    $upload_button.on("drop", (e) => {
        const files = e.originalEvent?.dataTransfer?.files;
        if (files === null || files === undefined || files.length === 0) {
            return false;
        }
        get_file_input()[0].files = files;
        e.preventDefault();
        return false;
    });

    get_file_input().attr("accept", supported_types.toString());
    get_file_input().on("change", (e) => {
        if (e.target.files?.length === 0) {
            $input_error.hide();
        } else if (e.target.files?.length === 1) {
            const file = e.target.files[0];
            if (file.size > max_file_upload_size * 1024 * 1024) {
                $input_error.text(
                    $t(
                        {defaultMessage: "File size must be at most {max_file_size} MiB."},
                        {max_file_size: max_file_upload_size},
                    ),
                );
                $input_error.show();
                clear();
            } else if (!is_image_format(file)) {
                $input_error.text($t({defaultMessage: "File type is not supported."}));
                $input_error.show();
                clear();
            } else {
                accept();
            }
        } else {
            $input_error.text($t({defaultMessage: "Please just upload one file."}));
        }
    });

    $upload_button.on("click", (e) => {
        get_file_input().trigger("click");
        e.preventDefault();
    });
}